Speed of Light in Inertial Ref Frames: Photon Perspective

In summary, according to the 2nd postulate of Special Relativity, the speed of light in vacuum is the same in all inertial reference frames, making it impossible for there to be a frame of reference of a single photon. Additionally, no matter how fast one may chase after a photon, it will always recede at the speed of light, regardless of their state of motion.
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Saptarshi Sarkar
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TL;DR Summary
What would be the speed of a photon in a beam of photons wrt another photon in the beam.
According to the 2nd postulate of Special Relativity, speed of light in vacuum is the same in all inertial reference frames.

If I take a beam of photons and see the other photons in the beam from a frame of reference of a single photon, do they look stationary or moving at the speed of light? Also, as the photon is itself moving with the doped how fast would the surrounding seem to move?
 
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As per the second postulate, the speed of light is the same in all inertial reference frames. Therefore an inertial reference frame in which light is at rest is a contradiction in terms. So there is no answer to your question - it is based on a faulty premise, namely that there is such a thing as the "frame of reference of a single photon".
 
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  • #3
Saptarshi Sarkar said:
Summary:: What would be the speed of a photon in a beam of photons wrt another photon in the beam.

According to the 2nd postulate of Special Relativity, speed of light in vacuum is the same in all inertial reference frames.

If I take a beam of photons and see the other photons in the beam from a frame of reference of a single photon, do they look stationary or moving at the speed of light? Also, as the photon is itself moving with the doped how fast would the surrounding seem to move?

There are no inertial frames moving at ##c## with respect to other inertial frames. In particular, there is no inertial frame moving along with a beam of photons.
 
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  • #4
Saptarshi Sarkar said:
If I take a beam of photons and see the other photons in the beam from a frame of reference of a single photon,

Imagine chasing that photon in an effort to catch up to it. No matter how fast you chase after it, it will forever recede from you at speed ##c##.
 
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  • #5
Mister T said:
Imagine chasing that photon in an effort to catch up to it. No matter how fast you chase after it, it will forever recede from you at speed ##c##.
And anyone watching you chase the flash of light, no matter their state of motion, will find that you are moving at less than ##c## while it is moving at ##c##... so no surprise that you can’t catch it.

(Of course @Mister T knows this - the comment is for others reading this thread)
 
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1. What is the speed of light in inertial reference frames?

The speed of light in inertial reference frames is always constant, no matter the relative motion of the observer or the source of light. This speed is approximately 299,792,458 meters per second in a vacuum.

2. How is the speed of light measured in inertial reference frames?

The speed of light in inertial reference frames is typically measured using a variety of experimental methods, such as the Michelson-Morley experiment and the Fizeau experiment. These experiments involve measuring the time it takes for light to travel between two points and using this information to calculate the speed of light.

3. What is the significance of the speed of light in inertial reference frames?

The speed of light in inertial reference frames is a fundamental constant in the universe and plays a crucial role in many physical theories, such as Einstein's theory of relativity. It also has practical applications in fields such as telecommunications and astronomy.

4. How does the speed of light in inertial reference frames differ from the speed of light in non-inertial reference frames?

In inertial reference frames, the speed of light is always constant. However, in non-inertial reference frames, such as those experiencing acceleration or gravitational forces, the speed of light may vary. This is known as gravitational time dilation and is predicted by Einstein's theory of general relativity.

5. Can anything travel faster than the speed of light in inertial reference frames?

According to our current understanding of physics, nothing can travel faster than the speed of light in inertial reference frames. This is known as the cosmic speed limit and is a fundamental principle in the laws of physics. However, there are some theoretical concepts, such as wormholes, that could potentially allow for faster-than-light travel, but these are still purely speculative and have not been proven to exist.

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