Ian Kelly <ian.g.ke...@gmail.com>: > Off-topic, c being a fundamental constant is actually in the latter > category. Its *exact* value is 299792458 m/s. > > The length of the meter, on the other hand, is defined as the distance > traveled by light in a vacuum in 1/299792458 seconds and is subject to > the precision of measurements.
Since both c and the second are exact magnitudes, so is the meter. The second [...] is quantitatively defined in terms of exactly 9,192,631,770 periods of a certain frequency of radiation from the caesium atom: a so-called atomic clock. <URL: https://en.wikipedia.org/wiki/Second> Marko -- https://mail.python.org/mailman/listinfo/python-list
