# Photons governing the electromagnetic field

1. May 24, 2010

### ranrod

As I understand it photons govern the electromagnetic field. I don't have an intuitive knowledge of what that means. Does anyone have an explanation, link or reference for an intuitive interpretation?

So if I rub a latex balloon against my clothes and then put it near my arm, I'll see all my arm hairs raise towards the balloon. Are there supposed to be a countless number of photons 'carrying' the electromagnetic force and traveling between the arm hairs and the balloon? That sounds counter-intuitive. Photons only travel in a straight line, don't they? But those curved magnetic-field lines that form around magnets have photons traveling through them? If you could somehow divert or absorb those photons, the magnet wouldn't work anymore?

I know an electron can 'shed' energy by releasing a photon and dropping its orbit, or 'absorb' a photon and go up an orbit. Is that what "photons govern the electromagnetic field" means? It sounds more like a symptom of electromagnetism rather than the governing factor.

2. May 24, 2010

### JDługosz

The elecromagnetic force is carred by so-called "virtual photons". The concept of a photon and charge are intimately linked. The "real" photons of light can be considered a side-effect of this relationship!

Virtual photons don't travel or behave in any manner that is at all familiar to everyday experience. They exist purely in the quantum realm. They might travel faster or slower than light, be heavy, or exist everywhere at once, to name a few things that get thrown out when trying to "explain" them.

You might try finding a book that's a gentle introduction to Symmetry and Gauge concepts. I rather like https://www.amazon.com/Force-Symmetry-Vincent-Icke/dp/052145591X/ref=cm_lm_byauthor_prod_0_1", which is see is under \$5 for a used copy.

Nothing "follows" the lines that are often visualized around a magnet. Those are another subject.

Last edited by a moderator: Apr 25, 2017
3. May 24, 2010

### ranrod

To what extent are virtual photons just a mathematical construct (or philosophical even), and to what extent are they supposed to represent what's really happening?