60秒科学:核武器与葡萄酒的关系（在线收听）

数千年来，大气中碳12和碳14的比例是稳定不变的，然而，二十多年以来的原子弹试验，使得碳14的水平增加。生长中的葡萄吸收了空气中的二氧化碳，而通过测试葡萄中的碳含量，就可以大致测出葡萄酒的酿造年代。

Here are two seemingly unrelated facts. One: from the late 1940s through 1963, we tested atomic bombs in the atmosphere. Two: wine lovers are sometimes duped into spending exorbitant amounts for fake vintage bottles that weren’t from the year they were supposedly grown.

But Graham Jones at Australia’s University of Adelaide thought he could use bomb information against counterfeit wines. [He talked about his research at the meeting of the American Chemical Society in San Francisco.] Carbon dating works by comparing the amount of carbon 14, which is a less common and less stable form of carbon, to the more abundant carbon 12.

For thousands of years, the ratio between the two has been the same. But those two decades of atomic bomb tests increased the C-14 in the atmosphere. And as growing grapes absorb carbon dioxide, they take in trace amounts of the heavier carbon isotope—which eventually show up in the wine.

The research team checked C-14 levels in 20 Australian red wines with vintages from 1958 to 1997. They compared the wine’s C-14 to C-14 in atmospheric samples from the same years. And found a direct match—C-14 levels could give away the vintage year for each wine.

So beware wine scammers. Because even at the atomic level, in vino veritas.

—Cynthia Graber

[The above text is an exact transcript of this podcast.]