Is an electron an excitation in a magnetic field?

In summary, the conversation discusses the concept of an electron and its description as an excitation in a magnetic field. There is confusion about this description and its meaning, as well as whether an electron can be created from a magnetic field. Further discussion is needed and sources should be provided to clarify the topic.
  • #1
CraigH
222
1
I didn't really know how to word this question, but what's confusing me is this: I was researching "what is an electron" and I read in many places that "an electron is an excitation in a magnetic field". But what does this mean? I thought that an electron is just a particle with mass and charge, and when a charge moves it creates a magnetic field. What does "an excitation in a magnetic field" mean?

Also does this mean that an electron could be created out of nowhere from a magnetic field? (I know mass cannot be created or destroyed but e=mc^2 so the mass would come from the energy)

Thanks!
 
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  • #2
CraigH said:
I read in many places that "an electron is an excitation in a magnetic field".

I do not think this is correct. That description would fit a photon, but not an electron.
 
  • #3
CraigH said:
Also does this mean that an electron could be created out of nowhere from a magnetic field? (I know mass cannot be created or destroyed but e=mc^2 so the mass would come from the energy)

Thanks!

Mass can be created and destroyed. Electrons can be created but only with its anti-particle (positron e+), otherwise that would violate the conservation of charge.
 
  • #4
JustinRyan said:
Mass can be created and destroyed. Electrons can be created but only with its anti-particle (positron e+), otherwise that would violate the conservation of charge.

Mass is never created or destroyed, only transferred from one place to another in different forms. (Just like energy)
 
  • #5
CraigH said:
I didn't really know how to word this question, but what's confusing me is this: I was researching "what is an electron" and I read in many places that "an electron is an excitation in a magnetic field". But what does this mean? I thought that an electron is just a particle with mass and charge, and when a charge moves it creates a magnetic field. What does "an excitation in a magnetic field" mean?

Also does this mean that an electron could be created out of nowhere from a magnetic field? (I know mass cannot be created or destroyed but e=mc^2 so the mass would come from the energy)

Thanks!

Could you share a few links with us so we can see where you got that information from?
 
  • #6
Drakkith said:
Mass is never created or destroyed, only transferred from one place to another in different forms. (Just like energy)

"The energy of this photon can be converted into mass through Einstein's equation E = m c2"

http://en.wikipedia.org/wiki/Pair_production
 
  • #7
JustinRyan said:
"The energy of this photon can be converted into mass through Einstein's equation E = m c2"

http://en.wikipedia.org/wiki/Pair_production

Ah, here we run into the problem of what "mass" means. Measure the mass of the system that includes the photon and atom, then measure the mass of the system after the photon has been converted into an electron-positron pair. The mass has not changed. This is because energy has mass, per the equation you linked, so the photon contributes to the mass of the system. However, at the same time, matter can be destroyed and created, and matter has invariant mass while photons do not. So yes, if we talk about invariant mass you would be correct, it can be created and destroyed when particles are.
 
  • #8
A photon doesn't have invariant mass, but a pair of photons can have invariant mass.
 
  • #9
CraigH said:
I didn't really know how to word this question, but what's confusing me is this: I was researching "what is an electron" and I read in many places that "an electron is an excitation in a magnetic field". But what does this mean? I thought that an electron is just a particle with mass and charge, and when a charge moves it creates a magnetic field. What does "an excitation in a magnetic field" mean?

Also does this mean that an electron could be created out of nowhere from a magnetic field? (I know mass cannot be created or destroyed but e=mc^2 so the mass would come from the energy)

Thanks!

As far as I understand it, (not far), according to quantum field theory an electron is an excitation of the electromagnetic field. As to exactly what this "means" you would have to get a graduate degree in physics (which I do not have either). It is worth noting that some particles like neutrinos are NOT excitations of the EM field, and hence as far as they are concerned electrons and protons and neutrons might as well not be there at all.

In EM fields of a quadrillion gauss in a vacuum, electron-position pairs will be spontaneously created.
 
  • #10
ImaLooser said:
As far as I understand it, (not far), according to quantum field theory an electron is an excitation of the electromagnetic field.
No,it is photon which arises as a quantum of excitation after quantizing the electromagnetic field.
 
  • #11
What's the source? It sounds very wrong.
 
  • #12
CraigH said:
I didn't really know how to word this question, but what's confusing me is this: I was researching "what is an electron" and I read in many places that "an electron is an excitation in a magnetic field". But what does this mean? I thought that an electron is just a particle with mass and charge, and when a charge moves it creates a magnetic field. What does "an excitation in a magnetic field" mean?

Also does this mean that an electron could be created out of nowhere from a magnetic field? (I know mass cannot be created or destroyed but e=mc^2 so the mass would come from the energy)

Thanks!

This is insufficient to start a topic. You have neglected to clearly cite your source. "Read in many places" is not a valid reference.

https://www.physicsforums.com/blog.php?b=2703 [Broken]

And I am thoroughly puzzled that there were so many responses to something like this without even checking if the starting point is even valid.

I strongly suggest we hold off further discussion on this till the OP comes back and provide these sources that we can check.

Zz.
 
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  • #13
zapper - OP question was legit. the standard model is a field model, not a particle model, and pretty much supports the concept that all "particles" are simply manifestations of the associated field. this is born out by the fact that no fundamental particles dispaly any spatial extension, ie, electrons and quarks are point particles, and their properties are manifestations of the field(s).

wiki article on QFT states:
"In QFT, photons are not thought of as "little billiard balls" but are rather viewed as field quanta – necessarily chunked ripples in a field, or "excitations", that "look like" particles. Fermions, like the electron, can also be described as ripples/excitations in a field, where each kind of fermion has its own field. In summary, the classical visualisation of "everything is particles and fields", in quantum field theory, resolves into "everything is particles", which then resolves into "everything is fields". In the end, particles are regarded as excited states of a field (field quanta). "
 
  • #14
jnorman said:
zapper - OP question was legit. the standard model is a field model, not a particle model, and pretty much supports the concept that all "particles" are simply manifestations of the associated field. this is born out by the fact that no fundamental particles dispaly any spatial extension, ie, electrons and quarks are point particles, and their properties are manifestations of the field(s).

wiki article on QFT states:
"In QFT, photons are not thought of as "little billiard balls" but are rather viewed as field quanta – necessarily chunked ripples in a field, or "excitations", that "look like" particles. Fermions, like the electron, can also be described as ripples/excitations in a field, where each kind of fermion has its own field. In summary, the classical visualisation of "everything is particles and fields", in quantum field theory, resolves into "everything is particles", which then resolves into "everything is fields". In the end, particles are regarded as excited states of a field (field quanta). "

Oh dear. And this somehow is compatible with electrons being an excitation SPECIFICALLY out of magnetic fields? What about them being vacuum excitations out of a fermionic ground state as well? See? I could spew such things endlessly as well!

Please reread my post. I did not ask about the legitimacy of the question, but rather the source. There is more to this than what we have been told. Furthermore, no one seems concerned on what the OP can comprehend. Don't you care even in the least bit if what you just wrote is understandable to the person who asked the question? This is not a place simply to show off our amazing breath of knowledge. This really isn't about you!

https://www.physicsforums.com/blog.php?b=2679 [Broken]Zz.
 
Last edited by a moderator:

1. What is an excitation in a magnetic field?

An excitation in a magnetic field refers to the movement or disturbance of charged particles, such as electrons, in response to a magnetic field. This can result in changes in the energy level or spin of the particles, leading to the emission or absorption of electromagnetic radiation.

2. How is an electron related to a magnetic field?

An electron is a subatomic particle that carries a negative charge. In the presence of a magnetic field, it can experience a force and undergo an excitation, causing it to move or change energy levels.

3. Is an electron the only particle that can be excited in a magnetic field?

No, other particles such as protons and neutrons can also be excited in a magnetic field. However, electrons are the most commonly studied due to their small size and high sensitivity to magnetic fields.

4. Can an electron be both in an excited state and a magnetic field at the same time?

Yes, an electron can be in an excited state while also experiencing a magnetic field. This can occur in a variety of situations, such as in a magnetic resonance imaging (MRI) machine, where the magnetic field is used to excite and manipulate the electrons in the body.

5. How does an electron's excitation in a magnetic field affect its behavior?

The excitation of an electron in a magnetic field can cause it to change its energy level or spin, which can impact its behavior. For example, an excited electron may emit or absorb photons, or it may exhibit different magnetic properties compared to a non-excited electron.

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