Work in pairs. Ask and answer questions about the inventions of the scientists.
A: What happened in 1894?
B: Alexander Popov invented the first radio.
A: What happened in… ?
The identity of the original inventor of radio, at the time called wireless telegraphy, is contentious. The controversy over who invented the radio, with the benefit of hindsight, can be broken down as follows:
1894 - Alexander Popov built his first radio receiver, which contained a coherer (detecting device consisting of tubes filled with iron filings).
1895, May 7 - Further refined as a lightning detector, it was presented on the Russian Physical and Chemical Society.
1893 - Nikola Tesla developed means to reliably produce radio frequencies, publicly demonstrated the principles of radio, and transmitted long-distance signals. He holds the US patent for the invention of the radio defined as "wireless transmission of data."
18967 - Guglielmo Marconi was an early radio experimenter. He founded the first commercial organization devoted to the development and use of radio. In 1909 – awarded the Noble prize.
1906 - Reginald Fessenden and Lee de Forest invented amplitude-modulated (AM) radio, so that more than one station can send signals (as opposed to spark-gap radio, where one transmitter covers the entire bandwidth of the spectrum).
1913 - Edwin H. Armstrong invented frequency-modulated (FM) radio, so that an audio signal can avoid "static," that is, interference from electrical equipment and atmospherics.
1893 – 1894 - Roberto Landell de Moura, a Brazilian priest and scientist, conducted experiments. He did not publicize his achievement until 1900 but later obtained Brazilian and American patents.
EXERCISE 5
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