万物简史 第223期:把铅撵出去(12)(在线收听) |
As always, however, nothing was quite as straightforward as such a breezy description makes it sound. Meteorites are not abundant and meteoritic samples not especially easy to get hold of. Moreover, Brown's measurement technique proved finicky in the extreme and needed much refinement. Above all, there was the problem that Patterson's samples were continuously and unaccountably contaminated with large doses of atmospheric lead whenever they were exposed to air. It was this that eventually led him to create a sterile laboratory—the world's first, according to at least one account. 然而,通常来说,总是说来容易做来难。陨石数量不多,陨石样品不是很容易能采集到手。而且,布朗的测量方法过分注重细节,需要做很多改进。最大的问题是,彼得森的样品只要接触空气,就莫名其妙地不断地受到大气里铅的严重污染。正是由于这个原因,他最后建立了一个消过毒的实验室──世界上第一个无菌实验室,至少有一份材料里是这么说的。
爱护地球
It took Patterson seven years of patient work just to assemble suitable samples for final testing. In the spring of 1953 he traveled to the Argonne National Laboratory in Illinois, where he was granted time on a late-model mass spectrograph, a machine capable of detecting and measuring the minute quantities of uranium and lead locked up in ancient crystals. When at last he had his results, Patterson was so excited that he drove straight to his boyhood home in Iowa and had his mother check him into a hospital because he thought he was having a heart attack.
彼得森任劳任怨地干了7年,才收集到可用于最后测试的样品。1953年春,他把样品送到伊利诺伊州的阿冈尼国家实验室。他及时获得了一台新型的质谱仪,可以用来发现和测定秘藏在古晶体里的微量铀和铅。彼得森终于得出了结果。他激动万分,直接驱车去艾奥瓦州他度过少年时代的家中,让他的母亲把他送进医院,因为他认为自己在发心脏病。
Soon afterward, at a meeting in Wisconsin, Patterson announced a definitive age for the Earth of 4,550 million years (plus or minus 70 million years)—"a figure that stands unchanged 50 years later," as McGrayne admiringly notes. After two hundred years of trying, the Earth finally had an age.
此后不久,在威斯康星州的一次会议上,彼得森宣布地球的确切年龄为45.5亿年(误差7000万年)──麦格雷恩赞赏地说:“这数字保持了50年。”经过200年的努力,地球终于有了个年龄。 |
原文地址:http://www.tingroom.com/lesson/syysdw/wwwjs/400013.html |