Science Experiments I Wish I Had

What do you get when you take a bottle of liquid hydrogen and place it in a garbage can with warm water at the bottom and then place 1500 ping pong balls on top of it?  This:

[youtube https://www.youtube.com/watch?v=Ldgp3Ton7R4]

The setup takes a little time so if you just want to watch the explosion, go to the half way mark.