Today I want to talk a little about another of the fundamental forces of nature, the **electromagnetic force**.

The electromagnetic force is that which occurs between particles with electric charge. Like any kind of force, it depends on what point of view we look at, we will have a different concept of that force. It is not the same to see it macroscopically than to see it at the atomic or quantum level. Although governed by the same equations, the calculations we will perform will be different.

Thus, at “standard” size we have the classical electromagnetism whose maximum exponent is Maxwell and his Maxwell equations that are a compendium of diverse other laws of other authors like Gauss, Faraday and Ampere. All a classic … differential.

At the atomic level, we consider the relativistic electromagnetic equations, which are the interactions existing at speeds close to light (that is why they are relativistic) and that, like everything relativistic, they develop through a tensor that gives us the electromagnetic field. Very cool.

And what matters to us as a fundamental force is that which exists at the quantum level. The quantum-level electromagnetic force is known as quantum electrodynamics.

Quantum electrodynamics, although it seems a lie, is based only on a single particle, the photon, and tells us how interactions with other fundamental particles (fermions) with electric charge. The way we calculate the interactions is based on wave equations of each of the fundamental particles (remembering fermions) and how these equations are modified by this force.

This way, in a very precise way, it may sound like a Chinese one, but it is not very complicated since the only thing that exists is, mathematically speaking and without entering much in the gauge groups (topological spaces and surjective applications, injective dicesis and bijective, with Projections … something like having a topological base space with other topological spaces associated with which we can pass through an application), tells us what are the permissible wave equations and the modifications that we can make.

And now that I reread it, it sounds just as complicated, but simplifying it more, just tells us what interactions can and can not be, simply.

The fact is that, as I put in the header image, the simplest and easiest way to understand it is thanks to the Feynman diagrams that help us understand these possible interactions with a simple glance, indicating that energy happens to Element and as when a photon strikes a particular fundamental particle and passes it to this particle.