Every atom in your body came from a star that exploded. And, the atoms in your left hand probably came from a different star than your right hand. It really is the most poetic thing I know about physics: You are all stardust. You couldn't be here, if stars hadn't exploded, because the elements — the carbon, the nitrogen, the oxygen, the iron, all the things that matter for evolution and for life — weren't created at the beginning of time. The stars died so that you could be here today.