Does photon have upper limit energy ?

In summary, there is no known upper limit on the maximal energy of photons. However, there are caveats to this information, and QFT may not be able to accurately represent energies beyond the Planck energy.
  • #1
magnetar
83
0
Does photon have upper limit energy ?

Does photon have upper limit energy(beyond gamma-ray) ?Thank you !
 
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  • #2
mmm...not really sure... but perhaps the Planck scale is the ultimate (so far)... you may have problems if your photon wavelength is shorter than the Planck length or at least the rules of the game may change (?)
 
  • #3
yes- Planck energy- a photon at Planck energy would have a wavelength equal to the Planck length-
 
  • #4
magnetar said:
Does photon have upper limit energy(beyond gamma-ray) ?Thank you !
No. There is no upper limit.
The Planck energy is large, but is not a limit.
 
  • #5
You may consider that a frequency higher than an inverse Planck time is not meaningful in current theories, so that we cannot give a clear meaning to a photon energy higher than 1/sqrt (hbar * G / c^5) * h.
 
  • #6
In current QFT, which is at the origin of the concept of what is a "photon", there is no official upper limit on what is the maximal energy of a photon.
However, there are two caveats:
- the first is that gravity (which is NOT included in QFT as we know it), suggests that there will be trouble around the Planck energy. In other words, we think that whatever QFT might say about arbitrarily high energies, it will not be correct because gravity will not only be not neglegible (as it is assumed in QFT), but it will rather be so dominant that it is meaningless to try to work with a theory that doesn't contain gravity
- QFT itself, as we know it, has a serious problem at high energies. We think that current QFT are "low energy effective" approximations to something else, and this approach is what justifies renormalisation schemes. This has nothing to do with Planck scales, but rather with the intrinsic structure of QFT.
 

1. What is the upper limit energy of a photon?

The upper limit energy of a photon is determined by its frequency. The higher the frequency, the higher the energy of the photon. However, there is no known upper limit for the energy of a photon.

2. Can a photon have infinite energy?

No, a photon cannot have infinite energy. According to Einstein's theory of relativity, the speed of light is the maximum speed in the universe. Therefore, the energy of a photon cannot exceed a certain limit.

3. How is the energy of a photon calculated?

The energy of a photon can be calculated using the formula E = hf, where E is the energy, h is Planck's constant, and f is the frequency of the photon.

4. Does the energy of a photon change with its wavelength?

Yes, the energy of a photon is directly proportional to its frequency, which is inversely proportional to its wavelength. This means that as the wavelength of a photon increases, its energy decreases.

5. Is there a difference between the energy of a photon and its momentum?

Yes, there is a difference between the energy of a photon and its momentum. While the energy of a photon is determined by its frequency, its momentum is determined by its wavelength. This is due to the wave-particle duality of photons, where they exhibit both particle-like and wave-like properties.

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