Hedy Lamarr made many attempts to escape the clutches of Fritz, including hiding out in a brothel and eventually slipping sleeping pills into the coffee of the maid assigned to watch her, switching clothes and escaping the castle in a maid's outfit. By the time she made her way to the United States and to Hollywood, she was a woman with a mission. And while she was involved in many other campaigns to fight the Nazi's, like the time she offered to kiss any man who purchased a $25,000 war bond - eventually raising $17 million - she was soon to go bigger, much bigger.
Lamarr eventually crossed paths with avant garde composer George Antheil, who happened to be her neighbor. Antheil was no stranger to controversy. He was famous for the Ballet Mécanique, a bizarre, stunningly loud, orchestra of propellers, bells and 16 synchronized player pianos. The piece was considered undignified and riotous in those days. And like the synchronized player pianos in his mechanized symphonies, together with Lamarr, he developed ideas that led to a key invention.
Lamarr learned many secrets during dinners Mandl threw for his friends and business associates as well as from observing Mandl's arms business. She conveyed to Antheil the fundamentally important idea that if one were to transmit coordinates to a guided torpedo from afar using a single control frequency, the enemy could easily jam the signal and send that missile awry. But she did not stop there, nor conjecture long upon a method of jamming enemy missiles. She wanted to give her new country an offensive advantage. She wanted to develop an unjammable guided missile. Lamarr and Antheil soon worked out the critically important next ingredient, whereby a random code, if used to change the channel on a radio transmitter, could be used to send information, provided the radio receiver could be synchronized to listen to the ever changing channels. Up until this time, pseudo-random codes were used to perhaps encrypt content, which was then sent over eavesdroppable single channels. The leap here was sending plain information using a secret "key" to rotate randomly through different radio channels quickly and undetectably.
In August 1942 Lamarr and Antheil were granted patent number 2,292,387 for a "Secret Communication System". (See the two images below.) The patent "relates broadly to secret communication systems involving the lie of carrier waves of different frequencies." This patent is the basis for Spread Spectrum communications, essential to technologies from cellular phones to WiFi 802.11 and for Global Positioning Systems. The United States Navstar Global Positioning System is itself arguably the world's single largest machine transmitting continuously using spread spectrum communications and is one of the most important pieces of technology of the 20th century and, some may say, the basis for the United States' modern military might. Today's hottest technologies owe a huge debt to the controversial and beautiful Hedy Lamarr.
It's important to note that Lamarr is the primary inventor on record as H.L Markey, her married name at the time.