There is no fundamental law of nature discovered so far that would stop us from colonizing other worlds. The problems seem to be related to either a) financial

There is no fundamental law of nature discovered so far that would stop us from colonizing other worlds. The problems seem to be related to either a) financial b) psychological c) engineering or d) physiological domains. Once a human society learns how to thrive on a single colony there is no reason it could not spread across the planet. You are right of course that interplanetary colonization is completely different thing from the European colonization of Americas. But it's quite silly to think it is childish. The thing is, we don't know what it would be like. So you could be proven right ("what a silly idea this was, let's go home") or you could be proven wrong (it turns out humans can thrive elsewhere and we become an interplanetary species).