Radio is a technology that transmits data to a remote point where a receiver detects the simple without the use of wire. Radio is thought to be AM or FM stations in terms of common glossary. In fact, radio waves are also used for receiving and sending data waves like satellite broadcasts, Bluetooth devices and wifi networks.
The history of radio dates back to the mid 1800s. It involved theory related to electricity and magnetism. Telegraph was the first available technology developed from this discovery although it required wire cables.
James Maxwell had developed his own theories related to electromagnetism in 1865. This led to the first true experiments of wireless. Many physicists like Thomas Edison, Mahlon Loomis and William Henry Ward patented methods of sending and receiving a wireless telegraph system but a working system was never demonstrated by them.
In 1884, Temistocle Calzecchi-Onesti invented a device which was subsequently refined. Edouard Branly later named it coherer in 1886. It was a glass tube filled with metal filings connected to electrical current producing an audible click in a sounder while receiving the signal. The coherer became the enabling technology allowing early radio signals to be received.
In 1887, Heinrich Hertz was the first person who had refined a system that allowed him to experiment with sending wireless signals to a wireless receiver. He was honored in 1933. In 1892, a Serbian-Croatian immigrant to the US, Nikola Tesla demonstrated the first complete radio transmitter and receiver system and became the first successful person invent radio. Unfortunately, there was a fire in his laboratory in 1895 and he could not demonstrate his radio. However in 1898, Tesla demonstrated the first radio later and filed patents for radio in early 1900s.
An Italian, Guglielmo Marconi was fascinated by the idea of wirelessly transmitting a telegraph signal. In 1894, he successfully invented a spark transmitter with an antenna. Unfortunately, the Italian Postal Service which controlled telegraph services were not interested in his experiment. He moved to England in 1896 where he successfully demonstrated his technology to the English Post Office who immediately recognized his services. Queen Victoria was also impressed by his invention. Marconi was related to British nobility who were powerful investors in his companies and in the emerging US markets.
In 1900, another American Reginald Fessenden demonstrated his new technology which was used by the weather department for sending information to ships at sea. He invented the Barretter detector allowing him to develop amplitude modulation (AM).
The 1920s was the true birth years of modern radio and almost every home owned a radio. Television started to catch up during the 1960s and it was a preferred medium of entertainment for Americans. However radio firmly held on in the car and by 1990s, many Americans listened to radio in their car or at work. Wirelessly broadcasting traffic reports, music and news to radio receivers still prevails despite the arrival of internet and satellite radio.