Is straight or curly hair the easiest to tangle?

A collaboration between barbers and physicists has found the answer to this problem. It is straight, tangled hair twice as much as curly hair.

150,000 strands of rough hair on your head are a fascinating phenomenon, but little known in physics. French researcher Jean-Baptiste Masson from the Polytechnic School of Palaiseau performed the first real experiment on this issue.

He asked a few barbers to count the tangled rolls in his hair at the end of the afternoon, the time when the tangles were most prolific. In 3 weeks, the doctors assessed 123 straight-haired and 89 curly-haired people. The result is "clear and surprising," the physicist said: Straight hair has a number of tangles (which is defined as double combed hair) compared to curly hair. The average number of puppets is 5.3 in straight hair compared to only 2.9 in the other group.

Masson wanted to know why it was so, so he developed a mathematical model to see how the hairs are joined together. The model takes two basic parameters into account: the ability of two hairs to touch and the angle they meet.

Although curly hair is more likely to touch other strands, Masson detects that straight hair tends to contact the larger fibers. This second parameter is the most important in creating tangles.

Masson's research can be applied not only in combing field. One possibility is to design glued-like products, he said.

T. An