In the last decades of the 19th century in several laboratories, experiments were carried out on electromagnetic waves and their propagation. The existence of those waves was hypothesized by J. C. Maxwell in 1862. H. Hertz provided the first experimental confirmation in 1887, and many researchers, including Augusto Righi, were involved in the study of the new phenomenon. It should be remembered that, one century before, some of the experiments of Galvani had observed phenomena connected with electromagnetic waves.

It was an outsider, a self-taught man - Guglielmo Marconi (1874-1937) - who realized the first practical application of the electromagnetic waves: wireless telegraphy, the first step in the history of radio communications. Thanks to his technological ability he set up his system of wireless telegraphy and was able, in 1895, to send a signal beyond the hill in front of his family house (near Bologna, Italy) at a distance of 2 km. In 1896 Marconi went to England where he patented his invention and pursued his idea of sending signals to far away stations and to ships.

Within five years Marconi found the money to accomplish a great undertaking: invisible signals, which only a few years before could not go beyond the walls of the scientific laboratories, were sent without wires to the other side of the Atlantic Ocean (1901).

The entire 20th century has been characterized by many developments in radio communications, televisions, and, more recently, radiotelephony (cellular systems).

1. The transmitter for “wireless telegraphy” made by Marconi (1895) for his first experiments at Sasso di Pontecchio (Bologna).
2. Marconi in front of the equipment with which, in 1899, transmitted electromagnetic waves across the English Channel.
3. One of the EUTELSAT satellites for TV and telecommunications.