It wasn’t a disaster, I promise. It was one of those moments that will make me smile for at least a week, whenever I happen to think of it. I am a TA this term for a very introductory-level geology class – it’s called Earth, Wind and Fire, just to give you a sense of how truly hardcore this course is. Anyway, there are four of us poor suckers TA-ing almost 300 students, so you can imagine that it gets stressful at the best of times. Add in the fact that two of our TAs are from China, and things get a bit scarier. I have nothing against my two colleagues – in fact I admire them tremendously for not only coming to a foreign country to study, but they have to teach in a strange language! Amazing. But it does make for some interesting meetings, especially when someone uses phrases like “dilly-dally” or “no tomfoolery in my lab sections!” Idiom is a wonderful thing.
So, next week we are running a lab about volcanoes and earthquakes. The volcanoes part is pretty easy – who wouldn’t want to look at a bunch of cool photos of mountains that explode? Really. But the earthquakes part is sometimes problematic – mysterious energy waves passing through the earth, invisible to us until they shake something hard enough to make it fall down. How on earth do you demonstrate something so laden with physics to a bunch of students who want to shrivel up and die when they meet the metric system? Answer: Slinky!
I’m telling you, this is my all-time favorite demo in intro geology. You get two students to stretch the slinky out over a long table, so it’s resting on the tabletop. Then you bunch up a few coils at one end, and let them go. Shazam! The coils shoot away down the length of the slinky: p-waves! Then you take over one end, and shake the slinky back and forth, making it wiggle: s-waves! I love this thing.
Explaining it to our two Chinese friends was surprisingly easy, which led me to assume that this demo is an international phenomenon. Wrong! At the end of the meeting, Yue and I were gathering up our stuff, when she asked me what the slinky was really for. Instantly, I knew we had to find some stairs.
I have never seen someone get such a thrill out of watching a slinky do its thing. Think back – try to remember the first time you ever saw this trick. I can’t. I bet you can’t either. But what a treat, watching Yue giggle like a little kid, and immediately take the slinky to the top stair for another go. Suddenly, this thing that I had learned to think of as a tool became a toy again. What a wonderful thing to have happen on a stress-filled Thursday afternoon.