I recently presented a session on teaching electricity at the Utah Science Teachers Association Conference. On my way home, I did quite a bit of photography of the snowy landscape, but one roadside slope caught my eye. Driving past, I saw something that I had only seen in books, and a few recent weather articles. Snow rollers! They are usually quite rare, and of the hundreds of snowy road cuts that I passed on the drive home, this was the only one that had them.

Don't let the title fool you. This experiment does not involve any explosions. Instead, we are going to explore the science of resonance. Resonance involves putting in small amounts of energy, at just the right time, to get stronger results. A good example is pushing a swing. Each push causes the person in the swing to go higher. We will lift a phone book high into the air by blowing on it.

This experiment came as an accidental discovery while working on a different experiment idea. I was playing with ideas for showing how inertia helps remove water from your clothes in the spin cycle of the washing machine. In the process, I saw something interesting, and made a wrong guess about the cause. That led to even more interesting discoveries. There are times when it is more fun to be wrong, because it lets you learn new things.

This experiment is an old one that may trick you at first. Once you think about the forces that are involved, it should make perfect sense.

I have taught several classes on Amusement Park Physics, and I usually include several activities on the carnival type games. Those games often use science, making something look simple and easy, when it is actually difficult to do. This activity is based on a carnival game where you try to swing a weight on a string and knock over a bottle.