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Noise is a fascinating topic. It seems a nuisance but if you investigate it you’re bound to find interesting phenomena. “Radio astronomy” is, at heart, a scienc

Noise is a fascinating topic. It seems a nuisance but if you investigate it you’re bound to find interesting phenomena. “Radio astronomy” is, at heart, a science of understanding and managing noise. E.g. * Schumann resonances are spectral peaks produced by radio signals “echoing” between the Earth and the ionosphere. https://en.wikipedia.org/wiki/Schumann_resonances https://en.wikipedia.org/wiki/Schumann_resonances * The cosmic microwave background radiation is a vestige of the Big Bang that was first discovered accidentally while investigating anomalous noise in a communications system. https://en.wikipedia.org/wiki/Discovery_of_cosmic_microwave_background_radiation https://en.wikipedia.org/wiki/Discovery_of_cosmic_microwave_... * Even if you can get an instrument far away from other noise sources, there is significant noise from physical processes inside the detector (thermal noise) and even statistical fluctuations owning to the discrete nature of photons themselves (shot noise)

azalemeth 5y ago
One of my favourite things about the Schumann resonances is how humanity effectively did an experiment on them: the Starfish Prime nuclear test several hundred km above Hawaii dumped a load of charged particles into the ionosphere, destroying several satellites in space at the time, and, yes, changing the spectrum of the Schumann resonances. This article made me very glad for Faraday cages!
BoxOfRain 5y ago
>Even if you can get an instrument far away from other noise sources, there is significant noise from physical processes inside the detector There's disorders which can make the brain's own noise consciously perceptible, even if you do away with the instruments there's still noise to contend with! Interestingly the visual aspects are very similar to old-fashioned analogue TV noise which gives the disorder its name, Visual Snow. Usually this noise is automatically filtered out but (at least according to the current theory) defects in the metabolism of certain parts of the brain prevent this, allowing it to become visible. https://c.tenor.com/9mivCGkZW70AAAAC/visual-snow.gif https://c.tenor.com/9mivCGkZW70AAAAC/visual-snow.gif

azalemeth 5y ago

One of my favourite things about the Schumann resonances is how humanity effectively did an experiment on them: the Starfish Prime nuclear test several hundred km above Hawaii dumped a load of charged particles into the ionosphere, destroying several satellites in space at the time, and, yes, changing the spectrum of the Schumann resonances. This article made me very glad for Faraday cages!

BoxOfRain 5y ago

>Even if you can get an instrument far away from other noise sources, there is significant noise from physical processes inside the detector There's disorders which can make the brain's own noise consciously perceptible, even if you do away with the instruments there's still noise to contend with! Interestingly the visual aspects are very similar to old-fashioned analogue TV noise which gives the disorder its name, Visual Snow. Usually this noise is automatically filtered out but (at least according to the current theory) defects in the metabolism of certain parts of the brain prevent this, allowing it to become visible. https://c.tenor.com/9mivCGkZW70AAAAC/visual-snow.gif https://c.tenor.com/9mivCGkZW70AAAAC/visual-snow.gif