Temistocle Calzecchi Onesti (December 14, 1853 – November 25, 1922) was an Italian physicist and inventor born at Lapedona, Italy, who demonstrated in experiments in 1884 through 1886 that iron filings contained in an insulating tube will conduct an electrical current under the action of an electromagnetic wave. This discovery was important for the later work of Sir Oliver Lodge, Edouard Branly, and Guglielmo Marconi in the development of the radio. Onesti died at Monterubbiano, Italy.

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