Electromagnetic waves
If the magnetic field changes at a constant rate, the electric field is constant
If the rate of change in the magnetic field varies, this produce a changing electric field, which can produce again a changing magnetic field and so on……--> possibility to propagate the electromagnetic field!!!!
Propagating electromagnetic field --> electromagnetic waves (Heinrich Hertz, 1887)
In order to generate electromagnetic waves, we need to change constantly the electric or magnetic field at one point of space with non-constant rate!
Electromagnetic waves: transverse waves (electric and magnetic field oscillates perpendicularly to each other, and to the direction of the propagation)
speed in vacuum: c=3 x 108 m/s;
light, together with many other radiation are electromagnetic waves!
As a function of the frequency many different waves!