With the old definitions, the values of the known constants were just approximat...

lmcarreiro on Nov 16, 2018 | parent | context | favorite | on: International System of Units overhauled in histor...

With the old definitions, the values of the known constants were just approximations, but now that the unit is defined based on the constants, we can consider the constant as being the exact value, no matter how imprecise it was when it was measured using old definitions of the units.

jobigoud on Nov 16, 2018 [–]

So it's the equivalent of removing a magic number from your code and putting it into a const variable.