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Cosmic rays do reach earth, and they can cause bit flips in memory. Generally any damage to human cells is repaired by cell reproduction. Cosmic rays are primar
by ChuckMcM 7y ago
Cosmic rays do reach earth, and they can cause bit flips in memory. Generally any damage to human cells is repaired by cell reproduction. Cosmic rays are primarily protons so they get generally channeled by the magnetic field to one of the poles, and the air provides some shielding as well, but even with all of that you can build a cosmic ray detector[1] and get the occasional ping.
Generally it isn't something to worry about. Should we have a star nearby go super nova on us, or if a gamma ray burst occurred nearby (from a black hole eating a big chunk of matter for example) it would be more problematic.
[1] Cosmic rays are distinguished from "regular" solar flux by the energy of their particles (not all of them have higher energy, but the ones that do are much more likely to be of cosmic rather than solar origin). A simple cosmic ray detector can be constructed by shielding a cloud chamber such that shielding blocks any events below your desired cut off level. Detection events are then most likely cosmic rays.
- beezle 7y agoIIRC most turn into muons or electron/positiron showers, depending on the incident angle. Recall a physics lab long ago playing with NaI scintillators and photomultipliers at 10kV to detect the muons from the showers.
- oliveshell 7y agoYeah, rather than reaching earth’s surface directly, it’s far more likely that a given cosmic ray will collide with molecules in the atmosphere, creating a particle shower [1]. Extremely high-energy cosmic rays are sometimes detected, however. The so-called “Oh-My-God particle“, detected in 1991, apparently carried as much energy as a baseball moving at 58 mph [2]. [1]: https://en.wikipedia.org/wiki/Particle_shower https://en.wikipedia.org/wiki/Particle_shower [2]: https://en.m.wikipedia.org/wiki/Oh-My-God_particle https://en.m.wikipedia.org/wiki/Oh-My-God_particle
- ChuckMcM 7y agoYou are correct, the cosmic rays you see in a cloud chamber are typically muons (and its pretty easy to make one with stuff you can get at the drug store (or apothecary if you're outside the US :-)). If you want to see the higher energy ones then shielding helps.
- snowwrestler 7y agoOn a more positive note, cosmic ray flux and the ensuing daughter products are used by geologists to date how long a particular rock has been buried or exposed. https://en.m.wikipedia.org/wiki/Surface_exposure_dating https://en.m.wikipedia.org/wiki/Surface_exposure_dating
- ecesena 7y agoMore or less, how often is “occasionally”? Can this be used as a source of randomness, like for example time as a Poisson?
- azalemeth 7y ago> More or less, how often is “occasionally”? Cosmic ray fluxes vary depending on the energy of the photon you're talking about, but the number of events is, on a human scale, surprisingly large. > Can this be used as a source of randomness, like for example time as a Poisson? Yes. Although from an electronics point of view, lower energy photons are _much_ easier to deal with. That's how random.org started -- https://www.random.org/history/ https://www.random.org/history/
- azalemeth 7y agoA good example of "bad things" happening would be Quantas Flight 72 [1], an event in 2008 in which an Airbus A320 made a series of uncommanded movements, because of a particularly strange design bug in one of its flight computers, the air reference data unit one. Despite being repeated in triplicate, a timing bug occasionally resulted in pitch down movements being voted on as the 'correct' thing to do. Unlike MCAS in the 737, these were _not_ repeated and ultimately the pilots were able to fly in 'alternate law', and land safely. Subsequent investigations believe that a cosmic ray induced bit flip is the most likely explanation. [1] https://en.wikipedia.org/wiki/Qantas_Flight_72 https://en.wikipedia.org/wiki/Qantas_Flight_72