There's beautiful symmetry in the fact that our lineage can be traced back to the stars. By that, we mean stars and people are made of the same stuff — starstuff — and that our existence wouldn't be possible if stars did not fuse primordial elements (like hydrogen and helium) into heavier ones. As Carl Sagan once pointed out, said elements went on to make up the nitrogen in our DNA, the calcium in our teeth, the iron in our blood, and the carbon that bonds these elements together.
Naturally, given the fact that stars can live for millions, even billions of years, accumulating a large amount of heavy elements should take a lot of time. But roughly how many stars had to die for us to live?
In a new video, Fraser Cain (from 'UniverseToday') tackles the question head-on.