The fundamental point in fabricating a chain reacting machine is of course to see to it that each fission produces a certain number of neutrons and some of these neutrons will again produce fission.
“有些时候,”维尼说,“最小小的东西却在你的心里占据着最大的空间。”
煤炭的真正价值在于我们如何负责任地开采和使用它。