Beginning of the Earth
What causes the magnetic field?
There are a great many things about the earth's magnetism that scientists still do not know. But the most widely accepted theory is that the magnetic field is set up by electric currents deep within the earth's liquid core. These currents are created when minerals of different temperatures and different electrical properties come together. This means that the inside of the earth is a huge, natural generator, which is constantly turning mechanical energy (the earth's rotation and the movement of the liquid core) into electrical energy. And, of course, we know that all magnetic fields are the result of electric currents, and all electric currents are surrounded by magnetic fields.
What causes the magnetic field?