Wavelength of photons exchanged between charged particles

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Discussion Overview

The discussion centers on the nature of photons exchanged between charged particles, specifically addressing whether these photons can be characterized by a wavelength and how this relates to the concept of virtual versus real photons. The scope includes theoretical considerations and conceptual clarifications regarding particle physics.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant suggests that when two electrons approach each other, they repel each other through the exchange of photons, questioning if there is a general range of wavelength for these photons and whether this depends on their approach speed.
  • Multiple participants assert that the photons involved in this exchange are virtual photons, which they claim do not have wavelengths and cannot be counted.
  • Another participant expresses confusion regarding the distinction between virtual and real photons, citing a Wikipedia article that discusses the implications of quantum mechanical uncertainty on the definitions of these particles.
  • One participant critiques the Wikipedia article, describing it as inconsistent and emphasizing that virtual photons are not real and lack wavelengths.
  • Another participant reiterates the confusion about the distinction between virtual and real photons, referencing the same Wikipedia article to support their view.

Areas of Agreement / Disagreement

Participants generally agree that virtual photons do not have wavelengths and are not real. However, there is disagreement regarding the clarity of the distinction between virtual and real photons, with some expressing confusion and others critiquing the sources that discuss these concepts.

Contextual Notes

The discussion highlights limitations in the definitions and understanding of virtual versus real photons, as well as the potential for ambiguity in sources like Wikipedia. The varying interpretations of the nature of virtual photons and their properties remain unresolved.

Sophrosyne
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When two electrons approach each other, there is a repulsion between them by the exchange of a photon as the electromagnetic force carrier. Is there a general range of wavelength of such photons? Does it depend on how rapidly these electrons are approaching each other?
 
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These are virtual photons. They are not real. They do not have wavelengths. You can't even count them.
 
Vanadium 50 said:
These are virtual photons. They are not real. They do not have wavelengths. You can't even count them.
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What confuses me about that is that it seems the distinction between virtual and real photons greys out a little and is often not so distinct. Let me quote from this Wikipedia article:

"As a consequence of quantum mechanical uncertainty, any object or process that exists for a limited time or in a limited volume cannot have a precisely defined energy or momentum. This is the reason that virtual particles – which exist only temporarily as they are exchanged between ordinary particles – do not necessarily obey the mass-shell relation. However, the longer a virtual particle exists, the more closely it adheres to the mass-shell relation. A "virtual" particle that exists for an arbitrarily long time is simply an ordinary particle – in that sense electromagnetic waves, e.g. in a microwave oven, consist of real photons rather than virtual ones. (A typical power oven emitting microwaves of roughly λ=3cm at a power of 700 W produces 1026[PLAIN]https://wikimedia.org/api/rest_v1/media/math/render/svg/a9abdbae5cf3b55fda1e1574a27911e0aed30f19real photons per second.)

However, all particles have a finite lifetime, as they are created and eventually destroyed by some processes. As such, there is no absolute distinction between "real" and "virtual" particles. In practice, the lifetime of "ordinary" particles is far longer than the lifetime of the virtual particles that contribute to processes in particle physics, and as such the distinction is useful to make."
https://en.m.wikipedia.org/wiki/Virtual_particle
 
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That Wikipedia article is a hot mess, with statements true in one context being sprinkled about in other contexts. Virtual photons are not real. They do not have wavelengths. You can't even count them.
 
Sophrosyne said:
What confuses me about that is that it seems the distinction between virtual and real photons greys out a little and is often not so distinct. Let me quote from this Wikipedia article:

Stuff like this is the reason that wikipedia is generally not an accepted source here.
 

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