How is the speed of light constant?

[nhmllr]

What experiments have been done to prove that the speed of light is constant among all frames of reference? Discounting the aehter, wouldn't the Michelson Morley experiment only be confusing if they already new about it's "constant-ness?"

 

[K^2]

They already did, because Maxwell's equations give you a constant c, without specifying coordinate system. So people thought that maybe Maxwell's equations are only valid in some special coordinate system, and so Michelson Morley experiment tried to verify that.

 

[nhmllr]

They already did, because Maxwell's equations give you a constant c, without specifying coordinate system. So people thought that maybe Maxwell's equations are only valid in some special coordinate system, and so Michelson Morley experiment tried to verify that.

Ohhhh ok. I've never looked at anything about electromagentism- thanks.