Watch the different sized circles bounce around.
I was following a tutorial written in Python to try to create my own physics engine in Scratch. I ran into problems after this point (you can see the remnants of me trying to add a gravity vector in the project), but I was able to make the circles bounce based on their size using math, and without physically "touching" the edge, or using an "if on edge, bounce" block. The tutorial I was following: http://www.petercollingridge.co.uk/book/export/html/6
