Overcoming the problem with FFT
The problem to distinguish a nuclear test from an earthquake. Every day around the world, there are close to 300 earthquakes with a magnitude of three or greater. Seismometer signal depends not only on the yield of the device but also on how deep it was buried. For a given yield, deeper explosions appear smaller. So, scientists wanted a method to reliably determine whether a given signal was a bomb or an earthquake, all the information needed was indeed present in the seismometer signal but the method to extract the information was needed. We had to find how much of different frequencies were present which meant Fourier transform of the signal needed to be taken. At the speed of 1960s computers, this calculation would take unrealistic amount of time and was not a practical solution to the problem. John Tukey American mathematician and statistician knew a way to compute discreet Fourier transforms with many fewer computations. It would mean that the calculation that would’ve taken over three years could be done in just 35 minutes. This has aptly become known as the Cooley-Tukey Fast Fourier Transform algorithm. Richard Lawrence Garwin (born April 19, 1928) is an American physicist learnt this method to run the FFT algorithm without disclosing that it was to detect underground Soviet nuclear tests.
Cooley and Tukey published the algorithm in a seminal 1965 paper and its use immediately took off, but it was too late to secure a comprehensive nuclear test ban. At the peak in the mid-1980s, 70,000 nuclear warheads were already in existence. If only this algorithm was found 5 years prior a comprehensive test ban could have been reached, stopping the nuclear arms race before it even started. Even more unfortunate thing is that FFT algorithm was already discovered all the way back in 1805 by Mathematician Carl Friedrich Gauss to determine the orbit of newly discovered asteroids and he never thought to publish that first insight. The reason his breakthrough was not widely adopted was because it only appeared after his death in volume three of his collected works and it was written with non-standard notation in a 19th century version of Latin.