ELECTROMAGNETISM.

So after reading about electricity and magnets, we can now join the 2 together to lern about electromagnetism.

Electromagnetism is one of the four fundamental reactions of nature. (The other forces are the strong nuclear force, the weak nuclear force and the gravitaional force.)

It is the force that causes the interaction between electrically charged particles. These particles are in electromagnetic fields.

The two ideas of elctricity and magnetism are interdependent because a changing electric field generates a magentic field, and a changing magnetic field produces an electric field.

The unification of this was a giant step forward in scientific discovery!

Basically, electromagnetism describes the interactions of light (that is electric fields and magnetic fields) on matter and charged particles.

The basics of electromagnetism were developed by physicists in the 19th century, mainly by James Clerk Maxwell who primarily unified the idea.

Electromagnetism obeys a set of equations called "Maxwell's equations" (http://en.wikipedia.org/wiki/Maxwell%27s_equations) and the electromagnetic force is given by the "Lorentz force law".

According to Maxwell's equations, the speed of light in a vacuum is a universal constant, dependent only on the electrical permittivity (permittivity is the measure of how much resistance is encountered when forming an electric field in a vacuum) and magnetic permeability (permeability is the measure of the ability of a material to support the formation of a magnetic field within itself) of free space.

There are also things called electromagnets. An electromagnet is a type of magnet whose magnetic field is produced by the flow of electric current. The magnetic field disappears when the current ceases.