The reason is not what you thought.
Nature’s greatest unsolved mystery has been solved. Well, maybe not the greatest, but certainly in the top million.
For decades, scientists have reasoned that the sound made when people crack their knuckles is caused by a bubble bursting within a joint. However, that theory has now been debunked by researchers at the University of Alberta. The team had a volunteer stick his hand in an MRI scanner and then filmed the inside of his knuckles as each finger was pulled.
Turns out the cracking sound is a result of a quick separation of the joint. It happens when a bubble forms, not when it collapses. Greg Kawchuk, a professor involved with what he calls the ‘Pull My Finger’ study, said about the results, “Our jaws hit floor. This is the exact answer. It feels pretty great.”
But what about the concerns that cracking your knuckles is bad for you and can cause arthritis? “It’s mostly an urban myth… perpetuated by mothers who are sick of hearing their kids crack their knuckles,” said Dr. Kevin deWeber, who studies sports medicine in Vancouver, Washington. In fact, he thinks knuckle cracking might actually be beneficial because it massages the joints.
You can check out video of the experiment below.
This study got me thinking about all of the other scientific mysteries that need to be solved. Things such as… Why is there more matter than antimatter? What is dark energy? And, most importantly, how can Shia LaBeouf possibly think he looks good with a rattail?