I don't know what you know about geology orchemistry, but
                  a large majority of the world is composed of silicate.  
                  Doesn't mean much to anyone, and really doesn’t pertain
                  to day-to-day life.  But one day, while sitting in
                  Geochemistry, my professor placed a different rock in  front
                  of everyone and told us our midterm assignment was to
                  write a paper telling him what our world would be like if
silicate was replaced by the predominate mineral in that rock.  A few
weeks later, and with five front and back pages of mathematical
equations just to determine what the oceans would be like, I wondered
how this assignment would ever affect me in real life.  Little did I know,
this one assignment would be the key to building my Sci-Fi world in my
romance novel.

It’s the little things that make the world
so believable.  No matter what I say here,
guaranteed you’ll find some resource
that says you have to do this, or do that
first.  Believe it or not, most of the things
are common sense; it’s putting them
together that is the hard part.  This is
just a general overview to get you started.
You can delve into each aspect far more
than I’m going to here.  

When I sat down to build my alternate solar system with multiple planets,
multiple suns, and multiple species, immediately that dreaded
geochemistry assignment came to mind.  I’ll admit I didn’t do the math.  I
mean, who would want to when it takes forever just to figure out the
chemical make up of the ocean.  Then there’s the life forms, weather, etc.,
etc., - yup, I skipped that part.  But the correlations stuck and I couldn’t
ignore them. Basically, what that assignment taught me was that
everything affects everything.  Sounds very vague, but it’s true.  Everything
from the age of the sun to the thickness of your plants leaves plays an
important part in building a world from the ground up.  

The first thing you need to look at when starting from scratch is the lay
out of your solar system.  Ask yourself, what kind of sun do you have?  
How old is it?  How far is your planet from it?  What size is it?  Is the
orbit of your planet long?  Short?  Elliptical?  Boring, I know.  But all of
these factors will limit the kind of life your world can support.  They’ll
affect the seasons (i.e. crop growth, etc.), length of days and years, and over
all environments.

Now for the second step – your planet.  Chances are, if you have life, you
have plate tectonics.  The reason I say this is that plate tectonics acts as a
renewal, of sorts.  While eruptions are destructive, they spread nutrients
plants and animals need.  It forms new land masses which provide
additional areas for your species to spread out.  Mountains, islands –
plate tectonics can build any number of things.  Your race can even use
geothermal activity as an energy source if they know how.  Still, if your
planet is too young, nothing could survive on it due to the constant
production of deadly gases.  Too old and your renewal slows down.

Then there’s the weather.  Weather is important for all kinds of reasons.  If
your planet is too close to the sun it may be too hot to allow for pooled
water.  If that’s the case, what are your inhabitants going to drink?  Too
cold and all the water is ice.  If your planet does have water, the tides
will be affected by the sun and moon.  So how many moons do you have?  
Would multiple moons affect sea level enough to where your inhabitants
couldn’t live within a certain distance to the ocean?  Would tides impede
sea travel during certain times of the year because of a moons orbit?  Or
maybe it wouldn’t, but here’s another problem to throw out at you - how
would your ocean currents affect your world’s environment?  If you look at
a map of the world, most of Europe is at the same latitude as Canada, but
it’s much warmer.  This largely due to the North Atlantic Current.  Does
your planet have a similar situation?  Does your planet even have
multiple types of environments, or just one?  Would you have hurricanes,
like we do coming off the coast of Africa?  As damaging as they are, they
do have benefits, such as relieving drought conditions.  What about rain
in general?  Without rain your mountains wouldn’t get snow and your
water sources wouldn’t recharge.  And you can’t have rain without air
currents, which also effect water currents.

And how does all this affect your inhabitants?  High moisture levels can
be potential breeding grounds for diseases (i.e. - West Nile or something
like it) and would play havoc on electronics.  Structures made of wood
would be susceptible to mold, which could cause housing and health
problems.  All of these are questions you need to ask yourself and no, you
won’t think of everything.  But if you get these basics down, the rest can
develop with your story.

The most important thing in building a world, in my opinion, is setting
the gravitational force, which can be a lot of fun.  Believe it or not,
gravity affects everything.  Sorry to throw some scientific jargon at you, but
here it is.  The average gravitational force of Earth is 9.8 m/s2.  So if you
drop something, ignoring resistance, your objects will increase in speed 22
mph for each second it drops.  If you have a higher gravity, then your
objects will speed up faster, and if you have a lower gravity, they won’t
drop as fast.  What does all this scientific mumbo jumbo mean to your
world?  This means everything from your mountains to your inhabitants
will be affected by your gravity setting and let’s face it; everything is as
lazy as it can get away with, including Mother Nature.  Whatever you are
trying to build will take the path of least resistance.  If your gravitational
force is higher than Earth’s standards, it’s easier to go out than up.  If it’s
lower, why bother spreading out when it can grow as tall as possible?

Even the amount of air on a planet is also directly proportional to your
gravitational force and altitude.  Have any of you traveled from Kansas to
Denver and wondered why you can’t perform the most basic of functions
normally for the first few days?  The reason is that the elevation in
Denver is about 4,000 feet higher than in KC, which makes the air in
Denver thinner and you aren’t use to it.  The same is true going from one
planet to another because not all planets are the same.  The more gravity
you have, the tighter it holds on to air.  See, I told you gravity affects

With less gravity, your tree line, mountains, and trees will be taller
because they don’t have to fight as much to grow.  Higher gravity would
mean your atmosphere won’t extend as high.  If you have a higher
gravitational force however, plants would need a thicker skin to with
stand down.  A thicker skin could prevent normal photosynthesis, so
where do they get food?  Maybe they don’t use photosynthesis but eat
critters they catch like the Venus Fly Trap.  Or maybe the light
wavelengths are different on your planet, allowing for easier
photosynthesis with their skin.  One beautiful part of changing your light
waves of your planet is that you get to change colors and build a world no
one has ever considered before.

While many things can affect light rays, the main things are your sun
and atmosphere.  Light also affects everything, because without light we
wouldn’t have warmth, wouldn’t have plants, and our bodies wouldn’t be
able to produce some chemicals we need for survival.  Different suns omit
different forms of light, depending on their age.  They also produce
different forms of radiation, which could be disastrous to the inhabitants
of your planet.  But since you’ve already set up your sun, we’ll talk about
atmosphere.  You still need oxygen and nitrogen in your environment to
support life - as we know it.  But maybe you don’t want your planet to
have an Ozone layer to keep the air around a planet, but want to use a
shield instead.  The shield would have a different chemical make up
than an O-zone layer, and would bend the sun’s rays as they come in.  
Different chemicals floating in your atmosphere would do the same thing.  
And both would change the color of everything in your world.

Every color of the rainbow hits everything, given the right conditions.  But
different objects reflect certain colors back and absorb the rest.  The colors
you see are the wavelengths reflected.  If you have a shield or certain
chemicals in your atmosphere that don’t allow a color to get through, say
yellow for example, then nothing in your world would be yellow -
however, your planet would look yellow from space because that color is
being reflected back.  Plus, since yellow is a prime color, you’d never have
green because the yellow couldn’t mix with blue.  Makes it kind of
interesting, huh?  So far we’ve just covered the basics and haven’t even
touched on life so we’re going to jump ahead.

Your animals would have to be able to survive in the environment you’ve
created.  If your gravity is high, would animals be able to fly?  These are
things you have to think about.  They’d have to possess strong wings and
still be able to be lifted by air.  Not only that, but the animals on that
planet would be really strong and probably slower, which would mean
their hunting patterns would be different.  On the other hand, if your
gravity was low, imagine how high a kangaroo could jump!  And since
most of your plants would be taller, your animals would have to either be
taller to reach their food source, which they probably would be because
they won’t have to fight as much gravity, or they would need to be able to

Now you can spend years building a world, and so far, we’ve got a good
start.  But we write romance, not Sci-Fi, so we aren’t as concerned about
the ‘what and why’ of the environment, but care more about the ‘who’
and how the environment shaped them.  This brings us right back to
gravity.  See, gravity is a force constantly working against you.  Every time
you lift your arm, you fight gravity.  So, if your characters live on a
stronger gravity planet, they have to fight more resistance to perform basic
functions, like lifting their arm.  Problem is, this would cause them to be
stronger, get bigger, and gravity would have more to pull on, forcing them
to become stronger, and - do you see the never ending cycle here?  But this
doesn’t just affect size; it also includes unconscious functions as well.  
Hair would grow faster, lungs would have to work harder to pull a
breath, and hearts would have to pump with more force just to maintain
normal blood flow.  To do that, your characters’ veins have to be tougher
to handle the force of the blood and all this can pose heath problems,
maybe even early death, especially if they leave their planet to go to
another one that doesn’t have such high gravity.

Just as an example, let’s send Joe from a higher gravity planet where he
lives to a lower gravity planet for vacation.  The second Joe left home he’d
start suffering side affects.  He might become light headed because his
lungs are used to working hard to suck in oxygen.  They’re still working
just as hard as before, but their sucking in less oxygen because the gravity
isn’t clinging to it as hard as it so a) there isn’t as much oxygen, and b)
there isn’t as much resistance.  His heart would still be pumping at the
same rate it has his whole life, but now it has less resistance, so he might
feel like his heart is racing.  Over time, he’ll become used to it, but until
then, he’ll remind you of Superman because what would seem like a light
brush to him could put someone through a wall on a planet with less
gravity.  And imagine being pregnant on a world with increased gravity.  
Depending on the increase, it could be like placing a brick on top of your
stomach!  Not to mention how many times you’d have to go to the
bathroom with something pulling the baby even more down on your

If we did the opposite, took someone from a lower gravity to a higher one.  
It would be the equivalent of putting weights on your wrists and ankles
and going about your day.  Imagine how tired a person would feel if they
had to fight harder to do everything, including breathing.  They might get
headaches, and numerous other health problems, even if everything in
both worlds are the same but the gravity.

These are just a few of the affects gravity would play on your characters.  
Above all, remember this is your world and your environment and
inhabitants can evolve to do what you want, because this is fiction.  This
all sounds really daunting, but in my opinion, it opens up all kinds of
doors to creativity, if you want to take them.  You could basically build
whatever you want; however, you’d have to be able to explain it and the
consequences it would have.  No, you don’t have to go out and do the
math or read a bunch of scientific books.  Just look around you, because
everything is interconnected.  Even slight changes can cause a rippling
effect in other areas you never would have suspected, and most of the
answers are right in front of you, if you’re observant.
Jackie Bannon
Looking for love and stepping into everything else
World Building 101