Photon: The Force Carrier That Moves at Light Speed

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Discussion Overview

The discussion revolves around the nature of photons as force carriers, particularly in the context of their interactions within quantum electrodynamics (QED). Participants explore concepts related to photon interactions, gauge fields, and the implications of these interactions in various physical theories.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • Some participants assert that photons do not interact with external forces but question how they can act as force carriers in phenomena like the photoelectric effect.
  • Others argue that misunderstanding arises from classical interpretations of photons, emphasizing their role as quanta of the electromagnetic field and their mediation of electromagnetic interactions.
  • There is contention regarding whether photons can interact with each other, with some claiming they do so through higher-order processes involving fermion pairs, while others maintain that photons do not interact directly.
  • Participants reference specific texts and calculations from QED to support their claims about photon interactions and scattering processes.
  • Some express frustration over the lack of clarity and insist on discussing specific texts to resolve misunderstandings.

Areas of Agreement / Disagreement

The discussion remains unresolved, with multiple competing views on the nature of photon interactions and the validity of claims made by participants. No consensus is reached regarding whether photons interact directly or through indirect processes.

Contextual Notes

Participants highlight the complexity of photon interactions, noting that interpretations can vary significantly based on the theoretical framework being applied. The discussion also reflects differing levels of understanding and interpretation of quantum electrodynamics.

scilover89
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Photon doesn't interact with external force and move with light speed. But why can it act as force carrier, play a role in photoelectric etc.?
 
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I think your question rise from the misunderstanding the concept of foton! and try to understand it with classical means.
when you quantize the electromagnetic field, you see a harmonic ossilator in somewhere. and they call it foton.
 
We address gauge fields to be carriers of "force".All 4 fundamental interactions are mediated by gauge fields...Photon is the quanta of the EM field,which is a gauge field and can mediate the EM interaction.

As for "external force",i don't see what you could possibly refer to.

As for "harmonic oscillators",the analogy is not good,not good at all...

Daniel.
 
scilover89 said:
Photon doesn't interact with external force

What, precisely, are you thinking about in connection with this statement? Photons most certainly do interact with charged particles via the electromagnetic interaction at its fundamental level.
 
jtbell said:
Photons most certainly do interact with charged particles via the electromagnetic interaction at its fundamental level.

Come again...?Photons interact with photons (in QED,not EW,or SM) via lepton-antilepton pairs,and viceversa...PHOTONS ARE ELECTROMAGNETIC INTERACTION...

Daniel.
 
dextercioby said:
Photons interact with photons (in QED,not EW,or SM) via lepton-antilepton pairs,


This is wrong. Photons do NOT mutually interact unlike the gluons from QCD for example. The emitted photons coming from matter-amtimatter interactions do NOT mutually interact


marlon
 
What...??Photons do interact,check QED again...Especially the last section from Ahizer & Berestetzkii,where the diff.cross-section for photon-photon scattering is computed...

Daniel.
 
dextercioby said:
What...??Photons do interact,check QED again...Especially the last section from Ahizer & Berestetzkii,where the diff.cross-section for photon-photon scattering is computed...

Daniel.

What is the gauge boson that mediates the foton-foton-interaction ?

Remember, this is a raethorical question, so don't try to give a right valid answer because there ain't no such gauge boson.

marlon
 
It's not a gauge-boson,there are 2 pairs of massive lepton-massive antilepton...Take the book,Marlon...:rolleyes:

Take the pencil.Compute the S-Matrix for QED in the 4-th order and then the amplitude of probability of transition between the initial state with 2 photons and final state with 2 photons...That is the simplest example of photon-photon scattering...

You claim to know so much,yet u sometimes cannot prove it...

Daniel.

P.S.Don't argue for the sake of arguing,especially when u're wrong...
 
  • #10
dextercioby said:
It's not a gauge-boson,there are 2 pairs of massive lepton-massive antilepton...Take the book,Marlon...:rolleyes:

Take the pencil.Compute the S-Matrix for QED in the 4-th order and then the amplitude of probability of transition between the initial state with 2 photons and final state with 2 photons...That is the simplest example of photon-photon scattering...

Sorry, this is just balony. I happened to have that book and you clearly are misinterpreting this content. What you write does NOT prove that photons interact. You are wrong on this specific argument for the above reason.

You claim to know so much,yet u sometimes cannot prove it...

Please, let us not get personal and please do try to stay more polite and mature in your answers.

P.S.Don't argue for the sake of arguing,especially when u're wrong...
I am not wrong, my dear friend. Don't deny the abelian field theory. Photons do not Interact, PERIOD.

marlon
 
  • #11
Nope.Electrons are scattered one on another (Mo/ller scattering),just the same way photons are scattered one on another...Electrons need a photon,photons,need 2 electrons and 2 positrons.

What is the specific chapter called...?

Daniel.
 
  • #12
Please, both of you. Somebody quote the relevant text from Ahizer & Berestetzkii and interpret it and discuss THAT. Get off this did-so, did-not third grade argument!
 
  • #13
Look,

From Quantum Electro Dynamics (QED) we know that Photons cannot couple directly to each other, since they don't carry charge, but they can interact through higher order processes:
A photon can, within the bounds of the uncertainty principle, fluctuate into a charged fermion/ anti-fermion pair, to either of which the other photon can couple. This fermion pair can be leptons or quarks.


It is misleading to say that photons interact because people will copare this to two charged particles interacting...This is a totally differe,t type of (indirect) interaction


marlon
 
  • #14
Last edited by a moderator:
  • #15
I'm glad we finally reached an agreement.

Daniel.
 

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