These are some pictures of a gyroscope that I made in the physics machine shop when I was an undergrad at the University of Washington. To give you an idea of the scale, the gyro alone weighs 13 pounds. The whole apparatus is about 40 pounds, approximately 2 feet across. It is made out of aluminum, which has been black anodized. It is driven by an electric motor at the center of the gyro, which spins at 3600 rpm. It takes about 20 minutes to stop spinning after you shut off the power! It is a great piece for demonstrating the surprising properties of angular momentum.

This is a close up of a cloud of charged chalk dust trapped in a "Paul Trap." The two spheres are grounded, and the ring is at 2000 VAC (60 Hz). The ring is about an inch across. The chalk dust is the white cloud in the center of the ring. The dust stays in the trap as long as one cares to keep it there - although I never ran the trap longer than about one month. The trap is named after Wolfgang Paul, who designed it to trap single charged particles, such as ions and electrons. He received the Nobel Prize for this in 1989. Here are some Paul Trap links.

Here I am teaching some third graders about the double pendulum, which is a chaotic system. This one is special because the upper pendulum is a bowling ball, but the lower pendulum is just a tiny ball. Each pendulum has about the same period taken separately, so that they are strongly coupled. If you swing the bowling ball just a little, with the lower ball starting from rest, very soon much of the energy of the bowling ball is transferred to the small ball, which results in a very large oscillation of the small ball. Children love it!

Here I spent the day with a fifth grade class building and launching model rockets. They go pretty high - between 300 and 1000 feet depending on the engine and how many stages the rocket has. They have parachutes so they aren't destroyed on landing. The one you see launching above landed in a nearby field near some curious horses. Note the model of the solar system (not to scale!) in the first picture. How appropriate!