there goes another relativity!!!

[dock]

as some member stated:
"the velocity of light is constant in vacuum"

i wonder:

"is it because the vacuum is all alike?"

"would the velocity of light be constant in same kind of waters?"

"would we have to define new theories for relativity then?"

[Integral]

I consider vacumn to be the absence of material particles (materials composed of atoms) so yes all vacumn is the same.

Of course light takes more time to transit a given distance in the presence of atomic material. Haven't you read a single thread concerning this? There are many.

Just like if you are dirving at 35km/h, it takes longer to go the same distance if you must stop a traffic lights every intersection then if there are no lights.

The theory of Relativity was derived with the speed of light in vacumn constant as a fundamental postulate. The speed of light in materials does not have any effect on this.

Be careful where you take this thread Dock!

[vacuum]

The principle of relativity by itself doesn't have to do anything with material(or absence of it) through which light travels. It simply(sic!) states that light travels with the constant velocity ( := c) in all frames of reference which move with constant speeds in respect to each other.