How crazy is this... water is liquid and then it's frozen. Just like that.
So when you watch this, the guy doesn’t know why the water is not frozen until he bangs it. The geek in me wanted to know. Here’s why: The water needs something to kick-start the freezing process and encourage a small number of the liquid molecules to get together in a regular arrangement to form ice. If you want to know more, read the simple science here.