Compton effect and Photoelectric effect explained by wave theory?

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Discussion Overview

The discussion revolves around the possibility of explaining the Compton effect and photoelectric effect using classical electromagnetic wave theory. Participants explore historical perspectives, recent interpretations, and the implications of quantum mechanics versus classical theories.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants reference the fifth edition of 'Physics' by Halliday, Resnick and Krane, which claims that both the photoelectric and Compton effects can be explained by classical electromagnetic wave theory, a view known since 1927.
  • One participant mentions that W.E. Lamb and M.O. Scully explicitly showed the photoelectric effect to be explainable by wave theory in 1969.
  • Another participant suggests that the modern quantization of the electromagnetic field may not be necessary to explain the gross features of the photoelectric effect, proposing that it could be described using a classical external field.
  • There is a reference to experiments by J.F. Clauser and later by P. Grangier, G. Roger, and A. Aspect, which are noted as being difficult to explain using wave theory.
  • Some participants express uncertainty regarding the consensus on the explanations for the Compton effect, indicating a lack of clear information found online.
  • One participant questions the understanding of the photoelectric effect, asking about the direction of photoelectric current and the behavior of current when the voltage is reduced to zero.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether the Compton effect can be explained by classical wave theory, and there are multiple competing views regarding the explanations of both the photoelectric and Compton effects.

Contextual Notes

Some limitations in the discussion include the dependence on specific definitions of classical and quantum theories, as well as unresolved mathematical steps in the arguments presented.

PrincePhoenix
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I have the fifth edition of 'Physics' by Halliday, Resnick and Krane.
In the chapter 'The Nature of Light' it is stated that it is possible to explain both photoelectric effect and Compton effect in classical electromagnetic wave theory and this has been known since 1927. It says that photoelectric effect was explicitly shown to be explainable by wave theory in 1969 by W.E. Lamb and M.O. Scully.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680009569_1968009569.pdf

It says that the experiment that really cannot be explained by the wave theory was conducted by J.F. Clauser in 1974 and then again corrected and performed by P. Grangier, G. Roger and A.Aspect in 1986.

However when I searched the internet, I didn't get anything for Compton effect and read this
https://www.physicsforums.com/showthread.php?t=372653

on physics forums. Although both the paper and most of the discussion is beyond my level, I can sense most people don't agree with it.

So what is the generally accepted view in this regard?

Thanks in advance.
 
Last edited:
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I think that what these people (Lamb, Jaynes,...) were trying to point out is that the modern quantization of the electromagnetic field (quantum optics) does not seem to be necessary to explain the gross features of these effects.

Einstein introduced the concept of the light quantum but did not define it very well. After that, quantum theory of particles was developed, in which there is no light quantum - just classical electromagnetic field.

Since the photoelectric effect is an effect stimulated by the _external_ field, there is a hope that it can be described by non-relativistic quantum theory with classical external field. The hope is there because similar thing is possible to do for the excitation of the atom; the time-dependent Hamiltonian containing the external electric field will cause the wave-function to change and the expectation value of its energy will rise.

It is conceivable that the quantized behaviour of the photoelectric effect is due to the quantumness of the particles, while the radiation can be described by the wave theory. I think it is not ruled out that one can invent some kind of Hamiltonian that would give you the resonance behaviour of wave-function for bounded electrons at the right frequency. But I do not know whether Lamb or Jaynes really succeeded.
 
PrincePhoenix said:
I have the fifth edition of 'Physics' by Halliday, Resnick and Krane.
In the chapter 'The Nature of Light' it is stated that it is possible to explain both photoelectric effect and Compton effect in classical electromagnetic wave theory and this has been known since 1927. It says that photoelectric effect was explicitly shown to be explainable by wave theory in 1969 by W.E. Lamb and M.O. Scully.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680009569_1968009569.pdf

It says that the experiment that really cannot be explained by the wave theory was conducted by J.F. Clauser in 1974 and then again corrected and performed by P. Grangier, G. Roger and A.Aspect in 1986.

However when I searched the internet, I didn't get anything for Compton effect and read this
https://www.physicsforums.com/showthread.php?t=372653

on physics forums. Although both the paper and most of the discussion is beyond my level, I can sense most people don't agree with it.

So what is the generally accepted view in this regard?

Thanks in advance.

This paper might help you in clarification of this a bit

http://people.whitman.edu/~beckmk/QM/grangier/Thorn_ajp.pdf

Note also that other phenomena, such as photon anti-bunching, have no classical wave explanation.

Zz.
 
I'm sorry I might have given wrong impression about my education level. I use the HRK for extra knowledge that I find interesting in my high school physics. I am actually only a high school student.
 
I have couple of questions from Photo Electric Effect, if you could answer 1. why is the direction of photoelectric current opposite to the motion of electrons . 2. if we reduce deltaV to 0 photoelectric current doesn't drop to zero. why?
 

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