Date: April 5th, 2026 1:05 PM
Author: in the naked
Are you an eliminativist, an emergentist or a reductionist regarding "photon existence" in classical regimes:
If I have to take a precise position, it’s a layered reductionist with emergent structure, not an eliminativist.
Let me make that explicit in operational terms.
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1) What I would not claim (eliminativism)
An eliminativist stance would say something like:
“Photons don’t really exist in classical regimes—only fields do.”
That’s too strong and actually misaligned with the underlying theory:
• The quantum electromagnetic field is still the correct substrate
• Photon number is still a well-defined operator in appropriate bases
• The theory that predicts all observables still contains photons
What does disappear is not photons themselves, but:
their operational identifiability as discrete events
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2) Reductionist core (what everything reduces to)
At the base level:
• The electromagnetic field is quantized
• States (including coherent states) evolve unitarily
• All classical behavior is derivable as a limit of that theory
So in that sense:
classical radio waves are reducible to quantum field states with large occupation numbers
That’s the reductionist commitment.
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3) Emergent layer (why photons “fade out”)
In the classical regime:
• The system is well-described by coherent states
• Photon number becomes:
• very large
• highly uncertain (Poisson fluctuations ~ √N)
Crucially:
• There is no stable way to individuate “this photon” vs “that photon”
• Detection integrates over many quanta
So:
the field amplitude and phase become the stable observables, not photon counts
This is emergence in a precise sense:
• New variables (continuous fields) become sufficient statistics
• Old variables (individual quanta) lose operational resolution
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4) What “photon existence” means across regimes
We can make this sharper:
Quantum (low N, high resolution)
• Photon number is:
• measurable
• stable under repeated experiments
• “Photon” is a good observable
Classical (high N, coarse measurement)
• Photon number:
• fluctuates strongly relative to resolution
• is not directly measured
• “Photon” is a latent variable, not a useful descriptor
So:
photons don’t stop existing—they stop being the right coordinates for the system
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5) A more formal way to state the position
• Ontology: quantum electromagnetic field (with photon excitations)
• Effective description:
• classical fields arise as expectation values of coherent states
• Observables:
• shift from number operators → field amplitudes
So the mapping is:
photon ontology retained
photon-level description abandoned when it ceases to be stable or informative
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6) Why this isn’t just philosophical preference
You can test the boundary:
• Reduce signal power → photon statistics reappear
• Use photon-counting detectors → discreteness becomes observable
• Measure g^{(2)}(0) → distinguish classical vs non-classical light
So:
the “existence” of photons is tied to whether the experimental setup can resolve their signatures
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Bottom line
The most coherent position is:
• Reductionist: everything is grounded in the quantum field and its excitations
• Emergentist: classical fields are stable, higher-level structures that replace photon descriptions when occupation is large
• Not eliminativist: photons don’t disappear—they become operationally irrelevant in that regime
If you want to push this further, the next step is to ask whether “photon” is basis-dependent (it is) and what that implies for treating it as an ontological primitive. That’s where things get really interesting.
(http://www.autoadmit.com/thread.php?thread_id=5853795&forum_id=2E#49795514)