Are we from the stars?
We are all made up of atoms. The number of protons in the nucleus of an atom tells us its name, or element, and there are 92 naturally occurring elements.
These elements are arranged in the periodic table in order of increasing number of protons. Many elements of the periodic table are necessary to build a human, and where do these elements come from? Well, while we acquire the elements we need to grow and flourish by eating, what is the source of elements for the plants or even for the soil for that matter? The story of how the elements were made dates back to an age of about a few hundred thousand years after the Big Bang. At these early times the elements of hydrogen and helium formed for the first time (and trace amounts of lithium and beryllium too). While this ‘birthday’ of the creation of the first two elements must have been an exciting day, at the same time hydrogen and helium do not give enough variety for life to emerge as we know it with its complicated chemistry. Even if it was not possible for complex life to form out of such simple ingredients, it was possible for stars to form out of this primordial hydrogen and helium. These stars, like all stars, are most simply described as factories with one focus for the vast majority of their lives: to create the element helium out of the element hydrogen. The most massive stars add richness to the story by making also elements other than helium later in life, thereby producing the first examples of the elements that we are made of, like carbon, oxygen, nitrogen, and so on. The most massive stars also all end their lives in giant explosions. In these explosions all the new elements are dispersed across vast distances in space. Eventually, some of these new elements eventually make their way to the massive cloud of gas and dust that was to become what we now call the Sun and the Earth. In sum, nearly all of the elements of the periodic table were made in stars, and we are made from many elements of the periodic table. So, in a sense yes, we are from the stars!
