Anyone looking for surefire ways to ruin a first date could do a lot worse than frequent knuckle-cracking. You could propose, for one, or pants the server, but why go through all that embarrassment when you could simply pressurize your finger bones and make a sonorous popping noise every couple of minutes? Cracking one’s knuckles has long been a vice for those with idle hands and a low-key scourge of polite society, and the debate about whether it’s merely rude or actually dangerous has gone on just as long. But now some new footage has cracked this whole thing wide open.
Speculation about just what’s responsible for the satisfying/creepy noise of cracked knuckles once leaned toward the theory that air bubbles were popping inside the joint. Thank God for science, though–a sentence scientists would hate–because a new study from the University of Alberta has taken the matter beneath the skin, where the truth lies. Researchers filmed knuckle-cracking action with an MRI machine for the first time ever, and determined that the noise actually stems from “the rapid separation of the bones.” Disgusting! No wonder it drives people crazy.

In conclusion, cracking your knuckles is reportedly safe, we know why it makes a distinctive, unpleasant noise, and we can now see what it looks like. All around, an important day in metacarpal history.
[via Happy Place]