Click and drag to rotate the camera.
	Control-click and drag to zoom in/out.
	Right-click and drag to translate the camera.
	Shift-click on a particle to select it, use the arrow keys to move it around.
	P: Add a particle of charge +2.
	N: Add a particle of charge -2.
	O: Add a neutral particle (charge 0).
	+: Increase the charge on the selected particle.
	-: Decrease the charge on the selected particle.
	X: Delete the selected particle.
	W: Toggle radial potential well on/off.
	]: Pause the the simulation
	I: Show/Hide instructions.