Repel - The charged particle simulator
What is it? Well, I thought it would be interesting to apply some simple rules to a type of java object, and see how it behaved in a 2D environment.
Why did I do it? Because it was fun, and I knew that the result would be a toy I could play with. Now I'm sharing it with you.
What do I do with it? First, try clicking in the large square open space. You will see particles (open blue circles) appear and start to move around. If you have a single particle, it will move to the exact center, as it is repelled equally by all edges. Create a second particle, and they will repel each other, and fight for the point of lowest energy in the box. As you add more particles, it gets very interesting. Try changing the size/charge of the particle by changing the selected number in the upper left-hand corner. If you hold the CTRL key down while clicking, it creates particles that cannot move (solid circles), but repel all the same. Experiment with left/right mouse clicks to change the polarity of the particles created. (I think on Mac, you have to option click to get a right mouse click).
Note: the tether button is a feature I never really finished - it simply grabs 2 objects at random, and attaches an elastic tether to them. Try clicking this button a few times, and see what happens!