For the first time , a team of researchers has get a line a hidden belowground necropolis underneath the street of Naples using negative muon imaging – essentially , cosmic ray of light particles .
In muon tomography , ormuography , scientists use cosmic irradiation to map antecedently - untouchable area . Muon particles are negatively - charge particles produced by cosmic rays that clash with atoms in the Earth ’s upper atmosphere . Around 10,000 muon reach Earth ’s aerofoil per square measure per minute . Muography uses these scatter rays to build three - dimensional models from the information revealed as the particles clear through varying density of obstructive aim , likewallsor floor .
A team of international researchers from Italy and Japan used this technique to represent the part of the remains of an ancient Greek city squall Neapolis underneath Naples , for the most part inaccessible to archaeological excavations due to the mellow universe compactness of the area .
The map produced by the team. Image credit: Tioukov et al., Scientific Reports 2023
" Remains of the ancient Neapolis with its buildings , street , aqueduct and necropolis made by the Greeks starting from the second one-half of the first millennium BC are bury more or less ten meter below the current street stratum of the metropolis of Naples , " the team write in their paper .
Muography is a great way to see through obstructive objects and has been used to canvass all sort , fromvolcanoesto fourteenth - hundred Chinesefortress wallsto ahidden roomin the Great Pyramid of Giza .
A former study attend at Neapolis , an ancient Hellenistical necropolis build by the Greeks in the fourth to third hundred BCE , hypothesized that there were more inhumation chambers to be find . The team was able to do so by using muon detectors 18 meters below street level inside an ancient root cellar , which had been converted into a food wine cellar in the 19th century .
Fragments of nearby Greek burial chambers from ancient Neapolis. Image credit: Tioukov et al., Scientific Reports 2023
" The first challenge was to plan a stocky muon detector with gamy angulate resolving , transportable in a narrow piazza and without access to the electrical energy power grid , " Giovanni De Lellis of the Federico II University and the National Institute of Nuclear Physics ( INFN ) of Naples say in astatement .
" The detector we have developed is free-base on the engineering we use in the subnuclear physics experiments at CERN , and at the INFN Gran Sasso National Laboratories , which read the property of neutrinos and search for disconsolate subject . "
They were forget for months , capturing around 10 million muons from which the team was able to produce a stereoscopic reconstruction .
" From the figure of muons that arrive at the demodulator from unlike direction , it is potential to calculate the density of the material they have passed through , " go author Valeri Tioukov , a researcher at the INFN of Naples , said . " We found an excess in the data point that can only be excuse by the presence of a fresh sepulture sleeping accommodation . "
Similar necropolis bedroom in the area bear ornate frescoes and sculptures left by wealthy Hellenistic kinfolk to honor their dead . The chamber has not yet been explore , other than by cosmic ray of light , of form .
The study was write inScientific Reports .
