Harvard boffins finally crack the mystery of squeaky sneakers

It is a sound evocative of high school: the characteristic squeak of sneakers on a basketball court. UK readers may, however, be familiar with the same sound from their trainers while playing badminton.

Whichever it is, how exactly the sound is produced has been a mystery - until now.

The high-pitched tones have often been attributed to the “stick-slip phenomenon,” which creates the sound from a violin bow moving against the instrument’s string. You can still read the explanation on the Wikipedia page.

But the problem is that the sound tends to show up at high sliding speeds, while it also has a well-defined pitch, the frequency of which is difficult to explain.

A team led by Harvard University postdoctoral researcher Adel Djellouli carried out an experimental analysis of the phenomenon and came up with an alternative to the stick-slip explanation.

They replicated the sneaker-court interface by testing rubber blocks ...