第九章 威力巨大的原子

　　While Einstein and Hubble were productively unraveling the large-scale structure of the cosmos, others were struggling to understand something closer to hand but in its way just as remote: the tiny and ever-mysterious atom. The great Caltech physicist Richard Feynman once observed that if you had to reduce scientific history to one important statement it would be “All things are made of atoms.” They are everywhere and they constitute every thing. Look around you. It is all atoms. Not just the solid things like walls and tables and sofas, but the air in between. And they are there in numbers that you really cannot conceive.

　　当爱因斯坦和哈勃在弄清宇宙的大尺度结构方面成果累累的时候，另一些人在努力搞懂近在手边的而从他们的角度来看又是非常遥远的东西：微小而又永远神秘的原子。加州理工学院伟大的物理学家理查德·费曼有一次发现，要是你不得不把科学史压缩成一句重要的话，它就会是：“一切东西都是由原子构成的。”哪里都有原子，原子构成一切。你四下里望一眼，全是原子。不但墙壁、桌子等等这样的固体是原子，中间的空气也是原子。原子大量存在，多得简直无法想像。

　　原子结构图

　　The basic working arrangement of atoms is the molecule (from the Latin for “little mass”). A molecule is simply two or more atoms working together in a more or less stable arrangement: add two atoms of hydrogen to one of oxygen and you have a molecule of water. Chemists tend to think in terms of molecules rather than elements in much the way that writers tend to think in terms of words and not letters, so it is molecules they count, and these are numerous to say the least. At sea level, at a temperature of 32 degrees Fahrenheit, one cubic centimeter of air (that is, a space about the size of a sugar cube) will contain 45 billion billion molecules. And they are in every single cubic centimeter you see around you. Think how many cubic centimeters there are in the world outside your window—how many sugar cubes it would take to fill that view. Then think how many it would take to build a universe. Atoms, in short, are very abundant.

　　原子的基本工作形式是分子（源自拉丁文，意思是“小团物质”）。一个分子就是两个或两个以上以相对稳定的形式一起工作的原子：一个氧原子加上两个氢原子，你就得到一个水分子。化学家往往以分子而不是以元素来考虑问题，就像作家往往以单词而不是以字母来考虑问题一样，因此他们计算的是分子。分子的数量起码可以说是很多的。在海平面的高度、零摄氏度温度的情况下，一立方厘米空气（大约相当于一块方糖所占的空间）所含的分子多达4500亿亿个。而你周围的每一立方厘米空间都有这么多分子。想一想，你窗外的世界有多少个立方厘米——要用多少块方糖才能填满你的视野。然后再想一想，要多少个这样的空间才能构成宇宙。总而言之，原子是很多的。