Trigger warning

Thought experiment

Sir, – Having read William Reville’s column referring to the Ship of Theseus (“Famous thought experiments”, Science, August 3rd), it reminded me of Trigger in the TV show Only Fools and Horses. Having being awarded by the local council for many years service with his sweeping brush, he went on to say he had the same brush all those years, only having to replace the head and handle a few times. – Yours, etc,

CHRISTOPHER KAVANAGH,

Donaghmede,

Dublin 13.