Can the Transverse Nature of a Wave from an Electron Gun be Observed?

In summary, an electron has corpuscular-wave dualism, and behaves both like a wave and like a particle.
  • #1
Martyn Arthur
101
18
TL;DR Summary
How do we know that a wave fired from an electron gun is transverse in transit?
Hi.
What equipment /mechanism / experimental procedure is used to determine that the nature of a wave fired from an electron gun is transverse in transit?
Thanks
Martyn
 
Physics news on Phys.org
  • #2
If a wave propagates through vacuum, is it transverse or longitudinal?

Will your electron propagate through a vacuum?
 
  • #3
Martyn Arthur said:
TL;DR Summary: How do we know that a wave fired from an electron gun is transverse in transit?

Hi.
What equipment /mechanism / experimental procedure is used to determine that the nature of a wave fired from an electron gun is transverse in transit?
Thanks
Martyn
An electron is a quantum particle. It's not a classical wave, and neither transverse nor longitudinal.
 
  • #4
PeroK said:
An electron is a quantum particle. It's not a classical wave, and neither transverse nor longitufinal
But a photon is also a quantum particle, not a classical wave, and is only longitudinal.

That said, I don't understand what the OP means and I suspect he doesn't either. If he can express this thought in terms of observables, it might be discussable, but as it is it's words words words. Like "a weath of pretty little flowers which smell bad."
 
  • #5
Vanadium 50 said:
But a photon is also a quantum particle, not a classical wave, and is only longitudinal.
Did you mean to say "is only transverse"?
 
  • Like
Likes gentzen
  • #6
Either. Depends on if you are talking spin or electric field direction. Which emphasizes the OPs confusion the description of a thing is not the same as the thing.
 
  • #7
Martyn Arthur said:
the nature of a wave fired from an electron gun is transverse in transit
Where did you read this? Can you give us a link or reference so we can see where you're "coming from" on this?
 
  • Like
Likes vanhees71
  • #8
Vanadium 50 said:
Either. Depends on if you are talking spin or electric field direction.
That's a good point, I was thinking only classically. Massless photons or gravitons do indeed always have longitudinal spin with transverse polarization. For massive electrons it seems polarization must refer to spin-up or spin-down with respect to some external magnetic field B. A e-beam is then "polarized" to the extent it consists of unequal numbers of electrons with up vs. down spins. If the B-field happens to be perpendicular to the beam propagation direction, might this then constitute "transverse electron polarization"?
 
  • #9
PeroK said:
An electron is a quantum particle. It's not a classical wave, and neither transverse nor longitudinal.
Of course you can have polarized electrons, i.e., electrons with their spin in a given direction.
 
  • #10
Vanadium 50 said:
Either. Depends on if you are talking spin or electric field direction. Which emphasizes the OPs confusion the description of a thing is not the same as the thing.
A photon can only be "transverse". A photon as a massless spin-1 particle, has only two polarization-degrees of freedom. The natural choice is helicity, i.e., the projection of total angular momentum to the direction of the momentum, and the helicity can only take the values ##\pm 1##. That's a subtlety of massless particles with spin. It has always only two helicity states ##\pm s## (with ##s \in \{1/2,1,3/2,\ldots \}##).
 
  • Like
Likes Hyperfine
  • #11
vanhees71 said:
A photon can only be "transverse".
A photon's electric field can only be "transverse". A photon's spin can only be "longitudunal."

(Convention is to talk about fields, trhough). What I tried to bring up, and obviously failed to do well, is that this is a description that depends on definition. You tell me the definition you use, and I'll tell you what names the physics requires.

When making a physical prediction, of course we get the same answer no matter which words we use. This is why I think the OP's question "which words do we use?" is ill=posed.
 
  • #12
Define what you mean by spin then. It's not possible to split the total angular momentum into spin and orbit parts in a gauge-invariant way!
 
  • Like
Likes LittleSchwinger
  • #13
As I recall, the electron has corpuscular-wave dualism! It behaves both like a wave and like a particle! There are many interesting things in the world))) So many discoveries are yet to come)))
 
  • #14
BillyDoster said:
As I recall, the electron has corpuscular-wave dualism! It behaves both like a wave and like a particle! There are many interesting things in the world))) So many discoveries are yet to come)))
QM explained that one!
 

Similar threads

Replies
8
Views
892
  • Quantum Physics
Replies
9
Views
443
Replies
10
Views
1K
  • Quantum Physics
2
Replies
36
Views
2K
Replies
28
Views
4K
  • Quantum Physics
2
Replies
39
Views
4K
Replies
23
Views
2K
  • Quantum Physics
Replies
14
Views
2K
  • Quantum Physics
4
Replies
124
Views
4K
  • Quantum Physics
Replies
33
Views
2K
Back
Top