What Is Being Disturbed in a Wave of Light?

[Jozers]

From doing physics lessons at school I understand that a wave is a regular pattern disturbance, however what I do not understand is what is actually being disturbed. For example, in a wave of light is it the light particles that are being disturbed? According to my teacher this is wrong, however he didn't know himself what the answer was.
Could someone explain if they know, what is disturbed?

 

[quasar987]

It's the medium in which the wave is propagating that is "disturbed".

Initially, the medium is at rest. Then some external factor causes a disturbance in the medium. (ex: a rock is thrown in the water) Because of the way the water molecules interact, this disturbance will spread in the form of a vertical displacement of the water molecules.

Light is a very special type of wave in that it does not need an medium in which to propagate. It is not a mechanical wave but rather the propagation of an electromagnetic disturbance. There are no solid particles that are displaced from their equilibrium position. It is only the amplitude of the electric and magnetic fields that are changed.