Outreach at Science on the Square 2025

Hi all,

As part of the Wonders of Physics Outreach Fellowship, I will get many opportunities to participate in physics outreach! Even though I joined recently, I already got to participate in one! This last Thursday, Madison had its Night Market and, as part of it, one of the events of the Wisconsin Science Festival: the Science on the Square!

In particular, this year’s theme was Sound, so we did many demos about sound, all surrounding the principle of resonance. Here’s some of the demos:

Singing Wine Cups

We had three wine cups, two of them with the same level of water and one with a different level. By rubbing your finger in the rim of the cup you could produce sound, in the resonance frequency of the cup. That by itself was pretty cool but more cool was when you put a little toothpick balancing in the rim of one of the two cups with same frequency, and then make the other one sing: the sound of the cup makes the other cup resonate and, consequentially, vibrate, which made the toothpick fall.

Singing Rods

We had many lengths of aluminum rods and when holding one, by pinching at the middle and rubbing one of the sides with rosin-covered fingers, you could make it resonate in its resonant frequency, and it was quite impressive how loud it got. People were very impressed. People also were surprised that, when I rubbed the smaller length rod, we got a higher pitch.

Tunning Forks

This demo was a bit free form. We had two E and one F tunning forks and people could play with them by hammering one and hearing the frequencies and getting a different frequency for whether they used the E or F. They could also play around with transmitting the the vibrations from one of the E box to the other. We also had a ping pong ball hanging from a stand, where you could put a tunning fork touching it and, when it vibrated, the pingpong ball got bounced by the vibrations. We also had a not-mounted tunning fork that we could use to just hold against the ping pong ball for dramatic bouncing.

Earthquake Machine

Our last demo was a plataform on rails that could be shaked back and forth, and it had many cardboard buildings built on top of springs, and various heights. People could then shake the table at various frequencies and note how different buildings would respond to the different frequencies. It was a very popular demo, specially for the kids!