Breakthrough: The Ideas That Changed the World

S1 E6 | CLIP

Hollywood Icon Hedy Lamarr

In 1941 the Nazi’s are winning the war in Europe. The Nazi U boats are fast and agile and the allied torpedoes are not very accurate. Hollywood star, a secret inventor, Hedy Lamarr is determined to help fight the Nazis. Inspired by a player piano, she invents a way to control torpedoes remotely and creates the world’s first secret communications system.

AIRED: May 22, 2019 | 0:02:56

- My mother said if I can make radio transmissions private,

then they can be used to alter the course

of torpedoes securely

and she came up with frequency hopping.

- [Narrator] The idea was straightforward at least.

- [Announcer] At the entrance of an air raid shelter here

and I must move this table.

- Instead of sending a signal signal

down one frequency band,

she breaks up the signal

and sends it across multiple frequency bands

and that makes it really hard to intercept.

- [Narrator] Anyone listening for a signal

on a single given frequency

would only hear a blip

making it impossible to jam

but as long as the sender and receiver are synchronized,

the signal makes perfect sense.

All Hedy needed was a mechanism

to implement her idea and that would take an encounter

with a Hollywood composer and a Player Piano.

George Antheil was famous for experimenting

with Player Pianos that played pre-arranged musical scores.

Holes were punched into a paper drum with 88 columns,

one column for each note.

When all the columns played back,

the full arrangement played out.

Hedy realized that she could apply a similar technique

to implement her channel hopping idea.

- She wrote her name in lipstick

on the windshield of his car

and she left and she said call me,

and so he did and he came over.

- [Narrator] Hedy and George quickly

sketched out their idea.

A transmitter sent signals to a receiver on the torpedo

continuously hopping between different radio frequencies.

They called it a spread spectrum guidance system.

- So, Tan, one of the most precious things I had

is this little tiny piece of paper.

This is the seminal moment

that this concept was drawn on paper.

And it's the back of an envelope.

- It's like they came up with the idea

and they had to find something to quickly jot it down

so they wouldn't lose the idea.

That spark of the invention.

- This is the first image of a communications system

which is secret, it's private,

nobody can jam that,

nobody can figure out where are you jumping to next.

- Absolutely.

It's amazing.