Vittorio Luzzati/National Portrait Gallery, London Hedy Lamarr, the movie star who is less well known as an inventor. n 1933, at age 19, she swam in the nude in the notorious Czech film "Ecstasy." Often called the most beautiful woman in the world, she married badly — to a domineering Austrian munitions manufacturer — and escaped by drugging the maid and climbing out a window. She made her way to Hollywood, where she starred in movies with Spencer Tracy, Clark Gable and Jimmy Stewart. Then there is the less known chapter of her life. In World War II, she...