I just read in Griffiths 'Electrodynamics' (chapter 12.3) how

[Lapidus]

I just read in Griffiths 'Electrodynamics' (chapter 12.3) how magnetism is a relativistic phenomenom, why there had to be a thing like magnetism just given electrostatics and relativity.

Is the same true for the weak force and the strong force? Is there also magnetism? If so, how is it observable?

thanks

 

[CheckMate]

Is the same true for the weak force and the strong force? Is there also magnetism? If so, how is it observable?

What do you mean by "is there also magnetism?". Of course there is, take two magnetic dipoles and play with them. And Magnetism is an "aspect" of the electromagnetic force, if that is answering your question.

 

[Lapidus]

We have electric charges, whith them there are associated an electric force and a magnetic force.

Due to relativity, magnetic and electric force rotate into each other. Different observers feel/ observe the electromagnetic field, described by an antisymmetric 2-rank tensor, differently.

What about the strong and weak charges, have they also a kind of magnetic force? Do different observeres feel different forces, like in EM observer do with the magnetic and the electric force?

 

[Lapidus]

So what's up here? Is my question complete bogus or why is no one replying?

We got
- gluons and the strong force
- W, Z bosons and the weak force
- photons and the electro-magnetic force

Why don't we have a strong-magnetic and a weak-magnetic force, too?

 

[Lapidus]

Yet another rephrasing of my question.

Why are photons associated with two forces, the magnetic and electric force, but the gluons and W,Z bosons only with one (the strong and the weak)?

 

[eXorikos]

There is not an electric force and a magnetic force. There is only the electromagnetic force. This is clear when using the relativistic notation. Electricity and magnetism go hand in hand.

I don't know enough QFT to answer your other questions.

 

[Lapidus]

There is not an electric force and a magnetic force. There is only the electromagnetic force. This is clear when using the relativistic notation. Electricity and magnetism go hand in hand.

I don't know enough QFT to answer your other questions.

Right. And as stated in an earlier post, due to relativity, magnetic and electric force rotate into each other. Different observers feel/ observe the electromagnetic field, described by an antisymmetric 2-rank tensor, differently.

But why are there two aspects, two observer dependent forces, i.e. electricity and magnetism, when it comes the photon/ the electromagneti force?

Why is that not for the gluon/strong force and W,Z bosons/weak force?

 

[blechman]

There are "electric" and "magnetic" forces for all of the forces, including QCD and electroweak. Indeed, you often hear people in nuclear physics talking about the "Chromomagnetic operator", which is the generalization of the magnetic force in QED.

However, it's not quite as useful as it is in QED, since these "forces" don't manifest themselves in the same way. Since the gluons have color charge, that means that the chromoelectric and chromomagnetic force fields are not "gauge invariant". This is very different than QED, where the photon is neutral and the E and B fields are "physical".

So the short answer is that there ARE such things as "electric" and "magnetic" fields in these other forces, but they are very different than the QED version, and are more "mathematical analogies" rather than actual physical objects.

BTW: there are also "gravitoelectric" and "gravitomagnetic" fields in General Relativity. Same kind of thing.

Hope that helps.

 

[hch71]

In fact, there is at least one area where the "chromomagnetic" aspect of the strong force is kind of physical. There is the so-called dual superconductor picture of confinement which asserts that quark confinement is due to a condensation of chromomagnetic monopoles. This is of course not a gauge invariant statement but still a mechanism that has its merits and is actively investigated today.

 

[Lapidus]

Thank you, Blechman and hch71!

Great answers!