Kind of a knowledge gap here, how does an electrical field generate a magnetic field and how does it produce stuff like radio waves?
In: Physics
The difference is whether you’re moving.
A changing electric field induces a magnetic field, and a changing magnetic field induces an electric field.
One way to change an electric field is to move the electric charges around. We call that an “electric current”, and it happens in wires for example. If you were moving along with the current at the same speed, you wouldn’t see the electrons moving, so you’d see the electric field as static and you wouldn’t observe the magnetic field.
An electromagnetic wave can be thought of as an electric field and a magnetic field traveling along together and constantly inducing each other, back and forth. It can also be thought of as a photon, i.e. a particle of light.
So you can create it by running an electric current through an antenna in a controlled way so that it radiates the correct frequency/amplitude/phase/whatever of light to carry the information you’re trying to send. When that wave reaches another antenna, the process happens in reverse (fields induce each other) and you get back the electricity with the same information inside.
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