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ted with Maxwell's thesis in 1888 and demonstrated that waves travelled in straight lines and could be reflected by a metal sheet. Augusto Righi, an Italian physicist, continued and refined Hertz's work, establishing the equality between electrical and optical vibrations. Another scientist, Temistocle Calzecchi-Onesti, constructed, in 1888, a tube due to his belief that electrical discharges of atmospheric perturbations influence iron filings. In 1894, Oliver Lodge named Temistocle's famous tube the 'coherer' and increased the reception gain of the hertzian waves. Alexander Popoff then created a vertical metal pole by using Lodge's coherer and collecting atmospheric disturbances in a rudimentary antenna.

The invention of these instruments helped Guglielmo Marconi's discovery who verified that electromagnetic waves travel between two points separated by an obstacle which led to the creation of the first radio transmitter. This experiment was repeated with larger spark gaps starting with 5 feet; expanded up to 100km and radiotelegraphy was born. The first radio station began operation in the 1920's. The broadcasting radio station was KDKA in Pittsburgh. This service became very popular and soon the concept spread around the globe. Early uses of radios were maritime, for sending telegraphic messages using Morse code between ships and land.

Radios were used to pass on orders and to communicate between armies and navies on both sides in World War I. Germany used radio communications for diplomatic messages once it discovered British had tapped its submarine cables. Besides broadcasting purposes, point-to-point broadcasting, including telephone messages and relays of radio programs became common in the 1920s and the 1930s. In the pre-war years, radios were the development of detection and locating aircrafts and ships by radars. As time progressed, so did the development of radio. Today, the concepts used in radios are also used in many modern devices that are now essential to our modern lives.

Inventions of radios ultimately lead to telephony (Mobile phones), videos (Television sends the picture as AM and the sound as AM or FM, with the sound carrier a fixed frequency), satellite navigation systems (Satellites with precision clocks, the satellite then transmits its position, and the time of the transmission, the receiver listens to four satellites, and can figure its position as being on a line that is tangent to a spherical shell around each satellite, determined by the time-of-flight of the radio signals from the satellite. A computer in the receiver does the math), radars (Detects objects at a distance by bouncing radio waves off them. The delay caused by the echo measures the distance and the direction of the beam determines the direction of the reflection), radio remote control (Radio remote controls use radio waves to transmit control data to a remote object as in some early forms of guided missile, some early TV remotes and a range of model boats, cars and airplanes while large industrial remote-controlled equipment such as cranes and switching locomotives now usually use digital radio techniques to ensure safety and reliability), heating (Radio-frequency energy generated for heating of objects is generally not intended to radiate outside of the generating equipment, to prevent interference with other radio signals. Microwave ovens use intense radio waves to heat food. Diathermy equipment is