Feynman diagrams - electrical charges

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Discussion Overview

The discussion revolves around the interpretation of Feynman diagrams in the context of electrical charges, specifically focusing on the interactions between like charges (e.g., two negatively charged electrons) and the role of photons in these interactions. Participants explore theoretical aspects, potential misconceptions, and the nature of forces at the subatomic level.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant questions whether a negatively charged particle emits photons in a specific direction towards another negatively charged particle and how this relates to their interaction.
  • Another participant suggests that if photons are emitted, they would be emitted in all directions, raising questions about their wavelength and detectability.
  • There is a proposal that the interaction between charges might be based on conservation of momentum, with one charge emitting a photon and the other being affected by it.
  • A participant corrects an earlier claim about charge interactions, noting that negative and positive charges attract rather than repel.
  • Some participants express skepticism about the literal interpretation of photon emission in Feynman diagrams, suggesting that virtual photons are mathematical constructs rather than real emissions.
  • Questions are raised about the understanding of the electric field between electrons at the subatomic level and requests for resources to learn about Feynman diagrams.

Areas of Agreement / Disagreement

Participants exhibit disagreement regarding the interpretation of photon emission in the context of charge interactions. While some acknowledge the role of virtual photons in theoretical frameworks, others question their physical reality. The discussion remains unresolved with multiple competing views on the nature of these interactions.

Contextual Notes

Participants highlight the limitations of interpreting Feynman diagrams literally and the potential confusion surrounding the concept of virtual photons. There is an acknowledgment of the complexity of interactions at the subatomic level, which may not be fully understood.

Who May Find This Useful

This discussion may be of interest to those studying quantum mechanics, particle physics, or anyone looking to deepen their understanding of Feynman diagrams and the interactions of electrical charges.

Camille
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I have a request for some explanation in Feynman diagram concerning repelling/attraction of electrical charges. I have been told that when two charges (say, e1(-) and the e2(-)) repel each other, a photon is being emitted from one of them, and the other charge is later being hit by this photon. There is some confusion I can see in this explanation.

First: Does the charge e1(-) emit just a beam of photons in the direction of charge e2(-)? If yes, then how is that this photons always hit charge e2(-) and never miss? Charge e2(-) could move before photons hit it.

Second: Or perhaps the charge e1(-) emitts photons constantly, in all directions. If that's so, what is the wavelength of those photons? Can we detect them?

Third: Does the interaction between charges is based purely on conservation of momentum? (I mean: charge e1(-) gives up some energy (mass of photon) and is therefore tilted outwards the system and charge e2(-), hit by the photon, also gets tilted - therefore we see the repelling.)

Fourth: In the system of e1(-) and e2(-), do they both emit photons in each other's direction?
 
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For one thing, a negative and a positive charge attract each other, not repel.

Feynman diagrams are just a convenient shorthand for a mathematical expansion. They shouldn't be taken too literally.
 
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Fair point, my error :D

But they must have something to do with the reality. Photons must be really emitted, right...?
 
Camille said:
But they must have something to do with the reality. Photons must be really emitted, right...?

Virtual photons are not really emitted. They are just terms in perturbation expansion. When 2 electrons meet, there is definitely something happening in the electromagnetic field between them, but the repulsive force is not caused by physical emission of photons.

The virtual photons (Green functions) are just a tool used to solve differential equations.
 
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Is it already known in physics what is happening in the electric field between the electrons? And I mean at the subatomic particles level.

Can someone share some materials from where I could learn to use and read Feynman diagrams in a more or less easy way?
 

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