Prince Rupert Glassdrop

Awesome science, beautiful imagery –

If you want a scientific display of the dangers of pent-up stress, Prince Rupert’s drops are it. After the trauma of being dropped molten-hot into a bucket of cold water, these glass balls, named for a 17th-century amateur scientist, turn into bundles of high tension. They’re impervious to even the strongest blows, until you find their hot button: Flick the tail, and they explode.

See the violent release of potential energy on video – Shattering the Strongest Glass on PopSci.com