Is c invariant in Accelerating frames?

In summary, the experts in the conversation discuss the measurement of light in an accelerating system and whether one-way measurements from front to back and vice versa would result in (c + v) = (c - v) = c as usual. They mention that coordinate velocity is dependent on the coordinate system used, while four-velocity is defined in a coordinate-independent geometric fashion. They also discuss how distances are defined differently in an accelerating space ship, leading to different measurements of the speed of light in different parts of the ship.
  • #36
=Klockan3;2307655]^^
.

The correct observation then is that time flows with different rates at different parts in the accelerating frame, if you consider this then C is constant. And yes, they have made experiments and shown that time dilation due to gravitation exists, don't know about acceleration but it would be really strange if it wasn't the same.
I think you misread my question:
austin0
Oh a related question. I assume that by this time light speed has been measured in all possible circumstances and directions. Do you know the results of actual tests up and down differing altitudes and potentials?

I am aware of the tests for dilation. And yes tests of accelerating clocks have confirmed dilation there to. I was wondering if tests with precision clocks had been made for light speed with and against the potential gradient or, to and from satellites to
earth etc.

As regards the original question. Can I interpret your answer as meaning that light would NOT be isotropic and invariant as directly observed as clock readings at the ends of the frame?
Thanks
 
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  • #37
Austin0 said:
As regards the original question. Can I interpret your answer as meaning that light would NOT be isotropic and invariant as directly observed as clock readings at the ends of the frame?
Thanks
Yes, things wouldn't make sense otherwise.

1: There is time dilation in this system.
2: Both observers agree of the distance of a light clock positioned at one of them directed orthogonally to the distance between them.
3: The distance between the observers is constant so they would both observe the same bouncing in the light clock.

If we sum these together then one observer will observe a different speed of light relative to their own time than the other, which is due to the time dilation, but if you consider proper time C is constant. This only occurs in GR and never in SR. SR only works between inertial frames, this is a single accelerating frame and you can't study it trying to break it down into inertial frames.
 
  • #38
Sorry, I didn't make myself clear.
I'm a bit irritated about you jumping in an already confused thread, claiming strange things.
Therefore I asked you to specify the coordinate system you're speaking of. If you fail to do so -what I, I admit, expect- it would hopefully show you and the OP that your claims are unfounded. If you can write down these coordinates and their relation to Rindler coordinates, I'll have to explain why they don't pertain to the OP's question.
 
  • #39
Klockan3 said:
And yes, they have made experiments and shown that time dilation due to gravitation exists, don't know about acceleration but it would be really strange if it wasn't the same.
It would be very strange, since the only reason time dilation exists due to gravity is due to the equivalence principle equating being "at rest" in a gravitational field to an accelerated reference frame, in which time dilation is expected between different positions in the frame.
 

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