12 ms·
Does space dust fall on the roof of my house?
- andai 2y agoI read about the magnet method when I was young. I always thought that was so cool. It never occurred to me until now that I never tried it!
- jmclnx 2y agoProbably, but neutrinos definitely pass through your house (and you).
- throwway120385 2y agoThat's horrible! What can we do to defend ourselves against this constant neutrino bombardment?
- btilly 2y agoA lead suit helps. Of course you'd want it to be something like a light year thick. That may be impractical. Plus there are minor structural problems, such as how to stop it from spontaneously collapsing into a black hole.
- deleted 2y ago[deleted]
- open_ 2y agoYour comment makes me want to re-read the hitchhiker's guide.
- dakr 2y agoAs I recall from school, your lead suit would need to be more than 3 lightyears thick to make the chance of a neutrino (that was already heading towards you) going through you fall to 50%.
- btilly 2y agoWhen I said helps, I didn't say by how much...
- Terr_ 2y agoI find I can almost always dodge them instead.
- adastra22 2y agoI don't have a SO account, so I'll post here. I'm having trouble finding the reference, but there's an IKEA in Sweden or Norway that is really far away from industrial pollution, and so gets basically no soot deposited on its perfectly white painted roof. Some intrepid amateur astronomer put 2 + 2 together and realized it's a perfect collection mechanism for space dust. They thoroughly cleaned the roof, then came back a week later and carefully collected the accumulated dust. Looking at it under a microscope confirmed minerals that only form in microgravity environments.
- recursivecaveat 2y agoReminds me of this hunt utilizing an English cathedral: https://www.bbc.com/news/uk-england-kent-66707859 https://www.bbc.com/news/uk-england-kent-66707859
- trte9343r4 2y agoSahara dust or vulcanic ash has a global reach, and easily reaches Norway.
- wongogue 2y agoYeah. If Sahara dust can travel 8,000km across the Atlantic, it can certainly reach Northern Europe.
- ta20240528 2y agoIt often does, turns snow orange in the Alps.
- ziofill 2y agoYou can also find it all over your car
- sandworm101 2y ago>> confirmed minerals that only form in microgravity environments. So? That doesn't mean they landed on the roof from space. The really tiny stuff can be blown around. It may land on the ground at point A and then be blown onto a roof miles away at point B. This is why we should not use the simple math of a roof's size to determine the rate of material falling from space.
- buildsjets 2y agoIt was demonstrated to me a a young kid that running a strong magnet through beach sand would collect tons of black magnetite, at least some of which is likely meteorite derived.
- 13of40 2y agoIf you ever get a chance to play with a magnet fishing magnet, it's fun to see how many straight-up magnetic rocks there are lying around, too. Probably not meteorites of course...
- Bloating 2y agoClearly explains the crumbs around be office chair
- dredmorbius 2y agoMore likely the roof than your basement, though in the latter case, you'd likely not need me to tell you ... A prime meteorite and meteoric-dust hunting ground is Antarctica. With an ice cap that's kilometres thick, odds are high that all rocks, and much dust, found on the surface of the snow are meteoric in origin. 2018 story on that: "Hot on the trail of Antarctic meteorites" <https://www.snexplores.org/article/hot-trail-antarctic-meteorites https://www.snexplores.org/article/hot-trail-antarctic-meteo...> And yes, there's a global warming angle on this as well: "Thousands of hidden meteorites could be lost forever as they sink in Antarctic ice, taking their cosmic secrets with them" <https://www.livescience.com/space/meteoroids/thousands-of-hidden-meteorites-could-be-lost-forever-as-they-sink-in-antarctic-ice-taking-their-cosmic-secrets-with-them https://www.livescience.com/space/meteoroids/thousands-of-hi...> (2024)
- einpoklum 2y agoI thought everything was space dust, in the final reckoning of things, wasn't it?
- RIMR 2y agoFor anyone interested in an archive link of the meat of this: https://web.archive.org/web/20240414181406/https://micro-meteorites.com/ https://web.archive.org/web/20240414181406/https://micro-met...
- jumploops 2y agoThe micro-meteorites.com website appears to be down, but you can see pictures from the book on the Internet Archive here[0] [0]https://archive.org/details/insearchofstardu0000lars/mode/1up https://archive.org/details/insearchofstardu0000lars/mode/1u...
- Keysh 2y agoThe site is back up again...
- aaron695 2y agoHere's a good video running through one way to do this at home - https://www.youtube.com/watch?v=9q3uNcJh4pc https://www.youtube.com/watch?v=9q3uNcJh4pc (I really like the ending, it's real science which is rare these days) There are a heap of better links to micrometeorites stories than this stackexchange. Discussed many times on HN.
- kornhole 2y ago[flagged]
- dotnet00 2y agoThe hilarity of this conspiracy is the simple fact that smart dust wouldn't offer any more surveillance benefit than the much easier task of just backdooring our devices.
- kornhole 2y agoMore people are using more secure devices. Smart dust is also intended for deployment in battlegrounds or adversarial areas where devices are not under NATO control. China already mostly controls devices in use, and Russia is preparing to block all IOS and Google Android.
- kornhole 2y agoThere is nothing secret about it. You can find a full document from the military explaining it here. https://www.drrobertyoung.com/post/enabling-battlespace-persistent-surveillance-the-form-function-and-future-of-smart-dust-military https://www.drrobertyoung.com/post/enabling-battlespace-pers...
- Animats 2y agoCover a baking tin with transparent film and put it outdoors. Micrometeorites have enough velocity to punch through, but windblown dirt rarely does. Classic grade school experiment.
- dredmorbius 2y agoReally? Wouldn't that be far more dependent on particle size? Micrometeorites are going to reach terminal velocity fairly quickly, and that's largely going to be based on particle size and density, rather than original velocity. Sand-grain-sized micrometeorites (or the sand-grain-sized surviving fragments of larger meteors) will have a terminal velocity of on the order of a metre per second or so.
- Animats 2y agoThat's enough to punch through thin plastic wrap. But if the pan is sheltered from wind, random dirt in the air won't punch through.
- Philips2u 2y ago[flagged]
- Amadainsibh 2y ago[flagged]
- nevergonna 2y ago[flagged]
- rachofsunshine 2y ago> An article by Phil Plait (The Bad Astronomer) says that each square meter of surface is hit by 1 - 2 micrometeorites per year. A much cooler way to put this is that if you spend 1 hour per day on average not under a roof, and if we ignore some complications, your expected micrometeorite-strikes-per-lifetime is about 0.5: (1/24 of the time outside) * (1.5 per meter squared per year) * (80 years) * (pi * 8 inches * 6 inches) = 0.486 [1] where the last term here is an approximate cross-sectional area of the human head as viewed from above. (Micrometeorites reach terminal velocity at a very high altitude, so they should be falling almost vertically as they strike the ground, minimizing your cross-sectional area unless you happen to be lying down.) Someone doing manual labor or other primarily-outdoor work has an expected-micrometeorites-per-lifetime much greater than 1, and therefore is overwhelmingly likely to have space dust in their hair at least once in their life. If you spend 8 hours outside per day (so your workday + some miscellaneous non-work time that covers days you're not working), your expected lifetime impacts is ~4, so your chance of >= 1 impact is 1 - Pois(0; 4) = 1 - e^-4 = about 98%. A better calculation would account for the fact that Earth's orbital motion makes the relative motion of impacts non-uniform in the same way the front of a moving car is hit by more raindrops than the rear. This means most strikes occur around dawn, because that's the time when you're on the "front" of the Earth as it moves in its orbit. Early-morning workers, like agricultural, sanitation, or custodial workers, might be out for the peak of impacts nearly every day, while the average reader here who drifts into the office hours after dawn (if at all) and spends most of their outdoor time in the evening might almost entirely miss their opportunity to have a bit of space fall on their head. (I think this is rather poetic: if you want to touch the stars, go pick up trash!) ----- [1] https://www.wolframalpha.com/input?i=%281+hour%2F24+hour%29+*+%286+in*8+in%29+*+%281.5+%2F+%28m%5E2+*+year%29%29+*+80+year https://www.wolframalpha.com/input?i=%281+hour%2F24+hour%29+...