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Everything Is Sine Waves
How the study of a heated piece of metal underpins most of our digital lives
Have you ever seen those visualizations that show you “sound waves” from someone speaking or from a piece of music? They look like what you would get when you give a toddler a pen and let them make scribbles:
Yet computers are able to make sense of this gibberish and do things like isolate different parts of a song or process a person’s speech before sending it out to someone else’s phone, etc…
Sound waves are just one example of a signal in the plethora of signals our digital lives depend on: image, video, GPS, temperature, motion,… the list is endless due to the proliferation of sensor devices. How can a computer take a signal that looks like random gibberish and find useful information in it? What does the above graph even mean?
The answer lies with a technique developed by a 19th century French mathematician who was studying the propagation of heat in solids. His results underpin most signal analysis in modern computers. What does heat propagation have to do with signals? And what in the world do sine waves have to do with it? And what are sine waves? Let me explain. I’ll try to avoid using equations as much as possible.
