Question

what is an electromagnetic wave?

Answer 1

Light, microwaves, x-rays, and TV and radio transmissions are all kinds of electromagnetic waves. They are all the same kind of wavy disturbance that repeats itself over a distance called the wavelength.

Answer 2

It was known for a long time that if you moved a magnet through a coil in wire that it would produce a current in the wire, even if there was no battery there. This is because the magnet has a constant magnetic field around it, and when you move the magnet, it causes the wire to experience a changing magnetic field in it.

So far, not so bad, a changing magnetic field induces an electric field.

Now what a fancy dude named Maxwell discovered by playing with capacitors was that there was a changing electric field creating a magnetic field. From here he figured out that an electric field and magnetic field could make each other in free space and showed that they sped forward at about 300 million meters per second, which was very close to the speed of light measured at the time.

So what IS an electromagnetic wave? Think of it like a photon or particle first and foremost. People will show you these "wave" pictures with arrows on them, but they don't exactly represent what's going on to the uninformed. You see, the light wave is in no way changing size and getting bigger or smaller. What's happening is as it travels its electric and magnetic field strength increases and decreases back and forth, and this is what constitutes its "wave".

A way to imagine it might be, a ball travelling at you and changing its color from red to blue back and forth. The faster it does so, the higher its frequency, but in no way is it waving up and down as it approaches you. This is similar to the electromagnetic wave. Now, that being said, this is an electric and magnetic field and they have direction in that if you put an electron in front of the electromagnetic wave it can be shot up, down or nowhere depending on how strong the electric field is in the photon as it travels.

I can elaborate more if you'd like, because this is one of my favorite subjects in physics.

Answer 3

@Kainui great

Answer 4

Thanks =D

Answer 5

http://en.wikipedia.org/wiki/Electromagnetic_radiation