More boring, but you still have that kind of colliding and bumping.

We need those things too, but we're also bumping up against their limits.

So one way to look for them is to build detectors that are extremely sensitive to a dark matter particle coming through and bumping it.

Some people watch this event because of a NASCAR like fascination with things bumping and grinding. Burning the parachute as it fell that was last weekend.

You don't see luminescence until the submersible begins to move forward through the water, but as it does, animals bumping into the screen are stimulated to bioluminesce.

So if you imagine a very, very big universe, an infinitely big universe, with randomly bumping into each other particles, there will occasionally be small fluctuations in the lower entropy states, and then they relax back.