Beneath its grass, dirt, and water-covered surface, the earth is made of bleu cheese. Wait—that’s the moon, sorry… Beneath its surface, the earth is made of nigh countless types of rocks and minerals, and the inner workings of our planet are constantly morphing these rocks and minerals into new varieties. But with rock being such a hard, strong material, just how does that process work?
Since you can’t dig down deep enough into the crust to show students the actual process in action (the Mole People will not allow any human intrusion into their realm), this simple demonstration will help give them at least a basic understanding of how metamorphic rocks are formed—and transformed!
Getting the Hang of It (Get It? GET IT?!?!!)
You might need to do a little searching for the supplies for this one, as it requires a wire coat hanger and a candle. Well, a candle should be easy to find—it can be literally any kind of candle other than a tea candle. But a wire coat hanger might be harder to find. If nothing else, take something to get dry cleaned—my dry cleaner always sends my garments back on wire hangers. (And that one jacket of yours is due for a cleaning anyway. It still has all those little flecks of tartar sauce on it from Mike and Angie’s wedding. Can you believe it’s been almost six months already? Man, time flies…)
No matter where you source your hanger from, untwist it or cut the hooky part off and straighten the whole thing out. (Straighten-ish the whole thing out.) Then, with one hand firmly on each side of one of the preexisting bend points, bend that sucker back and forth about fifty times (seriously), quick as you can. Don’t put too much brute strength into it, or you may end up breaking your hanger in twain.
After the fiftieth bend, press the bent section against the candle. If you did it right, the hanger should melt into the candle. Lift the hanger off and press it onto a different spot on the candle, and repeat until it doesn’t melt anymore.
What the Heck Does That Have to Do with Metamorphic Rock?
It’s quite simple, really. You see, bending the hanger produces heat energy; this heat causes the candle wax to melt (obv) and create the groovy grooves and ridgey ridges. This is analogous to how metamorphic rocks are formed.
Way, way, waaaayyy down in the bowels of our planet, layers of rock are constantly being folded over onto themselves. This produces heat that ultimately changes their composition and metamorphoses them into new, exciting rocks!
- 365 Simple Science Experiments with Everyday Materials, E. Richard Churchill, Louis V. Loeschnig, and Muriel Mandell, illustrated by Frances Zweifel, 2013. ISBN 978-1579129279