I am trying to understand how photons as the force carrier for the electromagnetic force (or field) manifest themselves in a flow of electric charge, i.e. an electric current. Both standard (classical) model explanations and field explanations are welcome. I am a layman, so ... be gentle?

After doing some reading, research, digging, and crying, I keep returning to some explanations that seem to describe the photon's role best (but yet, I still think they might be inaccurate).

For instance, someone described it this way: electrons move through a wire in a line (direct current) because they are repelled by each other, thus they "push" each other down the wire. This pushing is expressed by photons (some say "virtual", i.e. mathematical not "real", photons) being exchanged between the electrons that "push" the electrons away from each other. Yet, if these (virtual?) photons push out in all directions, they would push against both electrons in the wire (for a simplified line of single electrons each having one in "front" and one "behind"). However, the dry cell (battery) reaction forcing electrons out one end and drawing them in at the other tips the balance, if you will, keeping the electrons moving in the direction of the current.

Alternately, I've heard it this way: a photon is a ripple in the photon field. The "ripple" is what we have been trying to (somewhat inaccurately) describe with the word "particle". As the photon moves, it interacts with (some say "creates") an electric field and a magnetic field (the electric and magnetic fields are perpendicular to each other). The photons that make up a static electric or magnetic field are virtual, i.e. their energy and momentum don't satisfy the conditions of "real" photons: E = p*c. Photons are emitted and absorbed by charged particles constantly. A charged particle is thus constantly emitting and absorbing virtual (i.e. mathematically described) photons. Photons only interact with charged particles, not with each other. Every photon is surrounded by a group/cadre/entourage of electrons (and other charged particles), through these associated charged particles, a photon can interact with another photon. Presumptively (and likely erroneously), the movement of these photons drives the electrons down our wire to complete the electric circuit and are thus responsible for the electric current.

Finally, there is this thing (which I love): https://www.youtube.com/watch?v=rxqZczaSA9c

... but what the heck is that? An electron constantly sucking in photons and spitting them about, but what are the four "rings" they are going through? Ripples in the electromagnetic field?

  • 2
    $\begingroup$ It sounds like your understanding is pretty good already. Just a couple things to keep in mind. (1) Always keep the quantum and classical pictures separate. A connection between them is not straightforward. For example, as you have pointed out, it is incorrect to say, "a photon interacts with an electromagnetic field". (2) Imagine a train running on tracks at a constant speed with no friction. Do it's cars push each other? No. And yet it keeps running in the initial direction. Do they push if it runs with friction? Yes, but relatively little. Same with electrons in the wire, no surprises. $\endgroup$
    – safesphere
    Commented May 29, 2018 at 6:50
  • 3
    $\begingroup$ The youtube video you linked to has no scientific value whatsoever. Anyone can post a random animated picture and claim it represents some new theory. $\endgroup$ Commented May 29, 2018 at 11:43

2 Answers 2


The virtual photons you describe are physically the EM flux present on a direct electric current carrying wire of the electric and magnetic field inside and around the wire.

Both electric and magnetic flux it is known consists of these same coherent streams of virtual photons forming the E-field and M-field of the conductor wire in space. I don't know why this is not broadly mentioned in the literature which would resolve a lot of confusion around this subject, thus that both electric and magnetic flux therefore also the E and M interaction fields are made up from these same virtual photons and that only the curl and divergence of the flux lines of the field changes depending on the type of the field E or M.

It is true that the virtual photons are not exactly the same as normal photons of EM propagating waves of light. No one has observed them discretely in a lab. They are theorized to be the electromagnetic force carriers between electrons and other charged particles. However they share the same spin 1 value as normal photons. Therefore Bosons and since responsible for the electromagnetic interaction must be in general regarded as photons. Put simply, virtual photons are basically photons of very short wavelength exchanged between electrons.

According to quantum field theory QFT, any propagating disturbance in the photon quantum scalar field made up from these virtual photons (existing also in vacuum space) is considered to be a normal photon.

Imagine this virtual photons scalar field as a flat sheet extending in space and then you poke it with your finger and make a hump on its surface locally which you can then move along its surface , this would represent a normal photon.


Imagine a linear wire which is also a resistor. When a direct current passes through it, and two moving successive electrons are imagined; the second one should go towards the first one because of voltage; because of resistance the first one is slowed down, and the second one go nearer to the first one because of voltage. So, two successive electrons are forced to be nearer to each other. But they are same type (negative) of charged particles. So, they should try to be away from each other. Simultaneously, two successive electrons are forced to be nearer as well as farther. To avoid this situation, an energy is released in a wave form. This is light and this is an energy wave released from an electric field of electrons. Electric field is disturbed to produce light energy. On the other hand, when light energy is applied on a solar cell, electric field of electrons are disturbed and current is produced. Light is an electric field wave. Nodes may be imagined as photons in which light energy is consolidated. Coming away from usual explanations and keeping such imaginations would help to understand photons and light rays.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.