3.5 cm long, 1.5 cm in diameter... This small talisman, which may soon join the collections of the Musée des Écritures d'Ampus in the Haut-Var county of France, is very mysterious, and above all, very fragile. Made of metal wrapped around itself, it is engraved on the outside. To unravel its secrets without damaging it, scientists used tomography on the PSICHÉ beamline of SOLEIL, a technique similar to a medical scanner. Will a virtual unrolling of the talisman be possible?... Discover, along with the scientists, the astonishing results obtained during the very first day of study of this unique object.
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Voice over
This little talisman could soon be part of the collections at the Musée des Ecritures d'Ampus in the Haut-Var, but for now it is still a mystery. Not a lot is known about it: it is probably made of copper, it probably comes from Judea, it is probably over 1700 years old, it is probably engraved over its entire length.
Jean-Paul Itié, Emeritus Director of Research at Synchrotron SOLEIL
It is 3.5 cm long, 1.5 cm in diameter. It consists of pieces of coiled copper. Engravings can be seen on the external visible area. It is thought to be an amulet containing a text believed to bring good luck to the people that carried them.
Voice over
A magic formula to protect the wearer? A verse from the Bible for the person who doesn't know how to pray? Nobody knows yet. However, one thing is certain: the object is extremely fragile and cannot be unrolled. Consequently, scientists working on the PSICHÉ beamline have decided to use tomography, which is similar to a medical scanner, to unlock its secrets.
Andrew King, scientist on the PSICHÉ beamline at SOLEIL
If you break your arm an X-ray image will be taken to reveal the interior, it will be a simple projection of the object. In tomography, we add a rotation to the image, which means we take images from different angles, and from this series of 2D images, we can reconstruct the 3D shape of the object in question.
J.P. Itié
- I think it's best to start by a central section to test it out, and then continue with sections...
Jean-Paul Itié, Emeritus Director of Research at Synchrotron SOLEIL
It's quite exciting for us because it lets us see what's inside of an object without opening it.
Voice over
So the cylinder is installed facing the beamline detector. An initial scan where the talisman rotates at 360°. However, the X-rays are having great difficulty penetrating the object. It seems to be too dense, too absorbent. Is it really made of copper?
Jean-Paul Itié, Emeritus Director of Research at Synchrotron SOLEIL
If you look at the thickness of the rolled copper, it's relatively thick, and a piece of copper of this thickness, is not very easy to roll. So we think that there may be an alloy to make it softer.
Andrew King, scientist on the PSICHÉ beamline at SOLEIL
The problem is that the sample is quite wide and quite dense. The beam has to pass through it to cast a shadow on the detector. Currently, we don't really have enough of a signal passing through, so I'm gradually adjusting the beamline settings to obtain higher photon energies.
Voice over
After several hours of estimating, adjusting and testing, the radiation managed to pass through the talisman. The object's structure, with alternating layers of metal and air, begins to take shape on the screen. Then the coils of the scroll become clearly visible.
J.P. Itié, L. Henry, A. King
- If that's the broken part you see there, on the top right…
- Yes.
- It’s more like there...
- There we had...
- It’s more promising than I thought one hour ago or two.
So it's the most powerful energy that we've ever used. Now we are really at the limits of our equipment.
Voice over
Exploration of the parchment can begin. The 3D reconstruction of the object combined with dedicated software makes it possible to travel inside the talisman, moving from one coil to the next in search of any inscriptions.
J.P. Itié, L. Henry, A. King
- This line, here?
- You can see things here, that are lighter.
- Yes, maybe.
- Do you see what I mean?
- Do you see that letter there? This sort of "h"?
- I don't know if they're artefacts, but I see something that goes like this...
- But it could also be a "t".
- It could be writing.
- I wouldn't want to stake my reputation on it! Further work is needed?
- Yeah
- Maybe.
Andrew King, scientist on the PSICHÉ beamline at SOLEIL
Of course we all want to find something, so we tend to find the things we're looking for.
Jean-Paul Itié, Emeritus Director of Research at Synchrotron SOLEIL
It's essential to have a degree of uncertainty, that's the joy of research and its ultimate despair.
Andrew King, scientist on the PSICHÉ beamline at SOLEIL
If we find the same character in a second scan, it's a good indication that it wasn't an artefact, it was real.
Voice over
And while sometimes we need to be wary of appearances, sometimes we must also face facts.
J.P. Itié, L. Henry, A. King
- There's something there.
- That's a character. Can you move the main window? I think it's a "pi".
- It looks like a "pi", yeah.
- There's something there. Maybe there's some oxide, you can see it's a bit damaged.
- Yes, that’s clear, it’s an "o".
- We can start transcribing.
- There, I’m certain...
- Yes, there... There, do you admit?
- Yes, now I can see it's not an artefact.
Voice over
The letters are clearly visible on various parts of the scroll. A 10-hour full scan of the amulet can be run overnight, it's an essential step before attempting to virtually unroll the talisman.
Jean-Paul Itié, Emeritus Director of Research at Synchrotron SOLEIL
First of all, it's not easy to unroll a scroll. What's more, the scroll is crushed, it doesn't have a perfect cylindrical shape so there isn't a true spiral to unroll. There will be defects all over the crushed area, perhaps various copper thickness and so on.
Andrew King, scientist on the PSICHÉ beamline at SOLEIL
For the moment we're using something that already exists in 'ImageJ', where we can extract a curved section, but we need to place the curve where we want to see the surface. It's not automatic enough yet to unroll the whole scroll in the ideal case of unrolling the whole piece before us so that we can pass it on to someone competent who can read it.
Jean-Paul Itié, Emeritus Director of Research at Synchrotron SOLEIL
Even if we manage to flatten it out, we're not sure we'll be able to read the scroll, and what's more, we're not even sure we'll be able to translate it. For the moment we're still a little unsure as to the language on it, we think it's Hebrew, but we can't be sure.
Voice over
So the investigation must continue. In addition to reconstructing the history of the little amulet, these results could help archaeologists and archaeometrists in deciphering the thousands of ancient texts, papyri and parchments that have remained inaccessible up to now.
Postscript
A month later, X-ray fluorescence measurements obtained on the synchrotron SOLEIL PUMA beamline (Sebastian Schoeder manager) revealed a significant presence of lead in addition to brass (a copper and zinc alloy). The virtual unfolding of the scroll is progressing, and it is already evident that the characters observed are not Hebrew but rather Aramaic.