parent
  • jmcs
    +2

    The kilogram is still defined by a chunk of metal in France that has the annoying habit of losing mass. Hopefully we can get a precise and reproducible way to define it soon.

    • Guilhem
      +3

      When you define the second everything else is pretty easy. TIme => length => volume => weight (a fraction of a 1m^3 of pure water at SATP with no special isotopes for example.)