This brief essay from A Science Odyssey Web site describes the difference between FM and AM radio waves.

Radio waves have the longest wavelengths in the electromagnetic spectrum. This NASA article discusses AM, FM, TV, cell phone, as well as radio astronomy, which all use this technology.

This interactive activity from A Science Odyssey tracks the journey of a sound wave from the moment a musician sings into a microphone until his voice reaches the vibrating speakers of an AM Radio.

The discovery of radio waves, which was widely seen as confirmation of James Clerk Maxwell's electromagnetic theory and paved the way for numerous advances in communication technology, was made by German physicist Heinrich Hertz. In the...

From a course titled "Structure and Interpretation of Signals and Systems." A discussion of the entire radio spectrum, listing wavelength and frequency values for its various parts. The uses of each region of the radio spectrum is...

Wikipedia provides detailed information on radio telescopes, including an image, hyperlinked terms, and related topics.

Karl Jansky discovered extraterrestrial radio waves while investigating possible sources of interference in shortwave radio communications across the Atlantic for Bell Laboratories, and is often known as the father of radio astronomy....

This site details what radiation is, the physics of radiation, and radiative transfer as it occurs in nature. Content explores the electromagnetic spectrum, electromagnetic waves, properties of radiation, and solar radiation.

Ultraviolet (UV) light has shorter wavelengths than visible light. Though these waves are invisible to the human eye, some insects can see them. The specific wavelength values are given. Uses and applications of these waves are explained.

For a man whose career involved the entire known universe, John Kraus had a remarkably insular upbringing. He was born and raised in Ann Arbor, Michigan, and earned his bachelor's, master's and doctoral degrees in physics, all at the...

This Florida State University page introduces light as an electromagnetic wave and discusses the frequency and wavelength range of the various regions of the electromagnetic spectrum. Includes links to some interactive Java applets.

This site chronicles the father of wireless communication. Examines his life and how his accomplishments affected both society and warfare.

Infrared light lies between the visible and microwave portions of the electromagnetic spectrum. Infrared light has a range of wavelengths, just like visible light has wavelengths that range from red light to violet.

Nikola Tesla and Thomas Edison duke it out over the best way to transmit electricity and Heinrich Hertz is the first person (unbeknownst to him) to broadcast and receive radio waves.

This is the man who most encouraged Bell to invent the telephone. Bell said, "But for Henry, I never would have gone ahead with the telephone." This is a fascinating account both of Bell's invention and of Henry's life. Half a biography,...

Explore the electromagnetic spectrum and learn about each type of energy on the spectrum.

This site from MedicineNet.com gives an MRI description, why they're performed, risks, and patient preparation. A thorough explanation of the process is provided.

Wikipedia offers information on spectral line, a dark or bright line in an otherwise uniform and continuous spectrum.

This is a site from NASA that contains an interesting and fun way to learn about the electromagnetic spectrum. Kate receives a strange riddle from her grandfather. Find out what it says and go through the gateway to the Land of the Magic...

Provides some short biographical information on Guglielmo Marconi (1874-1937 CE). Discusses Marconi's scientific accomplishments.

A solid summary from the University of Oregon of the work of James Maxwell Clerk, Michael Faraday, and others in the field of electric and magnetic phenomena. This is a fine essay.

What is electromagnetic radiation and how does it work? Review a captioned graphic that explains electromagnetic radiation and the visible and invisible types of radiation on the electromagnetic spectrum.