- Metadata:
- #til2022 Baruch Plan
- An international organization would be in control of all nuclear products
- Russia rejected this plan and triggered the nuclear arms race
- #til2022 Peace Symbol
- Created with the combination of the semaphore letters of
N and D, which stands for “nuclear disarmament”
- First developed to detect underground nuclear tests with seismometers
- Now it is used in most compression algorithms and signal processing
- Fourier Transform decomposes any signal into the sum product of sine waves
- This is done by taking a sine (and cosine) wave and multiplying it into the signal and if the area under the product is non-zero then the sine wave is correlated with the signal and a component
- The size of the area is the relative amplitude of that sine wive
- Sweep across all frequencies of the sine (and cosine) wave
- Discrete Fourier Transform is used for discrete finite data which is what the seismometers record
- Requires a high number of calculations that scales with the number of samples $N^2$
- Fast Fourier Transform
- Discovered by Tukey and implemented by Cooley
- Scales with the number of samples $Nlog_2N$
- However, this wasn’t discovered in time so lots of underground testing were done during the arms race because the comprehensive test ban could not be established
- But it was, Gauss figured out Fourier Transform and FFT before Fourier and Tukey but it wasn’t published nor it was written in an easily accessible writing