Rob Cruickshank decided to embark on the important research of finding out the resonant frequency of googly eyes. He found it. It’s at around 433Mhz where the sound makes the googly eyes start to vibrate and get extra googly inside their plastic shell. Silly, hilarious and always a little creepy.
If you place a wineglass before a speaker emitting waves at the vessel’s resonant frequency, it will vibrate, or even shatter. But resonant frequencies aren’t unique to stemware; every object has one (or, more often, several). Even googly eyes.