*Make sure your volume is turned up.* Listen and watch the dots. Are they bouncing off each other, or are they passing through each other? Now press and hold the space key. Listen and watch the dots. Are they bouncing off each other, or are they passing through each other? How does it work? For some people, the sound of the balls bouncing off each other made all the difference. For other people, it was all about vision. Cool huh?
I got this idea off of the show Brain Games.