In a burst of brilliance in 1864, James Maxwell theorized that electromagnetic — radio and light — waves could travel through free space without the mythical “ether” or “quintessence.”
A few years later, Heinrich Rudolf Hertz — the unit of cycles per second is named for him — was able to prove electromagnetic waves could propagate through free space, which confirmed Maxwell's theory of electromagnetism.
In fact, for many years radio waves were called Hertzian waves. “Radio” is not an acronym or hyphenation but is derived from the word “radiation” or “to radiate.” Waldo Warren coined the word and it was adopted by the U.S. Navy in 1912.
You see, the electromagnetic spectrum contains radio waves, microwaves, infrared light, visible light, ultraviolet light, X-rays and Gamma rays. Those are all forms of electromagnetic radiation. The waves travel in interesting ways across our sky, in outer space and even into the earth and oceans.
Today, the majority of radio wave devices that most of us use every day operate by line of sight, which means the radio waves propagate in a straight line between the transmitter and receiver, including signals for broadcast TV, cell phones, walkie-talkies, wireless or Wi-Fi networks, telecommunications microwave links and even satellites. Other radio frequencies, like your AM — for amplitude modulation — radio band can bend over obstacles like hills and journey well beyond the horizon. Your FM — for frequency modulation — radio band tends to be more line-of-sight due to its shorter wavelength.
Much lower frequencies can penetrate through water and earth. Communications with submerged submarines and workers in mines use very long wavelengths. The Navy’s E-6 Mercury aircraft tows a 5-mile-long antenna in flight to communicate with our submarines, a very-long wavelength indeed.
Shortwave and other higher frequencies can travel across oceans and continents as they skip or refract off an abundant layer of electrons and ionized atoms called the ionosphere that can stretch from 30 miles above the Earth to the edge of space at 600 miles.
Some radio stations use shortwave to broadcast internationally. That method of broadcasting is dependent upon the upper atmosphere and is most reliable during winter’s long nights.
Wouldn't you know it, that is one of the frequency bands used by amateur radio operators. Since the early 1900s, no other group has made a greater contribution to radio communications than our treasured amateur or so-called ham radio operators. Even though they are licensed by the Federal Communications Commission, they are called amateur radio operators because the FCC has set aside certain noncommercial radio frequencies for their use.
Consequently, they are not allowed to accept any payment for their services.
But they are just as innovative today as they were 100 years ago.
Amateur radio operators have a distinguished history of public service as well as emergency communications.
You see, when severe weather, floods, earthquakes or wildfires occur, they can cause power outages or damage communications equipment, like cell phone towers.
When conditions like that arise, amateur radio emergency teams spring into action and relay "health and welfare" information and support first responders and government agencies with their radio equipment when other communications channels are inaccessible.
American broadcaster Art Bell, who passed away last week, became a licensed amateur radio operator at the age of 13. His call sign was W6OBB.
I would often listen to his show on Sunday nights driving home from Navy Reserve drill weekends at Naval Air Station Point Mugu.
There are many amateur radio clubs in the Central Valley. To lean more, please visit The National Association for Amateur Radio, San Joaquin Valley at http://www.arrl.org/Groups/view/san-joaquin-valley.