[MD] Constant

[david buchanan]

ADRIE said:
..the defined length of the standard meter, derived from the wavelenght of light...it's standardised, cannot change


Craig quipped:
 ...until the next time it does.



dmb says:

Not that it's relevant to the discussion, but the last time the standard length of a meter was defined it was my late, great father-in-law was the physicists who defined it. This also had the effect of redefining the speed of light. They say this re-definition is very, very precise and that things like GPS wouldn't work without that high level of accuracy. His name was Kenneth Evenson. After he died his partner in crime won a Noble Prize. Naturally, we (friends and family) like to think that he might have won too if he'd lived.