QUESTIONS

Q: Have physicists ever attempted to calculate the total number of atoms in the known universe? Dave Cullen, Leeds. Q: Discovery Of South America by Malcolm Slesser, published in 1970, says Venezuela practised uxoricide (wife killing). Did it? B. Darlow, Kempston, Beds. Q: How long could anyone survive on an apple a day?

Mark Cassidy, West Kingsdown, Kent.