- simearth manual
SimEarth - Manual
INTRODUCTION .......................... 1
GETTING STARTED........................ 11
FIRST LOOK ....................... 20
CREATING AND MODIFYING PLANETS ... 26
MODIFYING THE SIMULATION ......... 37
CONTROLLING THE SIMULATION ....... 46
MICE AND KEYBOARDS ............... 46
INPUT AND OUTPUT ................. 46
MENUS ............................ 48
WINDOWS .......................... 53
HELP WINDOW ..................... 53
NEW PLANET WINDOW................ 54
EDIT WINDOW ..................... 57
MAP WINDOW....................... 71
GAIA WINDOW ..................... 80
HISTORY WINDOW .................. 81
REPORT WINDOW.................... 83
TUTORIAL WINDOW ................. 90
GLOSSARY WINDOW ................. 90
MODEL CONTROL PANELS................ 94
TIME SCALES ........................ 100
INSIDE THE SIMULATION............... 122
GEOSPHERE ......................... 127
ATMOSPHERE ........................ 129
LIFE AND EVOLUTION ................ 133
ENERGY ............................ 145
AN INTRODUCTION TO EARTH SCIENCE.... 149
INTRODUCTION ..................... 151
GEOLOGY .......................... 153
CLIMATE .......................... 167
LIFE ............................. 178
HUMAN CIVILIZATIONS AND
TECHNOLOGY ...................... 190
THEORIES OF THE EARTH:
THE GAIA HYPOTHESIS............... 196
PROBLEMS AND SOLUTIONS .......... 202
GLOSSARY ........................ 204
PLANET SPECIFICATION SHEETS ..... 212
-= END OF CONTENTS =-
"is this a random world or did you planet ? " - THe most pondered
question by Sim-Earthling philosophers.
WHAT IS SIM-EARTH ?
SimEarth is a planet simulator--a model of a planet. It is a game, an
educational toy, and an enjoyable tool. With SimEarth you can take over
many included planets, or design and create your own.
SimEarth is based on the Gaia theory by James Lovelock, which suggests
that we look at our planet and the life on it as a whole, and not as
separate areas of study.
SimEarth treats the planet as a whole: life, climate, the atmosphere,
and the planet itself--from dirt and rock to the molten core all affect
You will see your planet as a whole--from a satellite's point of view,
at two levels of magnification.
SimEarth can be played in two modes: game and experimental. In game mode,
you will try to develop, manage, and preserve your planet within allotted
In experimental mode, you are given unlimited energy to mold your
planet. This allows you to set up any type of planet in any stage
of development, and then introduce any new factors you want and see
what happens. In this mode SimEarth is a "planetary spreadsheet."
Your SimEarth planets will be populated by electronic life-forms called
SimEarthlings--cousins of the Sims who populate SimCity (another fine
product from Maxis). SimEarthlings range from single celled
plants and animals to intelligent species.
Intelligent SimEarthlings are not limited to Humans--or even Mammals. There
can be intelligent Dinosaur SimEarthlings, intelligent Mollusk
SimEarthlings, even intelligent Insect SimEarthlings--but only one
intelligent life-form at a time.
A single planet can be populated by billions and billions of
SimEarthlings. Their welfare is in your hands.
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WHAT IS GAIA?
Gaia is a theory about the evolution of the Earth. A theory that sees
the evolution of the species of organisms by natural selection and the
evolution of the rocks, air and oceans as a single tightly coupled
process. In Gaia the organisms and their material environment together
constitute a system which is able to self-regulate climate and
The fact that the Earth's mean temperature has remained constant and
favourable for life for 3.6 billion years in spite of a rise in
output of heat from the Sun of 25%, and the fact that oxygen has
remained close to 21% of our atmosphere for 200 million years, can be
explained by Gaia theory but not by conventional science. Although it
is a scientific theory, the name Gaia was proposed by the novelist
Gaia became visible through the new knowledge about the Earth gained from
space and from the extensive investigations of the Earth's surface, oceans
and atmosphere during the past few decades. This view has in it
something of the poetic metaphor of a ship held by the sailors, but it
is also a hard science theory of our planet that came from a top-down
view from space. This theory is now up for trial, and the evidence
gathered from the Earth itself will decide on whether or not it
should be taken as scientific fact. Don't be misled by those who argue
that Gaia is untestable or teleological and therefore in error; their
criticism is mere opinion based on prejudice, not evidence. Even if
in the end Gaia should turn out to be no more than a poetic metaphor,
it would still have been worth thinking of the Earth as a living system.
Such thoughts have already led to discoveries about the Earth that could
not have come from conventional wisdom.
Gaia is a top-down view of the Earth as a single system, and is essentially
physiological. It is about the working of the whole system, not with
the separated parts of a planet divided arbitrarily into the biosphere, the
atmosphere, the lithosphere and the hydrosphere. These are not real
divisions of the Earth; they are spheres of influence inhabited by
All I ask is that you concede that there might be something in the
Gaia theory, which sees the Earth as a living system, to acknowledge
Gaia at least for the purpose of argument. I do not expect you to become
converts to a new Earth religion. I do not ask you to suspend your
common sense. All that I do ask is that you consider Gaia theory as
an alternative to the conventional wisdom of a dead planet made of
inanimate rocks, ocean and atmosphere merely inhabited by life.
Consider it as a real system, comprising all of life and all of its
environment tightly coupled so as to form a self-regulating entity.
Maybe you already have it in mind when you use that vague, ill-defined
word "Biosphere" that seems to have a different meaning for each occasion
of its use.
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I recognise that to view the Earth as if it were alive is just a
convenient, but different, way of organising the facts of the Earth. I
am of course prejudiced in favour of Gaia and have filled my life for
the past 25 years with the thought that Earth may be alive: not as the
ancients saw her--a sentient Goddess with a purpose and foresight--but
alive like a tree. A tree that quietly exists, never moving except to
sway in the wind, yet endlessly conversing with the sunlight
and the soil. Using sunlight and water and nutrient minerals to grow
and change. But all done so imperceptibly, that to me the old oak tree
on the green is the same as it was when I was a child.
SOFTWARE TOYS AND SYSTEM SIMULATIONS
SimEarth isn't exactly a game...it's what we call a "Software Toy." Toys,
by definition, are more flexible and open-ended than games.
As an example, compare a game, tennis, with a toy, a ball. In
every tennis game, there is one way to begin, one goal to pursue, and
one way to end. There are infinite variations in the middle, but they
all start the same way, chase the same goal, and end the same way.
A ball is more flexible--there are more things you can do with it.
With the ball, you can play tennis. You can play catch. You can throw it
at someone. You can bounce it. You can make up a hundred different
games using the ball.
Our Software Toys are programmable. Using the comparison with a ball, this
means that you can change the tennis ball into a football, baseball,
soccer ball, Ping Pong ball, etc., and play any and all the games you
play with those balls.
Besides games, there are other things you can do with a ball. You can
paint it, use it to plug a leaky roof, or just contemplate
its roundness (Fukkin heavy shit this h0h0!).
In SimEarth, the "toy" is a planet--a programmable planet that can
become an infinite number of planets.
So when you play with SimEarth, or any of our Software Toys, don't
limit yourself to trying to "win." Play with it. Experiment. Try new
things. Just have fun.
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There are many types of toys. SimEarth, like SimCity before it, is
a SYSTEM SIMULATION toy. In a system simulation, we provide you with
a set of RULES and TOOLS that describe, create and control a system.
In the case of SimEarth, the system is a planet.
Part of the challenge of playing with a SYSTEM SIMULATION toy is to
figure out how the system works and take control of it. As master of
the system you are free to use the TOOLS to create and control an
unlimited number of systems (in this case, planets) within the framework
provided by the RULES.
In SimEarth, the RULES to learn are based on global systems and management,
Chemical Factors : atmospheric composition, energy management
Geological Factors: climate, extraterrestrial collisions, continental
Biological Factors: formation of life, evolution, food supply, biome
types and distribution
Human Factors : wars, civilization, technology, waste control,
pollution, food supply, energy supply.
The TOOLS provide you with the ability to create, modify and manage
Create a planet in any of four Time Scales.
Physically modify the landscape of the planet.
Set the altitude of any spot on the planet.
Trigger events on the planet from hurricanes to volcanoes to meteor
Plant various biomes and life-forms anywhere on the planet.
Nurture a species to help it evolve intelligence.
Manage your planet by making use of the available maps and graphs.
But the most important TOOL of all is the simulator itself. Test your
plans, theories and ideas as you watch your planet develop or
decline. Customise the simulation by changing the rules that control
the geosphere, the atmosphere, the biosphere, and civilization, to suit
yourself or test life's adaptability to various conditions.
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SIMULATION LIMITATIONS AND BIASES
Anything as complicated as the Earth or an animal or even a city cannot be
completely defined by formulas and equations. Any model of something this
complicated cannot be completely accurate--but if you are aware of the
inaccuracies, the model can still be useful.
A street map is a model of a city. It isn't a completely accurate
representation of every detail of a city, but, within its limitations,
it's very useful. Most of us would be lost without one.
As a simulation of a real planetary system, SimEarth is a rough
caricature--an extreme simplification. We simulate many different
aspects of a planet, including climate, evolution, atmospheric
composition, and civilization, all on a personal computer.
A truly accurate simulation for a climate model alone has not yet
been realised even on today's most powerful super-computers. We designed
this simulation as accurately as we could while maintaining
compatibility with personal computers and including a gaming aspect.
A major limitation to this program is how evolution is treated. It
closely follows Earth's evolution. With very few exceptions, all the
life-forms represented here actually exist or existed on Earth. While
allowing many differences in which species succeed or fail--and eventually
gain sentience--the path from single-celled life to complex life is
roughly the same as on Earth.
Also, whatever species becomes intelligent--Mammal, Dinosaur, Fish,
etc.-- will develop civilizations, cities and technologies that
greatly resemble Human civilizations, cities and technologies.
SimEarth is based on the Gaia theory, as proposed by James Lovelock. Gaia
theory is controversial, and not an accepted truth in all
For this game, we are also making a few assumptions that are not
necessarily true. One of these assumptions is that intelligence is
an evolutionary advantage--we might just be flattering ourselves.
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The simulator in SimEarth is a very complex piece of modelling software.
It is constantly performing many checks, calculations and updates, as
well as keeping watch on the mouse and keyboard to respond to your demands.
When you load in a planet, give the simulator a minute or two to compile and
update maps and graphs.
When you make adjustments to the MODEL CONTROL PANELS, allow some time
for the changes to take effect.
Simulator reaction time is also greatly affected by your computer's
clock speed and type of microprocessor.
GOALS OF SIM EARTH
Each of the seven included scenario planets is actually a game in
itself that can be played at three levels of difficulty or in
experimental mode. Each scenario will present you with different
challenges in planet management.
TESTING THE GAIA HYPOTHESIS--DAISYWORLD
One of the main tenets of the Gaia hypothesis is that life itself
regulates the conditions on Earth that support life, including
temperature and atmospheric content.
One of the scenarios, Daisyworld, is a simplified simulation with
only eight life-forms: differently shaded daisies. This scenario is
based on the original Daisy-world computer model James Lovelock
designed to explain the Gaia hypothesis.
Experimenting with the Daisyworld Scenario will give you a visual
demonstration of the concept of Gaia and of life on Earth as a
A complete description of how and why the Daisyworld model works is found
later in this manual, in the "Scenarios" chapter.
TAKING ON THE ROLE OF GAIA
If you play any of the scenarios or random planets at the most difficult
level, all Gaian self-regulation will be disabled. You will have
to constantly monitor and adjust everything on the planet to keep
life in existence.
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YOUR OWN PLANETS
Besides the scenarios, you can create an unlimited number of different planets,
at various levels of difficulty.
FUN AND CHALLENGE
Running a planet is a real challenge for even an experienced gamer.
Design, modify, manage, and nurture a planet from creation through
formation of the oceans, to the appearance of life, through the
evolution of life, through the development of intelligence and
technology, to the point where your SimEarthlings can reach for the
Set up a planetary situation and just watch what happens.
Choose and help a particular species gain mastery of the planet.
Influence the life to keep it from destroying itself and the planet.
Perhaps the ultimate goal of SimEarth is for you to design, manage and
maintain the planet of your dreams. Your ideal planet may be a
high-tech society of intelligent humans (or intelligent dinosaurs) or a
limited-technology planet where the biosphere is never endangered.
YOUR OWN GOALS
It's your toy--you make the rules. You don't need a goal if you
don't want one. Just play.
ABOUT THIS MANUAL
This manual has two functions: to teach you how to use SimEarth and to
introduce you to the basics of Earth Science.
The majority of this manual describes the program SimEarth: how it
works, how to use it, how it deals with life, climate, geology, atmospheric
composition, civilization, etc.
The Introduction to Earth Science section of this manual deals with
many of the same things as they are in the real world, out of the
context of SimEarth.
This manual covers the SimEarth program for all computers. Any machine-
specific information for installing, starting, or using SimEarth
will be found on the included system card/addendum.
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In SimEarth there are two uses of energy. You, the player, use it
to make, mold, modify and manipulate the planet, and civilized
SimEarthlings make and use it to carry on their daily lives. A complete
explanation of energy and its uses in SimEarth is found in the
"Energy" chapter of this manual.
SIMEARTHLING USE OF ENERGY
Intelligent SimEarthlings will produce and use energy. You can control
their choice of energy sources and their use of the energy they
produce, but you don't have direct access to their energy for your
YOUR USE OF ENERGY
Depending on the difficulty level of the game, you will have different
amounts of energy to affect the planet and the simulation. These
amounts are both your starting supply and the maximum you can
accumulate at any one time.
If you are in experimental mode, you will have an unlimited supply of
Energy for a game comes from the stores of the planet itself in the
form of geothermal, wind, and solar energy, as well as fossil fuels. As
you deplete your energy supplies during a game, they will slowly build
back up over time as the planet increases its energy from the above
sources. This continual tapping of the planet's energies happens
Once life on your planet becomes intelligent, you will automatically
tap some of their energy. You can't just take the energy: a certain
amount will be added to your supply along with the energy tapped from
the planet itself.
The higher the level of technology on your planet, the more energy
you will receive.
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"All the world's a simulation and all the Sims and Simearthlings
merely players" - William Simspeare.
INSTALLING SIM EARTH
Please refer to the enclosed system card and machine-specific addendum for
installation instructions (ALREADY RELEASED SO I AINT DONE IT!).
SimEarth is a fairly complex program, with lots of windows, icons, buttons,
options, and control panels. To make your simulating experience easier,
there is a lot of help information included in the program.
THE HELP FUNCTION
Any time you want or need help, or aren't sure what something in the program
does, ask for help. Whenever you hold down the SHIFT KEY, you are in help
mode, and the cursor changes to /\HELP. Then click on anything anywhere
in SimEarth, and you will get a help message.
There is an on-line glossary that defines many of the words in the SimEarth
To access the glossary, open the WINDOWS MENU, and select GLOSSARY.
There is also a Glossary in the Appendix section of this manual.
There is a tutorial section in this manual. There is also
an on-line abbreviated version of the tutorial.
The on-line text-based tutorial is accessed by selecting TUTORIAL from the
WINDOWS MENU. You can even keep the TUTOIAL WINDOW open on the
screen while playing the game, and refer to it whenever you need.
Depending on your computer, you may or may not be able to have the on-line
tutorial open at the same time as other HELP WINDOWS.
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STARTING THE PROGRAM
Please refer to the system card or machine-specific addendum for
instructions in starting SimEarth.
The first time you start the program, you will see three windows: the TITLE
WINDOW, which goes away as soon as you click the mouse, the EDIT WINDOW,
which is your main planetary work space, and a HELP WINDOW, which will tell
you how to get started and how to get more help.
Whenever you start SimEarth, there will be no active planet. You
will have to select either NEW PLANET or LOAD PLANET from the FILE
MENU before the simulation will really start. This is to give you a
chance to look around, play with the various windows and controls, and
prepare yourself before things start to happen.
The following Tutorial section will guide you through the basics of
planet creation and manipulation.
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"Fools make a mock of Sim", simproverbs xiv.9
The purpose of this tutorial is to give you a quick tour of SimEarth's
menus, windows, and planet manipulation tools. It won't give every
detail of every item in the program. For in-depth explanations of
everything in the program see the Reference section of this manual.
Before beginning the tutorial, here are a few basic concepts and terms
to get you started.
SimEarth is based on the Gaia theory. Everything in the program is
interrelated: climate, animals, plants, and the planet itself all affect
A brief explanation of the Gaia theory is given in the Introduction in
the chapter "What is Gaia?" A demonstration of how Gaia works is found in
the Daisyworld section of the "Scenarios" chapter.
The term "planet" refers to the present planet, world, or scenario that
is loaded into memory and is being simulated.
You will view your planet from a satellite's point of view at two
different magnifications, and as either a flat robinson projection
or a globe.
In SimEarth and this manual, we use the terms "simulation" and "simulator"
to Represent the part of the program that is modelling the planet. When
you change or modify the simulation, you are changing variables and
parameters in the model, which in turn change the planet.
The ability to modify the simulation is a powerful tool both for the
gaming aspect and the experimental "planetary spreadsheet" aspect
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INPUT AND OUTPUT
SimEarth is a very complicated program. An important part of understanding
it is knowing where you can INPUT (change the planet or simulation), and
where you find OUTPUT (results of your INPUT).
There are three places for INPUT:
The FILE MENU for creating or loading planets;
The EDIT WINDOW for making local changes to spots on the planet; and
The MODEL CONTROL PANELS for modifying the simulation and changing the
The MODEL CONTROL PANELS are the only places in SimEarth that are INPUT
Everything else all the maps and graphs, even the EDIT WINDOW--supplies
In SimEarth, as on the real Earth, the level of solar radiation is
continually increasing. You only have 10 billion years before the planet
gets so hot that all life on it will die.
Technically, the Sun cools off as it expands into a red giant. As it
expands, it gets closer to the planet. From the planet's position,
the solar radiation is increasing even though the Sun is cooling.
There are four Time Scales in SimEarth: Ceologic, Evolution, Civilised, and
Technology. Each Time Scale simulates different periods of a planet's
development at different rates of speed.
You can begin a planet in any Time Scale, or start at the first
(Ceologic) and guide your planet through them all. A certain amount
of development must occur before advancing to the next one.
Biomes are ecological systems of plants and animals, such as Forest,
Desert and Jungle. Where a particular biome can survive depends on
temperature, rainfall and altitude. For the most part, biomes are used
in SimEarth to represent the plant life of a planet.
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Life-forms in SimEarth (SimEarthlings) range from single-celled
microbes in the ocean to complex, intelligent animals. Any multicellular
life-form in SimEarth can become intelligent.
Life will begin and evolve automatically in SimEarth. To a great extent,
you can affect the evolutionary path that life follows on your planet.
There are 15 classes of life represented in SimEarth. Each class of
life has 16 species. There are 240 possible forms of life, but not all
of them will develop or survive on any given planet.
The symbols that represent life in the EDIT WINDOW stand for a large
population of that life-form--not just one animal.
Each form of life has favourite biomes where it flourishes, and others
where it cannot survive at all.
The level of development of life controls the advancement of Time Scales.
Eventually, one type of SimEarthling will attain sentience. When this
happens, civilization begins. With civilization comes many new issues
and problems to deal with.
SimEarth simulates civilization with cities at seven levels of technology
ranging from the Stone Age of the distant past to the Nanotech Age of
There are two uses of energy in SimEarth: yours and the SimEarthlings.
You use energy each time you change the planet in the EDIT WINDOW or the
MODEL CONTROL PANELS. Creating and nurturing your planet within your
energy budget is one of the challenges of SimEarth.
Intelligent SimEarthlings produce and use energy. You can control
their energy production and use, but it's theirs--you can't use their
energy for planet manipulation.
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HELP AND THE GLOSSARY
On-line help is available anywhere at any time in SimEarth. To access
help, hold down the SHIFT KEY and click somewhere on the screen. A text
window will appear with the information you need.
One special use of the HELP WINDOW is the GLOSSARY. There may be some
words that you don't know in this program. If you choose GLOSSARY from
the WINDOWS MENU, a glossary of the words and terms used in this program
will appear in the HELP WINDOW.
ABOUT THIS TUTORIAL
This tutorial will be presented in three sections:
FIRST LOOK will introduce you to the various menus, windows, graphs, and
CREATING AND MODIFYING PLANETS will teach you how to create and save
planets; change the landform of a planet; place and move biomes, life
and cities on a planet; and trigger events such as volcanoes and
MODIFYING THE SIMULATION shows how you can use the MODEL CONTROL
PANELS to change global conditions on your planet.
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See the system card and addendum for your machine for
installation and startup instructions, and fire it up.
You Will see a MENU BAR across the top of the screen
plus three separate windows: a TITLE SCREEN, a HELP WINDOW,
and the MAP WINDOW.
The TITLE SCREEN introduces the program and gives credits.
Click on it to make it go away.
The HELP WINDOW holds text that will help you use and
understand SimEarth. You can request help on any icon, any
button, any window, any function, any anything in SimEarth.
The first time you start the program, the HELP WINDOW
will display text to help you get started.
You can change the size of the HELP WINDOW by clicking and dragging the SIZE
GADGET. You can move it around the screen by clicking and dragging the
To scroll through all the text in a HELP WINDOW click on the up or
down arrows in the SCROLL BAR on the right side of the window.
To make the HELP WINDOW go away, click in the CLOSE BOX.
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The MAP WINDOW gives you a view of your entire planet.
At the top of the MAP WINDOW is the TITLE BAR. It displays the name
of the current map display. You can move the MAP WINDOW around the
screen by clicking and dragging the TITLE BAR. At the left of the
TITLE BAR is the CLOSE BOX. If you click in this box the EDIT WINDOW
will close. To bring it back, select MAP from the WINDOWS MENU.
All windows, graphs and control panels have TITLE BARS and CLOSE BOXES.
The MAP WINDOW also has a DISPLAY AREA and a CONTROL PANEL. The
DISPLAY AREA shows the entire planet. A rectangle somewhere in this area
shows the part of the planet that will be displayed in the EDIT WINDOW,
your close-up view of the planet.
The CONTROL PANEL, at the bottom of the window, lets you select different
views of the planet that give you information about the land, water,
air, climate, life and civilization. The views are changed by clicking on
the 12 icons. Go ahead and click on them. Many of them won`t do much because
there is no active planet. To get the original view back, click on the
far left icon.
Clicking on the little buttons at the bottom that say GEOSPHERE,
ATMOSPHERE, BIO, and CIV will bring up various MODEL CONTROL
PANELS, and double-clicking on some of the icons will bring up graphs.
Don't worry about this now. If an unexpected small window pops up, close
it by clicking in its CLOSE BOX, or just click on any part of the
MAP WINDOW to bring it to the front.
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Near the right side of the CONTROL PANEL is the INFO BOX. It
displays various graphs and legends for each of the map views.
To the right of the INFO BOX are three buttons. The top one takes you
to the EDIT WINDOW; the bottom one changes the INFO BOX between graphs
and legends (when available).
The middle button, GLOBE, changes the flat map into a globe. All of
the map views are available on both the flat map and the globe.
Click on GLOBE again to return to the flat
At the top of the DISPLAY AREA is a MESSAGE BAR that will sometimes
appear and display messages to you from the simulation and from
the SimEarthlings that inhabit the planet.
At the moment, the MESSAGE BAR should say, "No Game in Progress. Use
'New Planet' to Start."
When SimEarth first starts, there is no actual planet or game
running. This gives you a chance to look around a little before things
start to happen. When you are ready to start playing, you must
choose NEW PLANET from the FILE MENU.
Before doing that, we'll take a quick look around.
Look at the MENUS along the top of the screen. If you are unfamiliar with
drop-down menus, check with the SimEarth addendum for your machine.
A complete description of every item on every menu is found in the
Reference section of this manual.
Open the FILE MENU. It is for starting new planets, loading and saving old
planets, printing, and quitting SimEarth.
Open the WINDOWS MENU. Use this menu to open the various SimEarth
Open the MODELS MENU. This menu gives you access to the four MODEL
CONTROL PANELS that you will use to modify the simulation.
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Open the GRAPHS MENU. This menu gives you access to the four graphs that
give you information on air, life and technology on the planet.
Open the OPTIONS MENU. It lets you Customise the program to your tastes.
Open the SPEED MENU. It lets you set the simulation speed of the game and
choose the way the date is displayed.
Open the DATASOUND MENU. It lets you control some of the sound in SimEarth.
Along with the MAP WINDOW, the most important window you will be using is
the EDIT WINDOW. To see it, choose EDIT from the WINDOWS MENU. For a
complete description of everything in the EDIT WINDOW, see the Reference
section of this manual.
The EDIT WINDOW is your close-up view of your planet. It is where
you will make modifications to the planet itself and the life on it.
The EDIT WINDOW also has a TITLE BAR, CONTROL PANEL, and a DISPLAY
AREA. You can use the TITLE BAR to close or move the window. The DISPLAY
AREA shows the area of the planet that is in the rectangle in the MAP
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Edit Window Control Panel
| _____ _____ |
| | | | | |
| |_____| |_____| |
| _____ _____ |
| | | | | |
| |_____| |_____| |
| _____ _____ |
| | | | | |
| |_____| |_____| |
| _________________ |
| _________________ |
|| Oceans ||
|| Biomes ||
|| Cities ||
|| Life ||
|| Events ||
| _________________ |
|| Heat ||
|| Rainfall ||
|| Winds ||
|| SeaFlow ||
|| SeaHeat ||
|| Magma ||
| _________________ |
|| 5000 ||
On the left side of the window is the EDIT WINDOW CONTROL PANEL. This is
where you choose your tools to modify the planet, and choose the data you want
to view in this window.
An easy way to find out what all the icons and buttons on the EDIT WINDOW
CONTROL PANEL do is to use the HELP function. Hold down the
SHIFT KEY and click on an icon or button. The HELP WINDOW will give you
information on the spot where you clicked.
In the lower-right corner is the SiZE BOX. Click and drag this box to
enlarge or shrink the size of the EDIT WINDOW.
The biggest part of this window is the DISPLAY AREA. This is the
close-up "satellite's eye view" of your planet. At this point you will
see only land and water in this area. The elevation of the land is shown
in shades--the lighter the shade, the higher the elevation.
To see different parts of the planet you must scroll the planet's
terrain under the window. Depending on your computer, you may or may not
have SCROLL BARS at the right and bottom of the EDIT WINDOW. If you
have SCROLL BARS, then use them (click on the arrows or the bar) to
scroll the terrain. If you don't have SCROLL BARS, then simply move
the mouse pointer to any edge or corner of the screen, and the display
Go to the WINDOWS MENU and open the TUTORIAL WINDOW. This is a HELP
WINDOW that introduces you to SimEarth and explains much of the program.
The tutorial that you are reading now is much more complete. Use the
on-line TUTORIAL WINDOW for a quick refresher course whenever you
> 24 <
There is also a HISTORY WINDOW that graphs 15 factors through the
history of your planet, and a REPORT WINDOW, which gives you feedback on
your planet's condition and your planet management skills. Since there
is no active planet yet, these windows won't tell you much. We'll come
back to them later.
Open the MODELS MENU and select GEOSPHERE. You will see the GEOSPHERE
MODEL CONTROL PANEL. Go back to the menu And select
ATMOSPHERE to see another CONTROL PANEL.
These CONTROL PANELS, four in all, let you modify the actual
simulation. You can only display one MODEL CONTROL PANEL
at a time. You can switch between them by clicking on the NEXT or
LAST buttons in the upper-right corner of the panel.
Open the GRAPHS MENU and select one of the graphs. Only one graph can
be viewed at a time. These graphs keep you informed on the status of
the Atmosphere, Biomes, Life, and Technology on your planet.
Let's build some planets.
> 25 <
CREATING AND MODIFYING PLANETS
CREATING A PLANET IN THE GEOLOGICAL TIMESCALE
Name your Planet:
Select NEW PLANET from the FILE MENU.
You will now be asked a question. The answer to the question will be found
at the back of the SimEarth manual in the PLANET SPECIFICATION SHEETS. Type
in the answer, and hit return.
You will see the NEW PLANET WINDOW.
At the top of this window, you select whether you want to play an easy,
average, or hard game. You can also select experimental mode, which gives
you an unlimited energy budget.
The bottom of the window gives you choices of planets. There are seven
scenarios--pre-set planets--that you can load, or you can create a random
Let's create a random planet in easy game mode. Click on EASY CAME in the
top section of the window, and click on the planet that says RANDOM PLANET.
Now you will see a dialog box asking you to name your planet and select
the Time Scale.
There are four Time Scales in SimEarth; each simulates different aspects of
planetary development. There is a complete description of each Time Scale in
the Reference section.
Click in the box next to GEOLOGIC it may already be selected(), then type
in a name for your planet--try GEOWORID and click the BEGIN button.
> 26 <
A new planet is born. Select the EDIT option in the WINDOWS MENU and
look at the EDIT WINDOW. In the TITLE BAR, along with the planet's name,
is the date-- the elapsed time since the planet was created. In the
SPEED MENU you can change the format of the date between RELATIVE
DATE (time elapsed since the beginning of the present Time Scale) and
ABSOLUTE DATE (time elapsed since the creation of the planet). Since
this planet is in the first Time Scale, the two are the same.
There will be no oceans for a while, and there is no atmosphere to burn up
Sit back for a couple minutes and watch, switching between the EDIT
and MAP WINDOWS. You will witness events: meteor strikes, volcanoes,
Soon oceans will form and life will form in the oceans.
TOURING THE PLANET
Bring the EDIT WINDOW to the front, and make it as big as you can.
Scroll around the planet and go sightseeing for a few minutes.
A lot is going on: time is passing very fast in this Time Scale. You can
see the continents drifting. Single-celled life is spreading. Meteors
hit the land and make craters that become lakes or hit the ocean and
cause tidal waves.
EDIT WINDOW CONTROL PANEL
Bring the EDIT WINDOW to the front and look at the EDIT WINDOW CONTROL
PANEL. At the top-left of the panel are six icons. Click on these
icons to activate tools for changing the planet. Below that is the
CURRENT TOOL DISPLAY. It shows which tool is being used and the cost
in energy to use it.
Click on each icon. The three on the left have submenus. Click and hold
to see them. Keep the mouse button down, and slide the pointer to an
option on the submenu to select it.
To get an explanation of what an icon does, hold down the SHIFT KEY
and click on the icon. The HELP WINDOW will explain what it does and
how to use it.
Below the icons are the DATA LAYER BUTTONS--five buttons that let you
decide what information about the planet will be displayed. You can have any,
all, or none of these on at once.
You can also get HELP WINDOW messages about these buttons.
> 27 <
Click on these, and play with them. When you turn off the display of
the oceans, you can see the elevation of the ocean floor. This doesn't
make the ocean go away, it just makes it invisible. Depending on how fast
you read, and how fast your computer is, you may or may not have life
or biomes to turn on and off at this time.
Below the DATA LAYER BUTTONS are the CLIMATE OVERLAY BUTTONS--six
buttons that let you turn on and off display of climactic information.
Only one of these can be on at a time.
You can also get HELP WINDOW messages about these buttons.
Go ahead and play with these for a while.
At the bottom of the EDIT WINDOW CONTROL PANEL is the AVAILABLE ENERGY
DISPLAY. In SimEarth, the price you pay to manipulate the planet is
This little box tells you how much you have left. As time passes,
your energy supply will slowly build back up, but it will never exceed
5000 in an easy game, or 2000 in an average or hard game. In
experimental mode, you have unlimited energy.
USING THE SET ALTITUDE TOOL
This tool has two modes: RAISE and LOWER. Click once on the SET
ALTITUDE icon. The icon will be highlighted. In the CURRENT TOOL
DISPLAY, you will see the SET ALTITUDE icon, but with only an up arrow
along with the cost to use it: 50n (energy units).
Only the up arrow is shown to indicate that this tool is in RAISE mode.
Scroll the EDIT WINDOW to a place on the planet that is mostly water
(make sure the display of oceans is on). Point to the water and click
and hold for a few seconds. You've just built an island. If you
watch for a while, you'll notice that the island moves and changes. That
is because time is moving so fast in this Time Scale that you can
see the continents moving (continental drift).
Now click on the SET ALTITUDE icon again. The icon in the CURRENT TOOL
DISPLAY shows only a down arrow to indicate that the tool is in LOWER mode.
The price to lower altitude is also 50 energy units.
Scroll over to a landmass, click and hold for a few seconds. You've just
dug a lake.
> 28 <
THE GAIA WINDOW
Select GAIA from the WINDOWS MENU. A small window appears with a
representation of Gaia--the planetary organism. This face will give
you constant feedback on the "mood of the planet."
Gaia's mood is based on how well life on the planet is doing.
The moods range from bliss to horror. Everything that happens and
everything you do affects the planet's mood.
You may want to keep this window showing in a corner of the screen to
give you constant feedback on your planetary management.
Gaia will sleep until life forms, then it will wake up. Its eyes
will follow the pointer around the screen. Please don't poke it in
Note: The Icons here are obvious for what they are. So i aint
pratting about trying to re-create em with Ansi.
Now for some real fun--triggering events. Make sure the EVENTS DATA LAYER
BUTTON in the EDIT WINDOW CONTROL PANEL is on.
Events are more than just disasters or occurrences: they are tools. They
can be helpful in shaping the land and changing the composition of
the atmosphere. They can also cause mass extinctions.
Remember, in SimEarth, everything is interrelated. To see how each
event can be used for good or bad, and its side effects that affect
the planet, see the "Events" chapter of the Reference section and use
the HELP function (hold the SHIFT KEY and click on the TRIGGER EVENTS icon).
Click and hold on the TRIGGER EVENT icon. You will see the submenu of
events. Slide the pointer until METEOR is highlighted, then release the
Scroll the EDIT WINDOW so water is showing. Click a few times on the ocean.
Meteors will crash into the water, creating tidal waves. When meteors
hit the water, they add a lot of moisture to the air, which will
increase rainfall and contribute to the greenhouse effect. To check
this, select AIR SAMPLE from the GRAPHS MENU, which will open the
ATMOSPHERIC COMPOSITION GRAPH. Look at the percentage of Water Vapor.
Go back to the EDIT WINDOW and drop a few more meteors in the ocean.
Check the Water Vapor percentage again.
> 29 <
Crash a few meteors into land. You will get huge craters. If they
are deep enough, they will become lakes. Crashing meteors into land
spews dust into the atmosphere. Too much dust in the air blocks
sunlight, which will kill plants (biomes), which will kill animals.
Check the dust levels in the ATMOSPHERIC COMPOSITION GRAPH before and
after triggering meteors.
Click and hold on the TRIGGER EVENT icon again, and select VOLCANO from
Trigger a volcano somewhere in the ocean--instant island. Volcanoes
in the water cause tidal waves, which can kill land life near
the coasts. Volcanoes also add dust and carbon dioxide to the atmosphere.
Now activate EARTHQUAKE on the TRIGGER EVENTS submenu. It has a sub-
submenu for choosing the direction of the earthquake's energy.
Earthquakes in SimEarth let you change the direction of the magma flow
under the surface of the earth, which affects continental drift. In other
words, earthquakes let you move continents. To easily see the results
of earthquakes, turn on the MAGMA CLIMATE LAYER BUTTON.
You can use earthquakes to build mountain ranges. Center
the EDIT WINDOW over a landmass, preferably an area at a
low altitude (you can use the SET ALTITUDE tool to lower it).
Near the top of the window, set off a few earthquakes that
expend their energy to the south. Near the bottom of the
window, set off a few earthquakes that expend their energy
to the north. This has the effect of squeezing the land from
both sides, and a mountain range will be pushed up where
the energy from the southbound and northbound quakes
The other events work the same way--they are useful tools with both
good and bad side effects. Take some time and play with them.
> 30 <
Open the WINDOWS MENU and select REPORT. The REPORT WINDOW tells you
how you, your planet, and your planet's life are doing.
The information displayed in the REPORT WINDOW varies for each Time Scale.
There is also a special REPORT WINDOW for the Daisyworld scenario and for
the two terraforming scenarios (Mars and Venus).
At the bottom of the window is your CURRENT TASK. This is what must be
accomplished before advancing to the next Time Scale, or successfully
completing a scenario.
Let's start a new planet in the Civilisation Time Scale and look
at the rest of our tools.
First, save the old planet to disk. Select SAVE AS... from the FILE MENU.
Choose the disk or directory you want to save to, and change the name
of the planet if you wish. Click the SAVE button. Refer to the
SimEarth addendum for details.
Select NEW PLANET from the FILE MENU. This time, choose experimental mode,
then click on the random planet.
When the Name and Time Scale dialog box appears, click in the box to
the left of "Civilised," type in the name CIVWORLD, and click the
> 31 <
INVESTIGATING THE NEW WORLD MAP WINDOW
Lets take a look around the new planet. Open the MAP WINDOW, if it isn't
already open, and have it display the world in the flat projection (not
the globe). At the bottom of the window is the MAP WINDOW CONTROL PANEL.
In this control panel are 12 icons that change the map display. They
are arranged in five groups: Geosphere, Hydrosphere, Atmosphere,
Bio(sphere), and Civ(ilization).
(Icons from Left to Right number 1-12!).
1.) The map now displayed is the Terrain Map, which corresponds with
the Terrain Map icon. Here you can see the continents and the
oceans, and the terrain level of the land. Click on the INFO BUTTON
in the lower-right corner of the window. The INFO BOX now displays
a legend to the map's altitude.
2.) Click on the Event Map icon. Now the map shows the land and water (no
altitude), plus tiny symbols that appear where events are occurring
(if they are occurring). The INFO BOX shows a legend to the event
3.) Click on the Drift Map icon. Now you see the direction of the
magma currents, which controls continental drift on your planet.
1.) Click on the Terrain Map icon. The drift is gone, and the
altitude display is back.
4.) The first icon in the Hydrosphere group is the Hide/Show Oceans icon.
This toggles on and off the view of the oceans. It can be used
along with any of the other icons. Click on it a couple times, but
when you are done, leave the display of oceans on.
5.) Click on the Ocean Temperature icon. You are shown the temperature
of the ocean in shades or colors. The INFO BOX displays a legend of
6.) Click on the next icon to see a display of ocean currents.
> 32 <
Now for the Atmosphere group. The three icons in this group display Air
Temperature, Rainfall, and Air Currents, respectively. Click on
each of them. The INFO BOX will display a legend for each display.
The Biosphere group only has two icons: Biomes shows the biome distribution
on the planet, and Life shows the diversity of life on the planet. Once
again, the INFO BOX displays a legend to help you interpret the map.
There is only one icon in the Civilisation group. It displays the
distribution of the seven levels of Technology on the planet.
The graphs will also give you information about this planet. Select
BIOMES from the GRAPHS MENU to see the BIOME RATIO GRAPH.
Biome Ratio Graph
This graph shows the relative amounts of each biome on the planet. Since
it shows changes over time, you can see the rise and fall of biomes
Life Class Ratio Graph
Select LIFE-FORMS from the GRAPHICS MENU to see the LIFE CLASS
RATIO GRAPH. This shows the relative amounts of each class of
life on the planet.
Technology Ratio Graph
Select TECHNOLOGY from the GRAPHS MENU to see the TECHNOLOGY RATIO
GRAPH. This shows the relative amount of each level of technology
on the planet.
> 33 <
Go back to the EDIT WINDOW, and look at the EDIT WINDOW CONTROL PANEL.
Turn on all the DATA LAYER BUTTONS.
Click on the EXAMINE icon (Magnifying Glass). Now click and hold on any
spot in the EDIT WINDOW DISPLAY AREA. A small window will pop up on
the screen that gives you data on the biomes, life, and Civilisation
in that spot.
While still holding down the mouse button, move the pointer around the EDIT
WINDOW. The data window will update to describe the spot under the pointer.
Take some time and use the EXAMINE tool to explore your world.
If you ask for HELP (hold down the SHIFT KEY and click) in the EDIT WINDOW
DISPLAY AREA it will bring up the same data window as the EXAMINE tool.
Now that we know something about the planet, let's shake things up
THE PLACE LIFE TOOL
Make sure the EDIT WINDOW is displayed, and the LIFE and CITIES DATA
LAYER BUTTONS are on. Click and hold on the PLACE LIFE icon.
> 34 <
You will see a submenu. This is where you choose life, civilisations
(cities), and terraformers to place on your planet.
The left side of the submenu is for selecting life. The top seven are
sea life, the bottom seven are land life.
On the right side, the top seven items are cities for your intelligent
SimEarthlings. The seven cities represent seven levels of
technology. Below the cities are seven terraformers. These are
tools that you will need to terraform Mars and Venus.
Select one of the life-forms on the left side of the submenu. Move
the pointer to the EDIT WINDOW DISPLAY AREA and click. The life-
form will be placed where you click.
Depending on the Time Scale and level of development on the
planet, some of the options on the Place Life submenu will not be
available. These include both life-forms and cities.
Just because you place life on the planet doesn't mean it will stay
there. If you place ocean life on the land or land life in the water,
it won't last long. Also, life-forms can only survive well in
A complete chart of what life can live in which biome is in the
"Life" chapter in the Reference section of this manual.
Notice that placing different life forms and cities costs
different amounts of energy, depending on the level of advancement of
the item you are placing.
THE PLANT BIOME TOOL
Just as you can place animal life on the planet, you can plant biomes.
Click and hold on the PLANT BIOME icon. You will see a submenu that
will allow you to choose a biome to plant.
The various biomes can only survive in certain climates--if you plant a
swamp in a polar icecap, it won't last long. A complete chart of what
biomes can survive in which climates is in the "Life" chapter in the
When planting biomes, you can click and hold the mouse button, and
slowly drag the mouse across the planet. The biomes will be continuously
"painted" onto the terrain.
> 35 <
THE MOVE TOOL
The last tool in the EDIT WINDOW is for moving biomes, life, and cities.
Click on the MOVE icon.
Move the pointer to the EDIT WINDOW DISPLAY AREA and click and hold on a
spot with life, a city, or a biome. Move the pointer to a different
spot, and release the mouse button.
Besides moving things, the MOVE tool is helpful for investigation. When
you have multiple data layers on, LIFE symbols will cover BIOME symbols,
and CITY symbols will cover both LIFE and BIOMES. To see what life or
biome is under a city, use the MOVE tool to lift it, then put it back
in the same place.
We've covered exploration and modification of the planet; now we'll
learn how to modify the simulation.
> 36 <
MODIFYING THE SIMULATION
In the EDIT WINDOW you change the planet. In fact, you only change
part of the planet. With the MODEL CONTROL PANELS, you make changes
to the actual model that controls the fate of the entire planet.
There are four MODEL CONTROL PANELS. One each to modify the simulation in
the following areas:
GEOSPHERE --the planet itself;
ATMOSPHERE --the planet's air and climate;
BIOSPHERE --life on the planet; and
CIVILISATION --the behaviour of the planet's sentient species.
This tutorial won't explain each and every control on each CONTROL PANEL. It
will explain what each CONTROL PANEL does, and how to use it. For a
complete description of the control panels, see the "Model Control
Panels" chapter in the Reference section.
You can also find out what each control does by using the HELP function: hold
down the SHIFT KEY and click on one of the controls. A HELP WINDOW will
appear with a description of what each individual control does.
GEOSPHERE CONTROL PANEL
The GEOSPHERE MODEL CONTROL PANEL controls the geologic aspects of a
planet. These aspects, such as continental drift and core
formation, change very slowly over millions of years. Since they change
so slowly, the only way to see them clearly is in the Geologic Time Scale.
Create a new, random planet in the Geologic Time Scale.
Close all the windows, except the MAP WINDOW. Open
the GEOSPHERE MODEL CONTROL PANEL. You can
either do this by selecting GEOSPHERE from the
MODELS MENU, or by clicking on the GEOSPHERE
button in the MAP WINDOW CONTROL PANEL.
Open the OPTIONS MENU and make sure UPDATE
BACKGROUND is on. (It will have a checkmark on the
left if it is on.) This will allow you to keep the MODEL
CONTROL PANEL in front and still see the changes in
the MAP WINDOW.
> 37 <
There are seven controls on this panel. Each control has a name and an
indicator. The indicator is usually an arrow. For this tutorial,
we'll concentrate on the CONTINENTAL DRIFT control because the results
of changing it are easy to see.
Click on the words CONTINENTAL DRIFT in the GEOSPHERE MODEL
CONTROL PANEL. The words and the arrow above those words will be
highlighted to show that this control is ready for your changes.
To change the settings, you will use the slider control on
the right side of the control panel. Click above or below the slider
to move it up or down one notch. You can also click and drag the slider.
If the oceans haven't formed yet on your newest planet, wait a
minute until they do, then continue.
Click and drag the slider all the way to the top, turning continental
drift to its maximum setting. Go to the SPEED MENU and set the simulator
to FAST. Watch the MAP WINDOW for a while: you will actually see the
Now turn the continental drift all the way down. The continents will slow
their movement to nearly nothing.
The other controls are operated the same way, and though the results of
changing them isn't as obvious as with continental drift, they all have
a powerful impact on the planet.
ATMOSPHERIC MODEL CONTROL PANEL.
Now open the ATMOSPHERE MODEL CONTROL PANEL. You can open it three
ways: select ATMOSPHERE from the MODELS MENU, click on the ATMOSPHERE
button on the MAP WINDOW CONTROL PANEL, or click the NEXT button in the
upper-right corner of the GEOSPHERE MODEL CONTROL PANEL.
> 38 <
The ATMOSPHERE MODEL CONTROL PANEL is effective in all four Time Scales.
Bring the MAP WINDOW to the front, and click on the AIR TEMPERA-
TURE icon. Click on the INFO BUTTON to display a color/shade legend
of the temperatures.
Bring the ATMOSPHERE MODEL CONTROL PANEL to the front. Click on SOLAR
INPUT, then drag the slider all the way to the top. You just
turned the heat from the Sun to maximum. Your planet will soon start
To add insult to Injury, turn GREENHOUSE EFFECT all the way up, and turn
CLOUD ALBEDO, SURFACE ALBEDO, and AIR-SEA THERMAL TRANSFER all the
way down. Each of these actions will contribute to global warming.
Click on the INFO BUTTON. It will now display a graph of the changes in air
temperature. Watch for a while. Soon the map and graph will show a rise in
temperature. If you leave it rising long enough, your oceans will boil
off and all life on the planet will die.
After a few minutes, set all the settings back to midway, and watch the
map and graph as everything begins to cool down.
BIOSPHERE MODEL CONTROL PANEL
The BIOSPHERE MODEL CONTROL PANEL is most effective in Evolution Time
Scale, but has some effect in the other Time Scales. It controls how the
simulation models life on the planet.
Create a new planet in the Evolution Time Scale, set the simulation
speed to FAST in the SPEED MENU, and open the BIOSPHERE MODEL CONTROL
PANEL. It can be opened from the menu, the MAP WINDOW CONTROL PANEL,
or the NEXT button on the ATMOSPHERE MODEL CONTROL PANEL.
Turn ADVANCE RATE, MUTATION RATE, and REPRODUCTION RATE on the
BIOSPHERE MODEL CONTROL PANEL all the way up.
The changes from this control panel are much less obvious than the
others. You can best see them in the HISTORY WiNDOW.
> 39 <
Open the HISTORY WINDOW by selecting HISTORY in the
The HISTORY WINDOW displays the changes in 15 factors
over time. Click on the DIVERSITY button to display the
changing number of species on the planet.
Watch for a few minutes, and the changes you made in the
BIOSPHERE MODEL CONTROL PANEL will cause a rise in
CIVILISATION MODEL CONTROL PANEL
The CIVILISATION MODEL CONTROL PANEL controls how the model deals with
your intelligent species. It is only useful in the Civilisation
and Technology Time Scales.
Open the CIVILISATION MODEL CONTROL PANEL. This control panel is one of
the main challenges of SimEarth. You decide what energy sources
the intelligent inhabitants of your planet will invest their time in,
and what they will do with the energy.
This is a very complex control panel. For a complete explanation, see the
"MODEL CONTROL PANEL" chapter in the Reference section of this manual.
The left side of the CIVILISATION MODEL CONTROL PANEL is for choosing the
energy sources to develop. These are set the same as settings on the other
control panels. Different energy sources are appropriate for
different levels of technology: you can make a Stone Age level
Civilisation spend a lot of time trying to develop nuclear energy,
but they don't have the knowledge or tools to succeed, and won't get
any return from it.
The more you invest in energy forms that are appropriate for the
technology level, the more energy the civilisations will have to use
for advancement to the next technology level.
> 40 <
The right side of the control panel is where you allocate energy. You
decide to what use the civilisations will put the energy they produce.
This side of the control panel works a little differently from the
left side. It is a ratio. All energy that is produced is used. The
higher the setting for each energy use, the higher the percentage of
the produced energy will be allocated to that use. If the settings are
all in the middle, or all the way up, the model interprets it the
same. The important thing here is the relative settings of each energy use.
Set your priorities and allocate to those uses you find most important.
The CIVILISATION MODEL CONTROL PANEL is closely related to the REPORT
Create a new planet in the Technology Time Scale. Make sure the UPDATE
BACKGROUND option is on.
Open the REPORT WINDOW, and arrange the screen so it and the
CIVILISATION MODEL CONTROL PANEL are both visible.
Take a look at the REPORT WINDOW. There is detailed information on the
planet's Civilised life. It tells you the class of your sentient
species, the highest and average (median) technology level, the
population, and quality of life. It also shows a chart of what biomes
your sentient species prefers to live in.
Below that is a section on energy that relates to the CIVILISATION MODEL
CONTROL PANEL. It lists the energy sources, and their efficiency. The
efficiency depends on the average level of technology on your planet.
To the left of each energy source are the hours per week your global
citizen works on this energy source. Below these hours are the total
hours per week intelligent SimEarthlings must work to survive.
As you turn the energy investments on the CIVILISATION MODEL CONTROL
PANEL up and down, the hours worked will rise and fall. Try it.
Keep this in mind when you set your energy investment--the work hours per
week affect the SimEarthling's quality of life.
> 41 <
Energy allocation in the CIVILISATION MODEL CONTROL PANEL affects every
aspect of the sentient SimEarthling's lives.
The results of your allocation are easy to see. Make sure the UPDATE
BACKGROUND option is on.
For an easy-to-see example, we'll look at PHILOSOPHY.
Allocating to PHILOSOPHY lessens the frequency and severity of
war. If you take all allocation away from PHILOSOPHY, wars will break
out all over the planet. These wars can be viewed in the EDIT WINDOW
and the HISTORY WINDOW.
Open the HISTORY WINDOW and arrange the screen so you
can see it along with the CIVILISATION MODEL CONTROL
PANEL. In the HISTORY WINDOW, turn the POPULATE and
WAR graphs on. Turn PHILOSOPHY all the way down in the
CIVILISATION MODEL CONTROL PANEL.
The occurrence of war will quickly rise. Eventually it will fall,
because so many of the sentient SimEarthlings have been
killed that there's no one left to fight.
Allocating or not allocating to the other energy uses can
have results as drastic as PHILOSOPHY. These results can
be seen in the EDIT, REPORT and MAP WINDOWS. Try
turning each one all the way up, then all the way down and
see what happens.
Allocating to SCIENCE will help your intelligent SimEarthlings
advance to higher levels of technology. No allocation to SCIENCE
will cause advancement to stop.
Allocate too much and they will advance too fast, and kill themselves.
Allocating to AGRICULTURE affects the food supply.
Allocating to MEDICINE affects the frequency and severity of plagues.
Allocating to ART/MEDIA affects the quality of life on your planet.
Your task here is making difficult choices and setting priorities.
> 42 <
Now you know the basics of SimEarth:
Opening and closing windows;
Creating and saving planets;
Getting information from maps and graphs;
Changing the planet in the EDIT WINDOW; and
Changing the simulation in the MODEL CONTROL PANELS.
Mastery of planet management takes a lot of time and experimentation.
You may even (heaven forbid) have to read the rest of this manual.
> 43 <
UNBLANK PAGE (Some weird shit going down here! .. Rb).
To keep this manual consistent by always having a chapter title
page on the right side, we either had to leave this page blank, say
something dumb like "This page intentionally left blank," or fill it up
Here are some profound thoughts and revelations that occurred to us while
In general, SimEarthlings are as lazy as Earthlings. They never want
to work, and especially hate physical labour. Whenever there are heavy
objects to move, they argue over who has to do it.
"I don't want to carry it--you carry it!"
"Not me--you carry it."
And that's how Eukaryotes evolved.
Of course, the usual solution is to hire a professional to do the work.
That's what Prokaryotes do for a living.
When you're sitting on top of the world, be careful not to break
SIMEARTHLING EXTINCT BLUES
My life-form's gone, but I don't worry,
'Cause I'm simulating on top of the world.
NOBODY READS GAME MANUALS
Hi Mom. I know nobody reads game manuals, but I knew you would. I worked
real hard on this manual, and...Mom...wake up Mom.
Where in the world is Carmen SimDiego?
> 44 <
"Love makes the world go round but a single click in the Edit
window makes it stop."
CONTROLLING THE SIMULATION
Depending on your computer, you may or may not have a mouse. If you do have
one, then you will want to use it--SimEarth is much easier to control with a
mouse than with a keyboard.
See the addendum for your computer for more information on using mice and
keyboards in SimEarth.
In general, you will use the mouse to select items from menus,
and to activate tools by clicking on icons. Once tools are activated,
SimEarth functions much like a paint program that "paints life
on a planet."
SimEarth has a lot of windows, graphs, and control panels, and
can get confusing. The easiest way to understand the program is to
know where you can INPUT information--add or change the planet or
model to suit yourself--and where to see OUTPUT, the information about
the planet and results of your INPUT.
There are three places to INPUT information: the FILE MENU, the EDIT WINDOW,
and the MODEL CONTROL PANELS.
By selecting NEW PLANET or LOAD PLANET from the FILE MENU, you remove
the existing planet or scenario from memory and load another planet
or scenario into the simulation.
The EDIT WINDOW is where you place life, change altitudes and trigger
When you do these things, you are INPUTTING DATA--changes to the planet.
Since this only affects the planet in the locale of your input, we
call this LOCAL INPUT.
The EDIT WINDOW is also a source of OUTPUT.
> 46 <
MODEL CONTROL PANELS
The four MODEL CONTROL PANELS are where you change the actual model.
These changes affect the entire planet, and change the
simulation itself. Since everything--the whole world--is affected, we
call this GLOBAL INPUT.
The MODEL CONTROL PANELS are the only places in SimEarth that are INPUT
Other than the MODEL CONTROL PANELS, every window in SimEarth gives
OUTPUT--information for you about the planet, the simulation, and the
results of your input.
> 47 <
The FILE MENU is for performing file and disk-related functions.
NEW PLANET brings up the NEW PLANET WINDOW, which allows you to pick
any of the seven included Scenarios, or a new, randomly generated
planet/game in any of three difficulty levels or experimental mode.
First, choose the difficulty level. There are three levels of
difficulty for games: easy, medium, and hard. There is also an
experimental mode that gives you an unlimited energy budget for
Next, pick a scenario or a random planet. If you choose random
planet, you will be shown a dialog box allowing you to name your new
world, choose the Time Scale, and either begin the new planet or
cancel. If you have a planet in progress that has not been saved, you
will be given the opportunity to save it before the new planet is
LOAD PLANET brings up a dialog box to allow you to load in a pre-existing
planet. If you have a planet in progress that has not been saved, you
will be given the opportunity to save it before loading a new one. See
the SimEarth addendum for your computer for details on loading planets.
SAVE PLANET saves your current planet to disk. If it has not been
saved before, it will bring up a dialog box window to allow you to
name your planet before saving it. See the SimEarth addendum for
your computer for details on saving planets.
SAVE AS brings up a dialog box, allowing you to change the name and/or
location of a previously saved planet.
PRINT or SNAPSHOT may or may not be present in your version of SimEarth.
See the SimEarth addendum for your machine for details.
QUIT ends your SimEarth session, with a final chance to save your
The WINDOWS MENU allows access to the various windows in SimEarth.
EDIT opens and/or brings the EDIT WINDOW to the front.
MAP opens and/or brings the MAP WINDOW to the front.
> 48 <
GAIA opens the CAIA WINDOW, which displays the face of the planet and
gives constant feedback on your actions and the state of life in
HISTORY opens and/or brings the HISTORY WINDOW to the front.
REPORT opens and/or brings the REPORT WINDOW to the front.
TUTORIAL opens and/or brings the TUTORIAL WINDOW to the front.
GLOSSARY opens a HELP WINDOW that displays a glossary of many earth
science terms used in SimEarth.
The MODELS MENU allows access to the various MODEL CONTROL PANELS that
let you adjust the inner workings of the simulation.
GEOSPHERE opens the Geosphere Model Control Panel.
ATMOSPHERE opens the Atmosphere Model Control Panel.
BIOSPHERE opens the Biosphere Model Control Panel.
CIVILISATION opens the Civilisation Model Control Panel.
The GRAPHS MENU allows access to the various graphs used in SimEarth.
AIR SAMPLE brings up the Atmospheric Composition graph.
BIOMES brings up the Biome Ratio graph.
LIFE FORMS brings up the Life Class Ratio graph.
TECHNOLOGY brings up the Technology Ratio graph.
The OPTIONS MENU lets you adjust many features of SimEarth to suit your
personal preferences. When the options are active, a checkmark will
appear to the left of the option.
GOTO EVENTS automatically transports you to the location of any event that
occurs. When this option is active, and when the EDIT WINDOW is in
the front, the area viewed in the EDIT WINDOW will jump to centre
on any events that occur. The default setting is off.
> 49 <
UPDATE BACKGROUND lets you choose whether or not all windows on the
screen will be animated and constantly updated. When this option
is inactive, only the front window will be animated and updated.
Having this option on greatly decreases the speed of the simulation. The
default setting depends on your machine's speed of operation.
This is especially useful for high-speed machines with large
monitors. If SimEarth runs too slowly, or you rarely display more than
one or two windows at a time, you may wish to turn this off.
COMPRESS EDIT SCREN is an option that can be very useful on computers with
small screens. When active, it changes the Edit WINDOW so it only
displays every other tile allowing you to see four times as much area.
The default setting is off.
MUSIC enables and disables music during the game. The default setting is on.
SOUND EFFECTS enables and disables sound during the game. The default
setting is on.
MESSAGES enables and disables the display of messages to you from the
simulator and the SimEarthlings that will appear throughout the game. The
default setting is on.
AUTOSCROLL allows automatic scrolling of the terrain in the EDIT WINDOW
when using any of the EDIT WINDOW icons near or at the edge of the
window. The default setting is on.
SAVE OPTIONS + WINDOWS saves your present configuration of options, open
windows, window sizes and window locations to disk as the
default configuration. You can use this option again at any time to
change the default settings.
> 50 <
The SPEED MENU allows you to set the simulation speed and date options.
FAST sets the simulation speed to the maximum available for your machine.
MODERATE sets the simulation speed to approximately 75% of the fast setting.
This is the default speed setting.
SLOW sets the simulation speed to approximately 25% of the fast setting.
PAUSE pauses the simulation. All the planet manipulation tools will
be available and active, but time will be stopped.
RELATIVE DATE displays the date as the number of years since the beginning
of the present Time Scale. This is the default date setting.
ABSOLUTE DATE displays the date as the number of years since the original
cooling of the planet. If you began your planet in a later Time
Scale, Absolute Date will estimate and add the time from earlier Time
The DATASOUND MENU controls the sound functions in SimEarth. The first two
items are ways of using the sound and the last seven items let you
choose the data from which the sound will be generated.
TONE MONITOR plays an intermittent, recurrent tone based on one of the data
settings. This is used for aural monitoring of data. For instance,
if you are trying to combat global warming, you could set the tone
monitor to report on air temperature. Every so often you will hear
a tone. The higher the tone, the higher the average global temperature.
You will hear the changes in temperature without having to look at the
air temperature map.
PLAY DATA SONG is an option that is more fun than useful. It takes 32
evenly spaced samples of the selected data from the top to
the bottom of the map, averages the values across the map, and plays
them as notes. For example, if air temperature is selected, then the
data song will convert the 32 data samples into 32 notes--the higher
the air temperature, the higher the pitch. The notes will be
lowest around the poles and highest near the equator.
ALTITUDE bases the sound on data in the Altitude array.
AIR TEMPERATURE bases the sound on data in the Air Temperature array.
> 51 <
RAINFALL bases the sound on data in the Rainfall array.
SEA TEMPERATURE bases the sound on data in the Sea Temperature array.
BIOMASS bases the sound on data in the Biome array.
LIFE bases the sound on data in the Life array.
CIVILISATION bases the sound on data in the Humans array.
> 52 <
There are many different windows in SimEarth. Here is a complete
description of each one.
There is on-screen help available for almost everything in SimEarth,
including all menus, buttons, icons, tools, graphs, and control panels.
Help windows are not available through the menus. To get HELP, press
and hold the SHIFT KEY. This will change your cursor to HELP MODE.
Then click on any item on the screen, and you will be shown a text
window with lots of information about that item.
If you ask for HELP in the DISPLAY AREA of the EDIT WINDOW, you will
get the same information window that is produced by the EXAMINE icon.
If you ask for HELP in the DISPLAY AREA of the MAP WINDOW, you will
get information on the active MAP WINDOW display.
There is a massive amount of information available in the HELP WINDOW.
Almost anything in the world (simulated, that is) that you want to know
about is in there.
The HELP WINDOW is your friend. Use it.
The on-line GLOSSARY is useful for getting help with definitions of
words in the program you may not be familiar with. The GLOSSARY is
available in the WINDOWS MENU.
> 53 <
NEW PLANET WINDOW
This is really a dialog box, not a window, but it is so important
that for the purposes of this manual, we are giving it a promotion.
Use this window for creating new, random planets, and for
starting the scenarios.
At the top of the window are settings that let you choose the
difficulty of the game or scenario. At the bottom of the window are
the scenarios and random planet buttons.
Any random planet or scenario can be played in Experimental Mode, Easy Game,
Average Game, or Hard Game.
Help is available on every setting and button in this window. Hold down the
SHIFT KEY and click on anything in the window to receive help. You can get
explanations of all the options and scenarios before beginning a game.
Use these settings to adjust difficulty levels for all games, scenarios,
random planets, and experiments. Just click on the button next to a
setting to choose it.
EXPERIMENTAL MODE allows you to load any of the scenarios or a random
planet and have unlimited energy for planet manipulation. With the
unlimited energy, you can set up any type of planet you want in
any stage of development, and add any other factors or conditions you
want. This mode is really a "planetary spreadsheet."
This is also a good mode for learning SimEarth.
> 54 <
The MODEL CONTROL PANELS will all be randomly set at "moderate" values
that should allow planetary progress without many changes.
EASY GAME is good for beginners. In an easy game, life appears and
evolves quickly and easily. In fact, it will take some effort on
your part to stop it.
Your starting energy level is 5000 E.U. (energy units)
The MODEL CONTROL PANELS will all be randomly set at "moderate" values.
AVERAGE GAME is a little more challenging. It will take some
effort on your part to get your planet progressing and keep it going.
Your starting energy level is 2000 E.U.
The MODEL CONTROL PANELS will all be randomly set at "extreme" values that
will require some fine tuning.
HARD GAME is really difficult. In fact, it's really very difficult.
Not only will you have to adjust the MODEL CONTROL PANELS, but you
will have to take on the role of Gaia.
The MODEL CONTROL PANELS will all be randomly set at "extreme" values that
will require some fine tuning.
All Gaian regulation of climate, atmosphere and life is turned off
and there will be no spontaneous generation of life--it's all in
CANCEL removes the NEW PLANET WINDOW in case you change your mind.
PLANETS AND SCENARIOS
Any planet or scenario can be played in Easy, Medium, or Hard
Game as well as Experimental Mode. For in-depth descriptions
of the scenarios see the "Scenarios" chapter of this manual. Just
click on one of the planets to choose it.
RANDOM PLANET creates a randomly generated planet in any
of the four Time Scales. When you choose this option, you will
be shown a dialog box that will let you pick the Time Scale and
name the planet.
> 55 <
AQUARIUM is a planet with no continents. It is a good starting point
for those who like to design their own landscapes.
STAG NATION is a planet in the early civilisation time scale. Sentient
life on this planet is limited to one small island. You can help
it spread, or eliminate it and try to bring another life form
EARTH CAMBRIAN ERA is a simulation of Earth in the Evolution time
scale. One of the best features of this scenario is that its
continental drift re-creates the reak Earths drift.
EARTH MODERN DAY - gives you a chance to take over the Earth of
today. Youll get to deal with all the problems we deal with in the
real world. This scenario is not recommended for escapists.
MARS gives you the chance to terraform Mars and turn it into
a planet capable of supporting Eart life-forms.
VENUS gives you the ultimate challenge in Terraforming.
DAISYWORLD is the original simpler versiob of the SimEarth simulation.
Daisyworld was originally devised by James Lovelock as a demonstration
of the Gaia theory.
> 56 <
THE EDIT WINDOW
The EDIT WINDOW is a close-up view of your planet. It is used for LOCAL
INPUT--making changes to the planet, and for OUTPUT--investigating the
planet and seeing the results of your input.
The EDIT WINDOW consists of four major parts: the TITLE BAR, the DISPLAY
AREA, the SCROLL BARS, and the EDIT WINDOW CONTROL PANEL.
Located at the top of the EDIT WINDOW, the TITLE BAR displays the name of
your planet and the date. The date can displayed as either the RELATIVE
date or the ABSOLUTE date, selected from the SPEED MENU.
On the left side of the TITLE BAR is the CLOSE BOX. Clicking in this
box will close the EDIT WINDOW. The window can be reopened by selecting
the item "EDIT" from the WINDOWS MENU.
On the right side of the TITLE BAR is the GROW BOX Clicking in this box
will make the EDIT WINDOW grow until it fills the entire screen. Clicking
it again will return the window to its former size.
The EDIT WINDOW can be moved around the screen by clicking and dragging the
> 57 <
EDIT WINDOW DISPLAY AREA
This is where you are shown your planet in a close-up view. The
information you are shown here is controlled by the EDIT WINDOW
There are two scales that can be shown in this display: Normal
and Compressed. If you select "Compress Edit Screen" from the
OPTIONS MENU, this window will only display every other tile. This
will give you less exact information, but will show you four times
as much of the area of your planet as the Normal view. This
is especially useful on machines with small screens (Mac Plus, SE,
SE/30). This is the view that prints out with the PRINT option on
the FILE MENU.
Using the HELP function (hold the SHIFT KEY and click) in
the EDIT WINDOW DISPLAY AREA will bring up a window
detailing all the information that the simulation has about
the spot where you clicked.
Messages from the simulation and the SimEarthlings will
sometimes appear at the top of the display area.
TERRAIN AND ELEVATION
There are 32 levels of terrain. The lighter the shade, the higher
the altitude. Each different shade represents a change of 500 meters.
Since altitude is measured from sea level, and sea level can be
anywhere--or nowhere--there is no exact altitude that can be assigned
to each shade.
There are three types of sea displays, depending on the depth of the water.
SHELF --O to 1000 meters deep
OCEAN --1001 to 2500 meters deep
DEEP SEA--greater than 2500 meters deep
SCROLLING THE TERRAIN
Depending on your computer, there may or may not be SCROLL BARS along the
right and bottom of the EDIT WINDOW. If they are there, you can use them
to scroll the terrain in the EDIT WINDOW to see different parts of
the planet. Click on the arrows or the bars, or drag the scroll box to
> 58 <
If there are no SCROLL BARS, then scrolling is accomplished by moving the
pointer to any edge or corner of the screen. For keyboard-controlled
scrolling, see the SimEarth addendum for your machine.
In the lower-right corner of the window is the SIZE BOX. Clicking and
dragging this box will allow you to re-size the EDIT WINDOW.
EDIT WINDOW CONTROL PANEL
This control panel is for controlling both the information viewed
in the EDIT WINDOW and for accessing the tools for planet modification.
Using the HELP function (hold the SHIFT KEY and click) in the CONTROL PANEL
will bring up a small window with information about each of the items and
There are four sections to the EDIT WINDOW CONTROL
PANEL: the TOOL ICONS, the CURRENT TOOL DISPLAY, the
DATA LAYER BUTTONS, and the CLIMATE OVERLAY BUTTONS.
By clicking on these icons, you access the tools for modify-
ing your planet. There are six icons, three of which have
submenus. Just below the Tool Icons is a box displaying the
active icon and giving budget information for using that
Every time you use one of the TOOL ICONS it will deplete
your precious energy stores.
PLACE Life allows you to choose and place life and
cities on the planet. This icon also allows you access
to various terraforming tools for use on Mars and Venus.
Use this tool to spread life on the planet, to set various life-
forms in competition with each other, and to test living
conditions for various life-forms.
> 59 <
To select a life-form, city, or terraformer, click and hold on the
PLACE LIFE icon. A submenu will appear. While holding the
mouse button down, move the pointer to highlight the life, city,
or terraformer of your choice, and then release the button.
Your choice will appear in the CURRENT TOOL DISPLAY, just
below the icons, along with the cost in energy to place or use it.
To place the life, city, or terraformer on the planet, point to a
spot in the display area and click.
There are 15 classes of life in SimEarth, seven in the sea, and
eight on land. Each class of life is represented in SimEarth by 16
Only 14 of the classes of life are available in the PLACE LIFE tool.
CARNIFEROUS mobile, carnivorous plants that can develop intelligence
will sometimes evolve, but cannot be placed.
There are seven types of cities, each representing a level of
Civilisation and technology. Most levels of technology are represented
by cities with three population densities. Each of these levels also
has a travelling population that represents sentients moving around,
as well as trade and communication. The exception to this is the
Nanotech Age, which is the highest level of technology in SimEarth.
It has four levels of density, and no travelling population: we assume
that they have matter transporters for instantaneous moving of people
There are seven terraformers.
A complete description of the 15 classes of life in SimEarth is found later
in this manual, in the chapter "Life." A complete description of the
cities is covered in the chapter "Civilization." The terraformers
will be covered in detail here.
> 60 <
The classes of life and cities available to place, with their cost
in energy, are:
SEA LIFE CLASSES
PROKARYOTE--Single-celled life with no nucleus (bacteria). 35 E.U.
EUKARYOTE --Single-celled life with nucleus (amebas). 70 E.U.
RADIATE --simple multi-celled life (starfish). 105 E.U.
ARTHROPOD --Crabs, lobsters, and craylish. 140 E.U.
MOLLUSK --Snails, clams, oysters, scallops, octopi, and squid. 115 E.U.
FISH --Fish. 210 E.U.
CETACEAN --Whales and dolphins. 245 E.U.
LAND LIFE CLASSES
TRICHORDATE--Simple animal with a three-chord spine. 280 E.U.
INSECT --You know what these are. 315 E.U.
AMPHIBIAN --Frogs, newts, and toads. 350 E.U.
REPTILE --lizards, snakes, and turtles. 385 E.U.
DINOSAUR --great big, huge reptiles. 420 E.U.
AVIAN --Birds. 455 E.U.
MAMMALS --Humans, apes, rodents, dogs, cats, etc. 490 E.U.
(Wheres the PiNK FLuFFY KiWiS ???? Hahaha Fukkas!)
The dates mentioned below are for reference to Earth only, and do
not necessarily correspond with dates in SimEarth.
STONE AGE -- oldest Human culture; used stone tools. 500 E.U.
BRONZE AGE -- Began circa 3500 B.C.; used bronze tools. 1000 E.U.
IRON AGE -- Began circa 1000 B.C.; used iron tools. 1500 E.U.
> 61 <
INDUSTRIAL AGE-- Began in late 18th century with the use of powered
machinery. 2000 E.U.
ATOMIC AGE --Began in the 1950s with the use of atomic power. 2500 E.U.
Information AGE--Begins circa 2000 A.D.--information is the most
important tool. 3000 E.U.
NANOTECH AGE --Begins sometime in the future, characterised by science
and technology beyond our imagination. 3500 E.U.
Terraformers are tools for turning Venus and Mars into earth-like planets.
They aren't needed on Earth, or planets that are earth-like to begin
with, but go ahead and try them to see what happens. Once placed,
Terraformers keep working. Don't place too many--the only way to stop one
is to hit it with a Meteor, Fire, or a Volcano.
BIOME FACTORY--When terraforming Mars or Venus, place the Biome
Factory instead of individual biomes. The Biome Factory, once
placed, looks at the terrain and climate and starts producing the
appropriate biome type that can survive there. It will also detect
changes in climate, and change the biomes it produces to a type that
will survive the changes. Biome Factories cost 500 E.U.
OXYGENATOR--The Oxygenator takes carbon dioxide (CO2) out of the
atmosphere and spits out free oxygen. Life requires a certain
percentage of oxygen, between 15 to 25%, to survive. Too much oxygen
on a planet will cause fires. Since it lessens the CO2, a greenhouse
gas, the Oxygenator will help cool a hot planet. An Oxygenator
costs 500 E.U.
N2 GENERATOR--The N2 (nitrogen) Generator is used to increase
atmospheric pressure on a planet. The atmospheric density affects
the planet's temperature--a denser atmosphere allows the planet
to retain more heat. The thinner the atmosphere, the colder the
planet. Also, having a denser atmosphere with lots of N2
stabilises the percentages of the other gases. An N2
Generator costs 500 E.U.
> 62 <
VAPORATOR - The vaporator spews water vapours into the atmosphere
raising the overall humidity of the planet and increasing rainfall.
A Vaportator costs 500 E.U.
CO2 GENERATOR - The CO2 Generator produces CO2 which is necessary
for plants to live. A CO2 generator costs 500E.U.
MONOLITH - The monolith isnt a terraforma but we didnt have anywhere
else to put it in the program. It is an Evolution speed-up device (our
thanks to Arthur C. Clarke) --> (And they call US pirates!! ;-)
The use it select the monolith then immediately click on a life-form.
There is a one-in-three chance of that life form suddenly mutating
to a higher level, which immediately moves you to the next Time
Scale. It costs 2500E.U. to use a Monolith, whether or not it works.
The monolith cant be used on all life forms - If you try to use the
monolith on a life-form that cannot mutate, the program will beep
at you, but there will be no energy charge.
A disadvantage of using the monlith is that you could jump ahead into
the civilization timescale before enough fossil fuels have been
generated, and civilisation will collapse. Also, you need a wide
population base to advance to the next technology level. Dont
rush to a new timescale at the expsense of your population.
If you successfully use the monolith in the technology time scale
it will bring about the exodus event.
ICE METEOR - The ice Meteor is a huge chunk of ice that you can crash
into a dry planet to add water to the planetary system. An Ice
Meteor costs 500E.U.
THE EXTINCT FUNCTION
An added feature of the PLACE LIFE tool is the EXTINCT FUNCTION. If
you want to remove a particular class of life from the planet, hold
down either the OPTION KEY or the CONTROL KEY (depending on
your machine), the click on the PLACE LIFE icon and select a life form
from the PLACE LIFE submenu. All oocurrences of the life form you
choose will dissappear.
> 63 <
The EXTINCT FUNCTION only works on life-forms--not on cities. If you want
to eliminate a life-form, you must do it before it reaches
sentience and builds cities.
The EVENT TRIGGER lets you select and activate various events at various
places on your planet.
The simulation will cause events to occur automatically, depending
on many factors including the age of the planet, the climate, air
and water temperatures, and sea level.
There are 11 possible events that occur in SimEarth. Three of
them, exodus, war and pollution, will occur, but cannot be
triggered by the user.
By triggering events yourself, you can learn the effects these
events have on local populations as well as to the planet as a whole.
To activate events, click and hold on the EVENT TRIGGER icon. A
submenu will appear, giving you a choice of eight events. While
the mouse button is still down, slide the pointer to the right so it
highlights the event you want to place, and release the button.
The selected event will appear in the CURRENT TOOL DISPLAY, just below the
icons, along with the cost in energy to trigger it.
Next, move the pointer to the DISPLAY AREA, and click the mouse button to
trigger an event on your planet. Click again in another place to
cause the same event.
A complete description of all events and their causes and effects will
be covered in the chapter "Events."
The available events in SimEarth, and their cost in energy, are:
Hurricane --High winds and rain. 50 E.U.
TIDAL WAVE --A huge, destructive ocean wave. 50 E.U.
METEOR --A huge rock from space that crashes into your planet.
VOLCANO --An explosive leak in the planet's surface that spews molten
rock. 50 E.U.
> 64 <
ATOMIC TEST --An atomic explosion. 50 E.U.
FIRE --Hot stuff. 50 E.U.
EARTHQUAKE --Shake, rattle and roll. 50 E.U. Clicking and holding
on the Earthquake icon brings up a submenu that allows
you to direct the Earthquake's energies.
PLAGUE --A deadly disease. 50 E.U.
PLANT BIOME --allows you to place or plant biomes onto your planet.
A biome is a major ecological community of plants and animals. Biomes will
automatically be placed on the planet by the simulation. Their quantity and
location is primarily controlled by altitude, temperature, and rainfall.
With this tool you can place any of the biomes anywhere on the planet at
any time. Of course, they won't necessarily stay there. An Arctic
biome will not last long in the hot equatorial zone, and a Jungle will
not thrive at a planet's pole.
Place biomes to experiment, and to help shape or speed up development
on your planet.
To use this tool, click and hold on the PLANT BIOME icon. A submenu
will appear, giving you a choice of eight biomes. While the mouse
button is still down, slide the pointer to the right so it highlights
the biome you want to plant, and release the button. The selected biome
will appear in the CURRENT TOOL
DISPLAY, just below the icons, along with the cost in energy to place
it. There is an energy cost of 50 E.U. for each biome planted.
Next, move the pointer to the DISPLAY AREA, and click the mouse button
to place a biome on your planet. The button can be held down while the
mouse is slowly moved to place multiple segments. A click will be
heard as each BIOME is placed. The pitch of the click will raise
and lower with the terrain altitude.
A complete description of all the biomes in SimEarth will be found later
in this manual in the chapter "Life." There are seven available biomes
in SimEarth, plus ROCK, which represents a lack of a biome in a location.
> 65 <
ROCK --No biome.
ARCTIC --Can survive in a cold and dry climate.
BOREAL FOREST--Can survive in cold temperatures, with moderate to
DESERT --Can survive in moderate to hot temperatures, with very
TEMPERATE GRASSLANDS--Can survive in areas with moderate
temperatures and rainfall.
FOREST --Can survive with moderate temperatures and high rainfall.
JUNGLE --Can survive with high temperatures and rainfall.
SWAMP --Can survive with high temperatures and moderate rainfall.
BIOME PREFERENCE CHART
DRY MODERATE WET
(<30 cm/yr) (30-90 cm/yr) (>90 cm/yr)
COLD(<0C) Arctic Boreal Forest Boreal Forest
MODERATE (0-25C) Desert Temp.Grasslands Forest
HOT (>25C) Desert Swamp Jungle
Biome preferences are also influenced by altitude and the
amount of CO2 in the atmosphere.
SET ALTITUDE allows you to raise or lower sections of land. There are 32
possible levels of terrain in SimEarth.
Use this tool to raise or level mountain ranges, create islands in
the ocean, or lakes in dry land. All these changes will have
impact on climate, rainfall, local biomes, and local life-forms.
Click on the SET ALTITUDE icon. Look at the CURRENT TOOL DISPLaY. It shows
that the SET ALTITUDE tool is active in "raise terrain" mode.
> 66 <
Move the pointer to the DISPLAY AREA. Click and hold the mouse button over
land or water, and the land around the pointer will be raised in altitude,
displayed by a lightening of the color or shade of the land.
Click on the SET ALTITUDE icon again, and look at the CURRENT TOOL DISPLAY.
It shows that the SET ALTITUDE tool is active in "lower terrain" mode.
Move the pointer to the DISPLAY AREA. Click and hold the mouse button over
land, and the land around the pointer will be lowered in altitude,
displayed by a darkening of the color or shade of the land.
Levels of terrain are displayed in shades. The lighter the shade, the
higher the altitude. Each different shade represents a change of
500 meters. Since altitude is measured from sea level, and sea level
can be anywhere--or nowhere--there is no exact altitude that can be
assigned to each shade.
The cost for using the SET ALTITUDE tool to raise or lower the
terrain is 50 E.U.
MOVING TOOL lets you pick any biome, niche, or Civilisation and move it.
This can be useful for transplanting populations to other
continents, or separating warring tribes. Since niches and biomes
can occupy the same space in the display, you can use this tool to
temporarily move the niche to see the biome that is displayed
Click on the MOVING TOOL icon to activate it, then click and hold on a
biome, niche or civilization. Drag the pointer to the destination
location, and release the mouse button.
The cost for using the MOVING TOOL is 30 E.U.
> 67 <
EXAMINE gives you information on individual spots in the DISPLAY AREA.
Click on the EXAMINE icon, and the mouse pointer changes to
a magnifying glass.
Then click and hold on a spot in the DISPLAY AREA. An information window
will appear, giving you all the information that the simulation
has about that spot.
If you click and hold the button, and slowly drag the pointer across
the screen, the information window will change and report on each section
as you point to it.
The EXAMINE function is very useful for gathering information about
specific areas of your planet. You will need this information for
planning your next moves in planet development.
The same information window can be accessed by using the HELP
function hold the SHIFT KEY or HELP KEY while clicking on a spot) in
the DISPLAY AREA.
The EXAMINE tool only gives information on places in the display window. For
information on icons and tools, use the HELP function.
The cost for using the EXAMINE tool is 5 E.U.
There are four sections to the EXAMINE WINDOW: the Biome Section,
the Life Section, the City Section, and the Altitude/Magma Section.
The Biome Section shows a picture of the local biome (if any), and a
description of its present condition, i.e., thriving, dying, etc. Next,
it displays the rainfall, air temperature (heat), and wind direction.
If there is no biome present, this section will display the message
If there is life, the Life Section shows a big picture of the
predominant class of non-sentient life in that location. (Sentient life
is treated separately in the City Section.) Below that are three small
pictures. The middle one is the present species of the class, the left
one is the species that it evolved from, and the right one is the
species that, if all goes well, it will evolve into.
> 68 <
Below that is a chart of how that life class gets along in the
various habitats, with picture rating of how happy the species are there:
(KEWL ANSIS HERE DUDEZ, REMEMBER TO VOTE FOR ME IN THE ANSI WORLD
CHARTS H0H0H0!!! )
X Can't live there.
8-( Can survive there, but it's miserable.
8-| Can survive there, and quite nicely.
If there is no life, this section will display the message "No Life."
If there are no sapients near, this section will display the message
If there are sapients, but no city, this section will display the
message "Lightly Inhabited."
If there is a city, this section displays a large picture of the
city, and tells the sapient class, the technology level, and the
This section, at the bottom of the window, displays this location's
altitude and direction of magma flow.
CURRENT TOOL DISPLAY
The CURRENT TOOL DISPLAY shows the active icon, tool, life-form, biome,
terraformer, or event, and the energy cost to use it.
DATA LAYER BUTTONS
These buttons control what data is displayed in the DISPLAY AREA. By
clicking on these buttons, you toggle on and off the various layers of
data. Using these buttons does not change the planet, or affect the
model in any way--it only changes your view of the planet.
The default settings for these buttons changes with the Time Scale. In the
Geologic Time Scale, the default setting has everything on except
BIOMES and CITIES. In the Evolution Time Scale, everything is on
except CITIES. In both the Civilisation and Technology Time Scales,
everything but LIFE defaults to the "on" setting.
> 69 <
OCEANS allows you to turn off and on the display of the Oceans, allowing
you to see the elevation of the sea bottom.
BIOMES allows you to turn off and on the display of Biomes, so you can
see the elevation of the terrain, and see Life and Cities more
ClTIES allows you to turn off and on the display of the Cities of the
current sentient species.
LIFE allows you to turn off and on the display of life-forms. Since
these are so numerous and fast-moving, you may want to turn these
off every so often to get a clearer view of the other things on
your planet. This display is of individual species, not classes
--there are 240 different species in SimEarth.
EVENTS allows you to turn off and on the display of Events.
CLIMATE OVERLAY BUTTONS
These buttons also control what data is displayed in the DISPLAY AREA. By
clicking on these buttons, you toggle on and off the various layers of
climate data. Using these buttons does not change the planet, or affect
the model in any way--it only changes your view of the planet.
The default setting for all these buttons is OFF. Only one climate
overlay can be active at any one time.
HEAT--A display of air temperature. Higher temperatures are represented by
RAINFALL--A display of average rainfall. Higher rainfall densities are
represented by darker shades.
WINDS --A display of the wind currents.
SEA FLOW--A display of the sea currents.
SEA HEAT--A display of water temperature. Higher temperatures are repre-
sented by darker shades.
MAGMA --A display of the magma currents under the planet's crust.
AUAILABLE ENERGY DISPLAY
This display lets you know how much energy you have left for
planet manipulation and modification. The maximum energy that can be
stored is set by the game level.
For a complete explanation, see the chapter "Energy."
> 70 <
The MAP WINDOW is your overview of the whole planet. It can be viewed as
a MAP WINDOW flat or spherical projection.
The MAP WINDOW consists of three major parts: the TITLE BAR, the MAP
DISPLAY AREA, and the CONTROL PANEL
The TITLE BAR displays the type of map being shown in the MAP DISPLAY
AREA and the date.
On the left side of the TITLE BAR is the CLOSE BOX. Clicking in this
box will close the MAP WINDOW. You can bring the window back by selecting
the MAP item in the WINDOWS MENU.
The MAP WINDOW can be moved on the screen by clicking and holding in the
TITLE BAR, and dragging the window to its new location.
MAP WINDOW DISPLAY AREA
The MAP WINDOW DISPLAY AREA is where the map of the planet is displayed.
There are many different types of displays and views of your planet,
which are selected in the MAP WINDOW CONTROL PANEL.
> 71 <
In the MAP DISPLAY AREA you will see the EDIT RECTANGLE. This rectangle
indicates the area of the world that is visible in the EDIT WINDOW. If
you double- click in the EDIT RECTANGLE, the EDIT WINDOW will be brought
to the front.
Messages from the simulation and the SimEarthlings sometimes appear at
the top of the MAP DISPLAY AREA.
MAP WINDOW CONTROL PANEL
The MAP WINDOW CONTROL PANEL allows you to look at various views of your
planet, giving different types of information in each view. From here
you can also access all of the MODEL CONTROL PANELS, the HISTORY WINDOW,
the EDIT WINDOW, and all the GRAPHS.
MAP DISPLAY ICONS
Along the top of the MAP WINDOW CONTROL PANEL, from the left, are 12
icons. Clicking on each of these icons displays different information in
the MAP DISPLAY AREA. These 12 displays are divided into five groups:
GEOSPHERE, HYDROSPHERE, ATMOSPHERE, BIO(SPHERE) and CIV(ILIZATION). A
MODEL CONTROL PANEL can be accessed for four of the five groups
(excluding HYDROSPHERE) by clicking on the name of that group.
The GEOSPHERE group gives information on the terrain, events and magma
flow of the planet. Clicking on the GEOSPHERE icon brings up the
GEOSPHERE MODEL CONTROL PANEL.
Shows oceans and altitude across the planet. Higher altitudes are shown
in lighter shades, lower altitudes are darker. Water is shown as either
blue or black, depending on your monitor.
A legend of the altitude is visible in the INFO BOX near the right side
of the MAP WINDOW CONTROL PANEL.
An extra feature accessed through this icon is a display of landmarks on
the scenario planets. Click and hold on the icon, and names of landmarks
will be displayed until you release the mouse button. This is available
only on scenario planets. Random planets have no landmarks. Landmarks
on Earth will stop being displayed 2,000,000 years in the future. We
figure the names will change by then.
> 72 <
Double-clicking in this icon will open the GAIA WINDOW.
GLOBAL EVENT MAP
Shows global events, such as hurricanes, forest fires, earthquakes,
meteorites, wars, etc., as small symbols.
A key to the symbols is visible in the INFO BOX near the right of the
CONTINENTAL DRIFT MAP
Shows the currents within the magma layer.
Magma is the hot molten rock within the earth, upon which the continental
plates are "floating." The currents here determine the direction and
speed of continental drift.
A legend of the magma current vectors is available for this map in the
This group gives information on the ocean. There is no
MODEL CONTROL PANEL for the Hydrosphere.
toggles the ocean display on and off so you can see the elevation of the
ocean floor. This doesn't make the ocean go away--it just makes it
invisible. This option is used in combination with other maps, and has
no legend in the INFO BOX.
Displays the average annual ocean temperature.
In most cases this will correspond closely with the air temperature, but
it will change much more slowly.
> 73 <
The INFO BOX can display both a legend to the ocean temperatures and a
graph of average ocean temperature over time. To switch between these
two displays, click on the INFO BUTTON in the lower-right corner of the
MAP WINDOW CONTROL PANEL.
displays the surface currents of the oceans.
A legend of ocean current vectors is available for this map in the INFO
This group displays information on the atmosphere and climate. Clicking
on the ATMOSPHERE icon brings up the ATMOSPHERE MODEL CONTROL PANEL.
Displays the average annual air temperature. The heat displayed here
comes primarily from the sun, and secondarily from warm ocean areas.
The INFO BOX can display both a legend of the air temperatures and a
graph of average air temperature over time. To switch between these two
displays, click on the INFO BUTTON in the lower-right corner of the MAP
WINDOW CONTROL PANEL.
Double-clicking on this icon will open the
ATMOSPHERlC COMPOSITION GRAPH.
Displays the average yearly rainfall. The heaviest
rainfall will usually be concentrated over the equator.
The INFO BOX can display both a legend for the rainfall map and a graph
of average rainfall over time. To switch between these two displays,
click on the INFO BUTTON in the lower-right corner of the MAP WINDOW
Double-clicking on this icon will open the ATMOSPHERIC COMPOSITION
> 74 <
Shows the average air currents. As with ocean currents, these are
determined by thermal disequilibrium and Coriolis effect.
A key to the air current vectors is available in the INFO BOX.
Double-clicking on this icon will open the ATMOSPHERlC COMPOSITION GRAPH.
This group gives information on the life on your planet. Clicking on the
Biosphere icon brings up the BIOSPHERE MODEL CONTROL PANEL.
Displays the distribution of biomes on your planet. C
The INFO BOX can display both a legend to biome distribution on the map L
and a graph of average biomass over time. To switch between these two +
displays, click on the INFO BUTTON in the lower-right corner of the MAP M
WINDOW CONTROL PANEL.
Double-clicking on this icon opens the BIOME RATIO GRAPH. E
Displays the diversity of life on your planet.
The INFO BOX can display both a legend to the life-forms and a graph of
genetic diversity over time. To switch between these two displays, click
on the INFO BUTTON in the lower-right corner of the MAP WINDOW CONTROL
Double-clicking on this icon will open the LIFE CLASS RATIO GRAPH.
This is where you will find worldwide information on civilisations on
your planet. Clicking on the Civilization icon brings up the
CIVILISATION MODEL CONTROL PANEL.
> 75 <
shows the distribution of civilisations on the planet.
More advanced civilisations will appear darker. Terraformers will be
shown on this map in black.
The INFO BOX can display both a legend to the civilisations on the planet
and a graph of the population of your sentient species over time. To
switch between these two displays, click on the INFO BUTTON in the
lower-right corner of the MAP WINDOW CONTROL PANEL.
Double-clicking on this icon will open the TECHNOLOGY RATIO GRAPH.
The INFO BOX is located just to the right of the Civilisation icon.
This box displays helpful information about the map view: legends to
help interpret the map, and graphs of the information displayed in the
map shown over time. These graphs correspond with the graphs in the
You can bring up the HISTORY WINDOW by double-clicking inside the INFO
Some map views have map legends to be displayed here, others have both
legends and graphs. HIDE/SHOW OCEANS has neither. Toggle between info
sets by clicking on the INFO BUTTON in the lower-right corner of the MAP
> 76 <
DAISYWORLD INFO DISPLAY
When in the Daisyworld Scenario, in the Biome view, the highlighted INFO
BOX displays the distribution of the different shades of daisies.
Continental DRIFT RECORD
If you click and hold on the INFO BOX (regardless of the status of the
INFO BUTTON) and slowly move the mouse back and forth, you will be shown
an animated history of continental drift on your planet.
Note: Two Events, Pollution and Exodus, are not included in the Event
Map legend, but will appear on the map when they occur.
> 77 <
There are three buttons on the far right side of the MAP CONTROL PANEL.
EDIT brings the EDIT WINDOW to the front.
GLOBE changes the MAP' WINDOW view from a flat robinson projection to a
spherically mapped globe projection. All maps and displays are available
in GLOBE mode--the MAP WINDOW CONTROL PANEL doesn't change. When in this
mode, the GLOBE BUTTON will be highlighted. Clicking on the GLOBE
BUTTON again will return you to the flat projection.
The EDIT RECTANGLE becomes an EDIT TRAPEZOID on the GLOBE. If you
double-click in the EDIT TRAPEZOID, the EDIT WINDOW will be brought to
Clicking, holding, and dragging the outer rim of the globe, will allow
you to move it on the screen.
The interior of the globe can be viewed by double-clicking on the globe,
anywhere but in the EDIT TRAPEZOID. Click again to return to the surface
of the planet.
toggles between different information views in the INFO BOX.
ACCESSING MODEL CONTROL PANELS
The MODEL CONTROL PANELS are available through the MODELS MENU, but they
can also be accessed by clicking on the icons CEOSPHERE, ATMOSPHERE,
BIOSPHERE, and CIVILISATION on the MAP CONTROL PANEL.
All graphs can be accessed both through the GRAPHS MENU and the MAP
CONTROL PANEL. They are opened by double-clicking on various icons in
the MAP CONTROL PANEL.
The ATMOSPHERIC COMPOSITION GRAPH is opened by double clicking on any of
the three ATMOSPHERE icons.
> 78 <
The BIOME RATIO GRAPH is opened by double-clicking on the BIOMES icon.
The LIFE CLASS RATIO GRAPH is opened by double-clicking on the life icon.
The TECHNOLOGY RATIO GRAPH is opened by double-clicking on the
ACCESSING OTHER WINDOWS
Double-click in the INFO BOX to open the HISTORY WINDOW.
Double-Click on the TERRAIN MAP icon to open the GAIA WINDOW.
ACCESS TO GRAPHS AND WINDOWS FROM MAP WINDOW CONTROL PANEL
-- A single line represents a single click.
== A double line represents a double click.
> 79 <
The GAIAWINDOW shows Gaia, a caricature of the Earth as one living
organism. This "face of the planet" will give you constant feedback on
the planet's "mood."
This window can be opened by selecting GAIA from the WINDOWS MENU, or by
double-clicking on the TERRAIN I MAP icon in the MAP WINDOW.
The planet's mood is based on how well life on the planet is doing. The
face will be asleep until life forms, then it will wake up. The moods
range from bliss to horror. Everything that happens and everything you
do affects the face.
At the bottom of this window is a little message bar that will display
messages from Gaia. In the upper-right corner of the window is the Sun.
As solar heat increases through time, the Sun will slowly begin to
enlarge. At the end of your planet's 10 billion-year life, the Sun will
burn up Gaia.
You may want to keep this window in a corner of the screen, and let it
guide you as you develop your planet.
Its eyes will follow the pointer around the screen. Please don't poke it
in the eye.
> 80 <
The HISTORY WINDOW provides a graphical record of many factors that
define H|STORY your planet.
Use this window for tracking the changes and development of your planet's
chemical: composition, temperature, humidity, life, events, and
This window is accessed through the WINDOWS MENU, and by double-clicking
on the INFO BOX in the MAP WINDOW CONTROL PANEL.
Click on any of the icons at the bottom of the window to toggle the
display of that factor on and off.
There are 15 items that can be displayed as a graph in this window. Up
to four items can be displayed at a time.
CO2 displays Carbon Dioxide levels in the atmosphere.
O2 displays Oxygen levels in the atmosphere.
CH4 displays Methane levels in the atmosphere.
SEA TEMPERATURE displays overall average temperature of the oceans.
AIR TEMPERATURE displays overall average temperature of the atmosphere.
RAINFALL displays overall average planetary rainfall.
POPULATION displays population of the sentient species on your planet.
BIOMASS displays the total weight of all plant and animal matter on the
planet. The biomass of Earth is 99% plant material.
DIVERSITY displays the number of different species of life on the planet.
Major extinctions will be visible here.
> 81 <
FOSSIL FUELS displays the amount of fossil fuel reserves still within the
planet. This amount grows during the Evolution Time Scale as biomass
decays, and is depleted by civilisation.
ATOMIC FUEL displays the amount of atomic fuel reserves within the
FOOD displays the total amount of food produced on the planet.
WAR displays the level of armed conflict across the planet.
PLAGUE displays the number of plague events that have occurred.
POLLUTION displays the total amount of toxic releases by the sentient
To keep the planet data file at a reasonable size, a complete history is
not saved with the planet. Once the graph goes off the left of the
HISTORY WINDOW it is lost forever.
There will be a dividing line to mark when one Time Scale ends and
The amount of time displayed per division in this window is different for
each of the Time Scales. The full width of the HISTORY WINDOW covers
1,000,000,000 years in the Geologic Time Scale;
70,000,000 years in the Evolution Time Scale;
2,500 years in the Civilisation Time Scale;
and 50 years in the Technology Time Scale.
> 82 <
The REPORT WINDOW
Is your main source of feedback on how well both you and life on your
planet are doing. The information in the REPORT WINDOW changes for the
various Time Scales, giving information that is useful for each era.
There is also a special REPORT WfNDOW for the Daisyworld Scenario.
REPORT WINDOW IN THE GEOLOGIC TIME SCALE
In this Time Scale, the REPORT WINDOW gives four items of information.
VIABILITY This rating tells you how hospitable your world is to multi-
celled animals. Viability is based on the oxygen and dust content of the
atmosphere. The rating levels are:
X Life cannot exist here.
;-( Life can exist, but barely.
;-| Life can exist fairly well.
Biomass is the total weight of all plants and animals on the planet. In
the Geologic Time Scale there are no plants, so the Biomass is formed
entirely of Eukaryotes. The theoretical maximum value for Biomass in
this Time Scale is 40,960.
This is a display of the most advanced microbe life-form.
Your CURRENT TASK is what needs to be accomplished before moving on to
the next Time Scale.
> 83 <
REPORT WINDOW IN THE EVOLUTION TIME SCALE
In this Time Scale, the REPORT WINDOW gives a few more items of
This is a display of the "race to intelligence." The three most advanced
forms of life are listed, and given an "intelligence" rating (IQ). This
rating is just a rough estimate of how advanced the life-forms are and
does not relate to human IQ levels.
This display show the leaders in the race to sentience. When a life-form
reaches an IQ of 100, it becomes sentient.
Biomass in the Evolution Time Scale consists of the com- bined mass of
both the animal life and the biomes--plant life. Jungles are the
richest, highest mass biomes, Deserts the poorest and lowest mass. The
theoretical maximum value for biomass is 180,224.
The icon shown for Biomass is the predominant biome.
This rating tells you how hospitable your world is to multi-celled
animals. Viability is based on the oxygen and dust content of the
atmosphere. The rating levels are the same as in the Geologic REPORT
The biomass requires CO2 for survival and growth. The Growth rating is
based on the CO2 content of the atmosphere.
Your CURRENT TASK is what needs to be accomplished before moving on to
the next Time Scale.
> 84 <
REPORT WINDOW IN THE CIVILISATION AND TECHNOLOGY TIME SCALES
In these Time Scales, you are given much more information.
This tells you what class of life is the dominant, intelligent species on
Tells you the highest level of Civilisation on your planet.
Tells you the average technology level of your planet
Population tells the current population of your planet's sentient
Gives an overall "quality of life" rating for the sentient species on
your planet. The two factors taken into consideration in this rating are
number of work hours per week, and your allocation of resources to Arts
and Media. It is difficult to have a life quality above tolerable in
lower technology levels.
The possible quality levels are: Heavenly, Marvelous, Good, Pleasant,
Tolerable Unpleasant, Bad, Miserable, and Hellish.
HABITATS shows the ability of your sentient species to survive in the
various biomes, and how well they are adapted to the habitat. The rating
X Can't live there at all.
;-( Can live there, but hates it.
;-| Can live there, and likes it.
> 85 <
Below the Habitats is a large section that deals with energy. To best
understand what happens here, look at the REPORT WINDOW and the
CIVILISATION MODEL CONTROL PANEL side-by-side.
WORK is the amount of hours per week that your sentient SimEarthlings
must work to survive. In SimEarth, we have simplified the concept of
work: all work produces energy.
The amount of time intelligent SimEarthlings work is divided between five
different energy sources. The amount of time worked to produce energy
from each of the five sources is set on the left side of the CIVILISATION
MODEL CONTROL PANEL. The total number of hours worked per week affects
the quality of life.
TYPES OF ENERGY
BIOENERGY-- Burning wood, animal power, plant power (farming), work done
by hand by the sentient species.
SOLAR/WlND-- Sun-drying of food and clothes, windmills, sailing ships,
solar heating, wind-powered generators, solar electric cells, satellites
collecting solar energy.
HYDRO/GEO -- Waterwheels, dams, steam power, hydroelectric power,
FOSSIL FUEL--Coal and oil made from long-dead animals.
NUCLEAR --Atomic power plants.
Is a rating of how much energy you receive for the amount of work put in.
The efficiency of each energy source varies with the level of
> 86 <
ENERGY EFFICIENCY VS. TECHNOLOGY LEVEL.
Bioenergy Solar/Wind Hydro Fossil Nuclear
---------- ----------- ------ ------- -------
Stone Age 40% 20% 10% 0% 0%
Bronze Age 40% 20% 30% 10% 0%
IronAge 60% 20% 30% 30% 0%
Industrial Age 60% 30% 50% 80% 10%
AtomicAge 70% 50% 50% 80% 80%
Information Age 80% 60% 60% 90% 90%
Nanotech Age 90% 80% 80% 90% 90%
The efficiency rating displayed and used in the REPORT WINDOW is averaged
over the number of the~various technologies. For example, if your planet
has one city in the Nanotech Age, and one city in the Stone Age, then the
displayed efficiency rating for Atomic Energy would be 45% (1 city * 90%
+ 1 city * 0%/2 cities).
This rating can be changed by the availability of resources. As fossil
fuel and atomic fuel run out, their efficiency rating declines to 0%.
ENERGY is the amount of each type of energy produced, with a total for all
combined energy sources.
All energy that is produced is used. The total energy produced will
roughly equal the total of all the allocated energy. There is some
energy lost, and some rounding off of numbers for the display, but
it all gets used.
ALLOCATION is what your sentients are doing with the energy. All the
energy produced is allocated and used. Allocation is set on the right
side of the CIVILISATION MODEL CONTROL PANEL
> 87 <
The possible uses that you can allocate energy to are:
PHILOSOPHY--Philosophy is a deterrent to war. Investing in philosophy
reduces the number and intensity of violent conflicts on your planet.
SCIENCE--Investing in science helps your civilisations advance to higher
technology levels. You must have at least some investment in science to
advance at all. Advancing technology levels too fast, or without a fair
share of philosophy, agriculture, medicine, and art/media does not
produce a stable, long-lasting civilization. If you invest too much too
soon in science, your population will die off from war and plague.
AGRlCULTURE-- Investing in agriculture increases food production, which
increases the rate of population growth of your sentient species.
MEDICINE--Investment in medicine reduces the number and severity of
ART/MEDIA--Investment in art/media improves the quality of life of your
SimEarthling global citizen.
CURRENT/TASK-- Tells you what needs to be accomplished to advance to the
next Time Scale.
REPORT WINDOW IN THE DAISYWORLD SCENARIO
In the Daisyworld Scenario, you are only given four items of information.
This is a display of the shade of the most populous Daisy.
This shows you how much open land there is on the planet to fill
This shows the most populous animal (if any) on the planet.
Your Daisy-raising goal.
> 88 <
REPORT WINDOW IN THE TERRAFORMING SCENARIOS
In the Terraforming Scenarios, Mars and Venus, you are given much of the
same information as in the CIVILISATION and TECHNOLOGY REPORT WINDOWS,
but with added terraforming progress feedback.
This rating tells you how hospitable your world is to life. Viability is
based on the oxygen and dust content of the atmosphere. The rating
levels are the same as in the geologicAL, CIVILISATION, and TECHNOLOGY
This is the biomass that you must attain before the planet is considered
This is your world's present biomass. The icon shown fo Biomass is the
This is the population your planet must reach to be considered colonized.
This is your present population.
HABITAT AND ENERGY
The HABITAT and ENERGY sections of this window are the same as in the
CIVILISATION and TECHNOLOGY REPORT WINDOWS, with two exceptions:
These sections will not appear in the window until you have begun the
colonisation process (placing sentient life on the planet).
The HABITAT section will always display the information for sentient
mammals since the majority of SimEarth players are mammals.
Your current task is to terraform and Colonise the planet.
> 89 <
The TUTORIAL WINDOW is a text window that gives a brief review
of the tutorial in this manual. It can be accessed through the
Like all help and text windows in SimEarth, it can be moved around the
screen and re-sized. Click on the up and down arrows in the Scroll Bar
on the right side of the window to scroll through the text.
Depending on your computer, you may or may not be able to have this window
open at the same time as the HELP WINDOW.
The GLOSSARY WINDOW is a special HELP WiNDOW that can be accessed through
the WINDOWS MENU. It gives definitions for words and terms that are used
in the SimEarth program.
Like all help and text windows in SimEarth, it can be moved around the
screen and resized. Click on the up and down arrows on the right side of
the window to scroll through the text.
> 90 <
There are four graph windows, which can be opened through the GRAPHS MENU
and through the MAP WINDOW icons. Only one GRAPH WINDOW can be
displayed at a time.
These windows can be moved around the screen by clicking and dragging the
TITLE BAR, and closed by clicking the CLOSE BOX.
Two of the graphs display their information over time as well as for the
present. The information is given in horizontal or vertical bars, with
the most current bar in front.
This graph is accessed either through the AIR SAMPLE item on the GRAPHS
MENU or by double-clicking on the AIR TEMPERATURE icon on the MAP
WINDOW CONTROL PANEL.
The ATMOSPHERIC COMPOSITION GRAPH gives only the atmospheric composition
for the present time. Its information is shown in horizontal bars.
It displays the chemical composition of your planet's atmosphere. It
gives the ratio in percentages of four gases--Nitrogen (N2), Oxygen (O2)
Carbon Dioxide (CO2), and Methane (CH)--plus dust particles and water
vapor (H20). It also gives the air pressure expressed in atmospheres.
The plusses and minuses at the end of the bars indicate whether that item
is increasing or decreasing. If there is no plus or minus after the bar,
the level is temporarily stable.
The shade or pattern of the bars is a scale indication.
Percentage is less than 1%.
Percentage is between 1 and 10%.
Percentage is above 10%.
The Air Pressure bar has its own shade, and does not change
with the percentage.
This graph is useful for monitoring trends in atmospheric composition:
Too little oxygen, and life will end.
Too much oxygen, and fires will burn all over the planet.
Too little carbon dioxide, and plants will die.
> 91 <
Too much carbon dioxide, and animals will become extinct.
Too much dust causes solar blockage and extinctions.
Water vapor affects rainfall.
Water vapor, carbon dioxide and methane are greenhouse gases--high levels
will increase the greenhouse warming effect.
BIOME RATIO GRAPH
This graph is accessed either through the BIOMES item on the GRAPHS MENU
or by double-clicking on the BIOMES icon on the MAP WINDOW CONTROL
It displays the relative amounts of the seven biomes on your planet over
This graph is useful for detecting and tracking trends in the dominant
When playing the Daisyworld Scenario, the BIOME RATIO GRAPH displays the
eight shades of daisies.
> 92 <
This graph is accessed either through the LIFE-FORMS item on the GRAPHS
MENU or by double-clicking on the LIFE icon on the MAP WINDOW
It displays the relative amounts of the life classes on your planet over
time. The 14 classes from the PLACE LIFE tool are, displayed, plus the
Carnifern: a mobile carnivorous plant that can achieve sentience.
This graph is useful for tracking trends in the life on your planet.
This graph is accessed either through the TECHNOLOGY item on the GRAPHS
MENU or by double clicking on the CIVILISATION icon on the MAP WINDOW
It displays the population ratio between the various levels of
Civilisation on your planet.
> 93 <
The four model control panels are used to obeserve and change the settings
of many variables in the model. These control panels are the only places in
Sim Earth that are used only for input.
These windows are reached either through the MODELS MENU or through
the MAP WINDOW CONTROL PANEL.
Only one MODEL CONTROL PANEL can be displayed at a time. You can
cycle through the four panels forward or backward by clicking on the NEXT
and LAST buttons in the upper right corner.
There are 16 possible settings for each item on each control panel.
To change model settings, first click on the item you want to change. The
name of the item and an indicator (usually an arrow) will become
highlighted. A dotted box will appear around the indicator and the SLIDER
CONTROL at the right of the panel will display the setting of the
Next, click on the SLIDER CONTROL above or below the slider to increase
or decrease the setting one increment. You can also click and drag the
slider to change settings.
Even though the life on your planet is self-regulating, and affects the
model, these changes are not shown on the model control panels. These
panels reflect you settings and display only your changes.
There will be a lag between the time you change a MODEL CONTROL PANEL
and the time your change takes effect.
The cost in energy for changing the control panel is 30E.U. per click
and 150E.U. per drag. For small changes use clicks. For big changes
If you change a panel from the lowest to the highest setting by clicking,
it will cost you 30 E.U * 15 clicks = 450EU. The same change by dragging
would cost 150EU. You would save a lot of energy by dragging instead of
If you change a panel setting one level, clicking would cost you 150
> 94 <
MODEL CONTROL PANELS
This MODEL CONTROL PANEL deals with the variable factors affecting the
Geosphere, Meteor Impacts, and the Axial Tilt of your planet.
It can be accessed through the MODELS MENU or by clicking on the GEOSPHERE
icon in the MAP WINDOW CONTROL PANEL.
The factors you can adjust are:
controls the frequency of periodic volcanic eruptions.
In early stages of the planet this will influence the
formation of continental areas.
controls the rate ot "smoothing" of the terrain by erosion.
Increasing erosion also increases CO2 in the atmosphere.
controls the rate at which the continents move on the
controls the temperature of the planet's core. The higher the
core heat, the larger and more severe the volcanos. Also, the hotter the
core, the more the direction of magma flow will change.
controls the rate at which the planetary core forms. As
the core forms, it gets larger. The size of the core affects the speed
at which the magma flows. The bigger the core, the slower the magma.
The slower the magma, the smaller the volcanos, and the slower the
controls the frequency of periodic meteor (or planetesimal)
controls the tilt of your planet's spin axis. This affects
the severity of the seasons--the greater the tilt, the greater the
seasonal severity. This is only noticeable in the two modern Time
Scales. The current tilt of the real Earth's axis is about 22 degrees
> 95 <
ATMOSPHERE MODEL CONTROL PANEL
This MODEL CONTROL PANEL deals with the variable factors affecting the
atmosphere of your planet.
It can be accessed through the MODELS MENU or by clicking on the
ATMOSPHERE icon in the MAP WINDOW CONTROL PANEL.
SOLAR INPUT controls
the incoming solar radiation (heat). This is
the amount of heat from the Sun that hits your planet.
Setting the slider all the way down will turn the sun off.
controls the reflectivity of the clouds, which controls
the amount of sunlight (heat) that passes through them to the
controls the intensity of the warming greenhouse effect. The
greenhouse effect is caused by certain gases that block outgoing
infrared radiation. In SimEarth, the greenhouse gases are water
vapor (H20), methane (CH4), and carbon dioxide (CO2)
controls the amount of clouds formed from a given
amount of evaporation.
controls the amount of rainfall on the planet.
controls the reflectivity of surface biomes. The
higher the albedo, the more solar radiation is reflected back into
Transfer controls the rate at which the air and ocean
can exchange heat.
> 96 <
BIOSPHERE MODEL CONTROL PANEL
This MODEL CONTROL PANEL deals with the variable factors affecting
the biosphere of your planet.
The factors you can adjust are:
Controls the temperature range in which life can survive. The
higher the setting, the wider the acceptable temperature range
Controls how quickly life as a whole will reproduce.
controls how much carbon dioxide is scrubbed from theair by the plants.
Controls the rate at which life-forms advance to the
next higher level of development towards intelligence. It is
usually a change of one species.
Controls the rate at which life-forms will mutate.
Mutations can jump ahead, skipping species, to the next class of
> 97 <
CIVILISATION MODEL CONTROL PANEL.
This panel is used to define and control the civilised, sentient
species on your planet. It is only useful in the Civilisation and
Technology Time Scales.
It can be accessed through the MODELS MENU or by clicking on the
CIVILISATION icon in the MAP WINDOW CONTROL PANEL.
The CIVILISATION MODEL CONTROL PANEL is one of the real challenges
of SimEarth. You must make some important decisions and set
priorities both for the types of energies you want to invest in and
the uses you want to put the energy to. This control panel has a
major effect on the REPORT WINDOW. It is a good idea to have these
two on the screen together.
The left side of the control panel is where you set your priorities
for investment in various types of energies.
The greater your priority, the longer you should make the bar next
to the choice. If you don't want to invest in a particular type of
energy at all, then shrink the bar to nothing.
The total amount of investment in all the types of energy sets the
amount of hours your global citizen must work per week. The work
week is a major factor affecting quality of life.
The types of energy you can invest in are:
BIOENERGY--Burning wood, animal power, plant power (farming),
work done by hand by the sentient species.
SOLAR/WlND--Sun drying of food and clothes, windmills, sailing
ships, solar heating, wind-powered generators, solar
electric cells, satellites collecting solar energy.
HYDRO/GEO --Waterwheels, dams, steam power, hydroelectric power,
> 98 <
FOSSIL FUEL--Coal made from long-dead animals.
NUCLEAR --Atomic reactors, bombs, etc.
The right side of the control panel is where you allocate the
energy. All energy produced is used.
Rather than actual numerical settings, allocations are ratios. This
means that you should adjust the length of the bars for each
allocation choice to show your priorities--the longer the bar, the
higher the priority.
If all the bars are all the way up, or all are in the middle, the
model interprets your settings the same. It is the differences in
lengths that matters, not the actual length.
It is best not to turn any of the settings all the way off. The
allocation setting has a feedback effect on the energy investment.
Low allocations can reduce the efficiency at which technologies can
produce the energy. This can make your technology level decline.
The uses to which you can put your energy are:
PHILOSOPHY--Philosophy is a deterrent to war. Investing in
philosophy reduces the number and intensity of violent conflicts on
SCIENCE-Investing in science helps your civilisations advance to
higher technology levels. You must have at least some
investment in science to advance at all. Advancing technology levels
too fast, or without a fair share of philosophy, agriculture,
medicine, and art/media does not produce a stable, long-lasting
civilisation. If you invest too much too soon in science,
your population will die off from war and plague.
Agriculture--investing in agriculture increases food production,
which increases the rate of population growth of your sentient
MEDICINE--investment in medicine reduces the number and severity of
ART/MEDIA--Investment in art/media improves the quality of life
of your SimEarthling global citizen.
> 99 <
TIME SCALES - INTRODUCTION TO TIME SCALES.
SimEarth runs in four different Time Scales: Geologic, Evolution,
Civilisation and Technology. Each Time Scale simulates a different
set of factors on the planet. You can start a planet at any Time
Scale, or start at the first (Geologic) and the game will
automatically evolve through all the Time Scales.
In the Civilisation and Technology Time Scales, you can rush the
intelligent SimEarthling's advance through the levels of
civilisations by model manipulation or by using the Monolith.
Advancing too fast is not necessarily a good thing. If you do not
allow enough time in the Geologic and Evolution Time Scales, there
won't be enough fossil fuel for the later Time Scales. You will
need a wide population base for continued advancement. If you push
a small group to advance before its population has built up, it will
stagnate and die out.
> 100 <
The GEOLOGIC Time Scale begins just after a planet is formed and
begins cooling. It ends with the development of multi-celled life.
This covers the time period on the real Earth from 4.5 billion
to 570 million years ago.
In this Time Scale, the planet changes very slowly, so the
simulation time is sped up to keep things moving. The
Time/Simulation cycle for this Time Scale is 10 million years. This
means that each time the program runs through one simulation cycle,
10 million years passes on the planet.
Your available energy builds up at 1 E.U. per Time/Simulation
The factors simulated in this Time Scale, in order of their
influence, are: continental drift, atmospheric composition,
extraterrestrial collisions, single- celled life, and climate.
The goal of this Time Scale is to manipulate all the simulated
factors to facilitate the formation of multicellular life, at which
time you will be advanced to the next and slower Time Scale,
Time moves very fast in this Time Scale, and your planet only has 10
billion years to live. If you want to complete all the Time Scales
before the end of your planet, you should try to reach the next Time
Scale when your planet is between three and four billion years old.
Don't advance too soon, or there will not be enough fossil fuels for
> 101 <
SUMMARY--GEOLOGIC TIME SCALE
Time/Slmulation cycle : 10 million years
Energy Increase/cycle : 1 E.U.
Time on real Earth : 4.5 to .570 billion years ago.
Factors Simulated : Continental drift.
Single Celled Life.
Advancement Conditions: Evolution of muti-cellular organisms.
Optimum advancement age: Between 3 and 4 billion years.
THINGS TO DO:
Spell your name in land masses.
Burn off oceans.
Make life impossible in a number of ways.
Use earthquakes to create mountain ranges.
Use meteors to create lakes.
Use meteors and hurricanes to increase rainfall.
Use earthquakes, volcanos and meteors to achieve the highest dust
level you can.
Using only events (not the ALTITUDE tool), try to recreate the
continents on Earth today. (Hint: you'll want to pause the simulation
or at least turn the core heat ail the way down to stop or slow
Play Bumper-continents. Get two or three friends, each build a small
continent, and take turns setting off earthquakes to propel the
continents into each other.
> 102 <
EVOLUTION TIME SCALE
The evolution time scale comes after the Geologic time scale. It begins
with the appearance of multi-cellular organisms and ends with the
development of intelligence.
Things change a little faster in this timescale than in the Geologic,
so the time scale/Simulation time has been lowered to 500,000 years.
Your available energy builds up at 1.EU per time/simulation cycle.
This timescale relates to the period of time on the real earth from
570 to .01 million years ago.
The factors simulated in this timescale are; life, biomes, climate,
atmpospheric composition and continental drift.
The goal of this timescale is to manipulate the simulation factors
and evolve intelligence, at which you will be advanced to the
Your planet has only 10 billion years to live. If you want to complete
all the time scales before the end of your planet, you should try to
reach the next timescale when your planet is between 5 and 6 billion
years old. Dont advance too soon, or there will not be enough fossil
fuels for future civilisations.
> 103 <
SUMMARY--EVOLUTION TIME SCALE
Time/Simulation cycle : 500,00 years
Energy Increase/cycle : 1 E.U.
Tbne on real Earth : 570 to .01 billion years ago.
Factors simulated : Life
Advancement conditions : Development of intelligence
Optimum advancement age : Between 5 and 6 billion years
THINGS TO DO:
Choose and help a particular class of life to develop intelligence.
Prevent particular species from developing intelligence.
Manipulate the evolutionary path.
Try to get Carniferns to reach intelligence without using the
Try to get the highest biomass rating you can.
Try to maintain a valley or island of dinosaurs in the
midst of a civilised world.
Play with the atmosphere and see what happens.
Raise the terrain all over the planet, and see what
See how much and how little of your planet you can have as
land without major repercussions to life.
> 104 <
CIVILISATION TIME SCALE
The Civilization Time Scale comes after the Evolution time scale It
begins with appearance of intelligent organisms and
ends with the Industrial Revolution.
Things change fast in this Time Scale, so the Time/Simulation cycle
has been lowered to 10 years.
Your available energy builds up at different rates, depending
on your highest available technology level:
2 E.U. per Time/Simulation cycle in the Stone Age,
3 E.U. per Time/Simulation cycle in the Bronze Age, and
4 E.U. per Time/Simulation cycle in the Iron Age.
This Time Scale relates to the period of time on the real Earth from
10,000 to 100 years ago.
The factors simulated in this Time Scale, in order of their
influence, are: Civilisation, life, biomes, climate, and
The goal of this Time Scale is to manipulate the simulation factors
and evolve higher levels of technology, at which time you will be
advanced to the Technology Time Scale.
Your planet only has 10 billion years to live. If you want to
complete all the Time Scales before the end of your planet, you
should try to reach the next Time Scale before your planet is 9.5
billion years old.
> 105 <
SUMMARY--CIVILISATION TIME SCALE
Time/Simulation cycle : 10 years
Energy increase/cycle : 2 EU - Stone age.
3 EU - Bronze age.
4 EU - Iron age.
Time on real EArth : 10,000 to 100 years ago
Factors simulated : Civilisation
Advancement conditions : Development of higher technology
Optimum advancement age : Less than 9.5 billion years
THINGS TO DO:
Cause or prevent wars.
Eliminate unwanted technologies.
Promote or eliminate various energy sources.
Mold the sentient species to your liking through the CIVILISATION
MODEL CONTROL PANEL.
Improve the quality of life for your sentient species.
Set up equivalent civilisations on different continents, and let them
race to the Technology age.
Vary the altitude, biomes, etc. for the two civilisations, and see what
helps and hinders.
Try to control pollution.
> 106 <
TECHNOLGOY TIME SCALE
The Technology Time Scale comes after the Civilisation Time Scale.
It begins with the appearance of high levels of technology, and ends
when technology evolves to the level when your planet can reproduce
itself through interstellar "genetic" seeding--the ability to
Colonise other planets.
When you complete this Time Scale, and achieve interstellar
migration, all Civilisation leaves the planet. The planet is then
turned into a wildlife reserve, and returns to the Evolution Time
Things change very fast in this Time Scale, so the Time/Simulation
cycle has been lowered to one year.
Your available energy builds up at different rates, depending on
your highest available technology level:
5 E.U. per Time/Simulation cycle in the Industrial Age,
6 E.U. per Time/Simulation cycle in the Atomic Age,
7 E.U. per Time/Simulation cycle in the Information Age, and
8 E.U. per Time/Simulation cycle in the Nanotech Age.
This Time Scale relates to the period of time on the real Earth from
100 years ago to the future.
The factors simulated in this Time Scale, in order of their influence, are:
Civilisation, life, biomes, sentient expansion, climate, and atmospheric
> 107 <
The goal of this Time Scale is to manipulate the simulation factors
and evolve a level of technology high enough to Colonise other
Your planet only has 10 billion years to live. You should try to
complete this Time Scale before the end of your planet.
SUMMARY--TECHNOLOGY TIME SCALE
Time/Simulation cycle : 1 years
Energy increase/cycle : 5 EU - Industrial Age.
6 EU - Atomic Age
7 EU - Information Age.
8 EU - Nanotech Age.
Time on real Earth : 100 years ago to the future.
Factors Simulated : Civilisation
Advancement conditions : Development of high enough technology
to colonise other planets.
Optimum advancement age : Less than 10 billion years old (before the
THINGS TO DO:
Prevent the sentient creatures from destroying themselves.
Cause or prevent wars.
Eliminate unwanted technologies.
Return the planet to ignorant bliss.
Move cities of different technologies close to each other, and see what
Test the greenhouse effect.
> 108 <
There are six scenario planets included with SimEarth, plus the
Daisyworld Scenario. They can all be played in easy, medium, hard,
and experimental modes.
Each scenario has a task for you to accomplish, but feel free to
just play with these worlds.
Scenarios are chosen and started in the NEW PLANET WINDOW.
> 109 <
Aquarium is a world that will never develop sentient life.
Sentience can only be reached in SimEarth by land animals. We hope
we're not offending any intelligent, purely aquatic aliens anywhere
in the universe, but as far as we can tell, Civilisation requires
the use of fire and the burning of fossil fuels to develop.
Intelligence in SimEarth requires land because of the need of fire,
tools, and forges. Water creatures can reach intelligence, but need
access to land for toolmaking.
The problem: No continents
Time Scale: Evolution
Your mission: Create continents on this planet so Civilisation can evolve.
The methods: The easy way is to use the SET ALTITUDE tool. A more
creative approach is to use events. The most subtle method is by
manipulating the MODEL CONTROL PANELS.
Hints: Make sure you keep plenty of shelves (shallow water) in your oceans.
Most marine life lives near the surface.
Notes: Aquarium is a good starting place for people who like to
design their own continents.
> 110 <
The civilisation on this world is stuck in the Stone Age. The
sentiet mammals are all stuck on a small island. They have no
room to expand, and are unable to develop or expand energy for
a technological jump.
The problem: Population stuck in the stone age.
Time Scale : Civilisation
Your Mission: Aid the population in a migration to larger land masses
and increase their level of science.
The Methods: The advancement in science will require manipulation of
the CIVILISATION MODEL CONTROL PANEL. The migration canbe performed
oin a number of ways, pick them up and move thenm to a larger sandmass
with the MOVING tool; build a land bridge for them to cross with
SET ALTITUDE tool; or use events.
Hints: If you use events to make a land bridge, be careful not to wipe
out your sentient population by accident.
Notes: If you dont like intelligent mammals, you can destroy the island
where they live and try to nurture another class of life to sentience.
> 111 <
EARTH: THE CAMBRIAN ERA
This scenario takes place on Earth 550 million years ago at the
beginning of the Cambrian era. Life on Earth at that time was
undergoing an explosion of diversification. Plants started moving
onto the land, followed by insects and other animals.
In this scenario, the drift of the continents will follow the drift
of Earth's continents. It starts with the supercontinent called
Pangaea, which then splits apart into the ancient continents of
Condwanaland and Laurasia.
Eventually, you will recognise the continents as we see them today.
The pre-programmed drift will continue into the future following
scientific predictions for about 200 million years. After that, the
simulation takes over and controls the drift.
The problem: Living in the past
Time Scale: Evolution
Your mission: Help evolution develop intelligent life while seeing
an instant replay of our planet's continental drift.
The methods: On this one, you can just sit back and watch, or get
involved in every planetary process. The continents will drift
whether or not any life is around to see where they go.
Hints: Beyond 200 million years in the future, the drift will
diverge from scientific predictions, and will be at the whim of our
> 112 <
To see a real instant replay of the continental drift, click and
hold on the INFO BOX and slowly drag the mouse back and forth.
Any changes you make to the continents by using events will
disappear. The continental drift will follow its pre-programmed
path no matter what you do.
Notes: Try to develop intelligence/Civilisation in your sentient
species just as the continents reach the stage of modern Earth. See
if you can create an earth with intelligent dinosaurs.
> 113 <
EARTH: MODERN DAY
This scenario takes place on the Earth of today. We live in a world
with pollution, war, famine, greenhouse warming, energy shortages,
and the possibility of nuclear winter.
The problems: Too many to list here. Read your newspaper.
Time Scale : Technology
Your mission: Solve all the world's problems and lead us into a
future of peace, abundant food, clean air, and plentiful energy.
The methods : If I knew how to solve all these problems, I'd be
running the U.N. instead of making computer games.
Hints: The best way to prevent war in SimEarth is to allocate
energy to philosophy in the CIVILISATION MODEL CONTROL PANEL.
Increasing allocation to Agriculture will increase the food supply.
Allocating to Art/Media improves the quality of life. Wars and
plague have a greater impact in this scenario than they do in the
Notes: This scenario can be difficult, but still more fun than the
real thing. If you click and hold on the Terrain Map Icon in the
MAP WINDOW, you will see the names of the continents displayed. If
you click and hold on the Drift icon in the MAP WINDOW you will see
the names of the major tectonic plates displayed.
> 114 <
For this scenario, you are a citizen in a nanotech level society.
Your home planet is overcrowded, and the population is increasing.
You show up for work, and find a memo from the boss that informs you
that you've been put in charge of a new project. The promotion
involves a small raise, but you'll have to move--to Mars. Your new
job is to turn Mars into a planet capable of supporting human life.
If you fail to complete this project within 500 years you'll be
The problem: No water, almost no atmospheric pressure, no oxygen,
no plants, no animals, no nothing except rock. The average
temperature is -53 degrees C.
Time Scale: Technology
Your mission: Terraform Mars and make it a place fit for human
occupation, and Colonise the planet.
The methods: The MODEL CONTROL PANELS (except for the CIVILISATION
MODEL CONTROL PANEL) have been disabled to make this a challenge.
You'll need the TERRAFORMERS available through the PLACE LIFE tool.
Gaian regulation has been disabled--no life will spontaneously
generate. The REPORT WINDOW gives you special feedback on your
> 115 <
Hints: Start off with a few ice meteors to create oceans. Then
start producing CO2 and other greenhouse gases to build up
atmospheric pressure and begin planetary warming. Use the CO2
generator or better yet, plant some single-Celled life in the
oceans--they are more efficient than terraformers at building an
Notes: Click and hold on the TERRAIN MAP icon in the MAP WINDOW to
see a display of Martian landmarks. Landmark names shown in all
capital letters designate large regions, other names designate
smaller regions or individual spots.
> 116 <
Venus is SimEarth's ultimate challenge in terraforming. While Mars
is far too cold, Venus is far too hot for life: its average
temperature is 417 degrees C.
The problem: Too hot for life
Time Scale: Technology
Your mission: Cool this planet down, and make it a fit place for Earth
The methods: The MODEL CONTROL PANELS (except for the
CIVILISATION MODEL CONTROL PANEL) have been disabled.
You'll need the TERRAFORMERS available through the PLACE LIFE
tool. Gaian regulation has been disabled--no life will
spontaneously generate. The REPORT WINDOW gives you special
feedback on your terraforming progress.
Hints: The first thing you have to do is cool the planet down. Ice
meteors won't help--but go ahead and try them if you want. It's so
hot that ice meteors melt and boil off into water vapor. Since
water vapor is a greenhouse gas, it just makes things hotter.
To cool things down, you've got to reduce the greenhouse effect.
The Oxygenator takes CO2 (a greenhouse gas) out of the atmosphere.
As soon as it cools enough, start placing biomes on Venus, which
will also lower the CO2 in the air. When placing biomes, remember
that the higher the elevation, the cooler the temperature.
Notes: Click and hold on the TERRAIN MAP icon in the MAP WINDOW to
see a display of Venusian landmarks. Landmark names shown in all
capital letters designate large regions, other names designate
> 117 <
Unlike the other scenario planets, the terrain of Daisyworld is
randomly generated each time you load it.
According to the Gaia theory, life and the environment together
constitute a system that self-regulates climate and atmospheric
This scenario is based on the original Daisyworld program James
Lovelock developed as a test of the Gaia theory.
During the past 3.6 billion years, the output of heat from the Sun
has increased by 25%, but the Earth's average temperature has
remained almost unchanged during the same time period.
According to theory, Gaia has controlled the temperature to keep
Earth cool enough for life. Daisyworld tests Gaia's ability to
In Daisyworld, as in all SimEarth planets and scenarios (and real
life), the Sun's heat output is slowly but constantly increasing.
If Gaian regulation works, the average temperature on the planet
should remain fairly constant in spite of the increasing solar
The biomes have been changed to eight shades of Daisies. The
different shades, ranging from white to black, reflect different
amounts of light and heat that regulate the planet's temperature.
Daisies are available for planting in the PLANT BIOME tool. The
ratio of the various shades of Daisies can be tracked in the BIOME
> 118 <
The problem: The heat from the Sun is steadily increasing. If it
isn't somehow regulated, the oceans will boil off and all life on
this planet will die.
Time Scale: N/A
Your mission: Test Caia's ability to regulate temperature, and fill
the world with Daisies.
The method: Keep an eye on the Temperature Map and the Air
Temperature graph in the HISTORY WINDOW to observe the regulation
The REPORT WINDOW gives you special feedback on your Daisy-raising
Hints and cautions: Place life on the planet to eat the Daisies.
See how this complication affects regulation.
Notes: There will eventually be a breakdown point where the heat
from the Sun is too great for Caia to regulate. Adding or
subtracting land areas where Daisies can live will move this
breakdown point forward or backwards.
Also note the change in the Daisies' color as the landmass increases
Try testing the stability of the system by killing off many of the
Daisies. How many can be killed before the system collapses? How
much of the planet's surface must be covered by Daisies for
regulation to occur?
HOW DAISYWORLD WORKS
Daisyworld is a planet like Earth, but with few clouds and a
constant low concentration of greenhouse gases. The output from the
planet's sun is constantly increasing.
The planet's temperature is a balance between the heat received from
the sun and the heat loss by radiation from the planet to space.
The albedo--the reflectiveness--of the planet determines the
The planet is well-seeded with Daisies, whose growth rate is a
function of temperature. There are two colors of Daisies: Black
and White, which only grow between 5 and 40 degrees C, and grow best
at 22.5 degrees C. Assume plenty of water and nutrients for the
> 119 <
Taking into account only the heat from the sun and the albedo of
the planet, we get the results in the following graphs.
The bottom graph shows the increasing solar heat (dotted line).
The temperature of the planet rises in direct proportion to the
increase of solar heat. The top graph shows life on the planet
(Daisies) during the same time.
When the temperature hits 5 degrees C the Daisies begin to grow.
When the temperature hits 40 degrees C they all die.
Now we add the albedo (heat and light reflectiveness) of the Daisies
to the system.
When the planet's temperature reaches 5 degrees C, Daisies begin to
grow. During the first season, the Black Daisies will grow better
since they will be warmer than the planet's surface (dark colors
absorb heat). White Daisies won't grow very well, since they
reflect heat and will be colder than the planet's surface.
At the end of the first season there will be many more Black Daisy
seeds in the soil that will soon grow. As the Black Daisies spread,
they will not only warm themselves, but the whole planet.
Eventually, because of the warming from both the Black Daisies and
the Sun, the planet's temperature will rise to 22.5 degrees C.
Since the Black Daisies are warmer than the planet, they are above
their optimum living temperature, and their growth rate will slow.
Since the White Daisies are cooler than the planet, they will start
to grow better as the temperature gets higher. When there are
enough White Daisies, they will reflect enough heat to cool the
> 120 <
Eventually, the solar heat gets so great that the White Daisies
cannot reflect enough heat to cool the planet.
The important thing to note here is that the life on the planet
affected the climate of the planet in a way that is beneficial to
life. It regulated the temperature, and nearly doubled the amount
of time life could survive.
This is only a simple demonstration, and only deals with one
life-form and one climactic feature, but it does demonstrates the
two-way connection between life and environment.
> 121 <
INSIDE THE SIMULATION EVENTS
Events are noteworthy occurrences on your planet. They will happen
randomly, controlled by the simulation, and you can cause most of
them to happen through the TRIGGER EVENTS TOOL in the EDIT WINDOW.
The cost in energy for triggering an event is 50 E.U.
There are 11 events in SimEarth, eight of which can be triggered
With winds of 74 m.p.h. or greater, usually accompanied by
rain, thunder and lightning. Hurricanes can cause tidal waves.
They can wipe out cities and destroy a lot of life. In SimEarth,
hurricanes are caused by warm oceans. The only way to defend
against them is to keep your oceans cool.
You can use hurricanes to increase rainfall in specific areas on
An unusually high sea wave that can be caused by earthquakes,
high winds, hurricanes, volcanos and meteor impact.
Tidal waves can destroy coastal cities and land life. They
generally travel from deeper water to shallower water.
Tidal waves are useful for eliminating unwanted coastal cities.
Meteors are huge hunks of rock from space that smash into the
planet, causing much damage and creating craters on land and tidal
waves in the sea.
> 122 <
Meteors that crash into the land will put dust into the air. Too
much dust will block the sun and cause extinctions. Meteors that
crash into water put water vapor into the air, increasing rainfall.
Meteorites also affect magma flow.
Meteors are useful for adding water vapor to the atmosphere
(increasing rainfall), creating lakes in large land masses, and
destroying pesky life-forms.
A volcano is a vent in the planetary crust that that lets a
flow of molten rock to the surface.
Volcanos raise the terrain elevation, creating mountains on land and
islands in the sea. Volcanos in the ocean cause tidal waves. The
severity of volcanos is less when the planet is young and the core
Volcanos in SimEarth are huge upwellings that make recent real Earth
events like Krakatoa look like pimples.
Volcanos put a lot of dust into the air, which can block the sun and
cause extinctions. They also add a lot of carbon dioxide to the
air, which is great ior plants, but above a certain point, bad for
Volcanos are useful for creating islands and mountains, and for
doing general damage to life-forms.
Atomic tests are the firing of atomic bomb. They occur `naturally`
in wars between groups of your sentient species.
Atomic tests do much damage, spread radiation, and put a lot of dust
into the atmosphere. Too many atomic tests can cause a nuclear
winter, which causes mass extinctions.
> 123 <
Atomic tests are useful as a destructive tool, and for testing the
effects of nuclear winter.
Fire occurs when the oxygen content of your atmosphere is too high.
To protect against fires, keep your oxygen levels down.
Fires are useful for regulating the oxygen in your atmosphere, and
causing general destruction.
A major shake-up of an area of the planet. When you point
to the Trigger Earthquake option a sub-submenu will appear,
allowing you to select the direction of energy expended by
the earthquake. This will let you affect continental drift.
Earthquakes under water will cause tidal waves.
When earthquakes appear naturally in SimEarth, they occur at plate
boundaries (places where two land masses meet). To avoid damage
from earthquakes, don't place cities near plate boundaries. To find
these boundaries, look at the MAGMA display in the EDIT WINDOW.
Wherever arrows that point in different directions are next to each
other is a plate boundary.
In SimEarth, earthquakes are very useful events. You can use them
to affect the movement of land masses, and change the magma flow.
Forcing two land masses into movement toward each other is a fun way
to create a mountain range.
To easily see the effect your earthquake has on the planet, turn on
the MAGMA layer in the EDIT WINDOW before you trigger it, and watch
the direction of the magma flow arrows change.
This is actuallythe opposite of what happens in the real world. We
have reversed cause and effect. In reality, earthquakes are caused
bythe movement of the plate boundaries, and don't cause or change
magma flow. It's not accurate, but its a great tool for making
> 124 <
Plagues are very dangerous diseases that can wipe out entire cities,
and will spread to nearby cities. They happen more often in
low-technology areas, but once they happen there, they can spread
to nearby high-technology areas.
To prevent plagues, you must invest in Medicine in the CIVILISATION
MODEL CONTROL PANEL Plagues aren't useful for anything but
Wars can be triggered by the TRIGGER EVENTS icon.
War in SimEarth represents battles between
cities, as well as rebellions and revolutions within cities.
Wars are often caused by competition for resources such as fossil
and atomic fuel. This is a self-regulating process: Cities grow
too big, too close, and too fast for the local fuel supply; they go
to war over the fuel; they kill enough of each other off so they can
all live happily on the existing fuel; then they declare peace.
Sometimes wars just happen--SimEarthlings can be as stupid as
World wars occur in higher technology levels, and consist of lots of
battles going on all over the planet.
The only way to prevent wars, or reduce the number and severity of
wars, is by allocating energy to Philosophy in the CIVILISATION
MODEL CONTROL PANEL.
Pollution events are warnings that the pollution in an area
of your planet has reached levels that are dangerous to life.
They are primarily caused by industrial waste and pollutants, and
can only be prevented and controlled by investing in non-polluting
> 125 <
Pollution events cannot be triggered by the TRIGGER EVENTS tool, but
if you want one, invest heavily in fossil fuels.
When the sentient SimEarthlings reach a high enough level of
development, they leave the planet to Colonise other worlds.
The planet is then "retired" to the status of a wildlife preserve
to be visited and cherished.
At this point, the planet returns to the Evolution Time Scale, and
the race to sentience begins again.
The EXODUS event is the closest thing in SimEarth to a "win
> 126 <
The Geosphere in SimEarth simulates planet formation, planetary
cooling, 6EOSPHERE continental drift, volcanic activity and erosion.
For an explanation of geology and atmosphere of the real Earth, take
a look at the Introduction to Earth Science section.
SimEarth simulates a planet just after interstellar dust has
condensed into a lump of dirt. It is tightly packed, with a molten
core. The surface is solid, but the ' J surface temperature is
still very hot. The atmosphere is mostly steam.
The flowing currents in the molten core cause parts of the solid
surface of the planet to start moving around, crashing into each
other. This crashing results in the creation of huge mountains and
With time, the core of the planet solidifies to a plastic
consistency, and gets larger as the planet gets olde The rate at
which the core forms can be set in GEOSPHERE MODEL CONTROL PANEL.
The larger the core, the smaller the magma layer. The smaller the
magma layer, the slower the magma currents, and the slower the
Continental drift is the movement of the solid crust of the planet
on the liquid magma inside the planet. The faster and stronger the
magma currents, the faster the drift. Continental drift is also
affected by core heat. The rate of continental drift can be set in
the GEOSPHERE MODEL CONTROL PANEL.
Core heat is the temperature of the planet's core. The higher the
core heat, the larger and more severe the volcanos are. Also, the
hotter the core, the more the direction of magma flow will change.
Core heat can be adjusted in the GEOSPHERE MODEL CONTROL PANEL.
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FORMATION OF THE OCEANS
The planet eventually cools enough for the steam in the atmosphere
to condense and form oceans. Once oceans are formed, your planet is
ready for life.
Volcanos are vents in the surface of the planet that allow magma to
flow to the surface. The volcanos in SimEarth are huge explosive
events that make recent volcanic activities like i~rakatoa look like
pimples. When volcanos occur in water, they create islands. When
they occur on land, they create great mountains . The frequency and
violence of volcanos is directly affected by core heat.
You can also control the frequency and violence of volcanos with the
GEOSPHERE MODEL CONTROL PANEL.
Erosion is the "smoothing" of the terrain bywind and water. Younger
planets will have higher, more jagged mountains than older planets
that have suffered the effects of erosion longer. Erosion aiso
creates large continentai shelves. The rate of erosion can be set
in the CEOSPHERE MODEL CONTROL PANEL.
Erosion increases the CO2 level in the atmosphere.
> 128 <
The atmosphere in SimEarth consists of four gases--Nitrogen (N2,
Oxygen (O2)' Carbon Dioxide (CO2) and Methane (CH4) plus water
vapor (H2O) and dust particles.
Nitrogen is released by the soil through geochemical reactions with
the air, and is absorbed into the soil by microbes. It is also
released into the atmosphere by volcanos. It is the most common gas
in the atmosphere.
Oxygen is released into the atmosphere by plants and microbes during
photosynthesis. It is consumed by animals and fires. Too little
oxygen in the atmosphere (<15%) and animal life can't survive. Too
much oxygen (>251Yo) and fires will break out all over the planet.
Fires act as an oxygen regulator.
Carbon dioxide is released into the atmosphere by geochemical
reactions and erosion, and is absorbed by plants and microbes. Too
little carbon dioxide (<.1%) and plants can~t survive. Carbon
dioxide is a greenhouse gas, and will contribute to global warming
due to the greenhouse effect. If your CO2 level exceeds 1% you will
have greenhouse warming.
Methane is released into the atmosphere by bacteria (prokaryotes).
It is a greenhouse gas, and will contribute to global warming
through the greenhouse effect.
Water vapor evaporates from warm oceans and lakes, and returns to
the land and seas through rainfall. Water vapor in the atmosphere
is increased by hurricanes and meteors hitting the oceans. Water
vapor is a greenhouse gas.
Dust is released into the air by volcanic activity, fires, nuclear
explosions, and meteor strikes. Too much dust in the atmosphere
causes solar blockage, planetary cooling, and mass extinctions.
> 129 <
Atmospheric pressure is a measure of how much atmosphere, by weight,
is around the planet. The air pressure of the real Earth is 1.0
atmospheres. A higher atmospheric pressure allows a planet to
better retain heat.
TRACKING THE ATMOSPHERE
You can keep track of your atmospheric composition by watching the
ATMOSPHERIC COMPOSITION GRAPH.
> 130 <
The climate of SimEarth is much simpler than on the real Earth.
climate, SimEarth primarily takes into account air currents, air
temperature, and rainfall.
Air currents, air temperature, and rainfall are influenced by sea
temperature, ocean currents, solar input, cloud formation, cloud
albedo, surface albedo, greenhouse effect, air-sea thermal transfer,
and atmospheric pressure.
In addition, ice caps indirectly affect climate through their
ability to cool the planet. Cold oceans are necessary for ice caps
In SimEarth, as on the real Earth, the heat from the Sun is slowly
The planetary winds.
The average annual air temperature. The heat displayed here comes
primarily from the sun, and secondarily from warm ocean areas.
The amount of rainfall on the planet. It includes all types of
The average annual ocean temperature. In most cases this will
correspond closely with the air temperature, but it will change much
The surface currents of the oceans.
The incoming solar radiation, also calledlnsolation. This is the
amount of energy that reaches the planet from the sun.
The amount of clouds formed from a given amount of evaporation.
The reflectivity of the clouds, which controls the amount of
sunlight (heat) that passes through them to the planet.
> 131 <
The reflectivity of surface biomes, and therefore the amount of
sunlight (heat) which is blocked by them.
The planet-warming greenhouse effect. The greenhouse effect is
caused by certain gases that block outgoing infrared radiation.
This keeps more of the Sun's heat in the atmosphere, which warms the
whole planet. In SimEarth, the greenhouse gases are water vapour
(HO2), methane (CH4), and carbon dioxide (CO2)
AIR-SEA THERMAL TRANSFER
The rate at which the air and ocean can exchange heat.
A measure of how much atmosphere, by weight, is around the planet.
The air pressure of the real Earth is 1.0 atmospheres. A higher
atmospheric pressure allows a planet to better retain heat.
You can affect the way SimEarth models climate by changing the
settings on the ATMOSPHERE MODEL CONTROL PANEL.
> 132 <
LIFE AND EVOLUTION
As far as the model in SimEarth is concerned, life is any plant or
animal on your planet.
The number and variety of plants, animals, niches and biomes
included in SimEarth has been limited to enable the model to run on
a home computer, but there are enough to demonstrate the principles
involved with planet management.
ORIGINS OF LIFE IN SIMEARTH
In SimEarth, the only necessary factor for life to form is the
presence of some deep sea (greater than 2500 meters deep) or ocean
(between 1000 and 2500 meters deep). We assume the presence of ail
necessary chemicals and elements.
Ocean will form as soon as the planet cools, and if there is some
deep ocean, life will form.
The formation of life on the real Earth is much more complicated,
and still very controversial.
LIFE IN SIMEARTH
Life in SimEarth is much simpler and less varied than on the real
Earth. SimEarth has 15 classes of life, each with 16 species. The
real Earth has millions of species.
SimEarth has seven biomes, the real Earth has many more.
EVOLUTION IN SIMEARTH
Evolution in SimEarth depends on many factors. For sea life to
evolve, there must be shallow shelves. For land life, there must be
the proper atmosphere, with enough carbon dioxide, oxygen, and air
pressure. The air and water temperatures must be within livable
limits. And there must be enough of the proper biome for the life
to evolve in.
Life advances from simple to more complex forms, and, hopefully, to
Evolutionary advancement also depends on population size. The more
of a life-form you have on your planet, the more likely it is to
advance to another level.
> 133 <
There are two sizes of steps SimEarthlings can take in their
progress towards sentience: ADVANCEMENT and MUTATION.
ADVANCEMENT is a small step. It is a step up to a more complex
species, but stays within the same class of life. The ADVANCEMENT
RATE can be set in the BIOSPHERE MODEL CONTROL PANEL.
MUTATION RATE is a big step. It is a jump to a new class of life.
There is competition within the evolutionary process.
If two life-forms land on the same spot, the more advanced one will
kill the other. The rating of which life- form is more advanced
than another involves, among other smaller factors, the class, the
species, and the IQ of each life-form. Some of these factors change
over time and vary with the planet, so there can be no win/lose
chart of life-form rankings.
Also, if and when a new, higher class of life mutates, it will take
precedence over all lower forms.
BIOMES IN SIMEARTH
There are seven available biomes in SimEarth, plus ROCK, which
represents a lack of a biome in a location. To survive and spread,
biomes require carbon dioxide and rainfall.
ROCK-- No biome.
ARCTlC-- Can survive in a cold and dry climate.
BOREAL FOREST-- Can survive in cold temperatures, with moderate to
DESERT-- Can survive in moderate to hot temperatures,
with very little rainfall.
> 134 <
TEMPERATE GRASSLANDS--Can survive in areas with moderate temperatures
FOREST--Can survive with moderate temperatures and high rainfall.
JUNGLE--Can survive with high temperatures and rainfall.
SWAMP --Can survive with high temperatures and moderate rainfall.
BIOME PREFERENCE CHART
DRY MODERATE WET
----------- ----------- ----------------
COLD (<0C) Arctic Boreal Forest Boreal Forest
MODERATE (0-25C) Desert Temp. Grasslands Forest
HOT (>25C) Desert Swamp Jungle
Biome preferences are also influenced by altitude and the amount of
CO2 in the atmosphere.
LIFEFORMS IN SIMEARTH
There are 15 classes of life represented in SimEarth; eight on land,
seven in the sea. Only 14 of these are available in the PLACE LIFE
tool. The 15th, the Carniferns--mobile, carnivorous plants that can
evolve sapience--will sometimes appear through evolution.
Each class consists of 16 species. There are a total of 240 species
in SimEarth. If a class of life reaches the 16th species, it
becomes sentient. You will never see the 16th species of many of
the classes unless you can help that class develop intelligence.
> 135 <
Below is an explanation of each class of life, with a graphic of all
16 species for that class of life. The possible evolutionary
advancements and mutations are also shown. Advancement is in steps
from left to right through ail the species of that class. Mutation
is a jump to a new class.
For each class of life below is a chart of its possible evolutionary
paths. The progression of advancement within the same class, from
simplest to most advanced (intelligent) is shown from left to right.
Possible mutations to higher classes of life are shown as steps up.
Only certain species within a class of life can mutate. There are
many evolutionary dead-ends.
SEA LIFE CLASSES
Simple single celled life that has no distinct nucleus, including bacteria
and blue-green algae. Prokaryotes release methane into the
atmosphere. In SimEarth, Prokaryotes are all treated as anaerobic,
methane consuming organisms, which is an extreme simplification.
The eight most advanced Prokaryote species can possibly mutate to
Single-celled life with a nucleus; includes all single-celled life
except prokaryotes. In SimEarth, all Eukaryotes are treated
as aerobic, photosynthesizing organisms, which is an extreme
Eukaryotes evolve from Prokaryotes. The four most evolved species
of Eukaryote can mutate into Radiates.
> 136 <
Simple, radially symmetrical multicellular life with definite tissue
layers (three at most), but no distinct internal organs, head, or
central nervous system. Includes jellyfish and sea anemones.
Radiates evolve from Eukaryotes. The first eight species of Radiate
can mutate into Arthropods. The next four species can mutate into
Animals with jointed legs and a hard outer skeleton, including
crabs, lobsters, and crayfish. (Spiders, scorpions, centipedes,
millipedes, and insects are - also arthropods, but they live on land.)
Arthropods evolve from Radiates. The first four species of
Arthropod can mutate into Mollusks, the next eight can mutate into
Fairly complex animals, most of which possess shells,
including snails, clams, oysters, scallops, octopi, and squid.
Mollusks evolve from ArthroDods. The middle eight species of Mollusks
can mutate into Fish.
> 137 <
Very advanced and complex sea life with an internal bony
Fish evolve from Mollusks. The first eight species of Fish
can mutate into Amphibians, the next four species can mutate into
Marine mammals with a highly developed nervous system,
including whales, dolphins, and porpoises.
Cetaceans can survive in Jungle biomes, as shown in the chart of
Life Classes and Preferred Biomes. They actually live in the
Jungle's rivers and tributaries that are too small to show in the.
Cetaceans evolve from Mammals. The last four species of Cetacean
can mutate back into Mammals.
LAND LIFE CLASSES
Trichordates were a class of animal with three-chord
spines. They lived and died out long ago on real Earth. We felt
sorry for them, and are giving them a chance for survival in
Trichordates evolve from Radiates and/or Fish. They cannot mutate
into anything else.
> 138 <
The most numerous type of life on Earth they have six legs and three
Insects evolve from Arthropods. Insects don't evolve
into anything else, but, as shown in the chart, there is a
co-evolution situation with Carniferns. The Carniferns don't actually
evolve from Insects: they evolve from plants because of the
presence of Insects.
Cold-blooded vertebrates somewhere between fish and reptiles,
including frogs, toads, and newts.
Amphibians evolve from Fish. The first eight species
of Amphibians can mutate into Reptiles.
Cold-blooded vertebrates, including
alligators, crocodiles, lizards, snakes, and turtles.
Reptiles evolve from Amphibians. The first eight
species of Reptile can mutate into Dinosaurs. The next four species
can mutate into Mammals.
> 139 <
Very big reptiles that long ago died out on real Earth.
SimEarth gives them a new lease on life.
Dinosaurs evolve from Reptiles. The first four
species of Dinosaurs can mutate into Avians. The next four species
can mutate into Mammals.
(A fancy word for bird.) Warm-blooded
vertebrates with bodies more or less completely covered by feathers,
with wings for forelimbs.
Avians evolve from Dinosaurs. Avians cannot mutate into anything else.
The highest form of vertebrate, including man, apes, rodents, dogs,
cats, etc. Mammals nourish their young with milk secreted from
mammary glands, and have skin more or less covered with hair.
Mammals evolve from Cetaceans, Reptiles, and/or Dinosaurs. The
middle eight species of Mammals can evolve into Cetaceans.
> 140 <
Carniferns will evolve, but are not available to manually
place with the PLACE LIFE tool. They are mobile, carnivorous plants
that for simulation purposes are treated like animals. They are
just above insects in evolutionary complexity, and evolved from
plants taking advantage of insects as a food source. They can
achieve intelligence, but it is rare.
Carniferns co-evolve with Insects. They actually evolve from
plants, but their existence depends of the existence of Insects.
CHARTS OF LIFE CLASSES AND PREFFERRED BIOMES
1 = X Life class cannot exist here.
2 = 8-( Can exist here, but barely.
3 = 8-| Can exist here fairly well.
4 = 8-( Paradise.
> 141 <
CIVILISATIONS IN SIM EARTH
There are seven levels of civilization represented in SimEarth, from
the Stone Age of our past to the Nanotech Age of our future. For an
in-depth look at these civilisations as they appeared on the real
Earth, see the Introduction to Earth Science section of this manual.
Civilisations are represented by cities and travelling populations.
Each city has three different population densities; the darker the
city icon, the higher the population. Travelling populations
represent expansion, communication and trade, and travel between
The Nanotech age has four levels of density, and no travelling
population. We assume they use transporters for trade and travel.
The advance of technology is a double-edged sword. Higher
technology allows more efficient use of energy, shorter working
weeks, and a higher quality of life. It also allows pollution,
competition for fuel sources, wars, world wars, atomic wars, and
other by-products of advanced civilisation.
Below is a description of the civilisations in SimEarth with the
graphics for the three (or four) levels of density and the
travelling populations Qf any), as they are displayed over land and
The Stone Age in SimEarth relates to civilisations
on the real Earth thought to begin as far back as a million
years ago, and lasting, in some places on the Earth, until
today. It is characterised by the use of stone tools.
The Bronze Age began with the regular use of metals for tools and
weapons. The earliest established Bronze Age dates back to 3500 B.C.
in the Middle East.
The Iron Age began nearly 2000 years ago, and still exists in places
today. It is characterised by the use of iron for tools and weapons.
> 142 <
The Industrial Age in SimEarth relates to the time from the
Industrial Revolution of the mid- 18th century to the beginning of
the Atomic Age. It is characterized by the use advanced tools and
The Atomic Age begins with the use of atomic energy. It is the present
highest technology level on the real Earth.
The Information Age in SimEarth is the next technological step
after the Atomic Age. In this age, information is the most
The ultimate level of technology in SimEarth is reached in the Nanotech
Age. This is far enough in the future that we can only guess and
dream about it. It will be characterised by a level of sophistication
and technology that allows terraforming and colonising other planets.
The Nanotech Age has four levels of density, and no travelling
population. We assume they use transporters for trade and travel.
ALTERNATE INTELLIGENT SPECIES
SimEarth doesn't limit intelligent species to humans or even just
mammals. Any class of life other than Prokaryote and Eukaryote--can
Development of civilisation in SimEarth requires land because of the
need of fire, tools, and forges. Water creatures can be civilised,
but need access to land for toolmaking.
In SimEarth, the most likely classes of life to evolve intelligence
are: reptiles, dinosaurs, birds, and mammals.
The next most likely group are: cetaceans, insects, amphibians, and
The least likely to evolve intelligence are: radiates, mollusks,
arthropods and fish.
> 143 <
Aside from the above ranking, the evolution of intelligence is
influenced by the amount of the proper biome for a species on the
planet. Also, if an evolutionarily higher form of life appears, it
will have an advantage over an advanced lower form of life.
All intelligent, sentient SimEarthlings act very much like humans in
development of civilization, cUies, industry, etc.
The Monolith is a tool to help accelerate the advancement of
intelligent species. It is an Evolution Speed-up Device (our thanks
to Arthur C. Clark). Once you select the Monolith, if you click on
a life-form, there is a one-in-three chance of that life-form
suddenly mutating to a higher level, which immediately moves you to
the next Time Scale. The Monolith won't work on all the animals.
If you try to use the Monolith on the wrong animal, the program will
beep at you, but there will be no energy charge. It costs 2500 E.U.
to use a Monolith--whether or not it works.
A disadvantage to using the Monolith is that you could jump ahead
into the civilisation Time Scale before enough fossil fuels have
been generated, and civilisation will collapse. You need a wide
population base to advance to the next technology level. Don't rush
to a new Time Scale at the expense of your population.
The main way you influence your sentient life-forms is by telling
them what energy sources to invest in, and how to allocate the
energy. This is done through the CIVILISATION MODEL CONTROL PANEL.
> 144 <
In SimEarth there are two uses of energy. You, the player, use it
to make, mold, modify and manipulate the planet, and civilised
SimEarthlings make and use it to carry on their daily lives.
The energy in SimEarth is measured in Energy Units, or E.U.
Intelligent SimEarthlings will produce and use energy. You can
control their choice of energy sources and their use of the energy
they produce, but you don't have direct access to their energy for
Depending on the difficulty level of the game, you will have
different amounts of energy to affect the planet and the simulation.
These amounts are both your starting supply and the maximum you can
accumulate at any one time.
If you are in experimental mode, you will have an unlimited support of
EXPERIMENTAL MODE Unlimited Energy
EASY GAME 5000 E.U.
MEDIUM GAME 2000 E.U.
HARD GAME 2000 E.U.
Energy for a game comes from the stores of the planet itself in the
form of geothermal, wind, and solar energy, as well as fossil fuels.
As you deplete your energy supplies during a game, it will slowly
build back up over time as the planet increases its energy from the
above sources. This continual tapping of the planet's energies
The amount of energy you have to use is displayed in the EDIT WINDOW
in the AVAILABLE ENERGY DISPLAY.
Your energy reserves are depleted by every action you take that
affects the planet or simulation. New energy becomes available on
the planet through time from various sources explained below. You
can tap some of this new energy. It will automatically be added to
your available energy each Time/Simulation cycle.
As technology develops, your sentient SimEarthlings generate energy
for their own use. As technology on the planet advances, they
generate more energy more efficiently.
> 145 <
You don't have direct access to the SimEarthlings' energy, but some
of it will be automatically tapped and added to your reserves. The
amount of energy automatically added to your reserves each
Time/Simulation cycle increases with the increasing level of
technology on your planet. The rate at which your energy reserves
increase is as follows:
GEOLOGIC TIME SCALE 1EU per cycle
EVOLUTION TIME SCALE 1EU per cycle
CIVILISATION TIME SCALE Stone Age 2EU per cycle
Bronze Age 3EU per cycle
Iron Age 4EU per cycle
TECHNOLOGY TIME SCALE Industrial Age 5EU per cycle
Atomic Age 6EU per cycle
Information Age 7EU per cycle
Nanotech Age 8EU per cycle.
SOURCES OF ENERGY
There are five sources of energy in SimEarth.
Burning wood, animal power, plant power (farming),
and work done by hand by the sentient species. Bioenergy gets more
efficient through time because of better, more efficient farming
tools, and scientific breakthroughs such as recycling biowaste into
fuel. Using bioenergy releases CO2 into the atmosphere, so it has a
minor polluting effect.
Sun-drying of food and clothes, windmills, sailing
ships, solar heating, wind-powered generators, solar electric cells,
and satellites collecting solar energy. Improves in efficiency as
Waterwheels, dams, steam power, hydroelectric power, and
geothermal power. Improves in efficiency as technology advances.
Coal made from long-dead animals. A by-product of
burning fossil fuels is the release of greenhouse gases into the
Atomic reactors, bombs, etc. Atomic explosions release
dust and radiation into the atmosphere.
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There is no free lunch in SimEarth, and the price you pay for
everything is energy. Here is the price list.
PLACE PROKARYOTE 35
PLACE EUKARYOTE 70
PLACE RADIATE 105
PLACE ARTHROPOD 140
PLACE MOLLUSK 175
PLACE FISH 210
PLACE CETACEAN 245
PLACE TRICHORDATE 280
PLACE INSECT 315
PLACE AMPHIBIAN 350
PLACE REPTILE 385
PLACE DINOSAUR 420
PLACE AVIAN 455
PLACE MAMMAL 490
PLACE STONE AGE 500
PLACE BRONZE AGE 1000
PLACE IRON AGE 1500
PLACE INDUSTRIAL AGE 2000
PLACE ATOMIC AGE 2500
PLACE INFORMATION AGE 3000
PLACE NANOTECH AGE 3500
PLACE BIOME FACTORY 500
PLACE OXYGENATOR 500
PLACE NO2 GENERATOR 500
PLACE VAPORATOR 500
PLACE CO2 GENERATOR 500
PLACE MONOLITH 2500
PLACE ICE METEOR 500
TRIGGER ANY EVENT 50
PLANT ANY BIOME 50
SET ALTITUDE 50
MOVE ANYTHING 30
EXAMINE ANYTHING 5
CHANGE CONTROL PANEL 30 per click
150 per drag.
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AN INTRODUCTION TO EARTH SCIENCE
SimEarth is a computer simulation of the Earth as a living system,
developed in the spirit of James Lovelock's Caia hypothesis. To get
the most out of SimEarth, a little background in earth science is
This section of the manual is a primer to give you a start in
understanding how our planet works. You will become familiar with
many cause and effect relationships that are key to the dynamic play
you will experience in SimEarth.
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In the last 30 years, more than 200 men and women from 18 nations
have travelled in space and looked back at earth. These astronauts
took beautiful pictures that provide a new look at our planet.
The view of Earth from space is having a deep impact on our culture:
it is changing the way we look at our world and our place in it. It
is a surprising view for those who came from a Western scientific
background in which the study of the Earth was divided up into
separate segments, and the Earth was viewed as a "dead" planet.
Earth science is a relatively recent approach to looking at our
planet. It encompasses all the other sciences focused on
understanding the Earth. It involves physics, chemistry, biology,
astronomy, psychology, sociology and other areas of research. James
Lovelock's Gaia hypothesis provides a framework for us to view the
planet as a living system.
EARTH AND THE OTHER PLANETS
Earth is different from every other planet in our solar system.
Earth is the biggest of the four inner planets. It is the
only planet with an atmosphere suitable for oxygen-breathing life.
The Earth also has the biggest moon in proportion to its size in the
Solar System: so big that some think we are a two-planet system.
No other planet (that we know of) has plate tectonics, a dynamic
atmosphere and a hydrosphere. No other planet has an atmospheric
composition like ours, nor the systems of life we have in our
biosphere. This is not to say that other planets have no life in
the broadest sense of the word, but not as we know it on Earth.
Earth scientists divide the earth into four interrelated components:
the LithoSphere-The solid, rocky part of the Earth: continents and
the Hydrosphere-the liquid part of the Earth: oceans, lakes and
the AtmoSphere -the gaseous part of the Earth: air and clouds; and
the Biosphere -the living part of the Earth: humans, plants and animals.
Mercury is the closest planet to the Sun and so small that the light
gases such as Oxygen (O2) and carbon dioxide(CO2) evaporated during the
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ABOUT THIS INTRODUCTION TO EARTH SCIENCE
Venus has so much carbon dioxide (CO2) that its surface temperature
is more than 700C--what is usually known as a runaway greenhouse
effect. Venus probably had some plate tectonics in the past, but no
Mars definitely had plate tectonics, volcanos, and mountains in the
past, but being smaller than the Earth, it cooled more rapidly and
is now geologically dead. The Martian atmosphere is so thin it
would be impossible for humans to survive in it.
The rest of the Solar System, which includes Jupiter, Neptune,
Saturn, Uranus and Pluto, are either so large or so far away from the
Sun that they are too cold for life. They are mostly gaseous,
unlike the rocky, solid inner planets.
This Introduction to Earth Science is presented in five sections:
Climate (Atmosphere and Hydrosphere)
Humans and Civilisations (Biosphere)
Theories of the Earth
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This section deals with the Lithosphere--the solid rocky part of the
Earth. It covers the following subjects:
* the Origin of the Earth;
* the Evolution of the Earth;
* the Composition and Structure of the Earth;
* Special Characteristics of the Earth; and
* the Divisions of the Earth.
THE ORIGIN OF THE EARTH.
How did our solar system come into existence? Scientists currently
lean towards the solar nebula hypothesis.
This hypothesis states the following series of events:
A primordial cloud of gas and dust, called a nebula, once rotated in
space. The gravitational attraction of the material inside the
nebula caused contraction of the primordial cloud, speeding up its
rotation. The shape changed to that of a flattened disk as a
consequence of the increased rotation. Matter then migrated towards
the centre, and formed what is called a proto Sun. The formation of
the proto-Sun and the possible explosion of a nearby supernova
caused the collapse of the nebula and triggered the formation of the
solar system. The collapse increased the temperature of the
proto-Sun due to a thermonuclear chain reaction (high-temperature
fusion of hydrogen atoms to form helium atoms). The proto-Sun
started to shine. Matter began to form out of the material in
space. The hot proto-Sun and the surrounding gas and dust that
still remained after the collapse began cooling down. Gaseous
material started to condense. Small chunks of matter called
planetesimals clumped together. The biggest ones pulled most of the
matter due to their higher gravitational attraction. If the
planetesimals were too close to the Sun the lightest materials
(hydrogen, helium, etc.) were blown away by the Sun's wind. The
planetesimals closest to the Sun were also composed of the densest
materials (the ones with the highest melting points), like
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iron. A good example is Mercury, with a density more than five
times the density of water. As the planetesimals got farther away
from the Sun and therefore colder, lighter materials, such as
silicon and oxygen, condensed and formed the rocky silicate planets
(Venus, Mars, Earth). The biggest and farthest-away planetesimals,
which eventually became the giant planets Jupiter and Saturn, were
able to retain the very light compounds such as hydrogen, methane
This hypothesis, although not completely tested, explains the basics
of planetary formation and gives us the background to develop
hypotheses for the evolution of the Earth from a condensed,
homogeneous planetesimal to the differentiated, layered medium it is
THE EVOLUTION OF THE EARTH
THE First BILLION YEARS
Age-dating of meteorites and the oldest rocks on the planet tell us
that the oldest solid rocks on the Earth are about four billion
years old, and that the Earth is about 4.7 billion years old.
Five billion years ago, what was later to become the Earth was a
homogeneous conglomeration of silicon compounds, some iron,
magnesium, and oxygen compounds, and smaller amounts of the other
The pre-Earth was not as large as the planet we know today. It grew
to its present size by the gradual addition of other planetesimals
and meteorite bombardment.
The continuous bombardment not only increased the size of the
planet, but it also heated it up. The rise in temperature due to
impacts and gravitational compression, linked with the radioactive
decay of heavy elements (which also produces heat), most likely
partially melted the primordial Earth. The partially molten Earth
was then affected bywhat is known as the iron catastrophe, which then
led to the formation of the core.
FORMATION OF THE EARTH'S CORE
Within the partially molten primordial Earth, iron droplets, denser
than the surrounding liquid, started falling towards the centre of
the planet forming a liquid iron core. Other dense elements (such
as nickel and gold) followed. Since then, the Earth's core has been
composed mainly of iron and nickel. Initially all liquid, it has
slowly cooled from the centre out, so that the Earth now has both an
inner solid core and outer liquid core. The outer core, being
liquid and very hot, convects like boiling water in a pan), which
generates the Earth's unique
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and strong magnetic field. The accumulation of iron at the centre
of the Earth released a large amount of energy that caused the rest
of the Earth to melt.
DIFFERENTIATION AND THE FORMATION OF THE ATMOSPHERE AND OCEANS.
The Earth, now almost completely molten, began a periof of rapid
The molten material, lighter than its surrounding solid parent, rose
to the surface of the Earth and formed a primitive crust. It later
separated into the lighter continental crust and the denser oceanic
crust. The material left between the dense icon core in the centre
and the core became the mantle.
Differentiation was also responsible for the initial escape of gases
from the interior, called OUTGASSING, which eventuially led to the
formation of the atmosphere and the oceans.
COMPOSITION AND STRUCTURE OF THE EARTH
The Earth is made of 3 main layers, the crust, the mantle and the
The crust is the uppermost layer of the Earth. There are two types
of crust:OCEANIC, made of basalt, and continental, composed mainly of
granite. Oceanic rock is dense, has deep trenches and varies from
six to ten kilometres in thickness. Continental crust is 35 kilometres
thick on average. The crust is rigid and elastic at the same time.
The mantle is divided into several layers and is separated from the
crust by a discontinuity, or break called the MOHOROVICIC. The
UPPERRMOST mantle extends for approiximately 100km under the MOHO,
below the oceanic and continental crust. This part of the mantle
is composed of mainly two minerals. (olivine and pyroxene)
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and has the same rheological (deforming) properties as the crust:
it is both rigid and elastic.
Because they have the same theological properties, the crust and
uppermost mantle behave in unity.
Together, the crust and uppermost mantle comprise the lithosphere,
which reaches down as far as 150 km belowthe surface. Surface plate
tectonics, which are described later in the manual, explain the
behavior of the lithosphere.
Below the lithosphere is the asthenosphere. This layer extends to a
depth of 300 km below the surface of the earth.
Composed of the same materials as the uppermost mantle, the
asthenosphere is considered a separate layer from the lithosphere
because it behaves differently. The asthenosphere is hotter,
weaker, and plastic: it deforms permanently under pressure. The
hotter a material gets the less elastic and more plastic it becomes.
To give you an example with everyday materials, let's use a rubber
band and toffee. An elastic rubber band stretches to a certain
limit and then it breaks--a sudden, clean break. If we release it
before it breaks it will go back to its original form. Toffee, on
the other hand, will deform plastically under the same forces. If
you pull on it, it stretches just like the rubber band, but if you
release it before it breaks it will stay stretched or deformed; it
will not bounce back to its original shape. The lithosphere acts
like the rubber band, the asthenosphere like the toffee.
Below the asthenosphere is the transition zone, the area between 300
and 700 km beneath the surface. The transition zone, although
hotter than the asthenosphere, is not partially molten.
The transition zone gets its name from the fact that the minerals
(mainly olivine and pyroxene, but also some garnet) transform to
denser forms within this region due to heat and pressure. They
reach their most dense possible structure at 700 km, the boundary
between the upper mantle (lithosphere, asthenosphere and transition
zone) and the lower mantle.
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The lower mantle extends from 700 km to 2700 km below the surface of
the Earth. From 2700 to 2900 km is another transition region that
separates the mantle and the core.
The centre of the Earth is called the core and has two layers. The
outer core, comprised of iron and nickel, extends from 2900 to 5120km
beneath the surface. The outer core is liquid and hot. The
motion of the fluid in this region generates the Earth's unique and
strong magnetic field.
The inner core begins at 5120 km and extends to the centre of the
Earth, 6400 km below the surface. The temperature at the centre of
the Earth is about 10,000C hotter than the surface of the Sun.
SPECIAL CHARACTERISTICS OF THE EARTH
The Earth possesses unique characteristics that separate it from the
rest of the planets: a powerful magnetic field, the presence of
plate tectonics which have changed the surface structure
significantly over time, and the existence of an atmosphere, oceans
By slow convective movements in the liquid iron core, electric
currents are produced in the core which generate and maintain the
Earth's magnetic field.
The magnetic field is what enables us to navigate the seas or find
our way through a deep forest by using a compass. In simple terms,
the Earth's magnetic field can be described as a giant magnet with
North and South poles. The North magnetic pole coincides with the
geographic North pole.
At certain points in time, the magnetic field reverses--the magnetic
North becomes South and magnetic South becomes North. By examining
very old rocks with magnetic minerals that preserve the orientation
of the magnetic field at the time they formed, geologists have been
able to construct the magnetic polarlty time scale, key in the
development of the theory of sea-floor spreading and plate
tectonics. The last magnetic field reversal was over a million
PLATE TECTONICS AND CONVECTION
The Earth is also unique in that its surface layer, the lithosphere,
is broken up into pieces, or plates, that move and deform. The
movement and deformation of the plates - -plate tectonics -- is
responsible for mountain building, earthquakes and volcanos. There
are 12 major plates on the planet.
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The plates move in response to the convection of the mantle
underneath. Convection is a mechanism of heat transfer in which hot
material from the bottom rises to the top (hotter material is less
dense and therefore weighs less), and the cooler surface material
sinks. Convection is the most effective form of heat transport.
ATMOSPHERE, OCEANS, AND LIFE
Another important characteristic of the Earth is its fluid sphere:
the atmosphere and oceans. Earth is the only planet in which
two-thirds of the surface is covered by water, and is surrounded by
an atmosphere composed mostly of oxygen and nitrogen. These two
features have enabled the Earth to develop an amazing variety of
There are many theories for the origin of the atmosphere and oceans.
The most widely accepted theory states that in the Earth's earliest
beginnings, it had no gaseous atmosphere. It was too small, and
didn't have enough gravity to retain the lighter gaseous elements
that existed at that time.
As time passed, the Earth increased in size and mass: large
meteorites and planetesimals added their mass by crashing into the
Earth, and the Earth's
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gravity attracted smaller particles of matter. Eventually Earth
was big enough to retain an atmosphere.
The original atmospheric gases (very different from todays oxygen-
nitrogen) must have been produced by outgassing during the initial
The early atmosphere must have been a similar composition to the
gases released during volcanic eruptions today, and consisted of
water vapour, hydrogen, hydrogen chlorides, carbon dioxide and
monoxide, and nitrogen. The light Hydrogen compounds could not and
cannot be held by Earths gravity, and so they must hav escaped
away as they do today. As the planet cooled, the water vapour in
the atmosphere condensed into water that formed the oceans.
The present atmospheric compoition was achieved later by several
chemical reactions and evolution of life.
INFLUENCE OF THE SUN AND MOON
The prescence of the moon has one major visible effect on the Earth,
most notably, the behaviour of the oceans in the form of tides. The
gravitational pull of the Moon and the Sun on the Earth causes the
sea level to alternately rise and fall during the day. Gravitational
effeects are observed in both the oceans and the solid earth, though
the latter can only be detected by very sensitive instruments.
The tides in the water can be seen and measured accurately and the
time of occurrence calculated. The side of the Earth facing the moon
feels the strongest tide and the side opposite to it feels the minimum
tide. As the Earth rotates the tides move around it. The sun, although
farther away, is so large that it has the same effect. Solar tides
are half the tide of lunar tides, and are not in phase with the lunar
tides. Solar tides occur every 24 hours, lunar tides occur every
When the earth, moon and sun line up the tides are very strong. These
are called spring tides and they occur every two weeks, at full and new
moon. When the moon and the sun are at right-angles to each other
with respect to the Earth we have the lowest tides, known as neap tides,
which will occur between first and third quarter moons.
Tides cause loss of energy through friction between the water and the
sea floor. The energy is enough to slow down the rotation of the earth
by a very small amount. This effectively lengthens the day.
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DIVISIONS OF THE EARTH
We can summarise the behaviour of the Earth in a fairly concise way
by dividing its processes in two: surface processes of the external
heat engine and internal processes of the internal heat engine.
A heat engine is a mechanism that converts high-temperature heat
(energy) into work. It is composed of four main "parts":
1) High T(temperature) source;
2) Working fluid;
3) Work to be done; and
4) Low T sink (something that cools by absorbing heat).
These parts in the internal and external heat engines are identified
EXTERNAL HEAT ENGINE INTERNAL HEAT ENGINE
SOURCE Radiation from the Sun Heat from radioactive decay
Latent heat from fusion of the
core Mantle rocks
WORKING Atmosphere and oceans Mantle rocks
WORK Erosion, weathering, etc. Plate Tectonics
SINK Outer space Outer space.
EXTERNAL HEAT ENGINE
Many of the surface processes of the Earth are the direct result of
the work done by the external heat engine. These processes are what
determine many, but not all, of the short- and long-term changes in
the Earth's landscape.
The processes that occur within the external heat engine can be
classified into four groups:
the set of processes that results in the loosening of soil
and rock, as well as its removal downhill or downwind.
The set of processes, chemical or physical, that
results in the breakup and decay of bedrock. Of the four processes,
this is now the most important for human concerns.
Weathering breaks up and chemically changes bedrock,
transforming it into soil essential for agriculture. Our abusive
agricultural system is eroding good soil at a rate faster
than it can be created by weathering.
the set of processes involved in moving loosened
material from one place to another.
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the set of processes resulting in the settling down of
the transported sediment.
These four processes are carried out by three main agents: wind,
water and glaciers.
Wind is an important agent of erosion and deposition. In deserts,
for example, all the erosion, transportation and deposition of sand
is exclusively carried out by winds. Normal winds can only carry
very small particles, but strong winds, as in the Sahara sandstorms,
can carry a markedly heavier load.
Water in its fluid form is the most important agent of erosion,
transport and deposition on the surface of the Earth. Water is also
important in chemical and physical weathering as it is the fluid
that enables many of the chemical reactions that break down bedrock;
it also enlarges cracks in the freezing and thawing processes.
Water causes erosion of soil by runoff after heavy rain, in river
channels kom the head to the mouth (mostly at the head), and by
ocean currents both along coasts and on the bottom of the ocean.
Water in rivers is extremely important in shaping the landscape,
i.e., the Grand Canyon and the Colorado River.
Transport of sediments by water occurs in runoff channels, in rivers
and in currents in the ocean or along the shore.
Water allows deposition of sediment in river channels and deltas.
Deposition by water is very clearly seen in the inside part of the
curves of rivers, in deltas, and also in the ocean bottom as a river
enters the ocean and dumps its sediment load on the bigger body of
Water reservoirs on land are rivers, groundwater and lakes.
Glaciers are also a reservoir of water, but they will be treated
Large bodies of water accumulated as ice are usually known as
glaciers. There are several types of glaciers: mountain glaciers
like those that covered Yosemite in California, continent-sized
glaciers known as ice-sheets like those in Greenland or Antarctica,
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Glaciers are a very powerful and rapid agent of erosion, transport
and deposition. Glaciers can carve a valley in a shorter time scale
than any river. They can transport sediment that ranges from sand
grains to boulders the size of a house.
Glacier landscapes are recognised by their U-shaped valleys, while
river valleys are V-shaped. The valley floors have striations
caused by the boulders scraping the bedrock, and the sides and end
of the valley have an assortment of rock sizes we generally call
OTHER SURFACE PROCESSES
Two hot topics of public debate are the processes and effects of
global warning and air pollution. The following section will lend
insight into these topics as we discuss the basics of the carbon
cycle and element transport by rivers to the oceans.
THE CARBON CYCLE
Carbon dioxide (CO2) is used by photosynthetic organisms (organisms
that make their own food) such as plants, to generate the complex
carbohydrates and the energy they need for survival. In this
process the carbon is locked up in complex molecules and oxygen is
returned to the atmosphere.
Non-photosynthetic organisms such as humans and other animals
breathe oxygen and give back CO2 to the atmosphere. When either
type of organism dies, the organic matter decays and the carbon in
the complex molecules is released generally in the form of CO2.
Carbon also accumulates to form fossil fuels that humans have
learned to use. Such burning of the carbon in these fuels releases
additional CO2 into the atmosphere, causing an unbalance or
destabilization in the natural equilibrium of the
atmosphere/biosphere dynamic relationship.
Cutting down forests or plants also creates a destabilization of the
environment, because it results in less photosynthesis. As a
result, less CO2 is consumed and less oxygen is produced.
The highest reservoir of carbon is found in rocks, especially in
limestone. The carbon is trapped in the limestone when marine
organisms, whose shells are made of calcUe, die and fall to the
bottom of the ocean and accumulate into thick layers. When the
layers compact and harden they become limestone. Most of the carbon
stays there until the ocean floor, and the limestone with it, is
consumed through earthquake and volcanic activity. Then the
limestone melts and the
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carbon in the form of CO2 gas is released through volcanos and
returned to the atmosphere.
The processes of weathering and erosion cause many elements trapped
in minerals to be transported back to the oceans, where they
interact with both the oceanic water and rocks.
For the purposes of studying the Earth, we need to know how these
elements are transported back to the oceans and how long they
interact with water before being trapped in minerals. This helps us
understand mountain-building activity, the measure of erosion rates,
and how rock/water interactions and basalt composition form the
For environmental reasons, knowledge of these processes is equally
important. It teaches us about the behaviour of toxic or radioactive
elements in the ocean that occur, for example, as a result of
disasters such as major oil spills. It also helps us understand the
effects of increased CO2 in the atmosphere, which occurs as a result
of the burning of fossil fuels by an ever-increasing population.
INTERNAL HEAT ENGINE-PLATE TECTONICS
The most outstanding achievement of the Earth sciences in all its
history was the advent of the theory of plate tectonics in the
1960s, which, with a few simple geometrical arguments, has organised
and explained the large-scale processes of the surface of the Earth.
Plate tectonics is the work done by the internal heat engine.
Early in the 1600s Sir Francis Bacon had already noticed the
jigsaw-puzzle features of the early maps produced by the explorers
of the New World. Later, Antonio Snider and Edouard Suess proposed
the existence of a giant super-continent, but it was not until the
late 1920s, 100 years after their first publication, that a
hypothesis explaining these features was proposed.
In 1929, Alfred Wegener, a meteorologist, proposed the Continental
Drift hypothesis. Wegener collected paleontological data on fossil
plants and animals in the Old and New worlds, as well as other
geological evidence (structures, rock types and ages across the
equatorial Atlantic) and proposed the existence of a giant
supercontinent that broke into the present continents 200 million
years ago. He named this continent Pangaea.
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Wegener's hypothesis was dismissed after 10 years because he failed
to present a valid mechanism that would satisfy the physicists and
geophysicists of the time. Ironically, 60 years later, continental
drift and plate tectonics are accepted as the ruling paradigm of the
earth sciences, but there still isn't a clear idea of the mechanism
that causes it.
Continental drift and plate tectonics were finally accepted in the
1960s after several geologists and geophysicists presented
incontrovertible evidence of sea-floor spreading, ocean consumption
and transform motions.
In simple terms, the earth's surface is not continuous and static,
but broken into pieces like a giant jigsaw puzzle. Those pieces can
be continental or oceanic. They move due to flow in the mantle
underneath the surface. With this simple explanation, plate
tectonics was used to explain the distribution and nature of
volcanos around the Pacific Ring of Fire and also the distribution
of earthquakes all around the world.
Plate tectonics is the theory that explains how the lithosphere is
broken into pieces called spherical caps that are internally rigid
and change in limited amounts only at boundaries. Three types of
boundaries exist: divergent (mid-ocean ridges), convergent
(subduction zones), and transform (faults). The caps move at
constant velocities which are continually being determined by the
convection in the mantle.
Before we explain the three different types of boundaries, or
margins, what follows is an explanation of volcanos and earthquakes.
A volcano is a land edifice that is slowly built up by the eruption
of hot molten rock (magma) on the surface of the Earth. The erupted
rocks, made up of many different compositions (cooled magma) are
called volcanic. If the molten rocks don't reach the surface, but
cool under the volcano, they are called plutonic.
The hot magma flowing on the surface is called lava. Volcanos can
be of very different types depending on the composition of the
rocks. The composition determines if the volcanos will erupt
quietly (Kilauea, Hawaii) or violently (Mt. Saint Helens,
Volcanos occur at two plate boundaries and also in the middle of
plates. When associated with convergent boundaries, they are
usually violent; when divergent they are under water and erupt
quietly. Intra-plate volcanos are often associated
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with hot-spots in the bottom of the mantle that produce chains of
volcanos such as we find in Hawaii. These are usually quiet
Knowing the plate boundaries is important in predicting which type
of eruption will occur so that volcanic hazards can be properly
evaluated. Big, violent eruptions can send so much material into
the atmosphere that it will change the color of sunsets or cool the
global temperature by a few degrees. This happened in the 1880s
when Krakatoa erupted in Indonesia. The sunsets were intensely red
for a year and England did not have a summer for two years.
An earthquake is the result of the sudden release of energy that has
been accumulating between two parts of the Earth divided by a
fracture we know as a fault. The energy accumulates because the
two sides of the fault cannot slide past each other easily; rather,
they find a lot of resistance to sliding and this resistance locks
the fault. When the resistance is higher than the blocks can stand,
the fault snaps and an earthquake occurs.
Earthquake magnitude is measured by the Richter scale, which is a
measure of the energy released by the earthquake. What we feel is
measured by a subjective scale of intensity called the Mercalli
scale. Earthquakes occur at all three plate boundaries because they
all divide blocks of the Earth, where there is resistance to
Earthquakes occur below the surface of the earth but are located by
latitude and longitude measurements. Such measurements, which act
like a grid around the entire surface of the Earth, are used to
define an earthquake epicenter. The depth of the earthquake is
called a focu-s or hypocenter. Earthquakes are classified by their
depths into shallow (0-70 km), intermediate (70-300 km) and deep
(300- 700 km). Big, shallow earthquakes like those on the San
Andreas fault are highly destructive.
In the 1950s it was discovered that in the middle of the oceans
there were very long mountain chains emitting volcanic material.
These chains, known as Mid-Ocean Ridges, are where new oceanic
floor (basalt) is constantly being created. The material builds up
symmetrically on both sides of the ridge with a deep central valley.
There are volcanos and shallow earthquakes there. This type of
boundary is called a constructive boundaRy because sea-floor
material is generated here.
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Mid-ocean ridges can be followed for a continuous 40,000 km from the
Atlantic to the Pacific, the Indian Ocean and so on.
The ridges are offset by faults known as transform faults. These
faults are plate boundaries that join ridges to ridges, ridges to
trenches, faults to trenches, and so on. Material is not created
nor destroyed at transform faults. They are vertical faults that
generate shallow earthquakes. The best example is the San Andreas
If material is created at the ridges and the Earth is not getting
bigger, ocean crust must be destroyed somewhere. This occurs at
convergent margins, also known as subduction zones. Here an oceanic
plate dives into the mantle under another younger and lighter
oceanic plate or continental plate, such as with the Pacific oceanic
plate under the continental South America. A continental plate
cannot subduct, so when two continents converge they crash together
in what is known as a continental collision, generating large
mountain chains, such as the Himalayas.
Subduction of an oceanic plate generates magma, which rises under
the overriding plate and builds a volcanic line such as what takes
place in the Andes. Subduction generates 99% of the seismic energy
released every year, in shallow, intermediate, and deep earthquakes.
It also generates the biggest earthquakes (9.5 on the Richter scale
in Chile, 1960; 9.0 in Alaska, 1964).
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The study of atmospheric and hydrospheric systems (air and oceans)
explains the climate of the planet. The greenhouse effect and other
present-day environmental problems are related to climate. Climate
is part of the external heat engine and is driven by the radiational
energy of the Sun.
The composition of our atmosphere is shown in Table 1. It is
composed of 78% nitrogen gas (N2), 21% oxygen (O2) about .93% argon
(A), and minor amounts of carbon dioxide (CO2). There are also
traces of nitrous oxide (NO2), methane (CH4) and sulfur dioxide
The atmosphere did not always have this composition--free oxygen was
not available until the first photosynthetic organisms appeared.
This will be covered later in the chapter on "Life."
The atmosphere is divided into four layers: troposphere,
stratosphere, mesosphere and thermosphere.
Ozone (03) is a compound of oxygen that absorbs and repels
a large percentage of the ultraviolet radiation in solar energy.
The ozone layer protects us from the deadly UV rays of the Sun's
radiation. Our use of chlorofluorocarbons enlarges the hole in the
ozone layer, which reduces this protection.
GAS CHEMICAL CONTENT
SYMBOL (% by volume)
Nitrogen N2 78.09
Oxygen O2 20.95
Argon A 0.93
Carbon dioxide CO2 0.03
Table 1 Principal Components of Dry Air
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Not just composed of water, oceans have many other elements in
solution such as sodium, potassium, and calcium, and gases such as
carbon dioxide (see Table 2). All of the dissolved elements are
critical for the survival of marine plants and animals.
Life in the deep oceans is limited greatly by the availability of
food and light. The zone of the ocean that is well-lighted is called
the euphotic zone (upper 200 meters) and the darker, deeper layers
are called the aphotic zone. The amount of oxygen available in the
oceans also decreases sharply at deeper levels.
The structure of the oceans detailed in the figure below shows that
water temperature decreases to 4C at a depth of 2000 meters in
tropical and temperate regions.
ELEMENT AMOUNT IN OCEAN RESIDENCE IN TIME.
Sodium 147*10^20 260,000,000
Magnesium 18*10^20 12,000,000
Potassium 5.3*10^20 11,000,000
Calcium 5.6*10^20 1,000,000
Silicon 5.2*10^18 8,000
Manganese 1.4*10^15 700
Iron 1.4*10^16 140
Aluminium 1.4*10^16 100
Table 2 Residence Time of Some Elements in Seawater
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SOLAR HEATING - INSOLATION
The energy to carry out processes on the surface of the Earth comes
from the Sun. Solar radiation, also known as insolation, is what
spurs life and geological processes on the Earth.
Since the birth of the Solar System, the Sun has been radiating heat
at a constantly increasing rate. This is the natural consequence of
the growth of a star. The life span of a star like the Sun is about
1400 billion years, which means that the Sun will last for
approximately another 10 billion years. The solar radiation will
increase with time and cause the surface temperature of the Earth to
get higher and higher until the Sun dies. When this finally
happens, life on the Earth will probably die unless forms of life
not dependent on photosynthesis evolve.
Climate is highly dependent on solar output variations. Seasons
(winter and summer) and climatic zones are dependent on solar
output. Figure 11 shows the angle of the Earth to the solar rays
with different seasons and at different latitudinal zones.
Variations in solar output do not follow just the seasonal cycle of
summer and winter. They also follow other longer cycles that are
directly related to long-period changes in temperature on the Earth,
such as during glaciations.
GLACIATIONS AND CHANGES IN THE ORBIT OF THE EARTH.
Scientists have argued for a long time on the cause of the recent
(10,000 to 15,000 years ago) ice ages since they were discovered by
Louis Agassiz in the 1800s.
In the 1930s, a mathematically sound hypothesis for glaciation and
long-period climate changes was proposed by Milutin Milankovitch, a
Yugoslavian astronomer. He proposed the astronomical theory of
climate, which says that variations in the Earth's orbit influence
climate by changing the seasonal and latitudinal distribution of
incoming solar radiation.
Incoming solar radiation falls at different angles in different
seasons. The angle of incidence depends on the tilt of the rotation
axis of the Earth (axial tilt). This tilt is technically called
obliquity, and is measured with respect to a plane that crosses the
Sun and contains the orbit of the Earth (plane of the ecliptic).
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Another factor that influences the angle of incidence of solar
radiation is the precession, or the measure of how the equinoxes
succeed each other and how this affects the seasonal configuration
of the Earth. Precession depends on the longitude of the perihelion
(the point at which the Earth is closer to the Sun).
A final factor that influences the angle of incidence of solar
radiation is eccentricity, which is a measure of how much the orbit
of the Earth around the Sun differs from a perfect circle.
Obliquity, eccentricity and precession of the equinoxes are called
the orbital parameters and variations in them determine changes in
the solar heating and therefore affect our climate. These
parameters cause changes with different period lengths:
Eccentricity Long-period cycles 95,000;136,000; 413,000years
Obliquity Medium-period cycles 41,000years
Precession Short-period cycles 19,000; 23,000years
Changes in climate are classified according to the lengths of their
Tectonic band more than 400,000 years
Milankovitch band 10,000 to 400,000 years
Millenium band 400 to 10,000 years
Decadal band 10 to 400 years
Interannual band 2.5 to 10 years
Annual band 0.5 to 2.5 years
Changes in the tectonic band are attributed to tectonic effects such
as mountain building. This is a current topic of research in
paleoclimatology and is known as Tectoclimatology.
Changes in the Milankovitch band are due to changes in the orbital
parameters mentioned above. These changes are the direct result of
the gravitational pull of the giant planets (Jupiter and Saturn) on
Changes in the millenium band are attributed to episodes of flux of
volcanic gases, and expansion and contraction of alpine glaciers.
Changes in the millenium band are due to episodes of explosive
Finally, changes in the annual and interannual band are attributed
to the well- known seasonal fluctuations of solar radiation. These
are probably due to
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motions of the Earth around its own orbit (wobbling of the axis of
rotation, for example) and not the geometry of the orbit as in the
A variation in the solar output that frequently occurs is related to
sunspot cycles. A sunspot is a dark area of the sun's surface,
which represents a region of lower temperature than the rest of the
sun's surface. Sunspot cycles are fluctuations in the ultraviolet
radiation from the Sun. The approximate duration of a cycle is 11
years. The influence of sunspot cycles on the climate is still a
controversial and constantly debated topic.
EARTH`S RESPONDING TO SOLAR HEATING
The Earth does not just passively absorb the radiation from the Sun,
but returns some of the radiation back to space. It does not emit
it back at the same frequency, but at a lower one. Emissions from
the Earth are in the infrared spectrum while radiation from the Sun
comes from the whole spectrum of light, from UV (ultraviolet) rays
to visible to IR (Infrared).
Part of the solar radiation (IN rays) is absorbed by the ozone
layer, part is reflected by clouds and solids, part is absorbed by
water vapour, dust particles and clouds, and 47% is absorbed by the
The overall albedo is the most important process preventing the Sun
from frying us. It is measured by the amount of the Sun's radiant
energy that is reflecting off clouds, water and land surfaces. This
reflectivity is called albedo.
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Albedo is the ratio of light reflected to light received. The
combination of the following mechanisms gives the total albedo of
Earth and atmosphere.
Orbiting satellites keep track of the albedo in order to monitor the
rate at which the earth's surface is heating when exposed to the
sun. Such instruments measure short-wave and infrared radiation,
both coming in from the sun and going out from the atmosphere and
the earth's surface below. The earth's average albedo has been
estimated at between 29% and 34%.
There are four major mechanisms for returning radiation to space:
* Reflection from dust, salt, ash and
smoke particles in the air;
* Reflection from clouds;
* Reflection from the ground; and
* Refraction by air molecules.
If a ray reaches the Earth after all these obstacles then it still
has to deal with the Earth's albedo. This varies depending on the
composition of the surface. The average surface albedo is only 4%
but in certain areas, for example the poles, the albedo is between
Because of its high albedo, the amount of snow that falls in a year
will affect the climate and the average temperature of the Earth.
The presence of more deserts will have the same effect. Deforestation,
even though its albedo is very low, also affects the weather
because more dry uncovered land with a high albedo gets exposed.
The Earth retains this heat and transports it from equatorial
latitudes to polar latitudes.
HEAT TRANSPORT & ATMOSPHERE OCEAN INTERACTIONS
The heat absorbed by the ground and by the ocean surface waters is
greater at the equator than at the poles because of the higher
amount of insolation at these regions. This heat is transported
from the equator to the poles both by the atmosphere and by the
oceans. In a general sense, the atmosphere does it using winds and
convection cells (like the mantle in the internal heat engine), and
the oceans using currents, both surface and deep.
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Atmospheric transport, or global circulation, takes place largely
due to winds. The pattern of global circulation is characterised by
permanent anticyclones and cyclones, called centres of action, and
by persistent wind systems.
At low latitudes near the Earth's surface, the easterly trade winds
dominate. At high latitudes and aloft, the prevailing westerlies
dominate. The occurrence of zonal winds is explained bythe
deflection of motions of the meridians due to the rotation of the
Earth. This is the Coriolis effect, which also says that particles
in the Northern hemisphere tend to go to the right and in the
Southern hemisphere to the left. The driving force for this
circulation is the variation in solar radiation with latitude.
Near the surface of the Earth the pressure is low at the equator and
high at the poles. This gives rise to a circulation along the
meridians, with the heated air rising near the equator and flowing
high towards the pole and the cooled air descending at high
latitudes and flowing towards the equator at the ground. The stream
of air moving towards the pole is deflected to the east by the
Coriolis force, originating westerly winds, and the one flowing
towards the equator at the ground will be deflected to generate the
easterlies. Friction with the surface of the Earth does not allow
the pressure and Coriolis force to balance so that the circulation
is not just zonal but also along the meridians.
The pattern of meridional circulation was discovered by George
Hadley in the 1700s and the circulation patterns along the meridians
are called Hadley cells. Since friction does not allow pressure and
Coriolis force to balance, the pressure force is greater at great
heights than the Coriolis force and the air at great heights is
pushed towards the poles. At high latitude the air tends to Equator
cool and descend, completing the meridional Hadley cell.
The Hadley cells, one in each hemisphere, perform the function of
transferring excess heat from the Sun at low latitudes to higher
latitudes. The true circulation pattern is not as simple as just
having a Hadley cell in each hemisphere because of a law of physics
called conservation of angular momentum. The results of applying
the law show that Hadley cells alone will cause very high-speed
winds, which in turn will cause great instability in the global
circulation pattern. Friction between the Earth and the atmosphere
also complicates simple Hadley cells.
Heat is also transported by waves and vortices. Waves in the
atmosphere are the result of the breakdown of the zonal flow due to
high-speed winds and lateral
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mixing of the air. Swirls or vortices and cyclones and anticyclones
also result from the breakdown of the zonal flow. These are very
effective at transporting the heat in the North-South direction.
Heat transport from solar radiation is also accomplished via oceanic
circulation. Circulation of the oceans is one of the main factors
in the total heat budget of the Earth.
Oceans act as a great reservoir of heat for the planet. The Sun's
energy heats up the surface of the ocean, which stores the heat and
transports it via oceanic currents both at the surface and at depth.
Like the atmosphere, the ocean currents move heat from low latitude
to high latitudes.
The oceans are very large reservoirs of water that can hold a lot of
heat without changing their average surface temperature by very
much. This is known as the climatic flywheel.
Oceans are better at holding heat than the ground or the air, and
absorb more heat per unit area at the equators than at the poles.
The heat is transferred to the colder areas by convection. This
moderating effect on the climate is easily observed in temperate
coastal regions where warm air from the seas is transferred to the
The wind-driven circulation of the oceans is strong, but extends
only within the upper 1000 meters of the ocean. The wind system
described in the previous sections exerts a stress on the surface of
the ocean, generating surface currents. The easterly trade winds
form the equatorial currents of all oceans.
When intersected by land these currents are deflected North and
South, as in the Atlantic and Pacific oceans. Deflected currents
travel along the western parts of the oceans and are called western
boundary currents--they are the strongest in all the oceans. One is
the Gulf Stream.
These currents are driven by the westerly winds across the ocean and
form currents that flow back into the equatorial region, completing
the convection cell, similar to what occurs in atmospheric
circulation. These cells or gyres occur in subtropical regions in
the N and S Pacific, N and S Atlantic and S Indian oceans. The N
and S gyres are separated by a countercurrent that flows east.
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In the N Indian Ocean a similar gyre is found, but this changes
direction every six months due to reversals in atmospheric
circulation called monsoons. Some weaker gyres are found in
northern subpolar regions. In southern gyres the flow is not
blocked by land, so the Antarctic circumpolar flows completely
around the world. The circulation is driven by differences in
pressures between high and low areas of the sea surface.
The action of the wind on the surface of the ocean also causes
vertical motion. These vertical currents are called upwellings and
occur when prevailing winds blow parallel to a coast. These
upwellings are in offshore and subsurface waters, which frequently
are rich in nutrients. When this is the case, an area of high
biological productivity may develop.
Variations in water density cause deep water circulation known as
thermohalline circulation. These density differences develop at the
air-sea interface and are the result of differences in the amount of
heat received and the effects of dilution and evaporation. The
dense, cold waters of high latitudes sink and slowly flow towards
the equator. This is a convective process, like that of the mantle
inside the Earth. This process occurs principally in two places,
the North Atlantic and the Antarctic.
The North Atlantic Deep Water is very clearly defined by its
temperature, oxygen content and salinity. The Antarctic Bottom
Water travels north along the ocean floor across the equator. The
bottom water path is influenced by the topography of the ocean
This cycle can be summarised as follows:
the wind blowing over surface waters generates waves, mixes the surface
waters and removes water vapour from the sea surface. The water
vapour is taken into the atmosphere by evaporation and transferred
to land by precipitation, which returns it to the rivers and
groundwater that eventually return it to the sea.
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GREENHOUSE EFFECT AND CLOUD COVER
AND THEIR INFLUENCE ON CLIMATE.
In recent years we have heard a lot about global warming and the
greenhouse effect due to increasing consumption of fossil fuels and
continuous deforestation, but few accurately know what the
greenhouse effect is and how to gauge its delicate balance on the
Earth. Not even the experts can predict the Earth's behaviour in
terms of global warming trends, because we don't know enough about
climatic fluctuations and CO2 levels in the past.
The greenhouse effect can be described as follows:
The atmosphere of the Earth is fairly transparent to the incoming
visible rays of the Sun, but 48% of the radiation is absorbed by the
ground and emitted back as infrared radiation. The atmosphere is
opaque to infrared because carbon dioxide and water vapour absorb the
radiation instead of allowing it to go back into space. This
absorbed radiation heats the atmosphere, which radiates heat back to
the Earth. Without this effect the Earth's surface temperature
would be below freezing and the oceans a mass of ice.
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Any process that alters the delicate balance of CO2 and water vapour
molecules may affect Earth's climate. Burning fossil fuels
increases the amount of CO2 in the atmosphere, and deforestation of
the Amazons prevents plants from taking CO2 and returning oxygen to
Since the beginning of the Industrial Revolution the amount of CO2
in the atmosphere has increased steadily to values that we think
have never been reached before. Some of these CO2 molecules
are taken from the atmosphere and dis solved in the oceans, because
nature tries to reestablish equilibrium, but we are releasing so
much CO2 that the planet cannot rebalance itself.
Increases in global temperature caused by the greenhouse effect may
also increase sea levels by 1O meters or more by melting part of the
Antarctic ice sheet. This could be devastating to many coastal
We have already discussed briefly the effect of cloud cover on
albedo and therefore on insolation. Cloud cover also affects the
reflection of incoming rays from the Sun. Clouds form as the result
of the condensation of rising hot air into the lower part of the
atmosphere. Clear air descends to the ground where it is heated,
then rises as it warms up; it goes up into the atmosphere where it
cools and condensates, trapping a lot of water vapour, which in turn
reflects the sunlight, making it less intense.
Global warming would evaporate more water and therefore more water
vapour will go into the atmosphere and be trapped into clouds which
will in turn cover more of the sky and decrease the intensity of
sunlight that comes in. This could balance warming, but water vapour
also traps infrared radiation.
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LIFE (Get one eh ?)
ORIGIN OF LIFE
Why does life flourish on the Earth and not on any other planet? In
this section we will take a look at the history of planetary
evolution from the origin of life up to vertebrates and humans.
In the early 1920s a young Russian biochemist, Aleksandr (ivanovitch)
Oparin, theorised that there must have been a beginning of life at a
certain point in Earth's history and that we could make intelligent
guesses as to when it was and how it occurred.
Oparin theorised that the atmosphere of the early Earth lacked
oxygen but contained gases such as ammonia, methane and hydrogen.
In that kind of atmosphere (without ozone), UV rays would have
energised the components and generated the first synthetic reactions
of organic compounds such as amino acids, the building block of
life. These in turn would clump together in long chains and
possibly take on the characteristics of the primitive cell. He
called this early amalgamation of compounds primordial soup.
In the 1950s Stanley Miller devised an experiment that demonstrated
how it may have happened. He built an apparatus that zapped a
primordial soup with electrical jolts comparable to lightning, and
produced amino acids. The step from amino acids to actual life and
genetic coding is not yet understood. Other theories suggest that
the early atmosphere was primarily carbon dioxide, water vapour and
nitrogen, as expected from degassing of the Earth. In this
environment, amino acids have also been produced.
Others propose that building blocks may have originated in nearby
comets and come to Earth on impacts. The origin of the nucleic
acids DNA and RNA that enable life to replicate and transmit
genetic information to the offspring is not clear, but it is
obvious that this was the final and most crucial step towards
If you ever watch the old "Star Trek" series, you may have seen a
couple of episodes in which they discuss the possibility of life
based on silicon instead of carbon (Si and C are of the same
chemical group and possess many of the same characteristics).
Silicon-based life is highly unlikely because one of the most
outstanding properties of carbon is that it is gaseous at room
temperature rather than solid like silicon. This property enabled
carbon to make organic compounds in the fluid state, at low
temperatures, with lower energy requirements than that of silicon.
Silicon is too heavy and too inert to react at the temperatures at
which life as we know it survives.
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The first known organisms on Earth are some carbonaceous remains of
primitive cells with no nucleus that date back 3.5 billion years.
Prokaryotes, which still exist today in bacteria, algae, ameba, and
other simple organisms, lack a nucleus, the central part that
contains all the genetic material, as well as specialised organelles
for other cellular activities. These first organisms were probably
anaerobic and fed on methane.
Two billion years ago, organised life--like
algae--were thriving on the planet. One billion years ago the
eukalyotic cell, the cell with a nucleus, developed. One of
the most popular theories on the origin of eukaryotes is that
two prokaryotic cells may have stayed together after mitosis
(cell division) or they may have started a symbiotic
relationship. One may have captured the other and from there the
"trapped one" would have developed into a nucleus, and
also into several different organelles that perform different activities,
such as breathing, metabolizing, etc. inside the cell.
This is seen in modern eukaryotes in that mitochondria
(the organelles that breathe for us) have their own genetic
material and replicate separately from the rest of the genetic
material in the cell.
Shortly after the evolution of eukaryotic cells (In geologic time),
the first multicellular organisms or metazoans evolved. With the
advent of metazoans a very diverse range of life-forms evolved,
including the development of soft-bodied organisms as seen in the
Ediacara fauna of Australia and the Burgess shale in Canada.
Six hundred million years ago, after the explosion of diversity of
soft-bodied organisms, the first shelled organisms developed in a
period called the Cambrian.
The rate of evolution between one billion years ago and 600 million
was so much higher than at earlier times that it could be termed
explosive. From a world dominated by algae and bacteria we passed
to a world full of different species that in some form or other
still survive today. There were more species alive at that time
than have evolved since.
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EVOLUTION OF OXYGEN RICH ATMOSPHERE AND PHOTOSYNTHESIS.
We have already stated that primitive life evolved in an anaerobic
atmosphere with little or no oxygen. Obviously, many changes have
occurred since. Even the Cambrian organisms needed oxygen to
Around three billion years ago (with the advent of blue-green algae)
organisms must have developed the ability to photosynthesize--take
CO2 from the atmosphere and with the aid of the sun's radiation,
break it down and use the carbon to make the food, complex
carbohydrates and other energy compounds that enabled the organism
to survive. In return the organisms give free oxygen back to the
The oxygen must have started to accumulate in the atmosphere, and
soon its levels would become high because few organisms were able to
breathe and deplete it. The accumulation of oxygen was poisonous to
many organisms, which must have died out as a consequence.
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Some time just before 600 million years ago the amount of oxygen
reached high enough levels to allow rapid evolution of the
invertebrates in the Paleozoic period. For the rest of the life of
the planet the amount of oxygen has been kept constant by
Life not only changed the atmosphere, but also changed the geology,
by originating new types of sediments, rocks and geographical
features such as coral reefs.
HISTORY AND DIVERSITY OF LIFE
Diversification of life had already taken place before the Cambrian
explosion. That diversification is hard to describe because of a
lack of fossil evidence, so we will concentrate on life from the
Cambrian period on.
CAMBRIAN PERIOD--INVASION OF THE SEAS
The Cambrian initiation was the beginning of organisms with hard
body parts or shells. This provided defence against predators and
also prompted better fossil preservation. The most common hard body
parts were made of calcite, chitin and SiO2. The fossil record
really begins at the beginning of the Cambrian era because of the
better preservation of hard body parts.
The first fossils with hard skeletal parts were the trilobite, an
extinct group of arthropods related to crabs, lobsters and shrimps.
These first trilobites had large eyes, long antennae, and a
well-developed nervous system. In the early Cambrian over 90% of
all the fossils specimens were trilobites. Other common animals
were the brachiopods, similar to clams, and some echinoderms
(starfishes and sand dollars). Many other organisms became extinct
and left no descendants. All these animals were marine and invaded
the seas all around the world. Other marine organisms such as
corals, mollusks, fish, etc., developed during the rest of the
Paleozoic and also into the Mesozoic and Cenozoic.
INVASION OF LAND: PLANTS AND ANIMALS
The most outstanding achievement of the post-Cambrian Paleozoic was
the invasion of land by the first plants and animals. This opened a
lot of new niches (ecological habitats) for animals to evolve.
Organisms that lived underwater had gills or special systems to
breathe, and in order to survive on land they needed to develop a
vascular system that enabled them to use oxygen or carbon dioxide
that was not dissolved in water. Plants did it first in the early
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Transition from water to land took place in the Devonian and the
mid-to-late Paleozoic periods. One of the reasons why it did not
take place earlier is that there were extensive shallow seas over
the land, so there was not very much dry land available.
Unfortunately the fossil record on land is not as good as the marine
record because preservation is a lot worse on land. The record is
spotty, discontinuous and full of gaps even in younger rocks.
PLANTS DO IT First
In the mid-to-late Paleozoic plants developed a vascular system that
allowed them to survive without being underwater. This system
consisted of very narrow, elongated hollow cells through which water
and food could circulate. It was also a way to maintain the needed
water balance inside their bodies. They also needed to develop a
rooting system (and plants need to be attached), and a support for
the body like cellulose or lignin. Once these adaptations were
developed, the first land plant could survive far away from water
and depend only on precipitation and groundwater.
Further into the Paleozoic era, larger and more plants developed.
The first land plants were small grass-like weeds or bushes. Later
into the Carboniferous period, large ferns took over, and shortly
after that came the conifers, which dominated most of the Mesozoic
era. It was not until the end of the Mesozoic and the beginning of
the Cenozoic that flowering plants, with their efficient repro-
ductive system, came along.
LAND ANIMALS AND THE EVOLUTION TO HUMANS
In this section we will concentrate on the evolution of vertebrates
after they reached the land, all the way to humans. We have not
included a discussion on the mechanisms of evolution itself,
although they will be mentioned in relation to theories of mass
extinctions. We leave it to the reader to consult more specialised
books on the subject.
The oldest known land animals including freshwater organisms were
invertebrates or arthropods. A land scorpion and a millipede were
found in early Devonian rocks. Insect-like fossils of this age have
also been found. Snails and slugs do not appear until the late
Paleozoic, after the tetrapods or four-legged vertebrates.
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Apart from a few anomalous organisms, vertebrates evolved straight
into fishes and from there into amphibians, reptiles, mammals and
birds. Fishes will not be discussed except for their link to the
invasion of land. Freshwater Devonian fishes, crossopterygians, had
both lungs and gills for breathing, so they developed the most
important adaptation for living on land: being able to breathe air
and not water. They also had thick fleshy fins, which enabled them
to walk. The fins gradually changed to short stubby legs. The bone
structure of these fishes matches those of the early amphibians.
These adaptations, which undoubtedly were meant at first only to
help them survive as successful freshwater fishes, then became
useful to transfer completely to land. They were probably forced to
transfer to land by changes in climate in the Devonian that dried up
freshwater niches. There must have also been more food available on
land as freshwater areas dried out.
After these fishes, the first real land animals in the fossil record
are amphibians, the ancestors to toads and frogs. These animals
lived on land near the water since they often had to go into the
water to breathe and breed. As evolution proceeded the amphibians
became better adapted to living on land by developing stronger
From one of the amphibian lineages the first reptiles evolved.
Reptiles started appearing in the Carboniferous period and began
dominating the environment up until the end of the Mesozoic era.
The reptiles had a big advantage over the amphibians--they didn't
need to go to the water to breed. Reptiles developed the amniotic
egg, an egg with a hard, porous shell, which allowed the egg to
survive without the constant presence of water for breathing.
Unlike the amphibians, the reptile youngsters developed right from
the egg without a larval or tadpole stage.
Several types of reptile lineages developed in the Paleozoic, but
the two most important and interesting to us are the Synapsida, or
mammal-like reptiles, from which mammals developed in the Mesozoic,
and the Diapsida, or ruling reptiles, which included the dinosaurs.
The end of the Paleozoic saw the development of many species of
reptiles, especially the dinosaurs, which also proliferated,
may be even more, throughout the Mesozoic. There were many kinds
of dinosaurs: herbivores, carnivores, flying, aquatic, etc.
Mammal-like reptiles developed in the Triassic (the beginning of the
Mesozoic). These reptiles had longer and stronger limbs than the
other reptiles and their brain cases became progressively larger.
Their dental structure approached that of modern mammals.
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The ruling reptiles had one important group, the thecodonts, which
then became the dinosaurs. These animals were bipedal and had tiny
skulls. The front limbs were not used for walking but for handling
food. Two main groups of dinosaurs became important: those with a
pelvic bone similar to other reptiles (saurischians) and those with
a pelvic girdle similar to birds (ornitischians). Saurischians were
small and from them developed the large predators of the late Mesozoic
such as Tyrannosaurus rex. Most dinosaurs nonetheless were herbivores,
From dinosaurs developed the first bird-like reptiles, and from them,
birds. A very famous bird-like reptile is Archaeopteryx, which had
feathers and a wing structure very similar to modern-day birds.
As mentioned before, mammals evolved from the Synapsida, the mammal-like
reptiles. The first mammals were small, with small brain apacity;
most of them were probably rodents (mice, etc.). Mammals were not
very common in the Mesozoic, except for rodents and monotremes
(duck-bill platypus). Not until after the demise of the dinosaurs
at the end of the Cretaceous did they start taking over the land,
especially with the evolution of placental and marsupial mammals.
Marsupials (kangaroos and opossums, for example) are animals that
give birth to young incapable of fending for themselves; the mother
keeps them in a pouch outside her body until they are fit for life
on their own. Many types of marsupials are only found in Australia
and New Zealand. This is because early during their speciation the
continents separated (the breakup of Pangaea), isolating Australia
from the rest of the world.
Placentals give birth to completely developed offspring that feed
from the milk produced by the mother's mammary glands. After a
short period of milking they are ready to start life on their own.
Mammals are very familiar to us: rodents, canines and felines (dogs
and cats), ruminants (cows), and others. Those most important in
human evolution are the primates.
Primates originated in the Early Tertiary period, after the demise
of the dinosaurs. They were omnivores rather than insectivores.
They adapted to life in trees, one of their fundamental evolutionary
steps was the development of a grasping hand with an opposable thumb.
Another adaptation was the forward migration of the eyes, which
provides stereoscopic or three dimensional vision.
Primates known to us are the simians (monkeys) and anthropoideans
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Simians were preceded by prosimians, which gave rise to the true
monkeys and apes of the simians. In the anthropoideans there are
three groups: New World monkeys, old World monkeys and Hominoids,
which includes human beings and apes. The only one we will talk
about in some detail is the Hominoids.
HOMINOIDS AND HUMAN EVOLUTION
The hominoids include the chimpanzee, the orangutan, the gorilla,
the gibbon and human beings. It isn't until the Oligocene
(-35-24 million years ago) that these groups start differentiating.
Of all these groups, one genus dating back to the late Miocene (-5 million
years ago) is apparently the direct ancestor to modern human beings.
This is the so-called Ramapitbfecus. Homo sapiens developed in the
Pleistocene about 4 million years ago during the glaciation epochs.
The upright posture and ground-dwelling habits of human beings were
already established in Ramapithecus. This is also true of other
apes. Grasping hands are common to all primates and the use of
tools is observed in chimpanzees. Language has been taught to
chimpanzees and gorillas, although their vocal chords are different
than ours. They can also teach it to their offspring as proven in
some recent experiments.
What makes human beings strikingly different than the rest of the
primates is their brain capacity--much larger with respect to their
size than any other primate.The development of a complete, complex
language is also a characteristic of human beings.
Human beings are the only animals that are capable of totally
modifying their environment, for better or for worse. They are the
only animal capable of creating new niches and modifying existing
Another characteristic that distinguishes a human being from an
animal is the ability to think of the long-term future. Human
beings and animals share the memory of the past and the living in
thepresent, but human beings are unique in predicting the future
and also in questioning their existence.
There are three principal stages in the evolution of early human
beings: Australopithecus, Homo erectus, and Homo sapiens. The first
stageis the one to which the famous Lucy, discovered by Donald Johannsen,
belongs. The Australopithecines were similar to modern human
beings, but although they used tools and weapons, they
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had very small brains. Homo erectus lived at the same time as the
Australopithecines, and may have developed independently. The
species was more advanced than the Australopithecines and had a
higher brain capacity. They used stone tools, such as hand axes,
made from flint. This specles became widely distributed and is the
direct ancestor of modern human beings.
Fossils of Homo erectus range in age from 700,000 to 200,000 years
old. Homo sapiens is contemporaneous in age with Homo erectus,
appearing for the first time 500,000 years ago. The first example
of sapiens is Neanderthal Man, a large-boned race that lived
100,000 years ago. After sapiens originated, different historical
ages developed, such as the Paleolithic and Neollthic.
A subject of great importance in a world with an ever-growing
population is the availability of food. The food chain is an
organisational scheme that describes which organisms feed on which,
and which ones are essential for the survival of the others. It is
like a pyramid because the organisms at the base are most abundant.
At the base of our food chain are organisms that produce their own
food: photosynthetic organisms such as bacteria, plants, and
plankton in the oceans. Upon these feed higher organisms,
herbivores (plant-eaters) and omnivores (eating both animal and
vegetable matter). If the plants were to die, all cows will die as
a consequence--there would be no food left for them.
On top of herbivores at the peak of the food chain are carnivores
(animal-eaters) and omnivores. Good examples are lions, tigers,
cats, dogs and humans.
If we kill photosynthetic organisms by deforestation, polluting the
oceans or by other environmental problems, we affect the base of the
food chain and decrease the possibility of survival of the top of
the chain--including ourselves.
Mass extinctions are very important events that affect the rates at
which evolution occurs. A mass extinction is defined as the death
of 70% or more of the total biomass of the planet at any given time.
Biomass is the total weight of all living matter on the planet.
Mass extinctions have occurred at least five times in the geologic
past within the Phanerozoic alone. Extinctions during and before
the Cambrian are difficult to document.
The most massive extinction known occurred 225 million years ago at
the Permian-Triassic boundary. Another one occurred at the next
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ssic-Jurassic, about 190 million years ago. During the Cretaceous
another important extinction occurred around 100 million years ago.
The second largest extinction was at the Cretaceous-Tertiary
boundary, when all the dinosaurs became extinct. The mass
extinction of the dinosaurs has become very famous partially due to
the hypothesis that the cause of the extinction was an
extraterrestrial object: a meteorite.
Mass extinctions are important because even though a large sector of
the population was wiped out, niches were left available for
newcomers that could adapt very fast and evolve rapidly into many
new species. This seems to be the case after every extinction--a
new group of living organisms takes over and evolves at a very high
rate. During periods of time without mass extinctions, species also
become extinct, but at a low rate, an event known as a background
extinction. Evolution also takes place very slowly during such
Are mass extinctions catastrophic or are they gradual events? The
debate continues. It was generally believed that mass extinctions
were a slow, gradual process like evolution but more and more
evidence is being uncovered concerning the sudden disappearance of
many unrelated species at the same time. This has been proven at
the Cretaceous-Tertiary boundary, where within one cen- timeter of
rock (which corresponds to a relatively short period of time) all
evidence of Cretaceous fossils disappears and Tertiary fossils come
into play. This kind of boundary impact layer can be seen in
NEMESIS AND THE IMPACT THEORY
We have mentioned the extinction 65 million years ago at the
Cretaceous- Tertiary boundary of dinosaurs. Dinosaurs were not the
only animals that died: ammonites very important marine fossils,
also went extinct, as well as many other land and marine animals and
One of the marine groups that went extinct is the planktic forams
(small, calcareous, floating unicellular organisms that lived in
Cretaceous seas). These organisms are found in limestones in the
Apennines of Italy. The last bed of the Cretaceous limestone has
bi~ planktic forams; the first bed of the Tertiary has one small
planktic foram and nothing else. In between is a layer of clay
about 3 cm thick known as the "boundary clay."
In 1980, Luis and Walter Alvarez from UC Berkeley took samples of
that clay to measure the amount of an element called irldium, which
is not very abundant on the Earth's surface but more abundant in
extraterrestrial objects. Iridium rains at a constant rate, which
made it very useful for measuring the amount of
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time it took to deposit the layer of clay and therefore how long it
took for the extinction to happen. When they measured the samples
of boundary clay, they found that the levels were low in the
limestone above and below the clay, but within the clay, iridium was
at a high peak--at the same level as that in meteorites and comets.
They hypothesized that the extra iridium was from extraterrestrial
sources, and that at the time of the Cretaceous-Tertiary extinction
there had been a large meteorite (10 km in diameter) that had hit
the Earth. The dust from the impact would have gone into the
atmosphere, causing total darkness for several months, inhibiting
photosynthesis and cutting the food chain at the base. Other
effects of the impact would have been extreme cold, heat and also
acid rain. Other evidence for impact, such as shocked minerals, was
found in Italy and in another 100 sites around the world, which made
plausible the global mass extinctions.
Against this hypothesis is the fact that the crater of the impact
has not been found, which may mean that it occurred in the ocean and
that part of the ocean has been subducted--it has moved underneath a
ridge in plate tectonic activity.
This hypothesis led to findings of many impact craters and also of
other boundaries associated with iridium anomalies. It also
generated interest in extinctions that seemed to repeat themselves
A study by two paleontologists from Chicago showed that there was a
certain cyclicity to extinctions occurring every 26-28 million years.
This led Rich Muller, an astrophysicist at U.C. Berkeley, to
hypothesize that the Sun has a companion star, Nemesis, which orbits
around the Sun in a tulip orbit with a period of 26-28 million years
and that at its perihelion it disturbed a belt of comets and
asteroids outside the Solar System. This sent comets and asteroids
into the inner Solar System and caused periodic comet showers on the
Earth, and as a consequence, periodic extinctions.
The original statistical data showing periodicity in mass
extinctions were sketchy and poorly constrained. To base Nemesis on
it was an exercise in creativity--the search for Nemesis has so far
For many a geologist, accepting a catastrophic extraterrestrial
event has been difficult, so, two Earth scientists from Dartmouth
University proposed that the extra iridium came from big volcanic
eruptions occurring at the same time as the extinctions. This was
hypothesised because iridium was found in the gases
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emitted by Kilauea. A candidate for the big volcanic event that
would have sent the iridium and dust in the atmosphere to stop
photosynthesis and kill the dinosaurs would be the Deccan Traps of
India, a big basaltic eruption dated at 66 million years. However,
no evidence of iridium has been found in the Deccan Traps, and the
type of volcanic eruption of these basalts was quiet and not violent
enough to send material into the stratosphere to orbit around the
Earth (as required by the global distribution of iridium). It also
would not produce impact minerals, although some scientists claim it
does (no evidence has been uncovered as to this effect). Volcanism
may have had something to do with local extinctions, but not at a
Finally, many argue that climatic fluctuations and changes in sea
level could have caused sudden extinctions. Although there are data
to support contemporaneous extinctions and climatic changes, it is
hard to see how gradual changes in the climate, changes in sea level
and slow glaciation, and interglaciation periods could have caused
sudden mass extinction of all types of animals, even those used to
living in cold climates.
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HUMAN CIVILISATIONS AND TECHNOLOGY
The developments--and disintegrations--of civilisations span
thousands of years, encompassing spectacular advances in knowledge
and sharply disruptive disturbances on the human and planetary
scale. This section will encapsulate the development of human
endeavour from the Paleolithic to the Atomic Ages, outlining the
technological movements that have accompanied and spurred the
advance of culture.
Civilisation is generally regarded as culture with a relatively high
degree of elaboration and technical development, often demarcated by
the complex of cultural elements that first appeared in human
history 6,000 to 8,000 years ago. At that time, on the basis of
agriculture, stock-raising and metallurgy, intensive occupational
specialisation began to appear in the river valleys of SW Asia.
However, the roots of those circumstances long predate that period
in several parts of the prehistoric world: Mesopotamia, Egypt,
China, Greece, India, Highland Peru, and elsewhere.
The specific characteristics of civilisation--food production, plant
and animal domestication, metallurgy, a high degree of occupational
specialisation, writing and the growth of cities--had their origins
in the Old Stone Age, the earliest period of human development
and the longest phase of humanity's history.
The Old Stone Age is approximately coextensive with the Pleistocene
geologic period, beginning about two million years ago and ending in
various places between 40,000 and 10,000 years ago, when it was
succeeded by the Mesolithic Period.
By far the most outstanding feature of the Paleolithic period was
the evolution of humans from an apelike creature, or near human, to
true Homo sapiens. This development was exceedingly slow and
continued through the three successive divisions of the period, the
Lower, Middle and Upper Paleolithic.
The most abundant remains of Paleolithic cultures are a variety of
stone tools whose distinct characteristics provide the basis for a
system of classification containing several toolmaking traditions or
industries. The oldest recognisable tools made by members of the
family of humankind are simple stone choppers, such as those
discovered at Olduvai Corge in Tanzania. These tools may have been
made over one million years ago by Australopithecus or by Homo
habilis. Fractured stone "tools" called eoliths have been
considered the earliest tools, but it has been difficult to
distinguish human-made from naturally produced modifications in such
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THE LOWER PALEOLITHIC
Lower Paleolithic stone industries of Homo erectus have been found
at various sites in China, Europe, Africa and Asia dating from
100,000 to 500,000 years ago. The stone tools of this period are of
the core type, made by chipping the stone to form a cutting edge, or
of the flake type, fashioned from fragments struck off a stone.
Hand axes were the typical tool of these early people, who were
hunters and food gatherers.
THE MIDDLE PALEOLITHIC
The Middle Paleolithic period is often associated with Neanderthals,
living between 40,000 and 100,000 years ago. Neanderthal remains
are often found in caves with evidence of the use of fire.
Neanderthals were hunters of prehistoric mammals and their cultural
remains, though unearthed chiefly in Europe, have also been found in
N Africa, Palestine and Siberia.
Stone tools of this period are of the flake tradition, and bone
implements, such as needles, indicate that crudely sewn furs and
skins were used as body covering.
THE UPPER PALEOLITHIC
The Upper Paleolithic saw the disappearance of Neanderthal in favour
of other Homo sapiens such as Cro-Magnon. The beginnings of
communal hunting and fishing are found here, as is the first
conclusive evidence of belief systems centering on magic and the
supernatural. Pit houses, the first human-made shelters were built,
sewn clothing was worn, and sculpture and painting originated.
Tools were of great variety, including flint and obsidian blades and
The final and perhaps most impressive phase of the Paleolithic
period is the Magdalenian period, in which communities of fisherman
and reindeer hunters used highly refined and varied tools and
weapons, and left an impressive array of cave paintings.
THE MESSOLITHIC PERIOD
This period began with the end of the last glacial period and
involved the gradual domestication of plants and animals and the
formation of settled communities at various times and places, some
overlapping into the considerable development of the Neolithic
Characteristic of the period were hunting and fishing settlements
along rivers and on lake shores. Pottery and the use of the bow
began to develop. Hafted axes and bone tools were found in the
Baltic region and N England, demonstrating strong advances over
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The Mesolithic period in several areas shows a gradual transition
from a food- collecting to a food-producing culture.
THE NEOLITHIC REVOLUTION
Toward the end of that last ice age, some 15,000 to 20,000 years
ago, a few of the human communities that were most favoured by
geography and climate began to make the transition from the long
period of Paleolithic savagery to a more settled way of life
depending on animal husbandry and agriculture.
This period of transition led to a marked rise in population, to a
growth in the size of communities, and to the beginnings of town
life. It is sometimes referred to as the Neolithic Revolution
because the speed of technological innovation increased so greatly
and the social and political organisation of human groups underwent
a corresponding increase in complexity.
The earliest known development of Neolithic culture was in SW Asia
between 8000 B.C. and 6000 B.C. Settled villages cultivating
wheat, barley and millet and raising cattle, sheep, goats and pigs
expanded. Neolithic culture and its innovations spread through
Europe, the Nile valley, the Indus valley ~ndia) and the Yellow
River valley (China).
By 1500 B.C., Neolithic cultures based on the cultivation of maize,
beans, squash and other plants were present in Mexico and South
America, leading to the rise of the Inca and Aztec civilisations and
spreading to other parts of the Americas by the time of European
THE BRONZE AGE
This is the period in the development of technology when metals were
first used regularly in the manufacture of tools and weapons. Pure
copper and bronze, an alloy of copper and tin, were used
indiscriminately at first; this early period is sometimes called the
The earliest use of cast metal can be deduced from clay models of
weapons; casting was certainly established in the Middle East by
3500 B.C. In the New World, the earliest bronze was cast in Bolivia
A.D. c.11O0. The Inca civilisation used bronze tools and weapons
but never mastered iron.
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The development of a metallurgical industry coincided with the rise
of urbanization. The organised operations of mining, smelting, and
casting undoubtedly required the specialisation of labour and the
production of surplus food to support a class of artisans, while the
search for raw materials stimulated the exploration and colonisation
of new territories.
THE IRON AGE
This period begins with the general use of iron and continues into
modern times. The use of smelted iron ornaments and ceremonial
weapons became common during the period extending from 1900 to 1400
B.C. About this time, the invention of tempering, the strengthening
of a metal by the application of heat or by alternate heating and
cooling, was made in the Hittite empire. After its downfall in 1200
B.C., the great waves of migrants spreading through S Europe and the
Middle East ensured the rapid transmission of iron technology.
The casting of iron did not become technically useful until the
Industrial Revolution. The people of the Iron Age developed the
basic economic innovations of the Bronze Age and laid the
foundations for feudal organization. Ox-drawn plows and wheeled
vehicles acquired a new importance and changed the agricultural
patterns. For the first time humans were able to exploit
efficiently the temperate forest. Villages were fortified, warfare
was conducted on horse- back and in horse-drawn chariots, and
alphabetic writing based on the Phoenician script became
CLASHES, CONQUESTS AND CHANGE.
Technical advances in weaponry and warfare helped an insignificant
pastoral settlement in Rome to become perhaps the world's most
successful empire supreme as a lawgiver and organiser, holding
sway over virtually all the then- known world.
From the establishment of the Roman republic around 500 B.C.
successive generations of Roman rulers expanded their territorial
acquisitions, and thus absorbed and exported the leading material,
social and intellectual advances of the day.
From the age of Caesar, (60 B.C.) Rome was foremost as the civiliser
of barbarians and the ruler of the older world. The empire
promulgated the ideals of Greek literature, architecture and
thought. The extensive system of Roman roads made transportation
easier than it was again to be until the development of railroads A
postal service was organised; commerce and industry, particularly by
sea, were greatly developed.
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At its height, imperial Rome counted well over one million
inhabitants. It was well-policed, sanitation was excellent, and
among the rich, such luxuries as central heating and running water
were not unknown. Decline came quickly, however. In 476 the last
emperor of the West, appropriately called Romulus Augustus, was
deposed by the Goths; this date is commonly accepted as the end of
the West Roman Empire, or Western Empire.
The so-called Dark Ages that followed in Western Europe could not
eradicate the profound imprint left by Roman civilisation.
This term is usually applied to the social and economic changes that
marked the transition from a stable agricultural and commercial
society to a modern industrial society relying on complex machinery
rather than tools. Historically, it refers primarily to the period
in British history from the middle of the 18th century to the middle
of the 19th century. Dramatic changes in the social and economic
structure took place: inventions and technological innovations cre-
ated the factory system of large-scale machine production, greater
economic specialisation emerged and the labouring population,
formerly employed pre- dominantly in agriculture (where production
was also on the rise), increasingly gathered in great urban
factory centres. The same process occurred at later times and in
changed tempo in other countries.
There has been much objection to the term because the word
"revolution" suggests sudden, violent, unparalleled change, whereas
the transformation was, to a great extent, gradual. Some historians
argue that the 13th and 16th centuries were also periods of
revolutionary economic change. The ground was prepared by the
voyages of discovery from Western Europe in the 15th and 16th
centuries, which led to a vast influx of precious metals from the
New World, raising prices, stimulating industry, and fostering a
money economy. Expansion of trade and the money economy stimulated
the development of new institutions of finance and credit.
In Britain's productive process, coal came to replace wood. Early
model steam engines were introduced to drain water and raise coal
from the mines. Factories and industrial towns sprang up. Canals
and roads were built, and the advent of the railroad and the
steamship widened the market for manufactured goods. The Bessemer
Process made a gigantic contribution, for it was largely responsible
for the extension of the use of steam and steel that were the two
chief features of industry in the middle of the 19th century. The
transformation of the United States into an industrial nation took
place largely after the Civil War and on the British model. The
Industrial Revolution was introduced by Europeans into Asia,
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and the last years of the 19th and the early 20th century saw the
development of industries in India, China and Japan.
The Industrial Revolution created a specialised and interdependent
economic life and made urban workers more completely dependent on
the will of their employers than the rural workers had been.
Relations between capital and labour were aggravated, and Marxism was
one product of this unrest.
The Industrial Revolution changed the face of nations, giving rise
to urban centres requiring vast municipal services. Technology was
praised by some factions as the mainspring of social progress and
the development of democracy, and criticised by others as the bane
of modern man, responsible for the tyranny of the machine and the
squalor of urban life.
Machines had vastly increased production, eased the toils of labour
and raised living standards, but often at a cost of environmental
pollution, depletion of natural resources, and the creation of
THE ATOMIC AGE
With the advent of the Atomic Age we must face the contemporary
dilemma of a highly technological society contemplating the
possibility that it could use its sophisticated techniques in order
to accomplish its own destruction. It is not a firm assumption to
identify technology with the "progressive" forces in contemporary
civilisation. The forces of technology will continue their
seemingly inexorable advance, bringing us in vitro fertilizations,
global satellite communications, genetic manipulations and B2
bombers, but the wisdom to manage these innovations is not a
guaranteed part of the package.
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THEORIES OF THE EARTH - THE GAIA HYPOTHESIS.
SimEarth is centered around a hypothesis of the evolution of the
Earth, life and atmosphere known as the GAIA HYPOTHESIS, proposed by
James Lovelock. The Gaia hypothesis is a holistic approach to
understanding life and natural phenomena as teleological
circumstances, that is, as existing because they fill a purpose and
not just because of happenstance. Here is a brief explanation of
what the Gaia hypothesis is and a few of the examples given by
Before we start talking about Gaia we need to define what the
feedback mechanisms "positive" and "negative" mean. A positive
feedback loop is also known in systems theory as a vicious circle or
catastrophic loop. As illustrated in Figure 20, a positive loop is
the one that causes continuous increase or decrease of a certain
condition resulting in a catastrophe. A negative feedback loop is a
self-regulating feedback loop or virtuous circle: a mechanism like
a thermostat, where if a certain condition increases, the next
decreases, resulting in equilibrium or self-regulation.
Most of Earth's systems, like the carbon cycle and the atmospheric
hydrologic cycle, are self-regulatory and tend toward equilibrium.
Nonetheless, most systems can be driven over the edge and would
never be able to self-regulate again if a certain critical threshold
of one of the conditions is reached. This could happen with
The Gaia hypothesis comes in two versions: the weak Gaia and the
strong Gaia. The strong Gaia says that the Earth is alive. The
weak Gaia says that life may have some regulatory effect on some of
the dynamic systems of the planet. We will explore in this manual
only the strong Gaia version. Please understand that although this
hypothesis is controversial and therefore not generally accepted in
the scientific community, it provides a useful framework for
understanding the Earth.
Gaia was developed by Lovelock during the time NASA was preparing
the Viking explorer for a trip to Mars. He was designing
instrumentation to test if there was life there. But in order to
test for life, Lovelock had to ask the question, "What is life?"
This work provided Lovelock the opportunity to reevaluate this
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Lovelock realised that we needn't go to Mars to find out if there
was life, because if there were, we would see changes reflected in
its atmospheric composition and other planetary features like those
we see on the Earth, which has a very peculiar atmosphere. Life as
we know it would affect the planet's atmosphere, as shown in Table 5.
GAS VENUS EARTH MARS EARTH
------ ---------- -------- ----------- ----------
CO2(%) 96.5 98 95 0.03
N2(%) 3.5 1.9 2.7 79
O2 trace 0.0 0.13 2.1
Ar 70.ppm 0.1 1.6 1
Methane 0.0 0.0 0.0 1.7 ppm
Surf.Temp 459C 240-340C -53C 13C
Total Pressure 90 bars 60 bars .0064 bars 1.0 bars
Table 5: Origin of atmospheric composition.
Lovelock invented a very simple world model called Daisyworld to
explain the tenets of the Gaia hypothesis. The parable of
Daisyworld begins by explaining that it is a fictitious planet in
which the life is represented by different-coloured daisies: dark,
light and neutral colors.
The planet is at the same distance from the Sun as the Earth, is the
same size as the Earth and has a little more land area than the
Earth. On this planet there is enough CO2 for daisies, but it does
not affect the climate like on the Earth and clouds do not exist.
The Sun increases its heat output with age. The optimum temperature
for daisies is about 20ø C. If the planet gets colder than 5C,
daisies will not grow. If it gets hotter than 40C, they will die.
The average temperature of the planet is determined by the albedo,
which is determined by the color of the daisies. A dark daisy
absorbs more heat and the temperature rises; a lighter daisy
reflects more heat and the temperature falls. This effect will make
white and dark daisies alternate in population size until they
eventually reach equilibrium, a condition in which all acting
influences are cancelled by others resulting in a stable, balanced,
or unchanging system. The
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effect will also control the temperature of the planet. When the
Sun gets hotter the temperature cannot be regulated anymore by the
daisies and they die--the planet becomes barren.
The Daisyworld model illustrates the following tenets of the Gaia
1. Living organisms grow vigorously, exploiting any environmental
opportunities that open
2. Organisms are subject to the rules of Darwinian natural selection
3. Organisms affect their physical and chemical environment, by
breathing, for example
4. Limits of constraints and bounds establish the limits of life
A version of the Daisyworld program is included as one of the
SimEarth scenarios. There is a complete discussion of how and why
Daisyworld works in the "Scenarios" chapter.
EVIDENCE OF REGULATION BY LIFE
Lovelock's book, The Ages of Gaia, examines the pollution of the
atmosphere by oxygen producers and its consequences.
Many nations are extremely concerned about global warming, but it is
not clearly understood how the Earth regulates the amount of CO2 in
the atmosphere. From the very beginning of life, CO2 has been
important in providing food for photosynthesizers, and as the
thermal cover to keep us warm. Biota Qife3 pumps CO2 from the
atmosphere; its level has been going down for the last 3.6 billion
The increase in CO2 due to the burning of fossil fuels is not much
more than a minor disturbance to the Earth, but tends to offset the
decline. Even though the quantities humans add may be small, if the
CO2 regulatory mechanism is reaching its capacity, then the plants
that evolved as the CO2 levels declined through Earth's history may
be affected. Also, the rapid rise of CO2 levels since the
Industrial Revolution may indicate that the regulatory pumps are not
working properly to remove the excessive CO2 from the atmosphere.
This change in CO2 is similar to the one that occurred naturally
from the last ice age, so it may affect the climate as much as
between the last ice age and now. We do not know enough about the
CO2 system to predict if the perturbation will self- regulate, cause
oscillations, chaotic changes or total failure.
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The possible climactic changes due to the increase in CO2 probably
won't have tragic consequences for the Earth and life as a whole,
but it may wipe out humanity along with many other species of plants
1. Francis, Peter, 1976, Volcanoes, Penguin Books, England
2. Press, F. and Siever, R., 1986, Earth, fourth edition, Freeman,
3. Skinner, B.J., and Porter, S.C., 1989, The Dynamic Earth, J. Wiley and Sons,
4. Uyeda, S1978, The New View of the Earth, Freeman, New York
1. Iribarne, J.V., and Cho, H., 1980, Atmospheric Physics, Reidel
Publishing Co., Holland
2. Neiburger, M., Edinger, J.G., and Bonner, W.D., 1982, Understanding Our
atmospheric environment.Freeman, New York
3. Riehl, H., 1978, Introduction to the Atmosphere, McGraw-Hill, New York
4 Ross, D., 1988, Introduction to Oceanography, Prentice-Hall, New Jersey
1. Lane, G., 1978, Life of the Past, Charles Merrill Publishing Co., London
2. McAlester, A.L., 1977, The History of Life, Prentice-Hall, New Jersey
3. Muller, R., 1988, Nemesis, the Death Star, Weidenfeld and Nicolson,
1. Lovelock, J., 1988, The Ages of Gaia, Norton, New York
2. Myers, Norman, 1984, Gaia, an Atlas of Planet Management, Anchor Press,
> 199 <
PROBLEMS AND SOLUTIONS
Here is a listing of common problems and challenges you will face,
their causes, and some suggestions on how to deal with them.
First, check CO2 levels. If high, use Oxygenator, or increase
Biomes to reduce CO2 levels.
You can also turn down solar input, raise cloud albedo, and turn
down greenhouse effect.
EVOLUTION IN THE WATER SEEMS TO STOP
Most advanced aquatic life forms live in shallow water. If there
are not enough shallow shelves, you will hit an evolutionary
dead-end. You can create shelves either by raising the ocean floor
or lowering the land. You can raise the ocean floor with the SET
ALTITUDE tool or with volcanos. You can lower the land with the SET
ALTITUDE tool or with meteors.
"... NEEDS ENERGY"
If you see a message that says that one of the disciplines
(Philosophy, Science, Agriculture, Medicine, Art/Media) needs
energy, increase their share of energy in the CIVILISATION MODEL
CONTROL PANEL, or increase the overall level of energy.
Overall energy is increased by doing more work, by increasing
population, and by concentrating on the most efficient energy
This is a warning that extinctions are imminent. There's not much
to be done except prepare for the worst and get ready to rebuild
Mass Extinctions are caused by too much dust or too little oxygen
(<20%) in the atmosphere.
Dust is put into the atmosphere by volcanos and meteor impacts.
Nothing but time removes dust from the atmosphere.
If oxygen levels are below 20%, use the Oxygenator terraforming
tool, or increase biomes.
> 202 <
FUELS RUNNING LOW
This is a warning that war is imminent. Change your energy usage to
Nuclear war is in progress. In SimEarth, this is caused by
competition for limited nuclear fuels. Reduce investment in nuclear
energy to halt the wars.
Caused by the radiation and dust in the air that result from
numerous nuclear explosions. Cut back on fuel usage, and
concentrate on keeping small pockets of your sentient species alive.
Eventually the dust will settle and the radiation zones will vanish.
Tidal waves can help clean up radiation in the oceans and on the
Pollution comes from industrial age technologies, as well as fossil
fuel usage. The best solution is to invest in science and advance
to the atomic era as quickly as possible.
> 203 <
Aerobic--Requires oxygen. This can apply to animals, machines or
Air Pressure--The pressure caused by air molecules
bouncing against a surface. Vacuum has no air pressure.
Albedo--The reflectivity of a surface. A surface with high albedo
will reflect sunlight. A surface with low albedo will absorb
sunlight. Snow (high albedo) reflects sunlight and remains cold.
Anaerobic--Does not require oxygen. This can apply to animals,
machines or processes.
Arctic--Areas that are snow or ice covered.
Cold and dry. See Tundra.
Arthropod--The phylum of animals which includes insects, crustaceans,
arachnids, and myriapods.
Atmosphere--The blanket of gases which envelop a planet.
Atomic Age--This era is characterised by Nuclear Power, Aircraft, Radio,
and Chemical Fertilisers.
Axis--The planetary centre of rotation. On Earth, the axis is
a line passing from the north pole to the south pole.
Biomass--The total dry weight of all living material on a
Biome--A major ecosystem such as temperate grassland,
forest or desert.
Biome Factory--A SimEarth tool which produces the best biome for
the environment it occupies.
Biosphere--The areas of a planet which are inhabited by life. On
Earth this is the crust, hydrosphere, and lower atmosphere.
Boreal--Also known as Boreal Forest. Biome designed for cool
regions with airborn moisture. The trees are usually conifers.
Bronze--An alloy of tin and copper that is stronger than either.
Bronze Age--This era is characterised by bronze tools, sail ships,
clay tablets and irrigation.
Carbon Dioxide (CO2)--A gas composed of two oxygen atoms and one carbon
atom. This gas is used by plants in photosynthesis and produced by
organisms as they respirate.
Carnifers--A SimEarth name for mobile, carnivorous plants.The Venus Flytrap
is the precursor to carniferns.
Cetaceans--The order of mammals that is exclusively aquatic.
This includes dolphins and whales.
CO2 Generator--A SimEarth tool that creates carbon dioxide for the
Class--The classification of life under Phylum. The major classes
of Chordata are fish, amphibian, reptile, avian, and mammal. See
> 204 <
Cloud Albedo--The albedo of clouds. High cloud albedo can keep Earth cool.
Conifer--Cone-bearing trees and shrubs. This includes evergreens, pines and
Continental drift--The theory that continents have changed position
on Earth. This is a component of Plate Tectonics.
Core--The extremely dense, fluid centre of Earth. It is probably
composed of molten iron. See Mantle.
Crust--This thin outer shell of the Earth is only a few miles
deep. See Mantle.
Clyosphere--The frozen regions such as the icecaps, tundra, and mountain
Desert--An ecosystem suited for hot weather and little water.
Dry Weight--The mass of an organism after the water has been removed.
Dust--In SimEarth, dust refers to airborne dust, ash and detritus. This
can darken a planet, reducing photosynthesis and absorbing heat.
Ecosystem--A group of plant and animal species living together in rough
Eukaryote--Single-cell microbes with a nucleus.
Evolution--The process by which life has changed and diversified.
Explosive Upwelling--Sometimes hot spots are very hot. This can lead
to a volcano that is a thousand times the size of any seen by
man. These upwellings spew the material for continents and are
Extinction--The elimination of one species.
Greenhouse Effect--Planetary heating induced by greenhouse gases.
Greenhouse Gases--Certain gases will let solar radiation enter the
atmosphere but not leave. The most common of these are carbon dioxide,
methane, and water vapor.
Hot Spot--Mantle material flows up and down as well as sideways. Hot magma
sometimes rises from the core to the crust creating a Hot Spot. See
Hydrosphere--The water portions of Earth. This includes oceans, lakes,
rivers, and clouds. SimEarth restricts the term to oceans.
Industrial Age--This era is characterised by the use of fossil-fuel
engines, automobiles, telephones, and animal husbandry.
Information Age--This era is characterised by computers, global
communications, robotic labour, and ecologic awareness.
Insolation--Incoming Solar radiation.
> 205 <
Iron Age--This era is characterised by iron tools, sextants, paper,
the printing press, and horse-drawn plows.
Kingdom--The most general classification of life in Biology. The
five kingdoms are prokaryotae, protoctista (eukaryotes), fungi, plantae
Jungle (Tropical Forest)--A biome that thrives in hot, wet climates.
Lava--The lighter materials of magma that come to the surface via
volcanos and upwellings.
Lithosphere--The rock portions of the planet: Plates, Crust,
Moho, Mantle, and Core.
Magma--Molten rock found beneath the Earth's crust. See Lava.
Mantle--The layer of magma between the crust and core of the Earth.
This area is constantly flowing at a speed measured in centimeters per
Mass Extinctions--At various times in Earth's history large numbers of
species have vanished. Records indicate that at each of these times
between 5% and 50% of the species became extinct. See Nemesis.
Methane (CH4)--A gas composed of one carbon atom and four hydrogen atoms.
It is primarily produced by primitive microbes which currently live in the
intestines of larger organisms.
Microbe--A single-celled organism.
Mollusk--Class of invertebrates that includes snails, mussels and octopus.
Monolith--A SimEarth tool for advancing life. Thank you Arthur C. Clark.
Moho--Also called the Mohorovicic discontinuity. The turbulent region
between the crust and the mantle.
Mutate--When an organism makes an inexact copy of itself. The variability
which allows evolution to occur.
N2 Generator--A SimEarth tool for introducing Nitrogen into the atmosphere.
Nanotech Age--This era is characterised by molecular construction, molecule-
sized machines, and completely automatic production.
Nemesis--The culprit in the periodic mass extinctions (every 25 million
years or so). Identity unknown, the two prime suspects are: Meteors
(caused by a dark star orbiting our Sun) and Explosive Upwellings.
Nitrogen--A gas composed of two nitrogen atoms. It is a heavy, stable gas
comprising 80% of Earth's atmosphere.
Noosphere--"The sphere of mind" which includes society and culture.
Order--The classification of life under Class. The major orders
of mammals are rodents, felines, canines, ruminants, primates and
Organism--An independent unit of life. All plants, animals and microbes are
> 206 <
Oxygen (O)--A gas composed of two oxygen atoms. This is used by organisms
when they respirate.
Oxygenator--A SimEarth tool that converts carbon dioxide to oxygen.
Photosynthesis--A process that uses light to create energy-storing
chemicals such as sugar. Oxygen is a byproduct of photosynthesis.
Plant--An organism that uses photosynthesis to feed itself.
Plate--A solid piece of the Earth's crust being pushed about by
Plate Tectonics--Theory that the Earth's crust is formed of mobile plates
sliding across the mantle. Even the ocean bottoms consist of plates.
Phylum--The classification of life under Kingdom. The major animal phylums
are chordates, arthropods and invertebrates. See Class.
Phytomass--The total dry weight of all plant material on a planet.
Planet--An astral body that orbits a sun.
Planetesimal--An small planet. Small usually means moon-sized or less.
Prokalyote--Primitive single-cell microbes with no nucleus.
Radiate--The class of invertebrates including jellyfish and starfish.
Sapient--An intelligent, tool-using organism.
Stone Age--This era is characterised by stone tools, domestication, fire, and
Surface Albedo--In SimEarth this refers to the albedo of your planetary
Swamp--Also known as tropical grasslands. This biome is composed of plants
and animals that thrive in slow shallow water and on muddy shorelines.
Terraform--The process of modifying an entire planet for a particular
Trichordate--A SimEarth term for an order of radiates with three radiating
Tundra--This biome is designed to survive periodic arctic conditions
and year-round cold weather.
Upwelling--When two plates pull apart, lava will flow up between them
forming small rises like the Mid-Atlantic Ridge. See Plate Tectonics.
Vaporator--A SimEarth tool that stimulates global plant growth.
Volcano--When a Hot Spot is over a thin section of crust, a volcano
can erupt. Volcanos spew lava and ash over an area, often forming new
Water Vapor (H20)--Water can be a gas with one oxygen atom and two
Zoomass--The total dry weight of all animal material on a planet.
> 207 <
Absolute Date 27, 51
Advance Rate 97
Agriculture 47, 88, 99
Air Currents 75, 131
Air Pollution 162
Air Pressure 204
AirSample 49, 91
AirTemperature 74, 81, 91, 131
Air-Sea Thermal Transfer 96, 132
Albedo 171-172, 204
Alternate Intelligent Species 143
Amphibians 139, 183
Anaerobic 179, 204
Aquarium 56, 110
Arctic 66, 134, 204
Art/Media 47, 88, 99
Arthropod 137, 181, 204
Atmosphere 3, 33, 49, 129, 130, 151, 158, 204
Atmosphere Croup 74
ATMOSPHERE MODEL CONTROL
PANEL 38, 39, 96
Atmosphere-Ocean Interaction 175
ATMOSPHERIC COMPOSITION GRAPH 30, 78, 91
Atmospheric Pressure 130, 132
Atmospheric Transport 173
Atomic Age 143, 195, 204
Atomic Fuel 82
Atomic Test 65, 123
AvailableEnergyDisplay 28, 70, 145
Average Game 55
Axial Tilt 95, 169
Bioenergy 86, 98, 147
Biomass 81, 83-84, 89, 204
Biome 17-18, 49, 65-66, 7S, 134, 204
Biome Factory 62, 204
Biome Preference Chart 66, 135
BIOME PATIO GRAPH 33, 79, 92
Biosphere 3, 49, 151, 204
Biosphere Group 75
BIOSPHERE MODEL CONTROL PANEL 39, 97
Birds 140, 183
Boreal Forest 66, 134, 204
Bronze Age 142, 192, 204
Cambrian Period 181
Carbon Cycle 162
Carbon Dioxide 81, 91, 129, 162, 204
Carniferns- 60, 141, 204
Cetaceans 138, 204
CH4 81, 91, 129, 206
Civilization 18, 49, 76, 142-144,190
Civilization Group 75
CIVILIZATION MODEL CONTROL PANEL
40-42, 87, 98
Civilization Time Scale 105-106
Climate 131, 132, 167
Climate Overlay Buttons 28, 70
Close Box 21
Cloud Albedo 96, 131, 205
Cloud Cover 177
Cloud Formation 96, 131
CO2 91, 129, 162, 204
CO2 Absorption 97
CO2 Generator 63, 204
Compress Edit Screen 50
Continental Drift 95, 127, 164, 205
Continental Drift Map 73
Continental Drift Record 77
Convergent Margin 166
Copper Age 192
Core 157, 205
Core Formation 95
Core Heat 95, 127
Coriolis Effect 173
Crust 155, 205
Current Task 31, 83-84, 88-89
Current Tool Display 27, 69
Daisyworld 7, 16, 56, 88, 118-121, 197-198
> 208 <
Daisyworld Info Box 77
DataLayer Buttons 27 69
DATASOUND MENU 51
Desert 66 134 205
Divergent Margin 165
Diversification of Life 181
Drift Map 32
Dry Weight 205
Earth CambrianEra 56 112
Earth ModernDay 56 114
Earthquake 30 65 124 165
Easy Game 55
EDIT WINDOW 17 23 46 57
EditWindowControl Panel 24 27-28 59
Edit Window Display Area 58
Edit Window Title Bar 57
Empty Space 88
Energy 9 18 86-87 145-147
Energy Ailocation 99
Energy Investment 98
Erosion 95 128 160
Eukaryotes 136 179 205
EventMap 32 73
Event Trigger 64
Evolution 133 206
Evolution Time Scale 103-104
Examine 34 68
Experimental Mode 54
Explosive Upwelling 205
External Heat Engine 160
Extinct Function 63
FiLE MENU 17 48
Fire 65 124
Fish 138 183
Flow Chart 148
Food Chain 186
Forest 66 135
Formation of the Oceans 128
Fossil Fuel 86 99 147
Fossil Fuels 82
Gaia 2-3 16 49
GaiaTheory 2-3 6 196
GAIA WINDOW 29 80
Geologic Time Scale 101-102
Geosphere 49 127-128 205
Geosphere Group 72
GEOSPHERE MODEL CONTROL PANEL 25 37-38 95
Glaciation 169 189
Global Event Map 73
Global Warming 162
Glossary 19 49
GLOSSARY WiNDOW 90
Goal Biomass 89
Goal Population 89
Goto Events 49
GRAPHS 33 91
GRAPHS MENU 25 49 91
Greenhouse Effect 39 96 132 176 205
Greenhouse Gases 205
H20 (water) 129 207
Hadley Cells 173
Hard Game 55
Heat Engine 160
Heat Storage 174
HELPWiNDOW 20 53
Hide/Show Oceans 73
Highest Technology 85
HlSTORY WiNDOW 25 40 81
Homo Erectus 186
Hot Spot 205
Human Evolution 185
Hurricane 64 122
Hydro/Geo 86 98 147
Hydrologic Cycle 175
Hydrosphere 3 151 205
Hydrosphere Group 73
Ice Meteor 63
Impact Theory 187
Industrial Age 143, 205
Industrial Revolution 194-195
Info Box 22, 76-77
Information Age 143, 205
Insolation 169, 205
Internal Heat Engine 163
Iron Age 142, 193, 206
J, K, L
Jungle 66, 135, 206
Land Life Classes 61
Life 18, 75, 133, 178
LIFE CLASSRATIO GRAPH 33, 79
Life Quality 85
Life-forms 49, 135
Lithosphere 3,151, 156, 206
Load Planet 48
Lovelock, James 2-3
Magnetic Field 157
Major Animal 88
Major Daisy 88
Mammals 140, 183, 184
Mantle 155, 206
Map Display Icons 72
MAP WiNDOW 21
Map Window Control Panel 21, 72
Map Window Display Area 71
Map Window Title Bar 71
Mars 56, 115-116
Mass Extinctions 186, 206
Median Technology 85
Medicine 42, 88-99
Meteor 29, 64, 122
Meteor Impact 95
Methane 81, 91, 129, 206
MODELCONTROLPANELS 7,17, 37, 46-47, 94
MODELS MENU 25, 49
Moho 155, 206
Mollusk 137, 206
Monolith 63, 144, 206
Move 36, 67
Moving Tool 67
Mutation Rate 97, 134
N2 91, 129, 206
N2 Generator 62, 206
Nanotech Age 143, 206
Nemesis 187, 206
New Planet 26, 48
NEW PLANET WiNDOW 26, 54
Nitrogen 91, 129, 206
Nuclear Energy 86, 99, 146
Nucleic Acids 178
o2 81, 91, 129, 207
Ocean Currents 74, 131
Ocean Temperature 32, 73
Oceanic Transport 174
Oceans 158, 168
OPTIONS MENU 37, 49
Origin of Life 178
Origin of the Earth 153
Oxygen 81, 91, 129, 207
Oxygenator 62, 207
Ozone Layer 171
Philosophy 42, 88, 99
Photosynthesis 180, 207
Place Life 34, 59-60, 93
Plague 65, 82, 125
> 210 <
Planet Formation 127
Planetary Cooling 127
PlantBiome 35 65
Plate Tectonics 157 163-164 207
Play Data Song 51
Poking Eyes 80
Pollution 82 125
Population 81 85 89
Primordial Soup 178
Prokaryotes 136 179
Radiation 1 23
Fainfall 74 81 96
Random Planet 55
Relative Date 27 51
REPORT WINDOW 31
Reproduction Rate 97
Reptiles 139 183
Rock 66 134
Save As 48
Save Options + Windows 50
Save Planet 48
Scenarios 7 109-117
Science 42 88 99
Sea Life Classes 61
Sea Temperature 81
Sentlent Type 85
Set Altitude 28 66
Simulatlon Flow Chart 148
Software Toy 4
Solar Heating 171
Solar Input 96 131
Solar Nebula Hypothesis 153
Solar Radiation 171
Solar/Wind 86 98 147
Sound Effects 50
SPEED MENU 51
Stag Nation 56 111
Stone Age 142 190 207
Surface Albedo 96 132 207
Surface Currents 174
Swamp 66 135 207
System Simulatlons 5
TECHNOLOGYRATIO GRAPH 33 79 93
Technology Time Scale 107-108
Temperate Grasslands 66 135
Terraln Map 32 72
Thermal Tolerance 97
Tidal Wave 64 122
Tlme Scales 17 100-108
Tone Monitor 51
Tool Icons 59
Transform Margin 166
TriggeringEvents 29-30 64
TUTORIAL WINDOW 24 90
UpdateBackground 37 50
Vaporator 63 207
Venus 56 117
Vlability 83-84 89
Volcanic Actlvity 95 128
Volcano 30 64 123 164 207
War 82 125
WaterVapor 129 207
WINDOWSMENU 29 48
> 211 <
PLANET SPECIFICATION SHEET:-
Year (Earth Days).................................87.97
Day (Earth Hours)....................................59
Density (water = 1).................................5.5
Surface Gravity (Earth = 1)........................ .38
Mass (x10,000,000,000,000)........................ .332
Distance From Sun (Million km).....................57.9
Distance From Sun (Million Miles).................35.99
Orbital Velocity (km/sec).........................47.73
Year (Earth Days).................................224.7
Day (Earth Hours)...................................243
Average Temperature (degrees C).....................477
Density (Water = 1)................................5.24
Surface Gravity (Earth = 1)......................... .9
Volume (Earth = 1)................................. .88
Distance From Sun (Million km)....................108.2
Distance From Sun (Million Miles).................67.24
Orbital Velocity (km/sec)............................35
Year (Earth Days)...................................687
Day (Earth Hours)...............................24h 37m
Average Temperature (Degrees C).....................-53
Density (Water = 1)................................3.94
Surface Gravity (Earth = 1)........................ .38
Mass (10,000,000,000,000) Gigatons................ .642
Volume (Earth = 1)................................. .15
Distance From Sun (Million km)....................227.9
Distance from Sun (Million Miles)................141.73
Orbital Velocity (km/sec)..........................24.1
Year (Earth Days)..............................10760.56
Day (Earth Hours)...............................10h 14m
Density (Water = 1).................................0.7
Surface Gravity (Earth = 1).........................1.3
Mass (10,000,000,000,000) Giagtons).................575
Distance From Sun (Million km)...................1427.7
Distance From Sun (Million Miles.)...............887.13
Year (EArth Days)..............................306854.9
DAy (Earth Hours)...............................10h 49m
Density (Water = 1).................................1.3
Surface Gravity (Earth = 1)........................0.93
Mass (X 10,000,000,000,000 Gigatons)...............88.2
Distance from Sun (Million Km)...................2870.5
Distance from Sun (Million miles)................1783.7
Orbital Velocity (km/sec)..........................6.36
Year (Earth Days)...............................60191.2
Day (Earth Hours)...............................15h 48m
Density (WAter = 1).................................1.8
Mass (X 10,000,000,000,000 gigatons).............103.89
Distance from Sun (Km)...........................4498.8
Distance from Sun (Miles)........................2795.5
Orbital Velocity (km/sec)..........................4.77
Year (Earth Days)...............................90474.9
Day (Earth Hours)..............................159h 19m
Density (Water = 1)...............................0.7(?)
Surface Gravity...................................0.03 (?)
Mass (X 10,000,000,000,000 Gigatons)..............0.06
Distance From Sun..(Million KM).................5902.8
Distance from Sun (Million Miles)...............3667.9