Have you ever dropped a Slinky from a window? Probably not. But a bunch of science nerds filmed it in slow motion to show everyone why it's so cool.

If you hold it from one end so the rest is just hanging, then let go, the bottom of the Slinky doesn't start falling until the rest of it catches up. It just freezes there in mid-air.

It's about 90 seconds of footage, followed by four minutes of them explaining the physics behind it.