For those not familiar with the technology, Lamarr helped invent a form of what we'd now call
spread spectrum radio. Basically everything you use for communication today is some form of spread spectrum-- WiFi, cellular, bluetooth, GPS...
Tech development always sounds like it used to be so much more glamorous-- a movie star and musician think to themselves, "how can we help prevent our torpedo communications from being jammed?" and answer "let's keep changing frequencies so the enemy doesn't know where to jam next-- it could work just like a player piano changes notes".
That is at least moderately misleading - frequency hopping had multiple inventors and to quote Wikipedia:
So while an impressive independent achievement - we cannot "thank" Hedy Lamarr for frequency hopping as some singular source of brilliance nor can we say their work led directly to its adoption today.
Singular, maybe not, but Lamarr's insight and ingenuity were brilliant in this case. As with every time "patent" and "invention" come into an MR discussion, it's important to remember that every invention has multiple inventors and is usually a sequence of small steps.
Turns out it's not the best package to stow in a torpedo, but the reason it had to be "rediscovered" is because the military classified the patent. There is documentary evidence that future frequency hopping systems were built with knowledge of her patent in mind-- first using the piano rolls in sonobuoys and then replacing the mechanical system with electronics once it became practical. It looks like most of the details are
buried in books more than online sources, but the Lamarr
Wikipedia page has some citations worth reading-- including the original NY Times article from 1941.
As far as whether she deserves "thanks", there are
65 spread spectrum patents that cite hers despite the fact that her patent apparently remained classified until it expired.
