most famous for her nude scenes, she actually had a brain on her shoulders:
The topic of their conversations soon turned to radio-controlled torpedoes, a key WWII weapon that could be easily detected and jammed by broadcasting interference. Harnessing the torpedo knowledge she acquired from the meetings she attended with her former husband, Lamarr began collaborating with Antheil on frequency hopping, a method for rapidly switching among random synchronized frequencies.
The pair's plan was to use a piano roll to randomly switch the signal sent from the control center to the torpedo in short bursts among 88 frequencies, much like the 88 keys on a piano's keyboard. The pair's "Secret Communications System" was granted US Patent No. 2,292,387 in 1942, but the technique was never adopted by the military during the war.
The patent resurfaced in the 1950s while private companies were developing a wireless technology called CDMA. Lamarr's method is still in use today by cell networks, Bluetooth devices and Wi-Fi.