Get Your Science On: Dark Vibrations

In this episode of Get Your Science On, Katie shows you a neat experiment that shows waves. You can build it with a vibrating back massager and some string.

What’s Happening?

The massager causes the string vibrates at a certain frequency. If a wave goes to the end of the string and bounces back at the same time another wave is coming, you can get a standing wave. A standing wave has places that don’t move at all which are called nodes, and places which move a lot which are called antinodes. The number of antinodes is called the harmonic. By pulling more or less on the string, you change the length of the string and the speed the waves move, and see different harmonics.

Build Your Own

To build this, we removed the cap on the massage head and drilled a small hole. Then we put a string through and tied it to a washer. Finally we glued the cap and washer back on to the massager. We used elastic cord, but you can also use other types of string. Try experimenting!