An actress with inventions on her mind
Hedy Lamarr came from Vienna and acted in films for the MGM studio in Hollywood. In her spare time she invented things. During the Second World War she wanted to help the Allies and became interested in the question of how to prevent radio signals from being jammed.
Hopping like on a piano
The idea was simple: the transmitter and the receiver would both keep switching frequency at the same moment, following the same secret sequence. Anyone who didn't know the sequence couldn't jam or eavesdrop on the signal. Antheil proposed synchronising it using perforated paper rolls like those in a player piano, with 88 frequencies standing in for the keys.
From torpedoes to Bluetooth
The Navy didn't use the patent during the war. Frequency hopping was applied later in military communications, and today it is used by Bluetooth, which hops between 79 channels up to 1,600 times a second. Thanks to this, Hedy Lamarr has become a symbol of the fact that anyone can be an inventor.