Where did Earth's Iron core come from and how did the mantle become molten?

So, you're saying here, "Aristotle "knew" the earth was very old because he jumped to a conclusion and "believed" it was eternal for a philosophical reason."He didn't "know" anything, he "believed" something. It turns out he was wrong on the length fo earth's existence, but correct, for incorrect reasons, that the earth is long.I could have two friends and one says, "The next car that comes down the road will be red." The next one says "The next car that comes down the road will not be red." One of my friends will be right, but neither of them "knew" the correct answer.