From Richard Breakspear
Your mention of Google’s use of the number e (approximately 2.71828) on advertising billboards (21 July, p 38) reminded me of a story about the physicist Richard Feynman.
While working in Los Alamos during the second world war, the remoteness and lack of entertainment led him to experiment with lock-picking, including opening the combination locks that protected some of his colleagues’ filing cabinets: it is said that he left fictitious notes from a spy in them. .
Shrewsbury, Shropshire, UK
