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]
[1] https://spectrum.ieee.org/muon-imaging-finds-hidden-chamber-...
One day hopefully we can find out if the remaining giant looking open area exists too!
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.
Building A DIY Muon Tomography Device For About $100
https://hackaday.com/2025/02/26/building-a-diy-muon-tomograp...
https://news.ycombinator.com/item?id=43195525 ("A $100 DIY muon tomographer (ieee.org)", 20 days ago, 45 comments)
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?
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.
Paranoia surrounding critical infrastructure is skyrocketing at the moment, and I'd say for a bunch of very good reasons.
[1] https://en.wikipedia.org/wiki/Moore_County_substation_attack
your neck may not be red because you get to sit inside while they keep your power on for you.
meanwhile you sit inside writing your hateful, elitist, garbage.
the conspiracy theories related to event you linked are ridiculous.
Before I got into IT I was working in construction for our local telco provider, believe me I have seen shit.
Sorry, couldn't resist. Agreed, it's a helpful explanation.
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.
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-oute...
You would expect ap to 2-3 muons per minute to pass through a typical sensor but you might not capture all of them.
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.
In open air at sea level, you would expect 1 muon to pass through any square cm of ground every minute, on average. With a sensor measuring 2-3 sq cm, oriented correctly, and exposing for a long enough time you would certainly expect to catch a few.
Unlike x-rays or gamma radiation, muons can pass through several km of dense matter and penetrate deep inside the earth before they decay. They can pass through solid lead. Direct particle collisions are rare but more likely when passing through large amounts of dense matter. The ionisation process can also reduce the speed and trajectory. Muon tomography works by comparing how much the muon count has been reduced compared to an expected background level.
The practice of capturing muons on camera is quite well established, see for example https://pmc.ncbi.nlm.nih.gov/articles/PMC10220736/
[0] https://www.epa.gov/radiation/radiation-sources-and-doses
Video on the subject: 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.
https://www.nationalgeographic.com/science/article/giza-pyra...
https://thedebrief.org/darpas-secretive-new-neutrino-detecto...
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-neutrin...
2. https://www.osti.gov/pages/biblio/1959810-evidence-antineutr...
I’m already using the €235,999 Harbor Freight version for my bridge tests
1. 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://www.discovertasmania.com.au/things-to-do/museums/mon...