Chapter 55 Who Says Radiation Detection Cannot Be Used to Authenticate Antiques?

The evidence room.

Long tables were arranged in a circle, with five professors and their assistants each occupying a corner.

As they were meticulously examining the items, a commotion arose outside the door: Guan Xingmin pushed Lin Sicheng into the room.

Wang Qizhi followed closely behind, treating the scene like a spectator enjoying a show.

They were arguing as they walked:

"Director Guan, using the naked eye to detect radiation? Aren't you making things difficult for people?"

"I'm not making things difficult for you; the leaders are making things difficult for me. Besides, did anyone say you aren't allowed to use instruments?"

"Then what's the difference between me measuring it and anyone else measuring it?"

"It's different, that's all!" Guan Xingmin lowered his voice. "Since you're already here, do me a favor: even if you're just going through the motions!"

Pushed and shoved, Lin Sicheng was practically forced to the edge of the long table, looking exceptionally hesitant.

He figured the leadership had probably just made an offhand remark, yet Guan Xingmin, despite supposedly being an expert, was actually executing the order with absolute meticulousness.

No exaggeration, if word got out, it would make anyone who knew the ropes laugh their heads off.

He helplessly gave a thumbs-up. "Director Guan, your execution capability—it's top-notch!"

"Nonsense, how else would I be a director?"

Lin Sicheng sighed, then looked at Wang Qizhi, who smiled and nodded.

When the superiors move their lips, the subordinates run their legs off... Try not running and see what happens.

Just as Guan Xingmin said: even if it's just going through the motions.

Lin Sicheng had no choice but to put on gloves and pick up the handheld radiation detector.

Its formal name was a Geiger counter, capable of detecting alpha, beta, gamma, and X-rays. Operation was extremely simple: turn on the switch, and numbers appeared on the small screen. If the radiation exceeded the safety threshold, it would sound an alarm and flash a red light.

And so, like a complete fool, Lin Sicheng held the palm-sized device and continuously scanned the cultural relics laid out on the long table.

The head of the evidence division and a female police officer stood on either side, holding folders and taking notes with utmost diligence.

Just ask yourself, was this setup formal or what?

The teaching assistants curled their lips in silent disdain: What kind of radiation values are you testing antiques for? Isn't this just making up the numbers to pad your merits?

Indeed, testing wasn't really done because it was essentially useless.

Shaking their heads and sighing, the professors returned to their respective duties.

Since it was quite simple and everyone had time to spare, Wang Qizhi asked again, "That revolving ewer—how did it fool carbon-14, thermoluminescence, and other dating instruments?"

"By exploiting the radioactive decay characteristics of atomic isotopes!"

Wang Qizhi nodded. "I understand the principle, but I'm asking how the artifact smugglers pulled the wool over everyone's eyes?"

Lin Sicheng shook his head. "I don't know!"

Wang Qizhi was half-sceptical. "You don't know?"

If you don't know, how could you dare pick up a stool and smash it, sending two "Hong Kong businessmen" to the hospital?

Lin Sicheng actually knew, but he couldn't say, because the technology involved was far too advanced, especially thermoluminescence.

To put it simply: crystals such as quartz, feldspar, and calcite in ceramic clay all have the property of absorbing radiation energy. However, once temperatures exceed 800 degrees Celsius, all the radiation energy is completely released.

This is equivalent to a factory reset after firing in a kiln; all radiation energy within the porcelain is zeroed out. Afterward, the mineral crystals begin absorbing radiation again at a constant rate. The longer the time passes, the more they absorb.

Thermoluminescence utilizes this exact property: a sample is taken and heated to around 500 degrees, causing the crystals to slowly release their energy. The total radiation energy is then measured to calculate the firing era of the porcelain.

Since a fake is newly fired, it naturally lacks any radiation energy. So how did they fool the instrument?

Adding a small amount of mineral elements currently undergoing radioactive decay will do the trick, such as depleted uranium. The more that is added, the further back in time the instrument will calculate the age to be.

However, there is a technological barrier, and it is extremely high. Few people domestically understand it, and almost none practice it.

Therefore, Lin Sicheng suspected that the revolving ewer was, nine times out of ten, the product of a foreign laboratory.

It wasn't surprising; things like this would only become more common in the future: roughly around 2015 or 2016, entire boatloads of Tang三彩 (Tang Sancai) and Yuan blue-and-white porcelain would be hauled in...

Wang Qizhi asked no further questions, and Lin Sicheng methodically continued going through the motions.

"Qing Kangxi imitation Ming Xuande 'Hu Musician' vase, radiation value 0.09 microsieverts..."

"Ming Wen Zhengming's 'Cold Crows in an Ancient Grove', 0.005... never mind, negligible..."

"Qing Xianfeng spring plum blossoms and snow glazed bowl, 0.12 microsieverts..."

After roughly testing twenty pieces, Lin Sicheng lost his patience. Seeing that the professors had already finished most of their appraisals, he rolled his eyes.

"Director Guan, shall we continue the inspection this afternoon?"

Wait until the afternoon? Lin Sicheng would have run off long ago!

"Just test a few more, just test a few more..." Guan Xingmin coaxed him like a child. "Tonight at the Tang Palace, aren't you going to thank Professor Wang?"

Lin Sicheng was stunned: After all this, I still have to foot the bill?

Forget it, helping someone to the end is the right thing to do.

Lin Sicheng continued: "Song Cizhou white-glazed black-flowered brush washer, 0.14 microsieverts..."

"Yuan dynasty Hetian jade white lion paperweight, 0.001, negligible..."

"Liao-Jin blue glazed openwork censer, 0.17 microsieverts..."

"Northern Song Shenzong Yuanfeng Tongbao, one box... negligible... Wait, is the machine broken?"

Having already walked past it, Lin Sicheng let out a sound of surprise.

Guan Xingmin and Wang Qizhi assumed something was wrong with the box of copper coins. But looking again at the radiation detector: 0.001... truly negligible.

Furthermore, these were copper coins, not mineral crystals, and they were covered in rust. Wasn't a low radiation value perfectly normal?

Then what was wrong?

As they stood there completely baffled, Lin Sicheng backtracked:

Liao-Jin blue glazed openwork censer, 0.17...
Yuan dynasty Hetian jade white lion paperweight, 0.001...
Song Cizhou white-glazed black-flowered brush washer, 0.14...

Lin Sicheng stared at the screen of the radiation detector and let out a "Ha."

What had he just said?

Mineral crystals absorb radiation energy at a constant rate. Setting aside the past, from the Yuan dynasty down to the present day spanning seven or eight hundred years, where had the radiation energy absorbed by this piece of jade gone?

The two men followed him closely. "What is it?"

"Hetian jade, 0.001?"

Still somewhat hungover, Wang Qizhi was still trying to figure out what Hetian jade had to do with 0.001, when Guan Xingmin's eyes bulged.

Even an ancient painting from the Ming dynasty measured 0.005, yet a jade lion from the Yuan dynasty was only 0.001?

The former was merely paper, processed by human hands, while the latter was jade, naturally carved. Yet the radiation amount of the paper painting was five times that of the jade?

This was even more ridiculous than asking Lin Sicheng to identify radiation sources with his naked eye...

Just as he was feeling utterly absurd, Lin Sicheng took the folder from the female police officer:

Item: Jade white lion paperweight.
Period: Yuan.
Material: Hetian jade.
Excavation site: Ancient tomb of the Yuan dynasty in Hengshan County, YL City (pending review).
Appraisal unit: Provincial Department Appraisal Center, Municipal Bureau Appraisal Center...
Appraisal members: ...

Flipping further down, to the second page:

Re-appraisal unit: Guidance Group of Northwest University School of Cultural Heritage.
Re-appraisal expert: Yu Zijian.

On the very line at the bottom, Professor Yu's prominent signature was boldly written.

Lin Sicheng frowned.

This jade lion was undoubtedly fake; that was beyond question. The problem was that neither the provincial department nor the municipal bureau had detected it.

The crucial point was: Professor Yu, the school's expert on stone carvings and jade artifacts, hadn't detected it either.

What should they do now?

Wang Qizhi reacted, his eyes wide as saucers: Who said you couldn't use radiation values to appraise antiques?

Wasn't it just successfully identified right here?

With a radiation value this low, there was no need for doubt: this jade lion definitely had a problem.

The trouble was, what should be done about Professor Yu's signature and this appraisal report?

As he pondered a solution, Lin Sicheng blinked. "It hasn't been stamped yet!"

Nonsense, the stamp was still in his bag!

Just as Wang Qizhi was wondering what the kid was up to, Lin Sicheng silently unlatched the folder and pulled out the second page—the re-appraisal report bearing Professor Yu's name.

With Wang Qizhi, Guan Xingmin, the section chief, and the female police officer—four people with eight eyes—watching under broad daylight, Lin Sicheng with utter calmness stuffed the sheet of paper straight into his trouser pocket.