During World War II, Lamarr learned that radio-controlled torpedoes, an emerging technology in naval war, could easily be jammed and set off course. She thought of creating a frequency-hopping signal that could not be tracked or jammed. She conceived an idea and contacted her friend, composer and pianist George Antheil, to help her implement it. Together they developed a device for doing that, when he succeeded by synchronizing a miniaturized player-piano mechanism with radio signals. They drafted designs for the frequency-hopping system, which they patented. Antheil recalled: