The Electromagnetic Spectrum is a range of frequencies and wavelengths of different types of waves that are emitted by bodies. The first two types on the spectrum are Radio waves and Microwaves. They both have long wavelengths and low frequencies.

Radio waves have a wavelength range of approximately 1 millimeter to 100 kilometers. They were first predicted to exist in 1864 by James Clerk Maxwell, but were later confirmed by Heinrich Hertz between the years of 1885 and 1889. Radio waves are used today to transmit radio and television signals. If you listen to the radio while you’re in a car, you’re probably familiar with FM and AM. In actuality are different types of Radio waves. FM waves have shorter wavelengths and higher frequencies than AM waves. This is why when you go under a bridge and have the FM radio on, you can still hear the station where as if you go under a bridge with the AM radio playing, you can’t hear the station. Radio waves are the longest types of waves on the Electromagnetic Spectrum.

Microwaves have a wavelength range of approximately 1 millimeter to 30 centimeters. These types of waves are used in radar systems, global navigation satellite systems, astronomy, and of course by microwaves to heat up your food. Microwaves were first used in radar in 1940 by Sir John Randall, and Dr. H.A. Boot when they created the magnetron; a device that produced microwaves that could detect aircrafts. Microwaves, even though much shorter than Radio waves, have the second longest wavelengths and second lowest frequencies on the electromagnetic spectrum.

Next on the Electromagnetic spectrum are Infrared Radiation, Visible Light, and Ultraviolet Light. These three types of waves are the middle of the spectrum and include waves that we can actually see.