World Radio Day

February 13 is World Radio Day,  which celebrates the radio as a way of educating people, providing information and promoting freedom of expression across cultures. 

Invention :  Inventors around the world were churning out new and exciting inventions left and right in the years leading up to the 20th century. Scientific work in radio technology was heating up too. Two men in particular, Serbian-American scientist Nikola Tesla and Italian physicist Guglielmo Marconi went head-to-head in what would become the race to invent the radio. But more than 100 years later, ask any two people who invented the radio and you're likely to get two different answers. The story is a murky one that mixes scientific discovery with lawsuits and good old-fashioned marketing. Let's see if we can untangle the threads.

After emigrating to the U.S. in 1884, Tesla invented the induction coil or Tesla coil, a device essential to sending and receiving radio waves and one the U.S. Patent Office would later say Marconi relied on for his work [source: Britannica]. But in 1895, a fire destroyed Tesla's lab as he prepared to send a radio signal approximately 50 miles (80 kilometers) to West Point, N.Y. 

Meanwhile, Marconi had been conducting his own experiments and in 1896, sent and received Morse code-based radio signals at distances spanning nearly 4 miles (6 kilometers) in England. That same year, he applied for, and was granted, the world's first patent in wireless telegraphy in England. 

In an ironic twist of fate, Marconi's company sued the U.S. government in 1943 for patent infringement during World War I. But the case never made it to court. Instead, to avoid the lawsuit altogether, the U.S. Supreme Court upheld patent 645,576, thus restoring Tesla (who had died a few months earlier) as the inventor of the radio. Nevertheless, many people still tend to think of Marconi as the father of the radio.

November 2, 1920: KDKA, the first commercial radio station in the United States, goes on the air in Pittsburgh. July 1, 1941: WBNT, the first commercial TV station, starts broadcasting. April 3, 1973: Martin Cooper of Motorola makes the world’s first cell phone call.

Radio has transformed society three times, not to mention giving birth to the entire field of electronics. Perhaps no invention of modern times has delivered so much while initially promising so little. When radio arrived at the end of the 19th century, few thought that “wireless” communications, in which intangible signals could be sent through the air over long distances, would be competitive in a world dominated by the telegraph and telephone. The early inventors studied the work of Scottish physicist James Clerk Maxwell, who had formulated a set of equations — “Maxwell’s equations” — that expressed the basic laws of electricity and magnetism, but as a purely theoretical exercise in understanding how nature works. His equations explained light as one form of electromagnetic radiation and predicted that there should be many other forms, invisible to the human eye. In the 1880s the German physicist Heinrich Rudolf Hertz validated Maxwell’s laws by detecting radio. 

Fortunately, other scientists and engineers saw the radio spectrum not as a curiosity but as a tool for a new kind of communication. The principle behind radio transmission is simple. Electrons moving through a wire create a magnetic field. Place another wire near the first and electrons will start to move in the second wire too. The signal travels between the wires because the magnetic field formed by the first wire — the transmitter — creates an electric field in space, which in turn creates a magnetic field, and so on, moving outward at the speed of light. When the second wire — the receiver — picks up that signal, the field is converted back into the motion of electrons, detectable as an electric current. In order to carry information, the transmitted signal has to vary over time. The easiest way to do this is simply to stop and start the current in the first wire, sending a message as a series of pulses. The flamboyant Serbian-born engineer Nikola Tesla followed that approach and transmitted a radio signal across a short distance in 1893.

.......... Yashila Barnwal

This blog post is part of the blog challenge ‘Blogaberry Dazzle’ hosted by Cindy D’Silva and Noor Anand Chawla, and generously SPONSORED BY Bugshield Clothing – Enjoy Outdoors More!