The reality of photons (real vs virtual etc)

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Discussion Overview

The discussion revolves around the nature of photons, specifically the distinction between real and virtual photons, and the challenges in observing photons compared to other elementary particles. Participants explore the implications of these distinctions for understanding electromagnetic (EM) fields and the mysteries surrounding them, including comparisons to dark matter and dark energy.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that all photons might be considered "virtual" in a conceptual sense, as they are constructs to explain observable phenomena in EM fields.
  • Others argue that dark matter and dark energy are more mysterious than the EM field, which is understood as a fundamental field not made up of anything else.
  • A participant asserts that current models of electromagnetism can predict and explain all known phenomena, suggesting a complete understanding within the modern experimental domain.
  • Concerns are raised about the ability to "see" photons compared to other particles, with some participants noting that photons can be recorded on photographic film, while others question the visibility of neutrons in cloud chambers.
  • There is a discussion about high-frequency photons, such as gamma radiation, and their impact on photographic film, referencing historical events like the Chernobyl nuclear reactor explosion.

Areas of Agreement / Disagreement

Participants express differing views on the nature of photons and the completeness of our understanding of the EM field. There is no consensus on whether the mysteries of the EM field are comparable to those of dark matter or dark energy.

Contextual Notes

Participants highlight limitations in observing certain particles and the definitions of "real" versus "virtual" photons, as well as the implications of these distinctions for understanding fundamental physics.

girts
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I mean there is this division between virtual (in static situations) and real photons as the quanta of the EM field, but aren't all photons essentially "virtual" in the sense that they are purely made up by us in order to explain why we see discrete impacts of specific energy for a given EM field on a given target etc?

What I want to ask by this is that for the elementary particles like electrons and protons/neutrons we can "see" them in more ways (cloud chambers etc) than we can see photons and for photons I assume we really don't have any real mechanism to "see" their existence at all apart from noticing the changes that happen when certain energy/frequency EM field is present within an area?PS. I do realize virtual photons are just an expression to describe situation of a static EM field versus normal photons that describe a dynamic EM field which can transfer energy.Would it be fair to say that excluding the fact that it is all around us and we have learned the working principle of the EM field, it's basics or whatever makes it up in the first place is just as much of a mystery to us as dark matter or dark energy?
Yet we don't say "dark EM field" but we say dark matter, but we do know some things about dark matter don't we? So in a sense we also know some things about the EM field and some others we simply can't know, where is the line between calling something solved and calling something "dark" given the fact that in physics many times certain aspects work the way they do without us having a real physical way of understanding the reasons behind that?
 
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Hi girts,
girts said:
Would it be fair to say that excluding the fact that it is all around us and we have learned the working principle of the EM field, it's basics or whatever makes it up in the first place is just as much of a mystery to us as dark matter or dark energy?
I'd say a definite no to that. Dark matter and dark energy are currently far more mysterious concepts than the EM field.
girts said:
it's basics or whatever makes it up in the first place is just as much of a mystery to us
To our current knowledge the EM field is one of the fundamental fields, that is, it is not made up of anything else.
girts said:
but we do know some things about dark matter don't we?
Not much that is certain. We think dark matter may exist, so we are looking for it.
girts said:
where is the line between calling something solved and calling something "dark" [...]
There is no fine line, "dark" is just a word.
girts said:
[...] given the fact that in physics many times certain aspects work the way they do without us having a real physical way of understanding the reasons behind that?
Physics is not about reasons. Physics is about models that can make predictions.
 
girts said:
aren't all photons essentially "virtual" in the sense that they are purely made up by us in order to explain why we see discrete impacts of specific energy for a given EM field on a given target etc?
No, that is only real photons. Virtual photons are not for that.

girts said:
Would it be fair to say that excluding the fact that it is all around us and we have learned the working principle of the EM field, it's basics or whatever makes it up in the first place is just as much of a mystery to us as dark matter or dark energy?
Not even remotely fair. Our current understanding of EM is complete within the modern domain of experimental inquiry. There is no know EM phenomenon or observation that we cannot predict or explain quantitatively with our current models. Thus, we understand EM completely in this domain.
 
girts said:
What I want to ask by this is that for the elementary particles like electrons and protons/neutrons we can "see" them in more ways (cloud chambers etc) than we can see photons and for photons I assume we really don't have any real mechanism to "see" their existence at all apart from noticing the changes that happen when certain energy/frequency EM field is present within an area?
How could we "see" neutrons in a cloud chamber? They're not charged.

In fact, photons are easier to "see" than many other particles whose reality you happily accept - photographic film records their impact quite nicely.
 
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Seeing photons do you mean high frequency ones like gamma radiation destroying a film like those in the early live recordings from the Chernobyl nuclear reactor explosion back in 1986?

I do remember seeing those bright little flashes on the video which i assume are gamma impacts right?
 
girts said:
Seeing photons do you mean high frequency ones like gamma radiation destroying a film like those in the early live recordings from the Chernobyl nuclear reactor explosion back in 1986?

well that and I suspect @Nugatory was referring to normal photographic film that capture photons quite well
 

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