There aren’t any awards to be won for solving science’s minor mysteries—why yawning is contagious, why puppies make us melt—but that doesn’t mean we don’t want the answers anyway. Add to those everyday puzzles the matter of knuckle-cracking. Why, exactly, should some of the body’s smallest joints produce such an outsized racket?
Now, a study in Scientific Reports at last provides an explanation. It’s a theory that was first posited as long ago as 1971, but had been furiously debated (as these things go) ever since. Thanks to some creative thinking and a new mathematical model, however, the matter may have been settled.
