The cause of that bone-chilling popping sound that we hear when we crack our knuckles has been a subject of debate for decades in the scientific world. However, the mystery might finally be revealed thanks to a computer model created by a team of researchers from France. According to the study, which the journal Scientific Reports recently published, that awful sound is actually caused by microscopic gas bubbles that are collapsing when we crack the knuckles. It’s interesting that this exact theory was actually proposed about 50 years ago. However, this recent paper used advanced technique to prove that it is indeed true.
It’s also worth noting that experts have been investigating the cause of this sound since the 1900s and are yet to reach a common ground. The biggest problem regarding this action is that it cannot really be visualized because it happens in only 300 milliseconds. However, experts have agreed on something: not everyone is able to create that popping sound. Also, not every finger will do that if cracked. Moreover, once cracked, you cannot do it again on the same finger for about 20 minutes.
The cause of the knuckles cracking sound
So, in order to shed some light on this mystery, the researchers used geometric representations of the metacarpophalangeal joint. That is the place where the magic happens. Then, they managed to convert them into mathematical equations. Finally, computer simulations showed what exactly happens in our knuckles when we crack them.
According to Abdul Bakarat, one of the researchers, the gas bubbles in the knuckles collapse when there’s enough pressure on the joint. What’s important is that those bubbles only partially collapse and still make the sound. This is why they don’t disappear even after the cracking happens. So, it seems that this decades-old mystery has finally been answered. So now, we can go back to cracking our knuckles every time we feel like it.
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