Huzzah! Another scientific mystery bites the dust! Scientists have finally cracked a problem that has "perplexed humanity since Leonardo da Vinci pondered it 500 years ago."
Learn all about the Rapunzel Number, which provides a key ratio needed to calculate the effect of gravity on hair relative to its length. In the right hands, this dangerous number can predict the shape of any ponytail:
Cambridge Professor Raymond Goldstein told Reuters that he and his colleagues took account of the stiffness of individual hairs, the effects of gravity and the average waviness of human hair to come up with their formula. [...]
"That determines whether the ponytail looks like a fan or whether it arcs over and becomes nearly vertical at the bottom," Goldstein said in a telephone interview.
The research also took into account how a bundle of hair is swelled by the outward pressure that arises from collisions between the component hairs.
Oh, he also mentioned how the Rapunzel Number would also help scientists deepend their understanding of fibers, as well as be useful in computer graphics and animation, but we all know that the real reason for the study is to break the stronghold of the hair stylist mafia on ponytail-wearing populace.