Why does toast often land butter-side down?

Floor detritus and butter on toast. Appealing.

16th September 2017
Why does toast often land butter-side down? (Getty)

Asked by: Coco Shang, Sevenoaks

For years this notorious example of Murphy’s Law – ‘If something can go wrong, it will’ – was dismissed by scientists who insisted toast was as likely to land butter-side up as down. Then, in 1996, I published a theoretical analysis of toast falling off a plate that suggested there should be a bias towards butter-side down landings.

In 2001, a nationwide experiment involving over 1,000 schoolchildren and 21,000 drops of toast confirmed the theory: toast falling off a plate lands butter-side down almost two-thirds of the time. Contrary to common belief, it’s nothing to do with one side being buttered. The explanation is that as the toast goes over the edge of the plate, it starts to rotate, but the spin-rate is too slow to bring the butter-side uppermost again by the time the toast hits the floor. 

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