Nucleosynthesis

This mini-series of shorts explains how human beings are made of interstellar particles: The atoms in our body—apart from the hydrogen—are all made of stars … by stellar nucleosynthesis. Nuclear reactions in their cores cause the stars on the main sequence to shine; off the main sequence, the energy comes from nuclear reactions in a shell—sometimes in more than one shell—around the core. There are several different nuclear reaction cycles or processes, but the end result is the fusion of hydrogen and helium to produce carbon, nitrogen, oxygen, … and the iron group. In the red giant phase of a star's life, much of this matter ends up in the interstellar medium … and one day in our human bodies.