[aristeides]

If the speed of light varies over time, then, given the relativity of time and space, doesn't that mean that the speed of light also varies from one place to another?

[vannrox]

YES Good Point.


If the speed of light varies over time...
Then...
Because time is but a human construct for the change of entropy in space,
That,
it varies as a function of location or space.
so...
IF so, then it must vary at different places.
Logic train chugging...
Further...if it varies at different locations...then
It must vary as a function of the attributes the the space it is in...
Or, to put it another way...
There must be elements in a given space that can alter the speed of light....

[RightWhale]

doesn't that mean that the speed of light also varies from one place to another?

Among some assumptions on the structure of the universe is that it is the same everywhere. If it turns out otherwise, then our theories will be complicated much more.