In Richard Rhodes’s Dark Sun: The Making of the Hydrogen Bomb, Rhodes quotes nuclear physicist Rudolf Peierls as saying that “[Traitor and spy Klaus Fuchs] was courteous and even-tempered. He was rather silent, unless one asked him a question, when he would give a full and articulate answer; for this Genia called ‘Penny-in-the-slot.'” That’s on page 57.

On page 175, Rhodes describes the famous Trinity atomic bomb test at Alamagordo, New Mexico, and quotes I. I. Rabi, another physicist, at length. Then Rhodes writes, “Fuchs was there to see the new thing he had caused to proliferate, the new control, but no one put a penny in his slot, so he left no record of how the unique experience affected him.” “No one put a penny in his slot:” the phrase does a lot of deft work in that sentence, pointing to the seeming incuriosity of everyone around Fuchs; to Fuchs’s character itself; to the way he responds rather than initiating (despite him working on atomic weapon initiator design). Rhodes takes what could have been an evocative-but-throwaway line and reconfigures it, connecting the two sections of the book through unusual but suddenly gorgeous language.

Another point about this pairing: it can’t really be generalized to a rule. Few if any writing books advise good writers to call back to an evocative description a hundred pages later, and to do so with an unexpected twist. Rhodes does it. He hits the high note here.

The book itself is about history, technology, politics, human motivation, human character, institutions, industrial organization, and many other topics. He writes, for example, about what made communism attractive to western communists, despite the fact that it doesn’t work. He writes, “Communism in any case was intensely fashionable at English universities between the World Wars.” It seems strange that anyone could have been attracted to Communism; as Stalin’s Great Terror unfolds through the 1930s, it becomes even stranger. Then again, socialism is having a strange vogue today, among people who seem not to quite understand what it entails (one definition, from Apple’s included Oxford American Diction: “a political and economic theory of social organization which advocates that the means of production, distribution, and exchange should be owned or regulated by the community as a whole.”) It’s possible of course for a “community” to own a company today, as with coops, or for individuals to own companies; they just tend to be outcompeted by publicly-owned companies, which ought to tell us something useful.

Still, Communism as a topic remains of interest not so much because of the fact that it fails, but because it could inspire people to betray their own, functional countries in favor of a dystopian hellscape like Soviet Russia. What makes a person do that? What does the motivation of a person doing that tell us about people as a whole, personality as a whole? What makes people choose and advocate for the clearly inferior choice? These are questions without final answers, which makes them interesting.