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Short · 2:09 · 2-min read

Hedy Lamarr The Most Beautiful Woman in Hollywood Was a Secret Inventor

Hollywood called her the most beautiful woman in the world. She was also an inventor, and the Navy turned her idea down.

Hedy Lamarr was born in Vienna in 1914. At 18 she was famous across Europe, and that same year she married Fritz Mandl, an arms dealer and one of the richest men in Austria. At his dinners and meetings she listened to engineers talk about weapons. In 1937 she fled, met the boss of MGM, and became Hedy Lamarr, "the most beautiful woman in the world".

During the Second World War she had an idea: radio-guided torpedoes could be jammed, so make the signal jump between frequencies in a pattern only the ship and the torpedo know. With the composer George Antheil, who knew how to keep player pianos in sync, she designed a system with 88 frequencies, like the 88 keys of a piano. They patented it in 1942. The Navy rejected it and told her to sell war bonds instead. The patent ran out in 1959, and only after that did the military start using the idea. In 1997 she finally received an award for her invention, and in 2014 she was inducted into the National Inventors Hall of Fame. Today, frequency hopping is part of Bluetooth.

Read the full story 2 min ↓

The facts behind this file

What the record shows

  • Born Hedwig Kiesler on 9 November 1914 in Vienna.
  • The film Ecstasy (1933) made her famous at 18; that year she married the arms dealer Friedrich Mandl.
  • With the composer George Antheil she patented a frequency-hopping system using 88 frequencies, like a player piano: US patent 2,292,387, granted 11 August 1942.
  • The Navy rejected it and suggested she sell war bonds instead.
  • She received the EFF Pioneer Award in 1997 and joined the National Inventors Hall of Fame in 2014. She died on 19 January 2000.

Legends, disputes & careful wording

  • That she was a 'prisoner' in her marriage and escaped disguised as a maid comes from her own, ghostwritten autobiography.
  • Frequency hopping existed before her patent. She did not invent Wi-Fi; Bluetooth uses frequency hopping, and Wi-Fi and GPS use related spread-spectrum ideas.

Main sources

  • US patent 2,292,387 (1942)

Spotted a mistake or know a better source? Tell us. How we check the facts.

Further reading

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Codes, signals & screensDenied the credit
Image & film credits
  • Hedy Lamarr, 1939: CC BY 4.0 · Louis B. Mayer, 1934: CC BY 4.0 · Schloss Schwarzenau: CC BY-SA 4.0.
  • Other images are public domain (Hedy Lamarr publicity portraits 1940, 1944 and 1949, with James Stewart c. 1940, George Antheil, US patent 2,292,387 and its case file). Video clips from Pexels. Music and sound made for this video.
In this story
  1. A curious child in Vienna
  2. The prisoner who listened
  3. "The most beautiful woman in the world"
  4. A signal that jumps
  5. Sell war bonds instead
  6. Recognition, late
  7. What it has to do with your phone

The full story · 2 min read

Hedy Lamarr: the film star whose invention the Navy turned down

Hollywood called Hedy Lamarr the most beautiful woman in the world. She was also an inventor, who patented a frequency-hopping system in 1942. The full story, and what her idea really has to do with your phone.

A curious child in Vienna

Hedy Lamarr was born Hedwig Kiesler on 9 November 1914 in Vienna. Her father, a bank director, took her on long walks and explained how machines worked. The curiosity stayed with her for life.

At eighteen she starred in the film Ecstasy (1933), which made her famous across Europe. That same year she married Friedrich "Fritz" Mandl, an arms dealer and one of the richest men in Austria.

The prisoner who listened

According to her own account, Mandl was controlling and she felt like a prisoner in his house. But at his dinners and business meetings she listened to engineers and officers discuss weapons, and she learned. In 1937 she left him. By her own account she escaped disguised as her maid. Both stories come from her autobiography, which was written with a ghostwriter, so the details cannot be checked.

"The most beautiful woman in the world"

In London she met Louis B. Mayer, head of the Hollywood studio MGM. He gave her a new name, Hedy Lamarr, and the studio promoted her as "the world's most beautiful woman". She became a star. Between films she worked on inventions.

A signal that jumps

During the Second World War, torpedoes could be guided by radio. Their weakness was that the enemy could jam the signal. Lamarr had an idea: make the signal jump between frequencies in a pattern that only the ship and the torpedo know. A jammer would never know where the signal would be next.

Her friend, the composer George Antheil, knew how to synchronise player pianos. Together they designed a system with 88 frequencies, like the 88 keys of a piano, synchronised by mechanisms similar to piano rolls. On 11 August 1942 they received US patent 2,292,387, issued under her married name at the time, Hedy Kiesler Markey.

Sell war bonds instead

The US Navy rejected the idea; the mechanism was too bulky for a torpedo, it was said. She was told she could help the war effort more by selling war bonds. She did, and she was very good at it.

Her patent expired in 1959. Similar frequency-hopping technology appeared in operational military systems from 1962.

Recognition, late

Her film career faded, and she spent her last years largely alone in Florida. In 1997 she received the Electronic Frontier Foundation's Pioneer Award for her invention. She died on 19 January 2000. In 2014 she was inducted into the National Inventors Hall of Fame.

What it has to do with your phone

Frequency hopping was not invented by Lamarr alone: the basic idea existed before her patent. And she did not invent Wi-Fi, as is sometimes claimed. But Bluetooth uses frequency hopping, and Wi-Fi and GPS rely on related spread-spectrum techniques. The film star the Navy turned away had seen something important, decades before the world caught up.

Sources

  • US patent 2,292,387 (1942)
  • Electronic Frontier Foundation, Pioneer Award 1997
  • National Inventors Hall of Fame
  • Wikipedia: Hedy Lamarr

Researched and written by Inventor Files, last checked 2026-10-31. Found a mistake? Tell us.

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