Watch What Happens When You Dump Lots Of Plastic Balls On An Escalator

Maybe not the safest thing to do, but pretty fun, anyway.  

Here's a couple guys who maybe don't do much for pedestrian safety, but had a novel idea.

They dumped a whole bunch of little plastic balls on an escalator to see what would happen.

The result is pretty fascinating: The balls try to roll down the stairs, but the escalator is going up, so many of the balls stay on the escalator, bouncing up and down as the escalator moves.

It's sort of a perpetual motion machine.

The video was released more than two years ago but has lately gone viral. It popped up on the Web site BoingBoing recently, via JWZ

Here's' the fun video: