It was meant to be witty more than informative, but it only has one meaning: to one significant figure would mean no more than 4.9% of physicists sell books. To

It was meant to be witty more than informative, but it only has one meaning: to one significant figure would mean no more than 4.9% of physicists sell books. To three, it's 00.049%. I think less than 1 in two thousand physicists being book authors is accurate.