Could photons emitted by high velocity electrons have a specific emission angle?

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Discussion Overview

The discussion revolves around the emission angles of photons from electrons moving at high velocities, particularly in the context of special relativity and electromagnetic wave propagation. Participants explore the implications of these angles on phenomena such as lasers and the potential for photons to re-enter the emitting electron.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that photons emitted by stationary electrons are perpendicular to the electron's body, while those emitted by high-velocity electrons may have different angles of emission.
  • Another participant questions the effects of high-velocity emission angles on lasers, particularly if the emission angle differs from the direction of travel.
  • There is speculation about whether photons emitted at high velocities could double back and re-enter the electron, leading to specific emission angles.
  • One participant proposes that the angle of photon propagation changes when boosting electromagnetic field equations, suggesting a connection to wave-4-vector notation.
  • Another participant introduces the concept of Cherenkov radiation, noting that it occurs when a particle exceeds the speed of light in a medium, but states this is not applicable in free space.

Areas of Agreement / Disagreement

Participants express differing views on the emission angles of photons at high velocities, with no consensus on the implications for lasers or the possibility of photons re-entering electrons. The discussion remains unresolved regarding the specific conditions under which these phenomena may occur.

Contextual Notes

Participants acknowledge the complexity of assigning unique values for the dimensions of a photon and the limitations of their assumptions regarding the behavior of photons in different frames of reference.

Skeptick
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Assumptions
A photon exist in three dimensions so it has length, width and height.

In fig 2 I show and electron that is stationary so it is in a moving frame of reference with a very small velocity say 10 m/sec. This fig is snapshots taken of the electron a times 1,2,3,4 etc as a photon is emitted by the electron and as can be seen the photon is emitted perpendicular to the average body of the electron.

In fig 1 I show the same set of snapshots except now the electron is in a moving frame of reference traveling at say 0.99 C. A t1 the photon has just started to be emitted from the electron, at t2 it is a little further out, as the photon has a finite length and so forth until it is completely emmitted.

I predict that at high velocities photons will emit at a different angle as opposed to photon emitted by a stationary or low velocity electron.

Is I possible at high velocity the photon may actually double back on itself and re-enter the electron? In which case electrons at high velocity will only be able to emit photons at specific angles ?

If there is resistance to the emmission then this would somehow create a doppler effect to wouldn't it?
 

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if this is right what effects would this have on a laser at very high velocity ?
 
If the emmission angle of the laser was at and angle to the direction of travle of the MFR
 
Skeptick said:
A photon exist in three dimensions so it has length, width and height.
A photon is a quantum of an EM wave, so since the wave propagates in all three spatial dimensions I think it is OK to say a photon exists in all three spatial dimensions in some sense. However, I doubt that you can assign unique values for the length, width, and height of a photon.

Skeptick said:
I predict that at high velocities photons will emit at a different angle as opposed to photon emitted by a stationary or low velocity electron.
If you boost the EM field equations you will indeed see that the angle of propagation changes. I think this idea is simplified in the wave-4-vector notation.

Skeptick said:
Is I possible at high velocity the photon may actually double back on itself and re-enter the electron? In which case electrons at high velocity will only be able to emit photons at specific angles ?
Only if the velocity of the particle is greater than the speed of light in the medium. When this happens you get Cherenkov radiation which is the EM equivalent of a bow wake or sonic boom. Of course, this is not possible in free space.
 

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