Undergrad What is the velocity of light in uniformly rotating frame?

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The discussion centers on the velocity of light in a uniformly rotating frame, highlighting that such a frame is non-inertial, which complicates the application of the speed of light postulate from Special Relativity (STR). Participants note that while the speed of light remains constant in inertial frames, it can vary in non-inertial frames, depending on how the frame is set up and how clocks are synchronized. An example involving Proxima Centauri illustrates that the perceived speed of celestial objects can change based on the observer's rotating reference frame. The calculations provided suggest that the velocity derived from Earth's rotation can exceed the speed of light, raising further questions about the implications of such findings. Ultimately, the conversation emphasizes the complexities of light's behavior in non-inertial frames.
pallab
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S'-frame of reference has uniform angular velocity with respect to the frame S. what is the velocity of light in S frame w.r.t S' ?
 
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pallab said:
S'-frame of reference has uniform angular velocity with respect to the frame S. what is the velocity of light in S frame w.r.t S' ?
What are your thoughts? What are the Relevant Equations? Is this for schoolwork?
 
berkeman said:
What are your thoughts? What are the Relevant Equations? Is this for schoolwork?
NO.
My friend asked me this question.but I don't know about GTR.I studied STR .According to postulate speed of light in vacuum is same in all inertial frames.But a frame with uniform angular velocity is not inertial frame and the speed of light which has same value not the velocity.
 
pallab said:
NO.
My friend asked me this question.but I don't know about GTR.I studied STR .According to postulate speed of light in vacuum is same in all inertial frames.But a frame with uniform angular velocity is not inertial frame and the speed of light which has same value not the velocity.
Start with something easy. What is the speed of Proxima Centauri (4.2 light years from earth) in a frame of reference anchored to the rotating earth?
 
jbriggs444 said:
Start with something easy. What is the speed of Proxima Centauri (4.2 light years from earth) in a frame of reference anchored to the rotating earth?
when the Earth approaches toward the Proxima Centauri its speed is more than the speed ,when Earth moves away from it,like the Earth's movement around the sun.
 
pallab said:
when the Earth approaches toward the Proxima Centauri its speed is more than the speed ,when Earth moves away from it,like the Earth's movement around the sun.
The Earth's velocity around the Sun is trivial. Ignore it. Forget about the Sun entirely.

The Earth is rotating once every 24 hours [approximately]. You anchor a frame of reference to it at this rotation rate. How does Proxima Centauri move from the point of view of this reference frame?
 
pallab said:
speed of light in vacuum is same in all inertial frames.But a frame with uniform angular velocity is not inertial frame
This is the key point. The speed of light is not limited in a non-inertial frame. It can be arbitrarily large or small.
 
The shortest totally correct answer is it depends on how you set up your rotating frame. Of specific interest is how you synchronize clocks in your "frame".
 
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jbriggs444 said:
The Earth's velocity around the Sun is trivial. Ignore it. Forget about the Sun entirely.

The Earth is rotating once every 24 hours [approximately]. You anchor a frame of reference to it at this rotation rate. How does Proxima Centauri move from the point of view of this reference frame?
v=2πR/T
now for Earth T=86400 sec.
and R=4.2 light years i.e. (9.46*1015)*4.2
so,v=2.8*1012 m/s , >c
 
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