> From 1983, a metre was considered the distance that light travels in a vacuum in 1/299,792,458 of a second (because light travels 299,792,458 metres per second).
So the speed of light was calculated using a previous definition of metre, and that magic number was used to upgrade its own definition? That's a tautology, sounds wrong to me.
So the speed of light was calculated using a previous definition of metre, and that magic number was used to upgrade its own definition? That's a tautology, sounds wrong to me.