For astir 650 years, the fortress walls successful the Chinese metropolis of Xi’an person served arsenic a formidable obstruction astir the cardinal city. At 12 meters precocious and up to 18 meters thick, they are impervious to astir everything — but subatomic particles called muons.
Now, acknowledgment to their penetrating abilities, muons whitethorn beryllium cardinal to ensuring that the walls that erstwhile protected the treasures of the archetypal Ming Dynasty — and are present a nationalist architectural treasure successful their ain close — basal for centuries more.
A refined detection method has provided the highest-resolution muon scans yet produced of immoderate archaeological structure, researchers study successful the Jan. 7 Journal of Applied Physics. The scans revealed interior density fluctuations arsenic tiny arsenic a metre crossed wrong 1 conception of the Xi’an ramparts. The fluctuations could beryllium signs of unsafe flaws oregon “hidden structures archaeologically absorbing for find and investigation,” says atomic physicist Zhiyi Liu of Lanzhou University successful China.
In this image, muons person revealed density anomalies successful a conception of the Xi’an fortress walls. All colors successful this crippled bespeak places wherever densities are little than mean for the structure, with the bluer portions showing wherever density is lowest.Xi’an City Wall Management Committee, G. Liu et al/Journal of Applied Physics 2023Muons are similar electrons, lone heavier. They rainfall down each implicit the planet, produced erstwhile charged particles called cosmic rays deed the atmosphere. Although muons tin question heavy into world and stone, they are scattered oregon absorbed depending connected the worldly they encounter. Counting the ones that walk done makes them useful for studying volcano interiors, scanning pyramids for hidden chambers and adjacent searching for contraband stashed successful containers impervious to X-rays (SN: 4/22/22).
Though muons watercourse down continuously, their numbers are tiny capable that the researchers had to deploy six detectors for a week astatine a clip to cod capable information for 3-D scans of the rampart.
It’s present up to conservationists to find however to code immoderate density fluctuations that mightiness bespeak unsafe flaws, oregon humanities surprises, wrong the Xi’an walls.
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