[AngryData]

What is the benefit of living on Mars, rather than a space based habitat that can attach to and mine asteroids or small moons for extra resources? Living in a "large" gravity well seems like all negatives to me in terms of expansion and resource extraction.

[tsimionescu]

To be fair, living in 0g is even less plausible than living in 0.3g long term. In particular, there is a good chance that animals can't reproduce in 0g - those that have been tried have definitely been unable (including insects and chicken - there is still a chance mammals could).

[AngryData]

You can spin for artificial gravity out in space though, which would be relatively simple to do provided you had any sort of space manufacturing capabilities.

[tsimionescu]

It's not actually simple at all. You need a massive station to actually spin in such a way that humans don't get dizzy just by crouching (you need the acceleration to be almost constant for the ~1.5m difference between a person lying down and a person standing up). You also require lots of fuel to actually maintain this constant acceleration. The larger everything is, the more problems you have with shielding and energy expenditure. Any malfunction of the spinning mechanism is likely to be catastrophic, as suddenly losing 'gravity' is can easily cause massive damage if people are living without care for this constant possibility.

Not to mention, this would not feel like living on Earth - there are many effects of spinning that do not approximate gravity well, such as the fact that forces acting on you depend on the direction of your movement relative to the direction of spin.