...and you're on record for that now. The problem here is that my answer has to be more involved than I've been able or willing to address this past week. I had one of the most severe colds I've had in my life and I wonder if it was H1N1. I'm still not completly through it but for the most part I am.
To answer your question seriously for the moment, setting the population of the rest of the universe aside, you're working on a different set of assumptions. Humanity at this point has no choice but to increase the application of technology to support a higher population density becuase the alternative is to NOT provide it-- and to do that implies killing people-- letting them die. The fear mongering about "over population" of the planet is a political effort-- intended to prevent the loss of political control by current power holders who I'm told represent a conspiracy. It's difficult to discuss issues with one hand tied behind my back as it is here in CF.
So the question of population coming into focus here. And you raise the image of stepping on babies and overcrowding and nowhere to escape to enjoy Walden's Pond. But this is absurd because the entire population of the world, according to some accounts could live comfortable in an area the size of Texas. Given a high enough technology, human population can live MORE comfortably in higher densities and we'll still have lots of "natural parkland" to "enjoy". I'll try to address the numbers in coming weeks.
Anonymous Hero pointed out that higher technologies in China are working to slow down the rate of increase of population growth but that's just one element of a bigger aspect of S curves. [+
] I like S-curves and I think it applies to human populations given particular technology levels described by energy flux density. But Fd will likely balk at that term... pretending it's not real or something... when it is. But this is the crux of the situation.
There are publications that we should refer to when discussing this... like Limits to Growth... which represents a hoax. The technologies change as we grow-- higher energy throughput involved in high speed rail for example compared to cars or trucks-- or planes-- becomes a nataral element of the higher Earth population future. The current power holders don't want that because they don't want the Third World coming up in the world. It's a political issue.
Well, this deserves more attention. But you don't have to go to Mars to relieve the population on Earth-- you have to go to Mars to challange society to develop new technologies that can also be applied on Earth to increase the health potential population on Earth. More healthy happy people is an end in and of itself in this world view... and it's actually a situation that cannot be stopped without intentionally genocidal policies. We're at a take off point in civilization-- and that's why we MUST apply 4th gen nuclear power now. It's not a problem. We are a species that MUST create new technologies-- which in turn by defintion increase the potential population density of our species.