Electromagnetic attraction. How?

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Discussion Overview

The discussion revolves around the concept of electromagnetic attraction, particularly focusing on the role of virtual particles and their implications in explaining forces. Participants explore theoretical explanations, mathematical interpretations, and the nature of attraction versus repulsion in the context of quantum field theory.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that a virtual particle with momentum can be understood as a plane wave, which may explain the attractive force between particles when momentum is transferred in a specific direction.
  • Another participant argues that the concept of virtual particles is insufficient for explaining forces and should remain within mathematical frameworks.
  • Some participants assert that virtual particles are not real and emphasize that attraction occurs because particles can lower their potential energy by moving closer together.
  • There is mention of a strict derivation of a static Coulomb potential in quantum electrodynamics (QED), indicating that a Coulomb force exists independently of virtual particles.
  • One participant expresses a desire for a more detailed explanation of the mechanisms behind attraction, questioning the accuracy of the initial explanation involving photon emission and absorption.
  • Another participant reiterates that virtual particles are mathematical constructs and that the notion of "trading messenger particles" is not a physical representation of reality, advocating for a focus on fields instead.

Areas of Agreement / Disagreement

Participants express differing views on the role and reality of virtual particles, with some advocating for their mathematical utility while others challenge their explanatory power. The discussion remains unresolved regarding the accuracy of the initial explanation of attraction and the mechanisms involved.

Contextual Notes

Participants highlight limitations in understanding attraction through virtual particles, pointing out that explanations may depend on mathematical interpretations and that the nature of forces may not be fully captured by simplified models.

salvestrom
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Repulsion's got a nice, 'this emits that, hits this; see Newton's third Law' explanation. Attraction. I found one thing. It says this:

A virtual particle with momentum p corresponds to a plane wave filling all of space, with no definite position at all. It doesn't matter which way the momentum points; that just determines how the wavefronts are oriented. Since the wave is everywhere, the photon can be created by one particle and absorbed by the other, no matter where they are. If the momentum transferred by the wave points in the direction from the receiving particle to the emitting one, the effect is that of an attractive force.

I guess the first question should be: is this accurate?

I have others, but it would seem better to not voice them until someone can confirm, or put it in otherwords.
 
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another example why the concept of virtual particles in laymen's terms is not sufficient to explain the forces and should therefore be avoided; you can understand attraction based on virtual particles only via the math
 
Yes, virtual particles are not real and should never leave their home in the math of perturbation series. That's why we call them virtual. Things attract because they are able to lower their potential energy by moving closer to one another.
 
even in QED there is a strict derivation of a "static Coulomb potential", i.e. there is a Coulomb force not mediated by virtual particles plus "virtual particles on top";
 
maverick_starstrider said:
Yes, virtual particles are not real and should never leave their home in the math of perturbation series. That's why we call them virtual. Things attract because they are able to lower their potential energy by moving closer to one another.

I was under the impression they were called virtual simply because they never exist long enough to be observed, only their effects.

Your last sentence doesn't really explain anything and comes rather close to giving them an intent to their action.

Repulsion has an explanation that is a consequence of something that the particles are continuously doing that causes a certain reaction if they get close enough. I'm looking for a less general explanation than this of what action and reaction is taking place when attraction occurs. My original post contains someone elses explanation which seems to say that a photon emitted by an electron, such that the photon is headed away from, say, a proton can end up hitting the proton from 'behind' so that the electron's knockback from emission and the protons push forward from absorption push the pair closer.

Is the original explanation accurate? Is my interpretation accurate?
 
salvestrom said:
I was under the impression they were called virtual simply because they never exist long enough to be observed, only their effects.

Your last sentence doesn't really explain anything and comes rather close to giving them an intent to their action.

Repulsion has an explanation that is a consequence of something that the particles are continuously doing that causes a certain reaction if they get close enough. I'm looking for a less general explanation than this of what action and reaction is taking place when attraction occurs. My original post contains someone elses explanation which seems to say that a photon emitted by an electron, such that the photon is headed away from, say, a proton can end up hitting the proton from 'behind' so that the electron's knockback from emission and the protons push forward from absorption push the pair closer.

Is the original explanation accurate? Is my interpretation accurate?

No, virtual particles are not real. They're a mathematical artifact of how we solve certain equations in quantum field theory. That's why we call them virtual. The whole picture of "trading messenger particles" isn't physical. Far better to stay with the concept of a field.
 

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