Faster than the speed of light

[DrGreg]

Funny thing is that the speed of light has been observed to be slowing down.
The speed of light is calculated using atomic clocks. Scientists have observed that, in fact, either the atomic orbits are slowing down, or the speed of light is slowing down because every once in a while you have to change the calculations to accurately fit the atomic clocks.

Is that true and accepted? Sounds like a big thing for a throwaway comment.

I'm guessing that Antymattar is getting confused with the leap second which we need to occasionally add to compensate for the fact that the Earth's rotation is very gradually slowing down. The second is defined using atomic clocks, not the Earth's rotation which is no longer reliable enough for accurate timing, which is why we have to add leap seconds to compensate.

Technically it's impossible for the speed of light to slow down since 1983, when the new definition of the metre fixed the speed of light at 299,792,458 m/s precisely.