bipm.org

5VdJR TIL that the scientific definition of a Kilogram uses the Planck constant(which gives the relationship between energy/mass and frequency of a photon) in its formula. Pg131
MeBJ0 TIL that the U.S. was one of the original 17 who signed the Treaty of the Metre (Convention du Mètre) and given two of the original forty cylinders that is know as the International Protoype Kilogram
gMm9A TIL Unit abbreviations start with a capital letter when they are named after someone (e.g. K for Kelvin, Hz for Hertz ...), otherwise they are lower case (e.g. m for meter, s for second …)