1865:
- Scottish physicist James Clerk Maxwell publishes a mathematical theory predicting the existence of electromagnetic waves.
1873:
- Irish physicist George Johnstone Stoney coins the term "radio."
1876:
- Scottish-born American inventor Alexander Graham Bell transmits speech through a primitive radiotelephone device he calls a "photophone," which uses light waves to transmit sound.
1886:
- German physicist Heinrich Hertz conducts experiments that confirm Maxwell's theory and demonstrate the existence of radio waves. Hertz's experiments lay the foundation for the development of radio technology.
1893:
- Serbian-American electrical engineer Nikola Tesla demonstrates a wireless communication device called a "Tesla coil" at the World's Columbian Exposition in Chicago.
1894:
- Italian inventor Guglielmo Marconi builds a wireless telegraphy system based on Hertz's work, transmitting signals over short distances.
1895:
- Marconi succeeds in transmitting a wireless signal over a distance of about 1.6 kilometers (1 mile). He transmits the Morse code letter "S" from Lavernock Point in Wales to Flat Holm Island in the Bristol Channel.
1896:
- Marconi achieves wireless transmission over a distance of about 24 kilometers (15 miles) across the English Channel.
1897:
- Marconi establishes the world's first commercial wireless telegraph station on the Isle of Wight in the United Kingdom.
1901:
- Marconi successfully transmits a wireless signal across the Atlantic Ocean from Poldhu, England, to Signal Hill, Newfoundland, a distance of about 3500 kilometers (2200 miles).
1906:
- The first transatlantic radiotelephone conversation takes place between Reginald Fessenden and a colleague in Brant Rock, Massachusetts, USA, and Machrihanish, Scotland.
1920:
- The first commercial radio broadcast takes place in Pittsburgh, USA, by station KDKA. The broadcast features the results of the presidential election.
1922:
- The British Broadcasting Company (BBC) is established in the United Kingdom, becoming one of the world's largest and most influential radio broadcasting organizations.
1927:
- The Federal Radio Commission (FRC), the predecessor to the Federal Communications Commission (FCC), is established in the United States to regulate radio communications.
Throughout the 20th century:
- Radio continues to evolve, with the development of new technologies such as FM (Frequency Modulation) broadcasting, transistor radios, and satellite radio.
Present:
- Radio remains a widely used medium for communication, entertainment, and information dissemination, with internet radio and digital radio gaining popularity in recent years.
