Okay, I'll bring my version of the space activity on the table, and take look at the answer present, here, their arguments, so as try to fish a little for the answer OP asks.
- Figure out how colonies work --- @Graham
- By definition, an isolated colony has to be self-supporting, otherwise it dies.
This is very good advice and a very good statement, unfortunately, the rest is so so.
Yes, fundamentals are derived from fundamentals, and what are the fundamental differences between living on a planet or in space.
Space, volume, surface
One of such fundamentals is - space is big, and a planet is small, and that has consequences.
As an example, if done right it can be a difference of energy available as per person or as per colony basis. Today on the planet we use around 6kWh per day per person, on average - it covers industries, it covers gas/energy used on transportation, so its averages on a scale of countries. So much energy per person is enough to run everything we know, observe, and is not enough for anything we do not do - proper recycling as an example.
- 6kWh per human per day is more like industrial countries average, worldwide is something around 2.4kWh (based on this if we multiply and divide)
In space for a colony size of the same 7-8-9-10 billion people, let's take 10 billion and 10kWh per day per human. In space, it means some solar energy production facility a square of 126km by 126km if the efficiency of energy conversion is 20%
Everyone can have different opinions on feasibility, but if we assume it possible, both for earth and space - and just focus for this case on the placement problem - in space putting this structure, one-piece - not a big problem, space - you have it, unlimited one. On a planet, or more specifically on a planet like earth atm, making the installation in one place, one can say Sahara, because they imagine it all 9 million square km of sand - which is not true. I mean picking a place for the thing isn't that easy and multiple factors have to be considered - not only for what and how energy is transported, but how materials are transported, how to service the thing, borders, ecologies, etc etc. One can say it is not feasible to build such a big thing in space, I can argue about it, but it is for sure not feasible to place the thing on the planet.
What about bigger stuff - a million square km? a billion square km? - in space, you name a number and if you have enough materials and capacities to build in space - you can have it, it is just a matter of - do you need it or not. On a planet - eeh, you may need it, but you can't have it for a list of reasons.
- and this is how you have enough materials to build stuff in space, not only this but it is one of the options
As a side note on space
- It is funny to look at those planet belters, which barely scavenge for piny amounts of energy for their survivial on a planet, from oil wells they say, and do not know what to do once it runs out, I laughed my ass off when I heard of it - @Some unknown O'Neil hab №9233 citizen
Initially, I was willing to go through all space is poor arguments, food is bad and such, but unfortunately, I have no time for it atm. But space having worse conditions for living is a very popular misconception. Space is potentially the most prosperous place one can live in. If you live in a society where the average energy is 6kWh per person per day - everything you see, everything you have, everything you use is the result made on this energy budget. And for space live this energy budget can easily be 100x, for your personal needs, with space induced energy consumption overhead to be covered by another patch of solar "panels" in space.
And who is poor then? Isn't it you? People of the planet who can't afford 2x energy expenses to have 100% trash recycling, for trash you produce and you scatter it all over the place - what are you so proud of?
I do pick recycling as a marker because it on its own isn't a problem, we can do it, we have technologies, we have the knowledge, it is not that much different or more sophisticated than getting a few grams of gold dust from a tonne of rocks. We could be doing it for a long time ago - but we can't afford these extra energy expenses - it is all because we are energy-poor on this planet. And it reflects in many things we do and in the ways we do.
- .... you can't get to own the entire colony: if you pretend to own it, enough of people disagree with your ownership ... --- @Adrian Colomitchi
This is another fine example of a planet guy thinking his planet things. Diving too deep in it is probably too much, but - why one should not own a colony, be our host, if we like it - we will live in it, if not, we kiss goodbye and make our own colonies and move to a better one.
On this planet, there are about 200 countries that are members of the UN. Some are big, some are small, some are prosperous some are not. But they all share one property, common for them all - they can't change their neighbors.
Imagine 10'000 space habitats, in space - small big, more successful, or less successful. They all can share the technologies, so it may not matter in terms of technologies available for them, for reasons out of the scope of the answer, but it starts as Graham said - "be self-sufficient, or die". Being self-sufficient in space is a necessity, and some may see it as a curse, but it is also a blessing.
So imagine all those space habs - besides technologies they share the capability to move those space habitats between orbits. yes, maybe not the fastest process, maybe not the easiest one, but some people here even think about how to launch space habitats in an interstellar voyage, so moving a few thousand km's or a million km, or changing orbit is a less ambitious task.
But it also means you can choose who your neighbors are. Being a neighbor in space may have a bit different taste in some aspects, then on a planet, but in essence, it is the same. So people aka colonies may cluster based on their good relationships. But also, if things develop not like as expected, they can leave the union, physically if required, taking their home with them.
Same on a smaller scale, and differently is true for space habitat itself, it isn't a big deal to build a second one if some community has 50/50 split - they can "divorce" without anyone losing too much in the process.
- surprisingly it may work even for One Man army, at least be quite close to it.
Techo bubble, space survival requires it .... but so as the planet does
It is true, for only one planet, maybe only one in the galaxy - one can live using a rock as a pillow and covering himself with a leaf. Our ancestors did so and we can imagine that this is a low-tech level of life. (do not be fooled, however, it still requires plenty of knowledge, or death is imminent)
And when we look at space, we see, those who do, that in space you do not have the so-called "safety net", and technology is what keeps you on-float and alive.
And some do point on that valid difference and say - see, that is why space sucks and who one would live there at all, here on earth we are so safe because of ...
- At least it was what they were saying in the pre-corona era, I mean some flaws are more obvious today, than a few years ago, but it is not the point.
Living like our great great great ancestors - eating bananas and covering ourselves with nothing - is now a luxury that not many can afford, and honestly is way less attractive in reality. On the planet we already depend heavily on the technologies we use - we depend on it for everything, maybe besides air, the rest is exactly like in space - if it breaks we start to die. On other planets - there is no difference with space, but limitations and problems of a planet 10x and up.
If we do the same for the planet, imagining like break down of a toilet bring down the whole station and everything there, if we do the same for the planet, for 90% of people outcome as of today, will be not less grim. But all that are just fantasies, good for a horror story, but which have nothing to do with how things are made, how things are designed. The only space thing most planeters can imagine is ISS, but transferring all the properties and problems of ISS to normal big colony installation, space habitat, is like comparing a tiny boat with a luxury cruiser - there is some similarity, they all float, but that pretty much where it ends and differences being.
I mean, Graham's advice - Figure out how colonies work - is very good.
Just a random one or the scale of things
It is part of big space thinking and that recycling.
Let's take this one - planeters are worrying about their planet getting a bit warmer - okay understandable, indeed the thing works out of spec they are used to, and it may have some negative and positive consequences, so for sure it is a thing to think about how to avoid bad and get the good stuff, it understandable. But then, what are they doing, what are solutions - planeters run around like headless chickens, instead of figuring out how to build a sun umbrella for the planet and earn additional benefits along the way. They like kinds in a box, who haven't seen the world.
Scale, the scale of problems people can take care of, people in space can take care of planetary problems - they have sufficient resources and opportunities, but when we look for a solution for planetary-scale problems within the planetary capacities - it indeed turns out to be a problem which yields nothing for decades over decades.
A guy in space can take the challenge because he can, the other question is just - is it interesting or not. For planet guys - they can't, they are limited in everything everywhere - they have to survive and do not break additional stuff, and thus it a different choice a different perspective for them. They are like ants, who see nothing but their anthill.
I'll wrap it here, even if there are more. But indeed first of all You have to understand the question - Why space? - so as the answer to it, then you can start getting some answers on differences it has.
here, real-world example - what planeters do - they laugh and downvote this, but for a space guy, it can be a history of how it was done, how they did come into existence, to what they should be grateful, in a similar way how planeters should be grateful to their ape ancestors.
I do not expect it to be some significant division line, no more that difference between city and village folks, I mean everyone is good and useful it just village is all they have soo, ...
Earth as a planet is an exclusive thing, it is very important for people, no matter are they in space or on the planet - it is a biological library and many things as consequence.
And people living on Earth are the library keepers if they are.
But mars guys - who wish to make second earth from the Mars planet - that is a, hmmm, to be polite, not very smart. You can be anything but that, you can be for research there, which is very important and may require millions and millions of people, hundred million people or more, or be a tourist there or anyone else besides those who wish to make second earth from the Mars planet.
About other planet colonies, there is no point in comparing them because of the absence of them for multiple reasons including practical ones. And if we compare space habs with the origin, then mental difference does not matter, people on Earth - they are there for keeping the library, for keeping the origin home working properly and they should have a proper mentality for that task. And if they aren't happy, welcome to space - gates are always open, for the land of opportunities, open at least for the next thousand years.