Have you ever heard of the Prince Rupert’s Drop? If not, we’ll explain. The Prince Rupert’s Drop (also known as Dutch tears) is formed when a drop of molten glass is submerged into cold water. As the drop falls into the water it forms a large, rounded front with a long tail, making it look a lot like a tadpole. What makes this glass so amazing is its incredible strength coupled with unbelievable fragility.

See, the front part of the Prince Rupert’s Drop is so strong that it can’t even be broken with a hammer. This is thanks to the high residual stress. As the glass cools from the outside, the front of the drop compresses into itself making it harder. The tail end of the drop, however, is extremely fragile. Any damage to the tail will cause the entire drop to explode.

In the video above YouTube channel SmarterEveryDay explains the science behind the drop and shows – with the help of a variety of high-speed camera’s – how the glass shatters.

Some years after making the original video, the channel has gone back to revisit the drop and its origin. In fact, they even head to London to see an original 17th Century paper written by Sir Robert Moray that discusses the Prince Rupert’s Drop. Watch the video below for some infor about the drop’s origin and then watch as they shoot it with a rifle to test its strength.

Videos credit: SmarterEveryDay