Exploding glass: slowed down

This is not a blog entry about state-of-the-art physics but it is about mechanics of solids which is a part of physics which is why it may have its place on TRF.

Prince Rupert's Drops are not named in this way because a prince invented them but because a prince brought them from North Germany or Bavaria or Holland to England in 1660.



They are created by rapidly cooling molten glass in water. This makes a tadpole-shaped structure.




This piece of glass turns out to be remarkably resilient because the pressure deep inside the drop is higher. It isn't easy to break it, unlike most of the floorball sticks I have bought in the last 5 years (not to mention a rib). Well, if you try, it does break.




But if you look what's happening each eight microseconds – if you look by a camera running at 130,000 fps – you will discover that it's not the hammer that breaks the glass. It's a seemingly innocent vibration spreading from the tail of the tadpole. The brand new video above kind of clearly and visually explains what's going on. Not even Prince Rupert could have seen such a clear history of his exploding glass.

Those 130,000 fps may sounds like a lot. But note that the LHC detectors effectively have 40,000,000 fps – there are about 600 million collisions per second but it doesn't hurt too much if some of them are clumped together. Well, there are also some other differences in the ATLAS/CMS "cameras" that make each of these detectors cost a billion of dollars, more than the camera used to create the video above. :-)

If you know how to explain that the tail matters so much and why the explosion ultimately runs in the outward directions – and not just back into the tail – you are invited to post your comment. ;-) For more similar videos, see the Smarter Every Day channel.