I wanted to figure out how to get gravity between these two objects. The best I could do was this--the light being "attracted" to the marble and following it around. Notice how I say "attracted;" you will see that real gravity tends to result in objects orbiting one another, or at least bouncing back and forth once they've passed each other. In this case, the light source moves closer to the marble by a ratio of 1 to 50 (1/50th of a step for every step's distance from the marble). It's neat, the program, but it's still not real gravity. (Hopefully, I'll be able to simulate real gravity sometime soon.)
