[frgewut]

Of course there are limits (e.g. mass of human population will never exceed Earth's mass etc). But what these limits are?

For example we can double the size of human economy by colonizing Mars. This sounds very achievable to me.

[crimsonalucard]

Limits are never reached, they are only approached asymptotically. Thus most people will never observe a limit in human innovation in their lifetimes, instead they will only observe an eternal slow down as innovation spends forever converging with the limit. This makes it impossible to prove (or disprove) that there is a limit to technology. One can only make an educated guess.

Have we reached the limits of human colonization? Are we approaching a limit? Mars may be possible, but it is an order of magnitude harder than colonizing the Americas. Colonizing the west happened only a couple years after Columbus discovered the new world. Mars was discovered 3 centuries ago... are we at a limit? How long will it take to colonize the nearest star?