" Think of the most fussy science teacher you ever had. The one who docked your grade if the sixth decimal place in your answer was rounded incorrectly; who tucked in his periodic table T-shirt, corrected every student who said " weight" when he or she meant " mass" , and made everyone, including himself, wear goggles even while mixing sugar water. Now try to imagine someone whom your teacher would hate for being anal-retentive. That is the kind of person who works for a bureau of standards and measurement. "