Blackett's War (13 page)

In April of 1922 a Dutch shipbuilding firm by the name of NV Ingenieurskantoor voor Scheepsbouw, or IvS, was established at The Hague. Its name translates as “Engineer Office for Shipbuilding.” In fact it was a dummy corporation set up by three German shipyards to begin building submarines to designs developed in Germany. Other German U-boat designs would be
built in Finland, Spain, and Japan over the next several years, ostensibly for these or other foreign navies but with intimate German technical involvement. The naval high command in 1926 selected for development several U-boat designs to meet the requirements for “Case A,” a war with France and Poland. In the summer of 1930 a group of German “tourists” arrived in Finland for an extended holiday. They were the first contingent of active duty German naval officers to begin training in U-boats, and for the next three months they carried out trials on a new 500-ton Finnish submarine that had been designed by IvS, and completed in Finland under the supervision of German engineers.
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IN 1932
Blackett began the work that would lead to his winning the Nobel Prize in physics sixteen years later. It was work revealing both about his experimental and analytical intuition, and of a small but significant rigidity in his approach. Researchers in France and the United States had recently reported discovering cloud chamber tracks apparently created by cosmic rays randomly passing through the chamber at the moment the vapor mixture had been expanded and photographed. Cosmic rays were charged particles created in outer space, and by measuring the curvature of the tracks when a strong magnetic field was applied it was possible to calculate their energy and mass; most were apparently single protons or electrons.

Randomly snapping and developing cloud chamber photographs in the hopes that every now and then one might happen to coincide with the moment a cosmic ray passed through was obviously an inefficient way to conduct science. Giuseppe Occhialini, a young Italian physicist, had been doing some work on detecting cosmic rays with Geiger counters, and he arrived at the Cavendish for what was intended to be a three-week visit. He stayed for three years, collaborating with Blackett on a series of experiments that would in no small measure contribute to C. P. Snow’s exultant declaration that “1932 was the most spectacular year in the history of science.”
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Occhialini (known as “Beppe”) instantly fell under the spell of Blackett and his combination of “the superlative artisan and the dedicated scientist,” as Occhialini would describe him. He recalled Blackett as a scientific and a personal inspiration,

Their idea for improving the process of capturing cosmic ray tracks was a melding of the techniques the two men had been working on independently. “The feeling between two partners in research is close to that between two mountain climbers on the same rope,” Occhialini said of their collaboration. Two Geiger counters, one above and one below the cloud chamber, were electronically linked to send an electric signal only when both detected a cosmic ray, indicating that the ray was passing through the plane of the chamber. The signal then operated a motor to expand the chamber and operate the camera shutter. If everything worked right, a cosmic ray track would show up on every photograph. “I can still see him, that Saturday morning when we first ran the chamber,” Occhialini wrote forty years later about Blackett’s reaction to that first test, “bursting out of the dark room with four dripping photographic plates held high, and shouting for all the Cavendish to hear, ‘One on each, Beppe, one on each!’ ”
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One of Blackett’s famous dictums to his students was, “You should treat your research like a military campaign.… Make sure you gather plenty of data!” With their automated system in place, Blackett and Occhialini proceeded to do just that, taking more than 700 photographs over the following months. In a nomination letter to the Nobel committee in 1948, his Cambridge colleague J. D. Bernal would observe of Blackett, “Two features characterize his work: the importance placed on statistics of an adequate number of observations; and the minute, critical and accurate study of rare individual events.”
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The second point was just as critical: the ability to focus on the anomalous, odd event was one of the distinguishing features of great scientists—Rutherford’s “genius to be astonished,” or what one insightful psychological study of scientists termed an “overalertness to relatively unimportant or tangential aspects of problems,” which leads scientists
to “look for and postulate significance in things which customarily would not be singled out.”

There was, this study went on to observe, something bordering on the “autistic” or even “paranoid” in the grandiosity of this kind of thinking that frequently leads successful scientists to impute great meaning to the seemingly trivial. Indeed,

That was Blackett precisely. “In most of his undertakings Blackett combined versatility of imagination with tough scepticism. He was not easily convinced even by his own ideas,” said Ivor Richards.
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In examining the 700 cloud chamber plates, Blackett found 14 that were a bit odd. A competing scientist, Carl Anderson at Caltech, was on the same track; the price of Blackett’s skepticism and thoroughness was that Anderson would just beat Blackett and Occhialini to publication with a brief announcement of a major new discovery. But Anderson’s was quickly followed in February 1933 by Blackett and Occhialini’s publication of a twenty-seven-page article meticulously describing their new method of “making particles of high energy take their own cloud photographs,” combined with the far more convincing and decisive proof they had found for the existence of a bizarre new particle.
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It was the first bit of antimatter ever discovered: the so-called positive electron, or positron.

The possibility that such a particle could exist had been raised a few years earlier by Paul Dirac, a shy, strange, and intense Cambridge theorist who had developed a mathematical formulation that combined quantum theory and relativity to explain the behavior of the electron. His equations
did not actually predict the existence of an antielectron, but it was a curious feature of them that they worked just as well from a mathematical standpoint for such a hypothetical particle possessing a positive charge and negative energy. Blackett realized that the fourteen odd tracks were consistent with a particle having the mass of an electron. But under an applied magnetic field they curved in the opposite direction from most of the electron tracks—indicating that they were carrying a positive rather than a negative charge.

Blackett would later explain his delay in publication by observing, a bit tongue in cheek, that no one had taken Dirac’s theory seriously at the time. But his own superabundance of caution was more to blame: determined to eliminate every other possible explanation, Blackett first carried out an exhaustive statistical analysis to establish how often positron-looking tracks might be produced by chance some other way. Finally satisfied, Blackett presented their findings at a meeting of the Royal Society on February 16, 1933. Unlike Anderson’s paper, Blackett and Occhialini’s explicitly made the connection to Dirac’s theory and also provided solid evidence of electrons and positrons being created simultaneously. Over the next two days the
New York Times
ran several stories about their discovery, reporting from London that it was being hailed by physicists as “one of the most momentous of the century.” Several nominating letters received by the Swedish Academy proposed that Anderson and Blackett share the Nobel Prize for their independent discovery of the positron. In the end, however, Anderson alone would receive the 1936 award for the milestone.
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With Blackett’s growing renown came increasing friction with Rutherford. Zuckerman would say of Blackett that he was “brought up more to give orders than to seek counsel … a man to whom thought and action were the same.” If anything, Blackett and Rutherford were too much alike in that way. Later that year the final eruption came between the two. Blackett emerged one day from Rutherford’s office “white-faced with rage,” recalled a colleague, and announced, “If physics laboratories have to be run dictatorially, I would rather be my own dictator.” Another colleague thought that Blackett had also become fed up with the “still feudal-Victorian environment of Cambridge,” which he found politically oppressive for a man of his increasingly left-wing views.
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In the fall of 1933 he moved to London and a position at Birkbeck College. Recently integrated into the University of London, Birkbeck had originally been founded as the London Mechanics’ Institute and retained its proletarian character, serving part-time and
evening students who were pursuing a degree while working a job. Blackett took a flat in Gordon Square, in the heart of Bloomsbury, and immediately began laying plans to expand his cosmic ray studies with a new detector incorporating a huge, 11-ton magnet to be installed 100 feet belowground in an abandoned platform of the Holborn Underground station. The London tabloid press, never at a loss for a cliché, hailed him as a new “Sherlock Holmes,” hunting beneath the streets of London for clues about the mysteries of the universe.
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IF BLACKETT STOOD OUT
from other left-wing intellectuals of the 1930s it was because he was no pacifist: for all of his political radicalization he always carried in his core a strand of the young naval cadet who had “enjoyed shooting at the enemy during the war.” But to most of his scientific colleagues, opposition to war and to the exploitation of science for war were part and parcel of their growing political activism. In June 1934, 40 percent of the physicists at the Cavendish Laboratory signed a letter circulated by the Cambridge Scientists’ Anti-War Group protesting the use of scientific research for military purposes.
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The group’s founder was J. D. Bernal, who was carrying out pioneering work at the Cavendish in the new science of crystallography, using X-rays to explore the three-dimensional structure of complex biological molecules. He was also a communist so thoroughly committed to Soviet Marxism that he would defend not only Stalin’s purges but even the pseudo-scientific claptrap of Trofim Lysenko, the uneducated peasant’s son whose theories about plant breeding would become Soviet orthodoxy and lead directly to the persecution of a generation of Soviet geneticists who dared to point out the fallacies of Lysenko’s assertions.

Bernal was, as well, a precocious social rebel of a type that would become tiresomely familiar in the 1960s, rationalizing a self-absorbed pursuit of sexual adventure as if he were somehow striking a blow for the liberation of mankind. Once, while his wife was six months pregnant, he managed to
have affairs with three other women during a single two-week period. Neither his radical politics nor his personal morals won him many admirers in Cambridge.
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The CSAWG, on the other hand, had attracted a broad spectrum of support since its founding two years earlier. Disarmament, renunciation of war, and even outright pacifism had become not merely respectable; they were seen by many from across the British political spectrum as the only sane course.

“The virtues of disarmament were extolled in the House of Commons by all parties,” wrote Winston Churchill in his account of the “locust years” leading up to the Second World War. He did not dwell on the merciless personal attacks he came under in the House, and in the press, for even suggesting there might be danger in a rearming Germany. The German delegation to the 1932 Geneva Disarmament Conference had demanded the removal of all remaining restrictions imposed by the Versailles treaty on the size of its military forces, and support in Britain for that step was considerable.
The Times
, the staid voice of the establishment, called for “the timely redress” of Germany’s “grievances”; the left-wing
New Statesman
, now under the editorship of Blackett’s old friend Kingsley Martin, endorsed “the unqualified recognition of the principle of the equality of states.” Churchill, by then a backbencher who had split with his own Conservative Party over its policies on India, rose to attack the British government’s proposal at Geneva that would slash France’s army by 60 percent and allow Germany’s to grow to the same size. Years later he vividly recalled the “look of pain and aversion” on the faces all around him when he was done. Members of all three parties, Tory, Liberal, and Labour, leapt to their feet to denounce him as “a disappointed office seeker,” a man on a “personal vendetta” out to “poison and vitiate the atmosphere” of peace and cooperation built at Geneva. He was a “scaremonger” and a “warmonger.”
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