Science. It isn’t always lab-coats and microscopes. Sometimes you get to break out the firearms and high-speed cameras and shoot stuff to further your understanding of physical properties. Like glass. You might think you know what happens when you shoot glass, but the video below has some surprises.
[Scroll Down for Video]
Odds are you’re not familiar with a Prince Rupert’s Drop. They begin with molten glass. There’s nothing unique about that. But that glass is allowed to drop into cold water. The result forms a bit of an abstract tear-drop shape.
The rapid cooling of the exterior hardens the glass into an unbreakable ball. This is due to the hardening of the exterior of the molten glass. The inside holds heat longer, which makes it less brittle. It is the same concept used to make the edge of a knife hard enough to hold an edge, and the spine of the knife flexible enough that it won’t break.
The Prince Rupert’s Drop is unbreakable. Well, almost unbreakable. As glass is, historically speaking, very breakable, the Prince Rupert’s Drop looks invincible.
But just the round bulb end. The long tail that forms is extremely fragile. The bulbous ball end is tempered. The tail cools so fast that it becomes brittle. The ball can withstand unimaginable force. The tail will break very easily. And when the tail snaps, it can send shock-waves through the rest of the drop, shattering the whole thing.
Scientists have been fascinated by the Prince Rupert’s Drop for centuries. High-speed cameras allow us even greater insight into how they behave. YouTuber SmarterEveryDay has a great video in which he shoots a bullet at the bulb end of a Prince Rupert’s drop. 150,000-frames-per-second of bullets smashing into the unbreakable bulb end.
The bullets (in this case, standard .22 rimfire rounds) are hitting at roughly 900 FPS. The glass doesn’t break when the bullet hits. Instead, the strike sends a shock-wave down the Prince Rupert’s Drop. When that wave hits the vulnerable and brittle tail, the Prince Rupert’s Drop shatters from the tail back to the tip.
The results are not only scientifically interesting, but visually stunning. The video is well worth watching and the images are exceptional.