About six and a half billion people use the metric system every single day.  That's more than the citizens of any single nation, the followers of any single religion or the speakers of any single language.  Sociologist Hector Vera has called the metric system “more popular than Jesus.” In our “≤ kg” episode, we told a bit of its epic history.  How it dates back to revolutionary-era France, where over 250,000 measures were in regular use. How the hungry and angry French peasants demanded a unified set of weights and measures. And how the revolutionary government wanted their system to ...