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Last Word is Â鶹´«Ã½â€™s long-running series in which readers give scientific answers to each other’s questions, ranging from the minutiae of everyday life to absurd astronomical hypotheticals. To answer a question or ask a new one, email lastword@newscientist.com
I recently bought plastic multi-coloured clothes pegs, which have slowly disintegrated in the sun except for the yellow ones. Why?
Peter Holness
Hertford, Hertfordshire, UK
The phenomenon that destroyed the non-yellow clothes pegs is called “unzipping”. Many years ago, a chemistry colleague told me about it. His explanation was that the sun emits high-energy photons capable of breaking…
