万物简史 第200期:威力巨大的原子(14)(在线收听

  The picture that nearly everybody has in mind of an atom is of an electron or two flying around a nucleus, like planets orbiting a sun. This image was created in 1904, based on little more than clever guesswork, by a Japanese physicist named Hantaro Nagaoka. It is completely wrong, but durable just the same. As Isaac Asimov liked to note, it inspired generations of science fiction writers to create stories of worlds within worlds, in which atoms become tiny inhabited solar systems or our solar system turns out to be merely a mote in some much larger scheme. Even now CERN, the European Organization for Nuclear Research, uses Nagaoka's image as a logo on its website. In fact, as physicists were soon to realize, electrons are not like orbiting planets at all, but more like the blades of a spinning fan, managing to fill every bit of space in their orbits simultaneously (but with the crucial difference that the blades of a fan only seem to be everywhere at once; electrons are ).

  差不多人人的脑海里都有一幅原子图,即一两个电子绕着原子核飞速转动,就像行星绕着太阳转动一样。这个形象是1904年由一位名叫长冈半太郎的日本物理学家创建的,完全是一种聪明的凭空想像。它是完全错的,但照样很有生命力。正如艾萨克·阿西莫夫喜欢指出的,它给了一代又一代的科幻作家灵感,创作了世界中的世界的故事,原子成了有人居住的太阳系,我们的太阳系成了一个大得多的体系里的一颗微粒。连欧洲核子研究中心也把长冈所提出的图像作为它网站的标记。物理学家很快就意识到,实际上,电子根本不像在轨道上运行的行星,更像是电扇旋转着的叶片,想要同时填满轨道上的每一空间。(但有个重要的不同之处,那就是,电扇叶片只是好像同时在每个地方,电子真的就同时在每个地方。)

  原子

  Needless to say, very little of this was understood in 1910 or for many years afterward. Rutherford's finding presented some large and immediate problems, not least that no electron should be able to orbit a nucleus without crashing. Conventional electrodynamic theory demanded that a flying electron should very quickly run out of energy—in only an instant or so—and spiral into the nucleus, with disastrous consequences for both. There was also the problem of how protons with their positive charges could bundle together inside the nucleus without blowing themselves and the rest of the atom apart. Clearly whatever was going on down there in the world of the very small was not governed by the laws that applied in the macro world where our expectations reside.

  不用说,在1910年,或在此后的许多年里,知道这类知识的人为数甚少。卢瑟福的发现马上产生了几个大问题。尤其是,围绕原子核转动的电子可能会坠毁。传统的电动力学理论认为,飞速转动的电子很快会把能量消耗殆尽——只是一刹那间——然后盘旋着飞进原子核,给二者都带来灾难性的后果。还有一个问题,带正电荷的质子怎么能一起待在原子核里面,而又不把自己及原子的其他部分炸得粉碎。显而易见,那个小天地里在发生的事,是不受适用于我们宏观世界的规律支配的。

  原文地址:http://www.tingroom.com/lesson/syysdw/wwwjs/394221.html