Blame me for being a madmen, but honestly, if we actually had a population problem, i'd send these peoples out on space travel anyway regardless of the radiation issues. If they make it, we get a new colony. If they don't, we get rid of some people on our planet.

On a side note.

Also, if we could build a big enough spaceship, whether it's slow or not would be irrelevant, because in a big enough spaceship where we can develop a self-sustaining ecosystem, with corresponding birth rates to meet the death rates in space, mankind will reach where they are meant to reach anyway. Though the people who reach our said potential colony won't be the same as the person we send up, but so long as somebody gets there, humankind gets a point.

I beg to differ. For as much as we love our home, it's a galactic question of whether we should put all our eggs in one basket. Yes, we may become more efficient, but what stops us from being more efficient everywhere? Your notion of money is actually irrelevant in the view of humanity, as money is merely our way of putting a value of things. I believe if we somehow encounter aliens, they'd be bamboozled with our concept of money.