During the late 1700s, revolutionaries shaping the new republic of France shed old traditions bound to royalty and religion.
This reinvention included creating a new system of measurement.
This system would be available to everyone, and be tied to fundamental properties of nature, “not from the length of the king’s arm, or something that changed over time”, Bruce Warrington, CEO and chief metrologist at the National Measurement Institute, says.
So mathematicians and scientists of the time decreed that the length of a metre — from the Greek word “metron”, meaning “a measure” — was equal to one 10-millionth of the distance from the North Pole to the equator through the Paris Observatory.
It fell to a pair of astronomers to calculate this distance, and after seven years, in 1799, they presented their final measurement to the French Academy of Sciences which made a “Metre of the Archives” in the form of a platinum bar.
(It was later found the astronomers were a bit off in their calculations, and the metre as we know it is 0.2 millimetres shorter than it should’ve been.)