We are made of star stuff
“The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of star stuff.”
These are the words of Carl Sagan, and today we learned exactly what he meant by those words. The world around us, you, me, and everything in between is made up of atoms. Atoms are the building blocks of our world, and they come in all sorts of “flavors”. We call these flavors “elements”, which includes the likes of Carbon, Oxygen, Iron, Sodium, and many more. But these elements didn’t always exist! Scientist theorize that originally, after the big bang, there were only three elements in existence: Hydrogen, Helium, and a bit of Lithium. These atoms, subject to gravity, collected together in the vastness of space, packing on top of themselves ever and ever so tightly as gravity collected more and more... until the forces upon them became so great that they got crushed together into brand new elements. At this point, a brand new star is born! Its core is a fusion reactor, fusing and combining elemental Hydrogen and Helium into heavier elements and then (if the star is massive enough) fusing those! Until a point, after which the star may explode in a supernova! Creating even more heavy elements in an incredible burst of energy that scatters its matter far and wide! It is from this kind of explosion that advanced elements like those we interact and exist as are spread across the cosmos to become the atoms that make up planets! And everything on planets, including you, me, animals, plants, rocks, water, clouds, metals, gases, etc. It’s truly an amazing concept to grok. We ARE the material of the universe, manifest as thinking beings capable of conceiving of itself. We are star stuff, beautiful beautiful star stuff.
For our activity, we collected some atoms that were specifically NOT forged from the heart of a star: Hydrogen! Using a process called electrolysis, we electrically separated water into its constituent atoms: Oxygen and Hydrogen. The Oxygen recombined with the steel terminal of the battery lead used, creating iron oxide or rust, but the Hydrogen bubbled off the other terminal which we collected in a test tube. To conclude our experiment, we released the gas near an open flame which produces a satisfying flaming *POP!*
This week Reactions is taking a look at some space science and chemistry. We're looking where the elements came from. As Carl Sagan famously said, "We are made of star stuff." Whoa. It's a mind-boggling thought, but what exactly did he mean?