Question about a photon's momentum.

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In summary, when light travels in a medium, its speed is reduced due to complex interactions with the medium. However, individual photons still travel at the speed of light. The Lorentz factor is not infinite in this case and photons still have momentum, which can be calculated using the equation p = E/c. There are FAQs and discussions that address this topic further.
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greswd
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When light travels in a medium, its speed is less than c.

Thus the lorentz factor is not infinite. Since photons have zero rest mass, does this also imply that the photons have zero momentum?
 
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The 'speed of light' in a medium is a complex subject that has been discussed at length in these forums. but individual photons still travel at 'c' in such a medium. the overall travel is slower than c. For example information transmission in fiber optic cable is a bit slower than in a vacuum.

Photons always have momentum.

In a medium there is a complex scattering and absorption interaction between photons , the phonons of of atomic structures such as lattices and atomic particles. There is a FAQ on this, but it is not so 'crystal clear' to me...and from another discussion:

Oh - hang on, found a FAQ:

https://www.physicsforums.com/showpost.php?p=899393 [Broken]

But see:
http://physics.stackexchange.com/que...-through-glass [Broken]
http://physics.stackexchange.com/que...qed-snells-law [Broken]
... many objections in the FAQ are addressed in these.
 
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1. What is a photon's momentum?

A photon's momentum is the amount of motion it possesses in a particular direction. It is a fundamental property of a photon, which is a tiny packet of energy that makes up light.

2. How is a photon's momentum calculated?

A photon's momentum can be calculated using the formula p = E/c, where p is momentum, E is energy, and c is the speed of light in a vacuum. This shows that a photon's momentum is directly proportional to its energy and inversely proportional to the speed of light.

3. Does a photon have mass?

No, a photon does not have mass. It is a massless particle, which means it has no rest mass. However, it does have energy and momentum.

4. Can a photon's momentum change?

Yes, a photon's momentum can change when it interacts with matter. For example, when a photon is absorbed or emitted by an atom, its momentum changes. This is the basis of many scientific technologies, such as solar cells and lasers.

5. How does a photon's momentum relate to its wavelength and frequency?

A photon's momentum is directly proportional to its wavelength and frequency. This means that photons with shorter wavelengths (higher frequency) have higher momentum, while photons with longer wavelengths (lower frequency) have lower momentum. This relationship is described by the formula p = h/λ, where h is the Planck's constant and λ is the wavelength.

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