'We're all made out of stardust' simply means that all of the higher chemical elements in our body were formed through the fission processes occuring in stars/supernovae.
During the big bang, energies and pressures were only high enough to have created the first few light elements, mainly hydrogen and helium (and they still account for the vast majority of particles in the current universe). Stars like our sun are essentially giant balls of hydrogen and helium (our sun gets all it's fuel from burning hydrogen), but stars larger than our own, once they've burnt all their low molecular weight fuel, explode as supernovae. The gravity sucks the matter into a small ball, creating immense heat and pressure which forces protons and neutrons together, forming higher molecular weight elements such as carbon and oxygen. The shockwave which follows such an explosion propels these elements out into space, where they can combine to make things like planets - and people.
To put it simply, the high molecular weight elements in our bodies - everything from the phosphorus in our DNA molecules to the iron in our haemoglobin, was produced from stars burning and exploding. Without these stars, we couldn't exist. We are all made of star dust.
During the big bang, energies and pressures were only high enough to have created the first few light elements, mainly hydrogen and helium (and they still account for the vast majority of particles in the current universe). Stars like our sun are essentially giant balls of hydrogen and helium (our sun gets all it's fuel from burning hydrogen), but stars larger than our own, once they've burnt all their low molecular weight fuel, explode as supernovae. The gravity sucks the matter into a small ball, creating immense heat and pressure which forces protons and neutrons together, forming higher molecular weight elements such as carbon and oxygen. The shockwave which follows such an explosion propels these elements out into space, where they can combine to make things like planets - and people.
To put it simply, the high molecular weight elements in our bodies - everything from the phosphorus in our DNA molecules to the iron in our haemoglobin, was produced from stars burning and exploding. Without these stars, we couldn't exist. We are all made of star dust.
