Mystery of Prince Rupert's Drop at 130,000 fps - Smarter Every Day 86

Prince Rupert's drops (also known as dragon tears) are beautiful explorations of tempering glass - like the Corelle plates that we demonstrate in the first year summer course - using the opposing stresses of the outside and inside glass to create phenomenal strength.

This video does some pretty stunning things with high-speed photography, showing the shockwave travelling down the tail of the drop to the head at over a mile a second.

The video explanation - using red-, white-, and blue-shirted versions of our host - is absolutely brilliant, doing a better job of showing the stresses than any other video that I've seen. Marvelous...stunning...

And, at 4:33, there's a tiny bit of type at the bottom of the screen that tells the actual amount of pressure involved in the Prince Rupert's drops.

Great, great, great video!

Why aren't they wearing gloves, though?

Here's a similar video from Theodore Grey's Popular Science column, Grey Matter.