Physicists reach atomic-scale telegraphy with light

In the 1880s Heinrich Hertz discovered that a spark jumping between two pieces of metal emits a flash of light—rapidly oscillating electromagnetic waves—which can be picked up by an antenna. To honor his groundbreaking work, the unit of frequency was named “Hertz” in 1930. Hertz’s findings were later used by Guglielmo Marconi (Nobel Prize in