Wrong,

**stephaneww**. This is

units of measurement. You have inked to the French Wikipedia so you must know that the

metre in SI (Système international) units is defined as "The distance travelled by light in vacuum in 1/299792458 second.". There are similar definitions not related to Planck units. Any

units of measurement. can be used by anyone. NASA used imperial (US) units until officially swapping to SI in 2007. We can convert to

Planck units if we want but that is stupid for normal uses, e.g. 1 metre is ~10-35 Planck lengths so why not just use SI and make the math easier?