Why does cling film wrinkle in neat lines?
Geometry and physics of wrinkling
Two physicists found simple rules for why stretched sheets, like cling film, wrinkle the way they do.
Ig Nobel 2007
Pull a thin sheet of plastic by its ends and it sprouts neat parallel wrinkles. Enrique Cerda and L. Mahadevan worked out the maths of how big and how far apart those wrinkles should be.
The answer depends on a tug-of-war between how hard the sheet is to bend and how hard it is to stretch, and the same simple rule fits sheets big and small. Crinkly cling film, explained at last.
Wrinkles aren’t messy. They’re following a formula.