BOOKS & ARTS COMMENT manipulating a force pervading in every- day matter, who ally to mount an insur- rection against the established order and Forgotten heroes of help destroy a giant, partially built beam machine,” writes Martin. The trajectory of US solid-state physics, he notes, “fol- the Enigma story lowed much the same plot”. Although he concedes that the SSC was more drasti- Joanne Baker enjoys a tale of the Polish cryptographers cally affected by the end of the cold war than by intradisciplinary critique, there is who paved the way for Alan Turing’s wartime feats. no doubt where Martin’s sympathies lie. He devotes most of his book to a detailed reconstruction of the intense lan Turing’s crucial unscrambling the mathematicians’ struggle, half a century earlier, for rec- of German messages in the Second families have shared ognition by solid-state physicists against World War was a tour de force of personal letters. the leadership of the APS, which was Acodebreaking. From 1940 onwards, Turing Turing unearths a itself frustrated and challenged by the and his team engineered hundreds of elec- remarkable tale of rapid growth in their ranks during the tronic machines, dubbed bombes, which intellect, bravery and 1940s. Physicists who worked on metals, decrypted the thousands of missives sent by camaraderie that ceramics and other domains straddling enemy commanders each day to guide their reads like a nail-biting fundamental and applied physics wanted soldiers. This deluge of knowledge short- spy novel. representation at APS meetings, leading ened the war. Bletchley Park, UK — the Polish skills in X, Y & Z: The to the creation of the Division of Solid secret centre where it all happened — rightly Real Story of cryptography and State Physics in 1947. The institutional gained its place in history. But as with all How Enigma Was radio engineer- gerrymandering had significant implica- breakthroughs, many more people laid the Broken ing came together tions for the APS, especially for its flagship foundations. DERMOT TURING during the 1920 journal, Physical Review. (Publishing is a In his book X, Y & Z, Dermot Turing, The History Press Russo-Polish War. fascinating leitmotif in Martin’s account.) the great mathematician’s nephew, tells the (2018) Signallers decoded This organizational innovation was gripping story of a band of Polish math- a telegram from Red achieved only after substantial resistance ematicians who worked out much about Army military commander Joseph Stalin, from some APS stalwarts, who perceived how German Enigma encoding machines which indicated that an attack on Warsaw the purity of their ranks as becoming sul- operated, years before Alan Turing did. was imminent. Jamming the Russians’ radio lied by industrial scientists. The stalwarts The Poles shared their secrets with French communications bought enough time to included Harvard University’s John Van and British intelligence services before and secure and save the city. Maksymilian Ciężki Vleck, even though he had trained many during the Second World War — the letters and Antoni Palluth were among those sig- of the leaders of the next generation, X, Y and Z were shorthand for the French, nallers. After the 1920 conflict, Ciężki including Anderson. Van Vleck’s objec- British and Polish codebreaking teams, became leader of a radio-intelligence unit. tions were littered with political language: respectively. Palluth set up a business making electronic he protested against the “Balkanization” The author’s research is painstaking. After equipment, including radios the size of a of the APS, and he thought the solid-state the war, military documents were scattered credit card for Polish secret agents. division was a “new-deal-bureaucratic” across Europe, and key French records In 1926, the German navy began to send scheme that ought to be resisted. The con- were declassified only in 2016. Many messages that were scrambled in a more servative Van Vleck was unhappy about original Polish papers were destroyed, but random way, making them almost impos- the direction that the United States — and sible to decipher. They were encoded using with it physics — was going. the typewriter-like Enigma machine. The This raises a broader point about keyboard was wired so that typing one letter Martin’s engaging book: the politics in it lit up a different one in a set of bulbs on top. are exclusive to the profession. He keeps Rotors altered the path of the electric circuit his gaze tightly trained on physicists as with every keystroke. The machines were they define physics to each other. The commercially available, but modified for ANNA ZYGALSKA-CANNON Vietnam War (and scientific work in sup- German military use. Without knowing the port of it), anti-Communism, civil rights precise setting of a machine, there was no and other political fault lines — which way to unpick the code. affected physicists no less than other citi- The book tells how Ciężki hired a group of zens — are mentioned in passing, if at all. mathematics students to crack the problem. Yet they must have mattered. Physics is They worked quietly in basements and in a defined not just by what physicists decide bunker deep in the woods. Marian Rejewski, it is, but by what the broader society will an alumnus of Poznań University in Poland, (or won’t) support. That decision is made was one of them. At the helm was Gwido within the halls of the APS, but also in Langer, a Pole who had worked in radio those of Congress. ■ intelligence for the Austrian army. Meanwhile, in France, Gustave Bertrand Michael D. Gordin is Rosengarten headed the equivalent unit. The French had Professor of Modern and Contemporary a more conventional approach to gather- History at Princeton University in ing information: good agents, clandestine New Jersey. meetings and generous pay-offs. Bertrand email: [email protected] Mathematician Marian Rejewski in 1942. managed two formidable spies. Rudolf ©2018 Spri nger Nature Li mited. All ri ghts reserved. ©2018 Spri nger Nature Li mited. All ri ghts reser20ved . SEPTEMBER 2018 | VOL 561 | NATURE | 307 COMMENT BOOKS & ARTS ANNA ZYGALSKA-CANNON Polish cryptographers, including Maksymilian Ciężki (seventh from left) and Gwido Langer (centre back, head just seen), pictured in southern France in 1941. Stallmann — code name Rex — was Polish mathematician, Jerzy Różycki, with The Polish insights saved him a year of work. a German card-sharp who had posed as realizing that this altered the frequency of When war broke out, the Polish radio- a baron to fleece casino-goers; he picked letters, revealing extra information. The intelligence unit was wound up. The up languages and people with ease. Rex team developed tools to work through codebreakers buried their notes and recruited Hans-Thilo Schmidt, or Agent the hundreds of permutations, including machines and fled. Some ended up Asche, whose brother was a colonel in the punched cards and a mechanical device in Algeria, the rest in France working German army. Schmidt supplied cases of with rotors that mimicked Enigma, which, for Bertrand, who had set up a radio- military documents to the French, which for uncertain reasons, the team called a intelligence group in a chateau in southern Rex received and Bertrand and his colleagues bomba. Both concepts were later used and France. In breathtaking passages, the book photographed in hotel bathrooms. developed by Alan Turing. reveals how most of the Polish codebreakers Bertrand built up a network for sharing Bertrand fed this information back to Brit- made it through the war, tapping into the intelligence, including with Poland and ain’s codebreakers, who come across in the French Resistance and dodging Germany’s the United Kingdom. In 1931, he agreed book as humorous but aloof. They called the military-intelligence services and secret to supply Langer with German military French dispatches police when France became occupied. As documents if the Poles would pass back — stamped TRÈS “Ciężki hired valuable assets, the codebreakers were not decrypted German messages. One of those SECRET in red — a group of allowed to fight. Touching photographs in documents, passed on by Schmidt, was a scarlet pimpernels. mathematics the book show them joking with each other manual for Enigma. In late July 1939, students who and spending time with girlfriends amid Langer, Ciężki and Rejewski leapt on it. just over a month worked in the devastation. They discovered that a panel added to the before the German Eventually, Ciężki and Langer were front of the machine altered the settings, army marched into basements and arrested and interned in the Sudetenland although they still could not tell how the Poland, Bertrand in a bunker deep (now part of the Czech Republic). After device was wired. They set about collect- arranged for the in the woods.” the war, they settled in Scotland. Palluth ing coded messages and applied their wits respected British was killed in Germany in 1945, when an to find clues. Sometimes, the senders made cryptologist Dillwyn ‘Dilly’ Knox (who was aeroplane factory in which he was working telling mistakes. The German soldiers already working on Enigma at Bletchley) to at Sachsenhausen concentration camp was might use simple sets of three letters, such meet Langer’s team near Warsaw. The Poles bombed. Bertrand artfully played all sides. as QQQ, to broadcast the settings to the wanted to pass on their knowledge. Initially Avoiding becoming a double agent, he ended receiver. Occasionally, the messages could angry that they had beaten him to it, Knox up a general. In 1972, he wrote a popular be guessed: for instance, they often said later sent the Poles a silk scarf printed with a French book about Enigma, and so the story maschine defekt. horse-racing scene to concede that they had of X, Y and Z and Bletchley began to seep out.