When world-building, the effects an environment has on a culture is fairly profound. For example, if the world has a fairly small star, the planet has to be fairly close to this sun in order to even be habitable. However, if the star is not particularly massive (a small star generally wouldn’t be), then the habitable range in that solar system could mean your planet is tidal locked. What happens then? Any species on the planet would exist in the shadows of this sun, for the parts of the planet that face it directly would be far too hot to allow for much life. Vice versa, the dark side would be too cold, since if it’s tidal locked, that side wouldn’t see the sun ever. So you have these twilight regions which could support life, but sentient life? That’s debatable.
So too small of a star won’t work. Too hot of a star will cause different problems; however, the habitable zone would be much further out, allowing for the planet to orbit and rotate on its axis freely. A strong magnetic field and a thick atmosphere would be needed in order to combat the solar wind and energy from the star itself. Water is also necessary for a planet, as well as plate tectonics, which allows for the movement of continents and magma. If a world is too seismically active, then volcanoes and earthquakes would be causing extinctions far too often, and life wouldn’t progress far beyond bacteria or simple multi-cell organisms.
As you can see, there’s a lot to consider if you’re going to build the planet and solar system itself. Once you have a star and a planet, you need to consider the effects moons, nearby planets, and asteroids may have on this planet. If it has more than one moon – especially if they’re fairly large moons – this means the planet will experience very high tidal effects. Tides in the ocean will be several orders of magnitude stronger than our planet’s, and this will also cause stress on the planet’s crust as well as its oceans. This will effect the landscape of the continents as well as the weather of your planet. If there is a large gas giant nearby, this also could provide stress on the planet and it’s moons, which could effect the weather, landscape, and so forth. If you want to go in depth, then I highly suggest World building: Science Fiction Writing by Stephen Gillett. This book is great at discussing how these various factors can influence your planet.
What about the effects of all of this on the cultures of the planet?
Take a look at someone who lives in a colder region as compared to a hotter region of the planet. The cold region focuses more on staying warm, conserving energy, building to keep out the often severe weather, and so their technology will differ from a society that is at the equator. A society at the equator may experience heavy rains or maybe droughts, but they don’t have the extreme temperatures the north has, so their technology would focus more on staying cool, building to maximize on breezes, and so forth.
A society deep inland will focus more on transportation over land, on how to navigate mountain ranges or desserts, and how to find water supplies. Inland societies will probably exist by rivers and/or lakes, to maximize on the fresh water supply and ability to transport goods on that river and/or lake. It’s generally not a good idea to build a town or city far from a source of water, for that’ll be one of the most important commodities of a civilization.
For a society by the ocean, they may also build their city at the mouth of a river or at a place that provides access to the ocean and has a fresh water lake nearby. If the society is human, the human body cannot metabolize sea water all that well, and so fresh water is necessary for survival. However, a society on the ocean will focus on navies, maritime transportation, and buildings that can weather hurricanes and other storms from the sea.
A society in a rainforest could capitalize on buildings within the trees themselves, on creating pathways through the trees, and so forth. Each different geographical area of the planet could affect a society in different ways depending on the geography and flora and fauna of the area.
Also, the myths of a society often derives from its location and from what the society sees in the sky. Take a look at the mythology of Earth and examine how it relates to the land and the sky seen by the people who created those myths. It’s these sorts of things you should consider as you build your societies.
If weather is harsh enough, it might drive the society to live more underground to avoid the worst of the storms; in this case, the society would focus more on cave systems, underground lakes and rivers, and building ways to secure their cities and towns in the case of earthquakes. They’d have to account for the lack of light since an underground place wouldn’t have sunlight filtering through to illuminate the area during the day. Also, there would have to be ways to allow fresh air (especially oxygen necessary for breathing) to circulate.
Plant and animal life could affect the society as well. Perhaps the planet has a lighter gravity than Earth; if so, then plants could grow larger if they had the right set of nutrients in the ground and atmosphere. This could allow for taller people; however, if these people were to fly to a planet with heavier gravity, they’d find it hard to walk and their body would struggle to keep itself going under the unusually heavy pressure of the foreign planet. For a person that was born on the planet with the heavier gravity, they’d be able to jump higher on the planet with the lighter gravity, and they’re weight would be much less; however, their body would still suffer as their bones and muscles atrophy a bit to account for the new environment. Upon their return to their heavier gravity world, they’d be fairly sick, forced into months of recovery. This concept is actually seen on Earth for astronauts that spend a significant time in space; no matter how much they may exercise in space or eat healthy foods, the super low gravity doesn’t exert the pressure their bodies are used to, and thus their bones and muscles atrophy due to this. Nearly all the astronauts that have been up in space for several months at a time, have to have a period of recovery once they return to Earth.
Speaking of months, how time is divided will also differ for societies. Some may base it off the lunar cycle, and some may use the solar cycle. However, how long a year is depends on the orbit of the planet. The length of day depends on the rotation of the planet, and if it has seasons depends on the tilt of the planet’s axis. These can all affect a society also.
There’s lots more to consider, but I just wanted to highlight some ideas on how the environment can affect a civilization.
Thoughts?