Let's face it, that's really what keeps science ticking. Rich Klein mentioned we don't know about some aspects about the work that he was talking on. And this is really what fuels science, searching for answers, understanding things that we don't know. Science is self-correcting, which is one of its wonderful attributes. We can correct things that were in error in the past, we can reform hypotheses, make them more robust.
Science has a wonderful self-correcting aspect.
What I'll be saying today, maybe in a year or two it will not be believed or thought to be as true, or, we may actually find some answers for some of the suggestions that have come up. Let's go back again to these origin of the Earth, 4.6 billion years ago. Planetesimals have accumulated, gravitationally started collapsing, compression, heat, a lot of radioactivity. Soon after, in the earliest history of the Earth after these cold planetesimals collected, the earth basically melted. It was a molten earth and then it cooled off.