B Photoelectric phenomenum can only be proved as a particle effect?

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Using quantum mechanics, the photoelectric effect is the traditional phenomenon that proves the light behavior as a particle (photons). But could the effect be proved by classical wave mechanics?
The main point of the photoelectric effect as a particle phenomenon is the threshold frequency. Now, degrading our actual atom quantum model to the old Bohr model, the ("wrong") idea of electron orbital frequency is applicable. In this case, we can observe that there is a correlation, or approximation (mainly for Rydberg atoms) between the last calculated electron "orbital frequency" and the photoelectric threshold frequency. This could pass a perception, that the photoelectric threshold frequency could have a kind of electron orbit "resonance" relation with the incident light frequency, removing the electron from the orbit only for frequencies equal to or bigger than this resonance. Lower frequencies of incident light would not pump the orbital electron, even for increased light levels.
 
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Arend said:
TL;DR Summary: Using quantum mechanics, the photoelectric effect is the traditional phenomenon that proves the light behavior as a particle (photons). But could the effect be proved by classical wave mechanics?
There is over one hundred years of exprimental evidence - beginning (but not ending) with the photoelectric effect - that defies classical EM and requires a new theory to explain. Quantum Mechanics is the name given to that theory, which explains the photoelectric effect, the atom and all of particle physics.

You're not the first person (and I assume you'll not be the last) to ask whether classical EM can explain everything. In light of one hundred years of experimental evidence to the contrary, it is not a serious question.
 
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PeroK said:
There is over one hundred years of experimental evidence - beginning (but not ending) with the photoelectric effect - that defies classical EM and requires a new theory to explain. Quantum Mechanics is the name given to that theory, which explains the photoelectric effect, the atom and all of particle physics.

You're not the first person (and I assume you'll not be the last) to ask whether classical EM can explain everything. In light of one hundred years of experimental evidence to the contrary, it is not a serious question.
You know PeroK, I have the naive or fooled idea that classical EM is just "messed" by the uncertainty, but still there ;) Thanks
 
Arend said:
TL;DR Summary: Using quantum mechanics, the photoelectric effect is the traditional phenomenon that proves the light behavior as a particle (photons). But could the effect be proved by classical wave mechanics?

The main point of the photoelectric effect as a particle phenomenon is the threshold frequency
I disagree. The threshold frequency is important, but not by itself the main point.

The main point is to find one model which explains the following three facts
1) below the threshold frequency no photo electrons are emitted at any intensity
2) above the threshold frequency the photo electron current is proportional to the intensity
3) above the threshold frequency the photo electron kinetic energy is proportional to the change in frequency from the threshold.

The point of the experiment is that you need one model that simultaneously explains all three of those observations. The classical model fails at 2 and 3 because the energy of a classical wave is in its intensity, not its frequency.
 
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You are using a beginner's idea of what light is, i.e., sometimes a particle or sometimes a wave.

In fact, it is neither.

https://www.physics.usu.edu/torre/3700_Spring_2015/What_is_a_photon.pdf

A photon is like a knot in the quantum electromagnetic field that permeates all of space. Electrons in atoms, being electrically charged, are coupled to the quantum electromagnetic field. If the field has a 'knot' (i.e., a photon is nearby), it perturbs the electron due to the coupling. This may result in the photon being destroyed, the electron gaining enough engergy and being ejected from the atom.

Thanks
Bill
 
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Arend said:
TL;DR Summary: Using quantum mechanics, the photoelectric effect is the traditional phenomenon that proves the light behavior as a particle (photons). But could the effect be proved by classical wave mechanics?

The main point of the photoelectric effect as a particle phenomenon is the threshold frequency. Now, degrading our actual atom quantum model to the old Bohr model, the ("wrong") idea of electron orbital frequency is applicable. In this case, we can observe that there is a correlation, or approximation (mainly for Rydberg atoms) between the last calculated electron "orbital frequency" and the photoelectric threshold frequency. This could pass a perception, that the photoelectric threshold frequency could have a kind of electron orbit "resonance" relation with the incident light frequency, removing the electron from the orbit only for frequencies equal to or bigger than this resonance. Lower frequencies of incident light would not pump the orbital electron, even for increased light levels.
M. O. Scully, M. S. Zubairy, Quantum Optics, Cambridge University Press, 1997
"as we shall see in later chapters of this book, there are many processes associated with the radiation-matter interaction which can be well explained by a semiclassical theory in which the field is treated classically and the matter is treated quantum mechanically. Examples of physical phenomena which can be explained either totally or largely by semiclassical theory include the photoelectric effect which was first explained semiclassically by Wentzel in 1927."
 
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Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
If we release an electron around a positively charged sphere, the initial state of electron is a linear combination of Hydrogen-like states. According to quantum mechanics, evolution of time would not change this initial state because the potential is time independent. However, classically we expect the electron to collide with the sphere. So, it seems that the quantum and classics predict different behaviours!
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