Scottish physicist James Clerk Maxwell(1831–79), wrote equation that are simply enlightening. He worked on the ideas of Faraday and Kelvin, and succeeded in unifying electricity and magnetism, identifying the electromagnetic nature of light, and postulating the existence of other electromagnetic radiation.
Visible light, x-rays, sunlight , radio waves, television waves, wifi signals, bluetooth signals, cell phone transmission, and GPS all consist solely of Electric and Magnetic Fields. And how they propagate and interact with materials is completely determined by the above 2 equations of Maxwell.
First equation: The electric flux through a closed surface is proportional to the total charge enclosed by that surface.
Second equation: Maxwell second equation is also a form of Gauss’s law, only with magnetic flux instead of electric flux.
Third equation is modified version of Faraday’s equation.
Speed of the waves