Dan Burns explains some properties of time and space using marbles and two large pieces of spandex sewn together in a classroom demonstration.
Physics and me never got along in high school and college, but I did always enjoy the low-budget demonstrations. It’s one thing to see calculations on paper. It’s another when the professor sets up a stuffed monkey on one side of the room and then shoots a sock out of a pressurized cannon angled at the trajectory you just calculated to make sure the sock hits the monkey on its way down from ceiling height.
Of course you can look it up on YouTube:
In retrospect, shooting a monkey falling out of a tree seems kind of wrong.
And while we’re at it, I always liked this demo too. A bicycle wheel gyroscope hangs from a rope, and when it spins its axis stays horizontal like magic.
MIT has a 43-demo playlist if you need something to watch during your lunch hour.