Gives me a headache because I can’t remember what that globe is called. It’s quite real. It’s similar to Prince Rupert Drops. I used to play with these in the physics lab. Check out this video, it’ll blow your mind:
http://www.youtube.com/watch?v=xe-f4gokRBs
http://physics.aps.org/articles/v6/60
Quenching and annealing in blacksmithing are as old as the hills. Still, pretty neat stuff and gives you a bunch to think about.
Wow, that was really cool!