11 ms·
Muons used to test the condition of a road bridge in Estonia
- schoen 2y agoI did not know this was a thing! https://en.wikipedia.org/wiki/Muon_tomography https://en.wikipedia.org/wiki/Muon_tomography
- unit149 2y ago[dead]
- tagami 2y agoHere is an example used in the mining industry. I heard them present at a NASA/USGS conference last month regarding in situ resource ultilization: https://ideon.ai/ https://ideon.ai/
- aigen000 2y agoIf I recall correctly, a similar method was used to discover a hidden passageway in the Egyptian pyramids.
- superjan 2y agoThis story? https://www.jst.go.jp/EN/achievements/research/pdf/mitsuhiro_nakamura2018.pdf https://www.jst.go.jp/EN/achievements/research/pdf/mitsuhiro...
- throw-qqqqq 2y agoYou do recall correctly! https://www.nationalgeographic.com/science/article/giza-pyramid-void-muon-radiography-cosmic-rays https://www.nationalgeographic.com/science/article/giza-pyra...
- dpedu 2y agoTwo voids were discovered - and the one you mentioned has since been breached and a camera inserted. I'm avoiding the word passageway because the general interpretation is that it seems to be an inspection space or stress relief chamber, as it sits directly above the "actual" entrance to the pyramid. Video on the subject: https://www.youtube.com/watch?v=49870qW9pQ8 https://www.youtube.com/watch?v=49870qW9pQ8 The second void is more exciting, in my option. It is much larger - it is thought to be of similar size of the Grand Gallery, and sits some distance above it.
- rdtsc 2y agoNeutrons can be used for these things as well. The advantage, say from x-rays, is attenuation is not by material density, where all metals will just look dark, but by thermal neutron absorption cross section. So boron might be dark, but metals won't be. Muons are much nicer as you don't have to carry a neutron source around with you. > However, if anyone is now thinking of standing under the bridge to get their body scanned, they shouldn't bother. First, they'd have to stand still for an hour, and second, the security patrol would be there within minutes. Security patrol will come and bother you if you hand around the bridge for a few minutes?
- thinkingQueen 2y ago> Security patrol will come and bother you if you hand around the bridge for a few minutes? There’s a land war in Europe. Hundreds of thousands have lost their lives during the past few years. There have been cases of sabotage against the Baltic states as well as the Nordic states. Things are pretty grim there and lurking around basic infrastructure pretty much guarantees a talk with the police.
- jldugger 2y agoPlus Estonia in particular is 200km away from St Petersberg, and 800km from Moscow. They are all but guaranteed to succumb to Russian expansion if allowed to continue unchecked.
- rdtsc 2y agoThat's certainly a good reason. Thanks for explaining!
- chrisweekly 2y agoHere I was thinking it had something to do with trolls... Sorry, couldn't resist. Agreed, it's a helpful explanation.
- barrenko 2y agoIt's a three days ride (at a leisure pace of like 40 km/h) from Crimea to Bruxelles.
- IndrekR 2y agoBit more info about the startup behind it: https://www.gscan.eu/ https://www.gscan.eu/
- csours 2y agohttps://en.wikipedia.org/wiki/Luis_Walter_Alvarez https://en.wikipedia.org/wiki/Luis_Walter_Alvarez Alvarez proposed muon tomography in 1965 to search the Egyptian pyramids for unknown chambers. Using naturally occurring cosmic rays, his plan was to place spark chambers, standard equipment in the high-energy particle physics of this time, beneath the Pyramid of Khafre in a known chamber. By measuring the counting rate of the cosmic rays in different directions the detector would reveal the existence of any void in the overlaying rock structure.[48]
- kulahan 2y agoThey were indeed able to do this after all [1], and found some unknown voids. [1] https://spectrum.ieee.org/muon-imaging-finds-hidden-chamber-in-great-pyramid-of-giza https://spectrum.ieee.org/muon-imaging-finds-hidden-chamber-...
- deleted 2y ago[deleted]
- lazide 2y agoAt least one was confirmed to indeed be exist - quite fascinating. One day hopefully we can find out if the remaining giant looking open area exists too!
- Cthulhu_ 2y agoWouldn't there be other ways to detect voids? Strong X-Rays, penetrating radar, or sound wave / seismic measurements taken from every outside and accessible inside space, combined into a 3d model / visualisation. Or is the stone used that impenetrable? I have no idea about these things.
- lazide 2y agoThose other methods do get used, but are of limited utility because the stone is that impenetrable - and it’s a masonry structure with a significant amount of joints, random small voids, etc. It really does benefit from something like muon/neutron radiation, where absorption is quite low/penetration quite high, so we can ‘see’ pass the first couple centimeters to meters.
- krzysiek 2y agoThey still do, but they used to too.
- megadata 2y agoMuons were also recently on hackaday. DIY ground penetrating radar ... Building A DIY Muon Tomography Device For About $100 https://hackaday.com/2025/02/26/building-a-diy-muon-tomography-device-for-about-100/ https://hackaday.com/2025/02/26/building-a-diy-muon-tomograp...
- perihelions 2y agoAlso on HN, https://news.ycombinator.com/item?id=43195525 https://news.ycombinator.com/item?id=43195525 ("A $100 DIY muon tomographer (ieee.org)", 20 days ago, 45 comments)
- dzhiurgis 2y agoWonder if one could use muography to detect passing submarines
- RickyS 2y agoIt's a bit challenging as the submarine would need to stand still for a while and not be very deep but some people has thought about that.
- cameldrv 2y agoAnother one along these lines is antineutrinos. They're created by fission reactions, so a nuclear reactor puts out a lot of them. From what's available in the open literature, this seems like it might be getting close to being practical.
- TheSpiceIsLife 2y agoFission reactors spew neutrinos, no need for anti-
- Timwi 2y agoAntineutrinos are produced in nuclear reactors when the radioactive products of nuclear fission undergo beta decay. Source: https://physics.aps.org/articles/v10/66 https://physics.aps.org/articles/v10/66
- TheSpiceIsLife 2y agoAh, right. This publication[1] says neutrinos, but the article it references says antineutrinos[2]. That explains my misunderstanding. 1 https://www.energy.gov/science/np/articles/detecting-neutrinos-nuclear-reactors-water https://www.energy.gov/science/np/articles/detecting-neutrin... 2. https://www.osti.gov/pages/biblio/1959810-evidence-antineutrinos-from-distant-reactors-using-pure-water-sno+ https://www.osti.gov/pages/biblio/1959810-evidence-antineutr...
- webdoodle 2y ago
- dinkblam 2y agoon that topic, rust costs us 3.4 trillion per year [1] and the (public) construction industry has not even started to address the issue [1] http://impact.nace.org/economic-impact.aspx http://impact.nace.org/economic-impact.aspx
- hugh-avherald 2y agoCan we have one topic on hackernews that doesn't mention rust?
- TheSpiceIsLife 2y agoCarefully and purposefully Oxidising Bridges with Rust.
- shepmaster 2y agoThat is a use of https://en.wikipedia.org/wiki/Weathering_steel https://en.wikipedia.org/wiki/Weathering_steel, actually!
- TheSpiceIsLife 2y agoYes! Commonly known in Australia by the brand name Corten (COR-TEN)[1]. 1. https://en.m.wikipedia.org/wiki/Weathering_steel https://en.m.wikipedia.org/wiki/Weathering_steel I laser cut and help press about half the cladding at MONA near Hobart, a gallery owned by professional gambler David Walsh. If you haven’t been, go! It’s an underground art gallery, complete with wind tunnel reminiscent of a vacuum cleaner tube, and a permanent installation of a digesting shit machine, amongst other subservience adult Disneyland weirdness. https://mona.net.au/visit https://mona.net.au/visit https://www.discovertasmania.com.au/things-to-do/museums/mona/ https://www.discovertasmania.com.au/things-to-do/museums/mon... https://en.m.wikipedia.org/wiki/Museum_of_Old_and_New_Art https://en.m.wikipedia.org/wiki/Museum_of_Old_and_New_Art https://en.m.wikipedia.org/wiki/David_Walsh_(art_collector) https://en.m.wikipedia.org/wiki/David_Walsh_(art_collector)
- aitchnyu 2y agoIs there a diagram of this? I'm imagining a plate that "see" at a 180 degree field of vision when cosmic rays hit it from every angle from the sky there are opaque things between the sky and sensor.
- teamonkey 2y agoMuons can be picked up by a standard DSLR. Put the cap on (remove the lens if possible), set it to continually take long exposures of 30s or more, put it in a sealed plastic box with some silica gel packets and put the whole thing in the fridge for a while. Most of the frames will just show noise from the sensor and electronics (the low temperature minimises that), but occasionally you'll see a bright streak as a muon hits it.
- agnishom 2y agoHow do you know it's related to a muon?
- kimixa 2y agoI'd think it's pretty much any high-energy ionizing radiation that causes those streaks - probably very few of which are muons. There are "local" sources of ionizing radiation pretty much everywhere. And if [0] is correct about the approximate muon flux - being that "about one per second passes through a volume the size of a person’s head.", the volume of a the CCD sensor that it would have to interact with is so much smaller (being some 10 microns thick) that I doubt it'll be "Take a few 30s exposures" sort of chance, so much as "Winning the lottery" level chance to actually have a muon pass through the sensor, and interact. [0] https://home.cern/science/physics/cosmic-rays-particles-outer-space https://home.cern/science/physics/cosmic-rays-particles-oute...
- teamonkey 2y agoIt doesn't have to hit the sensor, it needs to pass through it, so the thinness of it doesn't matter as much as the orientation; it's a matter of flux density. You would expect ap to 2-3 muons per minute to pass through a typical sensor but you might not capture all of them.
- kimixa 2y agoIt has to interact, otherwise it wouldn't be visible at all, as it's the interactions that the CCD detects. And as muons don't interact often, the can pass through a lot of matter without anything noticing - that's the reason why they can pass through the atmosphere to still be detected on the ground - or even deep underground, as many imaging detectors are used, to avoid other radiation sources that could cause noise while still penetrating the rock you want to image. Compared to hundreds of metres of rock in a deep mine, a fridge and roof is nothing.
- tomcam 2y ago> This week, a new technology was tested in Jõgisoo, Harju County, as part of a nearly €1.3 million research project. I’m already using the €235,999 Harbor Freight version for my bridge tests