Tangentially related, but when I was an undergrad at Caltech there was a device in a nook of the astrophysics building labeled "Gravitational wave generator" th

Tangentially related, but when I was an undergrad at Caltech there was a device in a nook of the astrophysics building labeled "Gravitational wave generator" that had the appropriate two-decades-outdated look of equipment you'd find in a random physics lab. It was two little weights in the shape of a dumbbell attached to a motor. There was a knob that allowed you to specify the frequency of the gravitational waves you wanted to generate, and when you flipped it on, the weights would start spinning, thereby generating gravitational waves at your specified frequency. I always found it amusing that someone went to the trouble to make that.