Da Vinci's Imitation Painting? (Continued)

At this, Wu Ke found it rather strange and asked, "I saw a magazine article last time that said carbon-14 testing of oil paintings could provide highly valuable reference data. Why don't you have Boss Nan do an appraisal?"

Carbon-14 is a radioactive isotope of carbon. It was first discovered in 1940. It is produced when cosmic rays strike nitrogen atoms in the air. Its half-life is approximately 5,730 years, and it decays through beta decay, with carbon-14 atoms transforming into nitrogen atoms.

Because the proportions of carbon's various isotopes in nature have remained stable, and because carbon is one of the elements found in organic matter, with a half-life of 5,730 years, people can estimate the approximate age of an ancient artifact by measuring its carbon-14 content. This method is called carbon dating. Carbon-14 testing has therefore been widely used in modern archaeology and appraisal.

Nan Nancai smiled faintly. "It's not that I don't want to do it, but carbon-14 doesn't produce authoritative results under every circumstance. I actually found this painting in a trash can. Under these conditions, even if I had it tested with carbon-14, the results would have no reference value at all."

Carbon-14 testing had its limitations. The massive amount of carbon produced by artificial nuclear explosions had a major impact on the atmosphere. Moreover, after the Industrial Revolution in the eighteenth century, ordinary carbon in the atmosphere increased substantially, greatly affecting the ratio of carbon elements. Internationally, the recognized starting point for BP in carbon-14 dating was 1950.

Generally speaking, the sample being tested had to be uncontaminated. If carbon from an earlier or later period was accidentally mixed in, the results would certainly differ greatly from what was actually wanted.

Therefore, without a strict explanation of the sampling process, any conclusion would be