The Measure of All Things: The Seven-Year Odyssey and Hidden Error That Transformed the World

In 1792, the French Academy of Sciences appointed two respected scientists to survey a north-south meridian from Dunkirk to Barcelona, for the purpose of determining the size (and shape) of the earth. Why is this important? Because it would establish an international basis for the meter, foundation of the metric system. It was expected that the work would be finished in about a year, but the expeditions, led by Pierre Francois Andre Méchain and Jean Baptiste Joseph Delambre, which were carried out amidst the chaos of the French Revolution, outlasted both the Academy and the monarchy. Ken Alder has located the lost correspondence between these two, and has discovered the surprising fact that Méchain’s guilt over the possibility of a critical error in a measurement near the southern end of the meridian led him to agonizing self-doubt that brought him close to what we would call a nervous breakdown and almost prevented his completion of the project (about seven years later than first expected).

Pick Attribution: 

Ken Alder

Publication Date: 
Tuesday, January 1, 2002