How Radios Were Invented
The credit of how radios were invented can not be allotted to one era or person. Radios were invented when a connection between electromagnetic current and light was established. The main contributors in the invention of radio were Heinrich Hertz, Guglielmo Marconi, James Clerk Maxwell and Mahlon Loomis.
Radio started as wireless telegraph. The first ones to adopt this system were the navy. Titanic’s disaster was a contribution of the weak faulty telegraph system. When Titanic was sending out panic location signals, the interference caused a delay in reception. Help could not reach on time and she sank without a trace.This was the time when radio as an appliance was not invented.
Radio was invented in a step wise series of discoveries and experimentation. Lee De Forest after the disaster started working on a stronger receiver which he called a responder. In the year 1890 Thomas Edison was developing light bulb and he discovered during his work, that electromagnetic waves were transferable in vacuum. John Embrose Fleming in 1904 discovered the change of alternating current into direct current after passing through vacuum. He added two electrodes to the setting and called it a diode.
James Clerk Maxwell discovered a relation between electric charge and magnetism. This phenomenon he named, electromagnetism. In 1864 he proved that there was a third factor, light involved in spreading the electromagnetic effect. This led to a cycle of the electric current and magnetic field. Electric current produced a magnetic field that in turn generated electric current.
James Clerk Maxwell proposed that a wave could be present between the two if another phenomenon, alternating current was introduced to the process. A changing electric charge will produce a changing magnetic field and vice versa. A wave should form in this alternation. This wave or radio wave later was utilized to transfer sound and pictures to receivers.
In the 1880's Heinrich Hertz got interseted in Maxwell's theory. While working on it he found that a current jumping to and fro from a wire to another could be the cause of such waves. He proved this theory by performing an experiment with two rods, acting as signal receivers. He proved in his experiment that these were electromagnetic waves.
Fleming became aware of the technology and was convinced it would prove fruitful in the field of radio transmission. He added a thin wire grid connecting the two diodes. This apparatus was capable of picking up electromagnetic signals and then their amplification so they became audible. Radio was invented with the help of this triode called transmission through vacuum tube. This same technology led to the invention of television later.