On December 12, 1901, a radio transmission received by Guglielmo Marconi resulted in the first transmission of a transatlantic wireless signal (Morse Code) from Poldhu, Cornwall, to St. John's, Newfoundland.
7. Voltage is sometimes referred to as EMF, or Electromotive...?
The term EMF, or Electromotive Force, its use now in decline, is attributed to Italian physicist Alessandro Volta (1745-1827). Today we generally use the term "voltage" - can you guess why we call it that?
CDs reproduce 44,100 samples per second. Which has a maximum frequency reproduction of 22,050 Hz, or just a hair past the upper limit of human hearing. In this way CDs can theoretically reproduce any frequency in the human hearing range.