Thank Sputnik for GPS

If you don’t believe good ideas can come from anywhere, here is some proof.

On October 4, 1957 (when I was nine years old), the USSR launched Sputnik, the world’s first artificial satellite. To say this unexpected breakthrough shook up the U.S. scientific community would be an understatement.

Two of those who took notice were researchers at the Applied Physics Lab associated with Johns Hopkins University. On their own time, they decided to try to listen for the satellite’s signal. Once they found the signal, which only took a couple of hours, they realized there were small variations caused by the Doppler effect (https://en.wikipedia.org/wiki/Doppler_effect). Investigating those variations led them to calculate Sputnik’s speed, and with some more calculations on a new UNIVAC computer, they eventually were able to map the satellite’s trajectory. All this from listening to “beep, beep, beep.”

Word of their accomplishment — calculating the unknown location of a satellite in space from a known location on the ground — got around. This caused people to wonder if it would be possible to compute the reverse — find an unknown location on the ground from a known location in space?

This was an especially important question at that time because, in the middle of the Cold War, the U.S. Navy was developing nuclear-powered ballistic missile submarines. But how do you accurately send a missile toward a target if you don’t know your exact launch point? “We’re somewhere in the Pacific Ocean” just wasn’t good enough.

That was the genesis of GPS, a military technology that was ultimately opened to civilian use for the benefit of all of us today. Especially me, because my sense of direction is horrible.

The complete story, including names, is 12:15 into a TED talk by Steven Johnson with the appropriate title of “Where Good Ideas Come From” (https://www.ted.com/talks/steven_johnson_where_good_ideas_come_from?).

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