In my Game Development classes, I commonly teach particle physics, to use for things like explosions and thrust. I'm wondering what other interesting things you might use particle physics for. Or different effects. Here is just a handful of some I've used.
Connective, like Leash/Elasticity/Follow/Evade
Bump Logic, Bounce, Screen Wrap.
One other odd one, was identifying the color/location of each pixel in an image, placing them in an array, using the location as a target with orbital gravity, randomizing each location, and adding friction. This created what appeared to be a star field that sat dormant, but when I activated its effects, all the stars on the screen pulled together to form an image. Was really interesting.
I would also use this to "morph" an image into another, but scattering the pixels and applying color changers to each particle, and adding a bunch of invisible particles where it needed to add them that faded in to view. It worked pretty nicely.
So, What other interesting particle effects have you seen/used. I'm creating a list for students to consider.