One in Five Stars Has Earth-sized Planet in Habitable Zone

[arcane1]

41. Where did this free energy come from?

Look at it this way: if a plague had wiped out Europe in 1491, and the "new" world was left alone, would North Americans have rockets and nuclear power today? No. It's not that they were less intelligent, it's that their culture was not based on industrial growth.

Or, if modern humans, descended from around 500 individuals, had died in a flood, then the earth today would have Neanderthals doing pretty much the same thing they always did. Intelligence and self awareness, even to our extreme, doesn't guarantee iron smelting and space travel.