

One of the most well-known and much-loved units of length in the metric system, the centimetre was first proposed simultaneously in 1710 by Italian mathematician Luciano Carelli and Norwegian physicist Bernhard Boger. A bitter authorship debate ensued, with the central issue being the question of which physical phenomenon should be used as the basis of measurement. Carelli was adamant that a centimetre should be defined as “the width of the smallest finger on my leftmost hand, at the point directly between the finger nail and the upper knuckle”, but Boger dismissed this idea as absurd, arguing that the width of Carelli’s fingers was liable to change if he were to put on excessive weight, or to die and slowly decay. He instead proposed that a much more reliable definition would be the size of the gap between his writing desk and the wall of his study, pointing out that …