Blown Away

Here's a cool bit of science and stuff:
There's these little guys known as Pistol Shrimp. They live at the bottom of the ocean and have giant forearm and little claw (not like Fiddler Crabs with big forearm and BIG claw). If you have a minute, check out this video here. The cool part is the other shrimp that gets launched away by the snap of the Pistol Shrimp.

In case you can't see the video, the pistol shrimp cocks his pincher open, waits, then SNAPS it shut so fast and so loud it BANGS and sends a shockwave that stuns or can even kill small fish and other shrimp (which then become food for the Pistol Shrimp). In slow motion and with special cameras you can see a bubble form, collapse, and even light up for just a bit. This is called a cavitation bubble. The claw moves so frikkin' fast that as the water clings to the backside of the claw, the water literally tears apart, creating a tiny vacuum void in the water. Water vaporizes at low pressures (like how water boils at lower temperatures at higher altitudes, there's less air pushing on the surface of the water) so a bit of water vapor fills the void/bubble. BUT, as the pressure around the water collapses the bubble again, the water vapor has to be forced back into liquid. This creates the crazy amount of energy given off as sound, light, and heat (around the temperature of the surface of the sun!!!) The light given off known as sonoluminescence and can be induced with ultrasonic sound waves as well.

These cavitation bubbles are not uncommon, but Pistol Shrimp are the first organisms discovered who use them. Cavitation can blow holes into boat propellors and pumps. Ultra-sonic baths work on the same principle to clean instruments and jewelry (the ultra-sonic scalers in some dental offices are often called cavitrons).