[Svartalfiar]

I'll take a pre-enlightenment system based on how people really live, than based on "the distance that light travels in a vacuum in exactly 1/299,792,458 of a second at mean sea level."

Well, the meter was actually defined as one ten-millionth of the distance from the equator to the north pole, on a line through Paris. The light speed definition was an arbitrary number that defined the meter by the speed of light, using the same size meter as previously defined, instead of using a more natural or even number.

[Dr. Sivana]

I know. So changes are made for whatever reason. It’s like the size of the king’s foot, only less frequent. They could have worked off of nautical miles, if they want to do the pole to pole thing. Does the size and shape of the earth change ever so slightly? Yes. Then you make adjustments as needed as we do with “leap seconds”. Thank God the calendar changes never took!