Low energy photon - electron collision

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Discussion Overview

The discussion revolves around the interaction between low energy photons and electrons, specifically addressing what occurs when a photon collides with an electron without sufficient energy to dislodge it or elevate it to a higher energy level. The scope includes theoretical implications and conceptual understanding of photon-electron interactions.

Discussion Character

  • Exploratory, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant suggests that nothing happens in such a collision, asserting that the probability of an electron existing between energy levels is zero, leading to a zero probability of energy absorption.
  • Another participant proposes that the photon will scatter, transferring some momentum and kinetic energy to the atom, resulting in a redshift of the photon, likening it to Compton scattering but with the mass of the atom considered instead of a free electron.
  • A third participant references the phenomenon in transparent objects, implying a connection to the scattering process without providing detailed analysis.

Areas of Agreement / Disagreement

Participants express differing views on the outcome of the photon-electron collision, with no consensus reached on whether any observable effect occurs.

Contextual Notes

There are assumptions regarding the nature of energy levels and the behavior of photons in interactions with electrons that remain unaddressed, as well as the implications of scattering in different contexts.

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Suppose a photon collides with an electron, but does not have enough energy to dislodge the electron or knock the electron into it's next energy level. What happens? Is the effect observed?
 
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Nothing happens. The probability that an electron exists between energy levels is zero, so the probability that it will absorb that level of energy is zero.
 
The photon will scatter off from its initial direction, transferring a little momentum and kinetic energy to the atom as a whole and losing a little bit of energy, thus becoming redshifted. It is like the Compton scattering, only that instead of the mass of a free electron, you should use the mass of the atom.
 
I believe this is what happens in transparent objects
https://www.youtube.com/watch?v=Omr0JNyDBI0
 
Last edited:

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