Eli5:Explain what an electromagnetic field is


Eli5:Explain what an electromagnetic field is

In: Physics

Imagine that all of space is filled with little arrows that can point in any direction and have different sizes. [Here’s a neat little visualization](https://demonstrations.wolfram.com/3DVectorFields/). Each arrow represents a direction by where it points, and the size represents a magnitude, or amount. That’s what a field is, and there are many different kinds of them beyond the electromagnetic one.

The electromagnetic field is the combination of 2 of these fields. One of them electric, the other magnetic. If you put something with electric charge like a balloon that’s been rubbed on a sweater, or a wire connected to a 120V plug in your house, then you get these “arrows” all around that object. Other nearby electrical charges “see” those arrows and “know” how to react by being attracted or repelled depending on the situation, hence why that staticky balloon will stick to you. The magnetic field is the same for magnetic stuff. If you could see the arrows from a bar magnet it’d look a bit like [this](https://schoolbag.info/physics/ap_physics_2017_1/ap_physics_2017_1.files/image335.jpg). If you set another magnet near, it “sees” those arrows and then they attract or repel each other.

So what about the electromagnetic field? Well, it can be viewed as 2 separate fields, but a while ago we realized that both the electric and magnetic forces were coupled in a specific way. If you move a magnet or an electric charge, it actually affects the other field. So in a way we have to view them as both being part of the same phenomena. So its 2 sets of arrows stacked on top of each other, and if the arrows in one field are changing, then it affects the arrows from the other field.

And if we want to get particular, those arrows are called “vectors”.