[thomma]

There may be an easy answer for this, but, if there is please forgive me.

I have posted previously about the supposed graviton, thanks for those that replied.

I understand that this graviton is the particle responsible for the effects of gravity. Is there a particle that is responsible for the effect of magnetism?

[John Cuthber]

Yes, the photon.

[DrRocket]

John Cuthber, on 15 December 2011 - 10:05 PM, said:

Yes, the photon.

Which has the distinction of having been shown to exist and which is described by a predictive theory, quantum electrodynamics.

[Greg Boyles]

John Cuthber, on 15 December 2011 - 10:05 PM, said:

Yes, the photon.

How are photons directly related to a magnetic field?

As I understand it magentic fields are directly related to electrons.

This post has been edited by Greg Boyles: 15 December 2011 - 10:08 PM

[John Cuthber]

They are the carrier of the electromagnetic force.
http://en.wikipedia....i/Force_carrier

"As I understand it magentic fields are directly related to electrons. "
indeed.
http://en.wikipedia....wiki/Proton_NMR
Count the electrons in a proton, yet it has a magnetic dipole.

[Greg Boyles]

John Cuthber, on 15 December 2011 - 10:15 PM, said:

They are the carrier of the electromagnetic force.
http://en.wikipedia....i/Force_carrier

"As I understand it magentic fields are directly related to electrons. "
indeed.
http://en.wikipedia....wiki/Proton_NMR
Count the electrons in a proton, yet it has a magnetic dipole.

Interesting, although not being particularly gifted at maths I find it difficult to grasp a lot of the details of the standard model.

[md65536]

John Cuthber, on 15 December 2011 - 10:15 PM, said:

They are the carrier of the electromagnetic force.

"Electromagnetism attracts electrons to an atomic nucleus to form atoms," [http://en.wikipedia....lectromagnetism]

This happens without photons being exchanged between electron and nucleus, right? Is it safe to say that for not all effects of electromagnetism is there a need (or in any sense, "existence") of a photon to have the effect? Eg. electrons are bound to atoms due to the electromagnetic force; considering only a single atom, no photon can definitively be said to actually exist until there is a transfer of energy via electromagnetic radiation?

In terms of gravitity and the hypothetical graviton, it could be that gravitation effects occur without gravitons, but that gravitons might "exist" anywhere that gravitational force information needs to be "carried", which would essentially be when there is a change.

The http://en.wikipedia....i/Force_carrier link says "it is thought that there may be particles called gravitons which are the excitations of gravitational waves" (tentative).
Also, it suggests that an answer to my question above is that any electromagnetic interaction can be thought of as carried out by "virtual particles", so whether or not particles actually exist in those cases is I guess somewhat up to interpretation?

Couldn't the existence of non-virtual (long-lived) particles such as photons be the same as the existence of virtual particles? Might they have no physical existence beside the measurable effect that has occurred, ie. that a force has been carried? Or is that in fact what defines their existence -- that electromagnetic force carrying (light) has been measured, while gravitational force carrying has not been observed? So detection of gravity waves would constitute that and would show that gravitons exist?

Sorry I realize with all these questions that I'm in over my head.

This post has been edited by md65536: 16 December 2011 - 04:18 AM