OUR BODIES NOW CONTAIN millions more atoms than when our life started. Where have these atoms come from? In this article I will show how they have come, ultimately, from the stars (yes, really). You are made of star stuff!

What kinds of atoms are found in our bodies? We are largely water. Water consists of hydrogen and oxygen atoms, bound together – two hydrogen and one oxygen atom per water molecule. Besides water there are calcium atoms in our bones, iron atoms making our blood red, and lots of carbon atoms in our tissues. There are also small, vital amounts of many other atoms, preserving, for example, our mental health. All these atoms (but especially carbon) can be combined in many different configurations to make many different molecules, and we will find these various molecular configurations in the different parts of our bodies. There are too many different atoms in our bodies for me to track them all, but if we can understand where the calcium, carbon, hydrogen, iron and oxygen came from in the first place, and how they got to be in our bodies, then we will understand the big picture.