Microwave + Toothpicks = Fun

Have you ever been bored sitting at home, saw your microwave sitting all by itself, and decided "Hey, I'm gonna put a light bulb in there and see what happens...?" This is essentially the kind of thing that I did this saturday afternoon. I'm in an organization on campus called SPICE (Students Participating in Chemical Education). In this organization, we perform chemical demonstrations for elementary and middle school aged kids at various schools and locations around Madison. The idea is to get those kids interested in learning and science, but for those of us in the organization, its just plain fun.

We're always looking for new demos to show kids, and recently, one of our members heard about lots of things that we can do with your everyday microwave and other various household items. All saturday, we tried out lots of different experiments to see how well they would fit in with our other demo shows (we always try to have scientific themes: solid/liquid/gas phases, polymers, gas expansion, etc.). I was really surprised at just how many sites there are on the internet that are dedicated to this specific topic (here is just one example: http://www.everist.org/special/mw_oven/). The only problem is, most of the sites just tell you how to do them, and don't give any explanation of why the experiment works, and now I'm going to be spending a good amount of time doing research on how these things work.


Here's a list of a few things that we put in the microwave:

1. Lightbulb - Apparently, if you put an average incandesent lightbulb (we used a 75 W bulb) in the microwave, it will light up. It uses the microwaves as energy in a similar fashion to when you screw it into a socket. What's even cooler is when you put it at the edge of the turntable, the bulb will flash in different colors and brightnesses due to the power variations of various regions in the microwave. However, you do need to put the bulb in water because it gets very hot.


2. CD - A CD is composed of several layers of material which contain metals, and when its exposed to microwaves, the different layers cause energy to arc across in a patterned fashion, which makes it look like lightning. The big problem with this is that it gives off quite a strong odor, which I'm told is vaporized metal and possibly arsenic. This is one of the things we need to work on a bit before we put it in a show.


3. Soap - If you take your typical bar of soap and put it in the microwave for about 3 minutes, it will grow and expand to about 4x its normal size. We figure this one is just based on gas expansion: the microwave causes any water in the soap to boil, create water vapor, and the soap traps the vapor in bubbles. All science aside, this one is just kinda cool to watch.


4. Toothpicks - This is by far my favorite. We took a toothpick and stood it upright in a cork in the microwave. When we lit the tip of the toothpick and started the microwave, it started shooting out fireballs. It was a little scary too, because when it shoots out the fireballs, there is a strange electrical noise that sounds like it might be power fluctuations. We don't quite know how this one works yet, but its still the coolest one I've seen.

I know it's kind of cliche, but I feel obligated to say that you probably shouldn't do this at home, kids. Knowing that you probably will, please be careful, and I am not responsible for any fires, explosions, power surges, injuries (mental or physical), or anything else related to anyone doing these experiments at home.

With that said: have fun!