More Than Star Dust, We're Made of the Big Bang Itself | Big Think

The work of stellar archaeology really goes to the heart of the ‘we are stardust’ and ‘we are children of the stars’ statement. You’ve probably heard it all, but what does it actually mean? We are mostly made; all humans and all life forms that we know of are made mostly of carbon and a bunch of other elements, but in much lesser quantities. Where does this carbon come from?

Well, you could say it comes from the Earth, and yes, that is true. But how did it get into the Earth, right? And so that is where astronomy comes in because there are multiple so-called nuclear synthesis processes that create elements, heavy elements. They fuse lighter ones into heavier ones, starting with hydrogen. Four hydrogen atoms come together and fuse into a helium atom. And if you throw three helium atoms together, you get a carbon nucleus.

And this is how carbon is created, and we are establishing how much carbon was created at various times in the universe, through which processes, in which types of stars, and what evolutionary phases of the stars this all happens. And so this is how we can piece together the chemical evolution of the universe; that is really the basis for any biological evolution to take place on Earth.

And I find it really exciting to go back and really look at the constituents of life separately. We have studies not just on carbon but also nitrogen, phosphorus, sulfur, oxygen, iron, and all the different elements through our work in stellar archaeology. And actually, if you come to think about it, the body is not just made of carbon but also a lot of water.

And there is hydrogen and oxygen in the water, and well, we know oxygen also comes from the stars. You add another helium nucleus to a carbon nucleus, and you get an oxygen nucleus. But the water, the hydrogen, that’s just protons. They were all formed in the Big Bang. So we actually carry about ten percent of our body weight in us that is Big Bang material.

The protons were all recycled numerous times throughout the stars, but the actual protons were made in the hot Big Bang when all the subatomic particles actually came together and formed protons and neutrons. And so that we are not just children of the stars. Actually, we are also children of the Big Bang.

And I think it’s really nice once in a while to reflect on that and really realize how much we are actually connected to the cosmos.