From the pointless science files: A group at Plymouth University decide to explode a bottle of liquid nitrogen in a bin full of ping pong balls.
For no apparent reason, a man who appears to be some sort of lecturer fills a bottle with liquid nitrogen. He then places that bottle into a dustbin which is filled with warm water. As assistant and him then cover the mixture with 1500 ping pong balls.
Instructing the observers to cover their ears, the bottle explodes and the ping pong balls shower everywhere.