# Are electronic transitions a result of a single photon?

Maurice Morelock
TL;DR Summary
E=hf, where f is the number of waves (each with h energy) passing a point in one sec.

Electronic transitions occur in a small fraction of a sec.

So for electronic excitation, are we talking about a single photon wave with an amplitude of hf?
E=hf

vanhees71
Maurice Morelock
Is the amplitude of the photon a function of hf?

Is the amplitude of the photon a function of hf?
Amplitude is a property of a classical wave. A photon is a quantum "particle of light", and does not have a property called "amplitude". Roughly, the amplitude of the classical wave corresponds to the number of photons.

vanhees71 and bhobba
Mentor
This is a beginner thread. The following is at the I level, but hopefully, you can glean a general idea of what is going on beyond basic HS textbooks and popularisations:
http://www.physics.usu.edu/torre/3700_Spring_2015/What_is_a_photon.pdf

When you come here for an answer, we give you the real deal, which unfortunately often requires more advanced knowledge to understand. This is one of those cases. Fingers crossed, you can still get something from it.

In fact, all particles, not just photons, are 'excitations' of an underlying quantum field (one for each particle) that pervades all space. At the elementary level, Rodney Brooks explains it here:
https://www.quantum-field-theory.net/

Or if you want to read a paper::
https://arxiv.org/pdf/1710.10291.pdf

But again, subtleties are going on Rodney, correctly at the beginner level, does not go into, e.g.:
https://cds.cern.ch/record/372369/files/9811072.pdf

Basically, QM violates outcome independence but not parameter independence. It needs to violate both to be non-local. For example, two particles can be in a state that is not two separate particles but a holistic single entity. It is subtle, but this is different from locality, as explained in the paper. We all have to start somewhere, and viewing QM as a quantum field is as good a place as any. And likely better than most.

Aso these days Schwingers Source Theory is seen as a precursor to Wilsons view of QFT that he won a Nobel Prize for:
https://quantumfrontiers.com/2013/06/18/we-are-all-wilsonians-now/

Thanks
Bill

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Maurice Morelock
Amplitude is a property of a classical wave. A photon is a quantum "particle of light", and does not have a property called "amplitude". Roughly, the amplitude of the classical wave corresponds to the number of photons.
Agreed, but is the number for the “packet” of photons = f?

Mentor
Agreed, but is the number for the “packet” of photons = f?
No. Photon number is not frequency.

You are trying to understand a quantum phenomenon with a classical model. That won't work.

vanhees71, bhobba and atyy