If I create a varying electric field and it will then create a varying magnetic field, so will it also create light? Will I see a light ray?

Question

If there is an electric field which is changing in time, lets say I create one, then it should create a varying magnetic field. So that means that there is an electromagnetic field, and oscillating electromagnetic field is light. So will I see light? A ray of light or something when I create a varying electric field?

Answer 1

Yes, that's correct in principle.

For visible light, the changes have to occur on time-scales of a femtosecond, $10^{-15}$ seconds, and on spatial scales of about a 100 nanometers, $10^{-7}$ meters, so you have to make the changes very quickly and in a very small space. Usually what you see comes from a whole bunch of little electrons wiggling around very fast.