In 2012, by the United Nations General Assembly, and it is celebrated on February 13th. This date coincides with the creation of the United Nations Radio.

It is an opportunity to promote international cooperation among radio broadcasters, encourage major networks and local radio stations to promote access to information and freedom of expression.

UNESCO

But how did radio emerge?

Electromagnetism Theory

Let's start with the theory of electromagnetism. Based on earlier studies, James Maxwell (1831 - 1879) predicted that electromagnetic waves, such as radio waves, could propagate freely through space without the need for a material medium. Through his equations, he described the fundamental laws of electromagnetic fields.

It was also Maxwell who concluded that these waves are composed of an electric field and a magnetic field that oscillate in perpendicular directions to each other.

The Proof of Electromagnetic Waves

A few years later, Heinrich Hertz (1857 – 1894) demonstrated the propagation of electromagnetic waves through experiments with radio waves. The researcher used an electric oscillator that generated a spark, which in turn produced electromagnetic waves that were sent by a transmitting antenna. To receive the transmitted signal, a receiving antenna was used, where an electric current was induced as a result of receiving the signals.

In this way, Hertz proved that electromagnetic waves traveled through the air, between the transmitting and receiving antennas.

Radio for Long-Distance Telegraphy

Guglielmo Marconi (1874 – 1937) explored wireless communication and contributed to the development of long-distance wireless telegraphy. In 1897, he founded the Marconi Wireless Telegraph Company.

In 1895, he achieved the first wireless telegraphic communication, transmitting a radio signal over a distance of approximately 1.5 km. Continuing to develop this technology, in 1901, he also carried out the first transatlantic communication: a signal was transmitted in Morse code from England and received in Canada.

The First Music Broadcast

Around the same time, Reginald Fessenden (1866 – 1932) was working on a sound transmission system through radio waves, conducting research on amplitude modulation (AM). Using this method, the scientist transmitted the first sound signal over a distance of approximately 1.6 km via wireless communication.

Later, on Christmas Eve of 1906, he successfully carried out the first broadcast of a music and voice program over a long distance.