- #31
Pseudo Epsilon
- 103
- 0
and is there a minimum frequency that an electron can emit?
Is there a limit to how much energy can be stored in a photon?
Click For Summary
There is no theoretical limit to the energy that can be stored in a photon, as its energy is defined by the equation E=hf, where frequency can be arbitrarily high. The highest measured photon energy is 16 TeV, with potential theories suggesting energies up to 10^19 eV. While there are no upper limits on photon energy, high-energy photons can interact with cosmic background radiation, leading to a filtering effect known as the Greisen–Zatsepin–Kuzmin limit. The discussion also touches on the nature of photons, emphasizing their properties beyond just energy, and explores the implications of photon collisions and the potential for producing high-energy photons through various processes. Overall, the conversation highlights the complexities of photon energy and interactions in the universe.
- #32
Pseudo Epsilon
- 103
- 0
otherwise an electron at zero kelvin could emit a photon tap into zero point energy by emmiting a radio wave with a very long wavelenth?
- #33
Pseudo Epsilon
- 103
- 0
so the universe is definantly finite?Nugatory said:
- #34
e.chaniotakis
- 80
- 3
Well, about high energy gammas, the most energetic ones are produced in violent phenomena in the cosmos.
(e.g in AGN's , GRBs etc).
There are also photons produced in the p+γ(CMB)->π0 +p, π0->γγ
The maximum energy gained by photons this way is of order ~10^19 eV.
The gammas however interact with CMB photons via the γ+γ=>e+e process and rapidly lose energy this way
Electrons on the other hand either interact via inverse compton or by bremsstrahlung and create more photons which interact/radiate again, leading to measured photons in the GeV-TeV range on earth.
These are the gammas we measure in our air shower arrays:)
(e.g in AGN's , GRBs etc).
There are also photons produced in the p+γ(CMB)->π0 +p, π0->γγ
The maximum energy gained by photons this way is of order ~10^19 eV.
The gammas however interact with CMB photons via the γ+γ=>e+e process and rapidly lose energy this way
Electrons on the other hand either interact via inverse compton or by bremsstrahlung and create more photons which interact/radiate again, leading to measured photons in the GeV-TeV range on earth.
These are the gammas we measure in our air shower arrays:)
- #35
Pseudo Epsilon
- 103
- 0
there a has to be a limit tn mthe lowest frequency,otherwise an electron at zero kelvin could emit a photon tap into zero point energy by emmiting a radio wave with a very long wavelenth. Where is my logic faulty?
- #36
mikeph
- 1,229
- 18
"zero kelvin electron" sounds a bit faulty
If there is no limit to the universal rate of expansion then I see no limit to the amount of cosmological red-shift endured by a photon, and so no limit on the wavelength of a photon. If the cosmic expansion continues, which looks fairly likely, surely an unattenuated photon will eventually have an arbitrarily long wavelength after enough time elapses.
If there is no limit to the universal rate of expansion then I see no limit to the amount of cosmological red-shift endured by a photon, and so no limit on the wavelength of a photon. If the cosmic expansion continues, which looks fairly likely, surely an unattenuated photon will eventually have an arbitrarily long wavelength after enough time elapses.
- #37
e.chaniotakis
- 80
- 3
About the GZK cutoff, yes it exists (or so we believe) which prohibits us from observing protons more energetic than 6*10^19 eV (taken that the interaction length of the proton in the CMB is lower than the proton source- Earth distance). Of course, there might be a way for a (e.g)10^25eV proton to be created and its interactions to create high energy gammas before it is attenuated by the CMB.. Just speculating.
Or there might be some more exotic production channels for gammas that do not respect the GZK cutoff.. But these are all speculations (to be answered by Pierre Augere and IceCube hopefully).
About why gamma gamma interactions occure, check the so called "Delbruck scattering".
Now, about the low energy photons I have no better explanation than the one proposed by MikeyW
Or there might be some more exotic production channels for gammas that do not respect the GZK cutoff.. But these are all speculations (to be answered by Pierre Augere and IceCube hopefully).
About why gamma gamma interactions occure, check the so called "Delbruck scattering".
Now, about the low energy photons I have no better explanation than the one proposed by MikeyW
- #38
OmCheeto
Gold Member
- 2,493
- 3,460
Vanadium 50 said:
I like Lurch's argument about the "Planck length".
---------------------------
pppppppppppppps. Why is this in the "General Physics" section?
and yes, I did self sensor my "I'm smarter than Einstein and Feynman combined, to the 12th power!", 47 comments
- #39
Pseudo Epsilon
- 103
- 0
it was moved from general physics.
- #40
Pseudo Epsilon
- 103
- 0
it was moved from quantum physics.
- #41
Pseudo Epsilon
- 103
- 0
concerning blue and redshifting: if you travel at c parellel to light the magnetic component disapears. What happens concerning the magnetic part of em radiation if a tachyon is traveling parellel to it?0_0
- #42
OmCheeto
Gold Member
- 2,493
- 3,460
OmCheeto said:
hmmm... Regarding V50's comment, the extractable energy of the universe, and the "Oh My God Particle" I studied this morning;
Given that I have a mass of roughly 68 kilograms, and given the limited total extractable energy of the universe to accelerate "me", relative to the "OMG Particle", there is of course, a practical limit.
unsubscribe.
- #43
Pseudo Epsilon
- 103
- 0
and what would happen?Pseudo Epsilon said:
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