- #1
kurious
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If a photon was made from more than one particle, how would quantum field theory be modified?
Quantum Field Theory: What if Photon Made from Multiple Particles?
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Discussion Overview
The discussion revolves around the theoretical implications of considering a photon as being composed of multiple particles, specifically in the context of quantum field theory. Participants explore the mathematical representation of photons and the potential for alternative models involving fermionic fields.
Discussion Character
- Debate/contested
- Technical explanation
- Conceptual clarification
Main Points Raised
- Some participants propose that a spin 1 field, like the photon, can be represented as a combination of two spin 1/2 fields, referencing historical ideas attributed to Schwinger.
- Others challenge this notion, emphasizing that conventional treatments of quantum electrodynamics (QED) represent the photon field as a vector potential and not as a combination of fermionic fields.
- A participant questions how the mass spin = 0 state would be suppressed in theories treating the photon as two fermions, indicating a lack of clarity in existing theories.
- Some participants express skepticism about the validity of theories that treat photons as two fermions, noting that they have not encountered credible references supporting this idea.
- There is mention of Bose-Einstein condensates (BEC) as an example of fermionic fields that can exhibit bosonic behavior, suggesting a potential analogy to the discussion about photons.
- Several participants express uncertainty about the details of these theories and request references or sources to substantiate claims made in the discussion.
Areas of Agreement / Disagreement
Participants do not reach a consensus on the validity of treating photons as composed of multiple particles, with multiple competing views and significant uncertainty expressed regarding the implications and existing theories.
Contextual Notes
Limitations include the lack of established references for the claims made about photons being represented as fermions, as well as unresolved questions about the suppression of certain states in these theoretical frameworks.
- #2
selfAdjoint
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A spin 1 field, like the photon's, can be represented as the combination of two spin 1/2 fields. This is an idea that IIRC goes back to Schwinger. It's just math, because the spin 1/2 fields are not observed, and don't have any collective effects that are observed either. Note the difference from quarks, which are not observed but whose collective effects can be calculated and matched to experimental results.
Various people have put forward theories with these unobservable fermions generating the photons, but I have yet to see one that is well enough constructed in detail for other physicists to take it seriously.
Contrary to what you often hear, physics is not averse to wild and crazy ideas per se. But it does require that creators do their homework and link their theories to observation. All the fantastic level of detail observation that 100 years of experiment have given us, and which ordinary quantum mechanics does link to successfully. Just shouting over and over that my theory is important and the wicked old scientists are suppressing it won't work.
Various people have put forward theories with these unobservable fermions generating the photons, but I have yet to see one that is well enough constructed in detail for other physicists to take it seriously.
Contrary to what you often hear, physics is not averse to wild and crazy ideas per se. But it does require that creators do their homework and link their theories to observation. All the fantastic level of detail observation that 100 years of experiment have given us, and which ordinary quantum mechanics does link to successfully. Just shouting over and over that my theory is important and the wicked old scientists are suppressing it won't work.
- #3
lethe
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a photon is represented as two fermions? what the... can you provide a reference for this? every treatment of QED i have ever seen treated the photon field as a vector potential, satisfying commutation relations (not anticommutation). I have never seen this done, but I have read that some people have also tried quantizing the field strength itself, instead of the vector potential, but either way, it is still a bosonic field.selfAdjoint said:
i am not saying you are wrong, nor trying to get into an argument with you, but i am just saying that I have never heard of what you are saying, and would like you to back it up with some references.
selfAdjoint: please provide a reference that shows the photon field being represented as two fermionic fields!
- #4
quantumdude
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I've never read any theory that treats the photon as two fermions, but does not sound all that far fetched. Consider a BEC formed by rubidium atoms for an example of a collection of fermion fields that obeys Bose-Einstein statistics.
- #5
quantumdude
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SelfAdjoint:
In these theories in which the photon is treated as two fermions, how is the MS=0 state suppressed, so that the eigenvalues of Jz are restricted to ±1? A would-be theorist (p_mintz) posted his idea for treating the photon as 2 fermions over a year ago and I asked him the same question, but he had no answer for me.
edit: fixed a typo
In these theories in which the photon is treated as two fermions, how is the MS=0 state suppressed, so that the eigenvalues of Jz are restricted to ±1? A would-be theorist (p_mintz) posted his idea for treating the photon as 2 fermions over a year ago and I asked him the same question, but he had no answer for me.
edit: fixed a typo
- #6
selfAdjoint
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Tom, I haven't a clue. I haven't studied any of these theories deeply.
- #7
lethe
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selfAdjoint: can you provide a reference, a source, a name, for a theory that treats the photon as two fermions?selfAdjoint said:
- #8
selfAdjoint
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Well the one I can't stand is from our occasional poster dr Ameen. And Tom just mentioned another one. Hey, I never said they were reasonable!
- #9
lethe
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were you referring to crackpot theories?selfAdjoint said:
- #10
kurious
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How is the M spin = 0 state suppressed?
A good point.I'll let you know when my theory can explain it!
This is the crux of the matter.
A good point.I'll let you know when my theory can explain it!
This is the crux of the matter.
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