ABSTRACT
This chapter begins with history of microwaves over 200 years ago, to a time when electricity, magnetism and light were three distinct phenomena, each wondrous in their own right, but entirely unconnected in the minds of the scientist of the day. Jocelyn Bell first thought was that it was a message from another world, or maybe an interstellar navigation and timing beacon for extraterrestrial spacecraft. They even gave it a name, among themselves, of LGM-1 — the acronym standing for Little Green Men. Newton model was that there are three different groups of cones in the retina, each of which is particularly sensitive to one of three colours: red, green and blue. The conventional understanding of the electromagnetic spectrum — running in wavelength from gamma rays to X-rays to ultraviolet light to visible light to infrared to radio waves — is due to Maxwell.
