Showing that Physics is Fun
Kevin Thomas and Ed Ott

When someone asks us what we are studying, we proudly reply, “Physics.” The most common reactions include widened eyes, a whistle of pity/awe, pained looks, and “Wow, you must be geniuses.” Contrary to popular belief, the majority of us are of average intelligence. We simply enjoy learning how things work in the natural world. Why does lightning blow up trees but not people? If a laser used in surgery can cut through skin, why doesn’t the laser in a CD player? How does the moon affect the tides? How do we measure the distances to stars we cannot even see without high power telescopes? How does cable TV work? These are questions we can answer by studying physics.

Recently we had the opportunity to give a presentation to a group of junior high school students on how physics is fun. Armed with a battery of cool physics toys borrowed from department technician Steve Anderson, we met with what looked like a herd of sleepy cows. But when we brought out our first demo, we had our students’ attention for sure.

Mechanics is the best place to start, because it is the basis of motion. From sports to cars, bridges to buildings, mechanics is the study of movement and change on the large scale. The energy and angle required to throw something over a specified distance is one example. How fast will an object free fall when dropped from any height? What is the maximum speed one can travel while rounding a curve? We used common sports situations like baseball and hockey to illustrate these concepts.

We explained the simplicity of waves in terms of sound. Using a long metal wire slinky and a tuning fork, we explained the Doppler effect and produced sounds that someone in another room would have sworn were the sound of shots from a Star Wars Blaster. Our audience’s enthusiasm was beginning to show; it looked like the force was with us.

Although their interest waned when we started on light, all it took was a laser to regain their attention. It’s amazing what a little chalk dust and some scattered photons can do. They were impressed by our retroreflector, a device similar to one which allowed scientists to measure the distance to the moon with reflected laser light, and our flashlight demonstration of how a laser actually works. But their real enthusiasm was evident during the next part of the presentation.

The audible crack of a stun gun is a great attention-getter when speaking to kids, and it made a wonderful segue into the topic of electricity and magnetism. We showed them the power of a Jacob’s Ladder by torching some paper with the spark of electricity, and the effect of a magnet on a beam of electrons. The students could see that despite the fact that the electron beam looked just like the laser, a magnetic field changed its path, whereas the magnet did nothing to the light of the laser beam.

We ended with a question and answer period and (of course) a gratuitous plug for the study of science, telling the students what exciting breakthroughs the future holds, and that any of them could be a part of it. We emphasized that they shouldn’t worry about the difficulty of learning the math and other such things right now as these concepts can be learned later. The study of physics unlocks the door to an exciting world waiting for discovery.