What moves in a magnetic field?

[Ozfer]

So if you have a permanent magnet what is moving along the magnetic field lines? Electrons? Photons?

 

[Drakkith]

Nothing is moving along the field lines. Field lines don't even exist. They just help us visualize the magnetic field around the magnet. They're like the latitude and longitude lines on a globe or the contour lines on a topographic map that represent elevation.

 

[Ozfer]

I don't mean the field lines themselves. What is changing in the magnetized area?

 

[Drakkith]

I'm sorry I don't understand your question. Can you elaborate a bit or give a specific example/setup?

 

[Ozfer]

What on the atomic level is changing that causes magnets to pull?

 

[Drakkith]

Nothing. It is an inherent property of the electromagnetic force. Just like how opposite electric charges attract. Now, that doesn't mean that a magnetic field can't cause changes to the atomic structure of matter, it just means that these changes aren't the direct cause of the attraction.

 

[Ozfer]

Does a magnet attract faster than the speed of light?

 

[Drakkith]

What does that mean? How is the speed of an attractive force measured?

 

[Ozfer]

Okay so say a magnet was placed at a specific position A. Say 1 meter away is position B. Does the affect of the magnet or light reach position B faster.

 

[Nugatory]

Okay so say a magnet was placed at a specific position A. Say 1 meter away is position B. Does the affect of the magnet or light reach position B faster.

Both arrive at the same time because they are the same thing - light is electromagnetic radiation, which is to say a propagating change in the electromagnetic field.

 

[Drakkith]

Okay so say a magnet was placed at a specific position A. Say 1 meter away is position B. Does the affect of the magnet or light reach position B faster.

Well, remember that we can't just pop things into existence in real life, so the answer to questions like this may not always be meaningful. We'd have to move magnets into position from somewhere else or assemble them out of matter.

However, let's say that we have a magnet at position A, and position B is located 1 meter away. By moving the magnet we would create a change in the field. This change would propagate at light speed from point A to point B.

Does that help?

 

[Ozfer]

So maybe I just have a problem with my understanding of the electromagnetic spectrum but how exactly does magnetism fall into that? Everything on the electromagnetic spectrum has a wavelength and I believe is photons but magnets do not?

Also does everything with a magnetic force affect everything else the same way gravity does?

and thanks for answering my questions

 

[Drakkith]

So maybe I just have a problem with my understanding of the electromagnetic spectrum but how exactly does magnetism fall into that? Everything on the electromagnetic spectrum has a wavelength and I believe is photons but magnets do not?

The electromagnetic spectrum refers to the range of frequencies/wavelengths of electromagnetic radiation, which are waves in the electromagnetic field. A static magnetic field is not a wave and cannot be said to have a frequency or wavelength. It wouldn't fall on the spectrum at all.

 

[anorlunda]

What on the atomic level is changing that causes magnets to pull?

You are confusing us and yourself by using the words move and change in your question. Please try again. What are you really asking.

Is your question, "What is the difference between magnetic and non-magnetic materials?"

 

[Ozfer]

What is the difference between a magnetic field from a magnet and the electromagnetic field? How do they interact?

 

[Drakkith]

What is the difference between a magnetic field from a magnet and the electromagnetic field?

The magnetic field is a manifestation of the electromagnetic field. Basically, it turns out that electric field and electric phenomena (such as the attraction of electrically charged particles) can be linked to magnetic field and magnetic phenomena (such as the attraction between magnets) in such a way as to suggest that they are actually the same thing just manifesting in a different way. For example, a moving electric charge produces a magnetic field in addition to the electric field is normally has. A moving magnet produces an electric field in addition to the magnetic field it usually has. Scientists ended up developing a handful of equations that can describe all electric and magnetic phenomena. These equations are called Maxwell's Equations and are extremely important. Everything from the circuit laws that govern computers and the wiring in your house to the behavior of plasma inside a fusion reactor can be derived from these equations.

Because a handful of equations can describe all of these different electric and magnetic phenomena, scientists choose to label them all as being manifestations of a single force, the electromagnetic force. This also requires that we unify the magnetic and electric fields into a single electromagnetic field.

 

[Ozfer]

Since magnetism is a non-contact force and electric field is a wave of particles of energy(photons) why are these considered the same thing? They seem to both behave very differently and their definitions seem very different.

Doesn't electric field not put a force upon things while magnetism is defined as a force? It doesn't seem to be the electric field that causes the magnetic field but instead the moving of electrons in the wire.

 

[Drakkith]

Since magnetism is a non-contact force and electric field is a wave of particles of energy(photons) why are these considered the same thing?

The electric field is not a wave of photons, it is a type of field (which has a specific definition in science), and I just explained why the electric and magnetic fields are considered different manifestations of the same thing. They are described by the same math and can both be easily "transformed" from one to the other just by moving a particle or magnet. The basic fact that transforming one to the other requires only relative motion means that we really never find one without the other. It's just that in a stationary situation we find that either the electric or magnetic components are zero.

Doesn't electric field not put a force upon things while magnetism is defined as a force?

I don't know what you mean. Electrically charged particles feel forces. These forces can be electric, magnetic, or a combination of electric and magnetic forces. The fact that opposite charges attract each other through their electric fields is the fundamental reason why we have atoms and molecules. If they didn't, then the protons and electrons making up atoms would not bond to each other.

It doesn't seem to be the electric field that causes the magnetic field but instead the moving of electrons in the wire.

You are correct. Neither the electric field nor the magnetic field cause the other. Moving charges are one source of magnetic fields, but even a stationary electron has a magnetic field, despite having no motion. The magnetic field of a permanent magnet also requires no movement of charges.

 

[Ozfer]

Sorry I meant, Since magnetism is a non-contact force and electromagnetic field is a wave of particles of energy(photons) why are these considered the same thing? Just because they can be converted doesn't make them the same. That would be like saying kinetic and potential energy is the same thing since they can be converted and where you find one you can find the other or the other is 0.

 

[Drakkith]

Sorry I meant, Since magnetism is a non-contact force and electromagnetic field is a wave of particles of energy(photons)

The EM field is not a wave of particles. It is a field. An EM wave is probably what you're thinking of, but that's a wave within the EM field. The field itself is not a wave.

why are these considered the same thing? Just because they can be converted doesn't make them the same. That would be like saying kinetic and potential energy is the same thing since they can be converted and where you find one you can find the other or the other is 0.

They are the same thing. Or rather they are manifestations of the same thing. Both kinetic energy and potential energy are forms of energy.

 

[Ozfer]

Okay fine I might not be phrasing it right because I don't know all the lingo but your just disagreeing with my wording instead of the concept. If we are saying all forms of energy are the same because they are energy and also magnetic fields are the same I am just going to have to disagree with that as I don't think it is true.

 

[Electric to be]

Sorry I meant, Since magnetism is a non-contact force and electromagnetic field is a wave of particles of energy(photons) why are these considered the same thing? Just because they can be converted doesn't make them the same. That would be like saying kinetic and potential energy is the same thing since they can be converted and where you find one you can find the other or the other is 0.

The force caused by a magnetic field on a moving charge isn't the same thing as the magnetic (electromagnetic) field itself. You have the field, and then you have the interaction of charges with the field. That is known as the force. There is energy stored in the electromagnetic field. Energy in the electromagnetic field can be transferred to charges as kinetic energy through these interactions labeled as "force".

I wouldn't worry so much about photons until you understand these basic concepts of electromagnetism first, as photons are a whole different animal to tackle.

 

[Drakkith]

Okay fine I might not be phrasing it right because I don't know all the lingo but your just disagreeing with my wording instead of the concept.

Are you talking about the fields vs waves thing, or the magnetic vs electric thing? Or both?
In any case, I don't feel that I've done so. The phrasing and the concepts typically go hand-in-hand, though admittedly not always.

If we are saying all forms of energy are the same because they are energy and also magnetic fields are the same I am just going to have to disagree with that as I don't think it is true.

Kinetic and potential energy are not the same things, but they are both classified as manifestations of energy because of how closely related they are. Similarly, electric and magnetic fields are not the same thing, but they are heavily related, so much so that we classify them under a single, unified field, the EM field. Whether we unify the two or treat them a separate fields is irrelevant, as it wouldn't change any of the math whatsoever, so it's mostly just a categorization and convenience issue.

 

[Drakkith]

Thread re-opened. I would like to remind members to keep in mind that this is a B-level thread and highly advanced explanations should not be posted here.

 

[tijana]

EM is a wave? And photons that are carrying "light" are mass less particles? And particles can be behave as wave too? Is EM wave or not?

 

[davenn]

EM is a wave?

EM energy travels as a wave --- a disturbance in the Electromagnetic Field

And photons that are carrying "light" are mass less particles?

photons are the energy carriers of the EM wave and yes they are massless

Is EM wave or not?

what did I say in my first response ?

 

[anorlunda]

Since magnetism is a non-contact force and electric field is a wave of particles of energy(photons) why are these considered the same thing? They seem to both behave very differently and their definitions seem very different.

Doesn't electric field not put a force upon things while magnetism is defined as a force? It doesn't seem to be the electric field that causes the magnetic field but instead the moving of electrons in the wire.

You have multiple misconceptions about how things are defined. You also have trouble phrasing your questions. We are also having trouble answering because this is a B level thread, and some of those things need I or A level answers to explain properly.

Everything that @Drakkith told you is correct, but hard to understand if you have wrong preconceptions. Go back and reread those answers carefully word by word, and don't ask him to say it in other words.

You may also benefit from these Wikipedia articlea. Note that the quote below also says that electric fields, magnetic fields and light are all aspects of the same thing. That is pretty advanced concept and hard for anyone at the B level to swallow, but it's true.

Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs between electrically charged particles. The electromagnetic force usually exhibits electromagnetic fields such as electric fields, magnetic fields, and light

Also the article https://en.wikipedia.org/wiki/Classical_electromagnetism

Do you understand calculus? If yes, I have another recommended way that you can learn this stuff.

 

[tijana]

EM energy travels as a wave --- a disturbance in the Electromagnetic Field
photons are the energy carriers of the EM wave and yes they are massless
what did I say in my first response ?

Thank you. :)

So disturbance is explained how? I mean nature of it. Resonance?

 

[davenn]

So disturbance is explained how?

oscillating/accelerating charged particles, either electrons or protons, will emit EM radiation/energy it will radiate out from the source just like the waves radiate out across a pond when you toss a pebble into the water.. Think of the water as the E/M field, it is always there, the waves are just disturbances in that field

 

[Drakkith]

So disturbance is explained how? I mean nature of it. Resonance?

It's a propagating change in the EM field that can be modeled by a wave equation.

 

[tijana]

oscillating/accelerating charged particles, either electrons or protons, will emit EM radiation/energy it will radiate out from the source just like the waves radiate out across a pond when you toss a pebble into the water.. Think of the water as the E/M field, it is always there, the waves are just disturbances in that field

Thanks