From yardsticks to metre rule

摘要

A GOOD unit of measurement, writes Robert Crease, must satisfy three conditions. It has to be easy to relate to, match the things it is meant to measure in scale (no point using inches to describe geographical distances) and be stable. In his new book, "World in the Balance", Mr Crease, who teaches philosophy at Stony Brook University on Long Island and writes a column for the magazine Physics World, describes man's quest for that metrological holy grail. In the process, he shows that the story of metrology, not obvious material for a page-turner, can in the right hands make for a riveting read.