At last, a burning question has been answered. How can we predict the shape of a ponytail? Raymond Goldstein of the University of Cambridge, Patrick Warren from Unilever R&D Port Sunlight and Robin Ball from the University of Warwick have succeeded where others have failed. We now can predict the shape of ponytails. Before you scoff, bear in mind that this information could prove invaluable in the development of both textiles and computer animation. OK, you can now scoff if you like.
When hair is gathered together, the thickness of individual hairs, total number of hairs and curliness of each hair all affect what the resulting ponytail will look like. The researchers used samples of real human hair to compare actual ponytails with models predicted by their derived ponytail equation.
The best part of this work is that we have a new mathematical term: the Rapunzel number. The Rapunzel number describes the ratio between the total length of the ponytail and the degree to which gravity acts on the hair. In other words, it explains why some ponytails will hang limply and other spring outwards from their clamps. Obviously, the elasticity and curliness of the hair make all the difference. I look forward to picking up some 'Rapunzel number five--because I'm worth it' in the near future.