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Why does a duvet bag up all the other items in the washing machine?

It’s a stochastic process with a filter, says one reader, while another nods to the duvet’s place as apex predator of the washing machine ecosystem

2BE3Y6H Bedding and sheets are freshly laundered and are hanging out to dry on a washing line in residential back garden.

Why, if an unfastened duvet cover is put into a washing machine, does it bag up all the other items in there to be washed?

Garry Trethewey
Arkaroola Wilderness Sanctuary,
South Australia

It is a stochastic process with a filter. Imagine a modified pool table with 10 balls, oscillating sides and a single pocket in the middle. The balls would move around randomly, but, now and then, one would fall into the pocket. This can give the impression of some sort of intentionality – “the thing that makes balls collect in the pocket”.

Your duvet cover is like that. Imagine chucking socks at it from random directions. From the right (for example), they will collect in the bag; from the left, they won’t.

Peter Coates

Yukon, Canada

Everyone knows that duvet covers are the apex predators of the washing machine ecosystem.

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