万物简史 第216期:把铅撵出去(5)（在线收听） |
Chlorofluorocarbons are also not very abundant—they constitute only about one part per billion of the atmosphere as a whole—but they are extravagantly destructive. One pound of CFCs can capture and annihilate seventy thousand pounds of atmospheric ozone. CFCs also hang around for a long time—about a century on average—wreaking havoc all the while. They are also great heat sponges. A single CFC molecule is about ten thousand times more efficient at exacerbating greenhouse effects than a molecule of carbon dioxide—and carbon dioxide is of course no slouch itself as a greenhouse gas. In short, chlorofluorocarbons may ultimately prove to be just about the worst invention of the twentieth century. 含氯氟烃的量也不大──只占整个大气的大约十亿分之一──但是，这种气体的破坏力很强。1千克含氯氟烃能在大气里捕捉和消灭7万千克臭氧。含氯氟烃悬浮的时间还很长──平均一个世纪左右──不停地造成破坏。它吸收大量热量。一个含氯氟烃分子增加温室效应的本事，要比一个二氧化碳分子强1万倍左右──当然，二氧化碳本身也是加剧温室效应的能手。总之，最后可能证明，含氯氟烃差不多是20世纪最糟糕的发明。
Midgley never knew this because he died long before anyone realized how destructive CFCs were. His death was itself memorably unusual. After becoming crippled with polio, Midgley invented a contraption involving a series of motorized pulleys that automatically raised or turned him in bed. In 1944, he became entangled in the cords as the machine went into action and was strangled.
这一点米奇利永远不会知道。在人们意识到含氯氟烃的破坏力之前，他早已不在人世。他的死亡本身也是极不寻常的。米奇利患脊髓灰质炎变成跛子以后，发明了一个机械装置，利用一系列机动滑轮自动帮他在床上抬身或翻身。1944年，当这台机器启动的时候，他被缠在绳索里窒息而死。
If you were interested in finding out the ages of things, the University of Chicago in the 1940s was the place to be. Willard Libby was in the process of inventing radiocarbon dating, allowing scientists to get an accurate reading of the age of bones and other organic remains, something they had never been able to do before.
要是你对确定事物的年龄感兴趣，20世纪40年代的芝加哥大学是个该去的地方。威拉德·利比快要发明放射性碳年代测定法，使科学家们能测出骨头和别的有机残骸的精确年代，这在过去是办不到的。 |
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