Some days you just have to get messy. The Kids Crew kids were feeling cooped up after a rainy week, so we decided to make some alien slime with them. Tiffany started us off with a polymer lesson about atoms and molecules, and how by adding different molecules to each tiny chain, we would give the polymers different properties – a little Borax for bounce, a little glue (polyvinyl acetate) for stretch, a little more Borax to get the gobs to break into blunt jiggly cubes. Everything’s made of molecules,Tiffany said, even you. Jashawn, one of our youngest boys who’s been last to grow out of his wide-eyed wonder, piped up: “I heard we were all made of stardust.”
“Yes of course,” I said, the way teachers do when they’re out of their depth. Despite one astrophysics class in college, the last time I’d thought seriously about the Big Bang was when I was only a few years older than Jashawn is now, and my dad took me to the planetarium in Washington DC for a Girls in Science night. We spent the whole bus ride home poring over a Big Bang book and talking about stars.
Jashawn is right, I told the kids after a few more days and a bit more research. The Big Bang only produced hydrogen and helium; everything else had to be fused together from those initial building blocks at the heart of each new swirling star. Gravity pulled the gassy swirls inward until the cores were dense furnaces burning at 10 million degrees Celsius, hot enough to fuse the hydrogen and helium nuclei into heavier elements. Once the stars had burned through their supplies of hydrogen and helium, those heavier products become the fuel to produce even heavier products, and on and on. The bigger and denser and older the star, the heavier the elements that could be created there. The heavy iron in JaShawn’s blood probably fell to Earth after a dying supernova exploded, scattering its last products across the universe as it blew apart. Stardust indeed.
May this slime inspire such exciting digressions in your classroom:
BORAX SLIME RECIPE
Mix up a solution of one part Elmer’s glue to one part water.
Mix up another solution of one part borax to one part water. Stir to make sure all the borax dissolves.
Mix the two solutions together in a Ziploc bag, slowly adding the borax solution into the glue solution one splash at at a time until you achieve the desired consistency. Add a bit of food coloring.