EINSTEIN AND SZILARD IN PRINCETON
The Pioneers of Nuclear Science as Colleagues, Friends, and NeighborsBy William Lanouette, Ph.D.
The Lewis B. Cuyler Lecture
Historical Society of Princeton
Nassau Club, Princeton, February 9, 2011
Albert Einstein is probably the most famous Princeton resident of the 20th Century (except, perhaps, for Woodrow Wilson or Bill Bradley or Brooke Shields). But he’s clearly the most famous scientist in modern history. By contrast, his friend and colleague Leo Szilard was a shadowy figure in the history of nuclear science – essential to its progress, yet now mostly forgotten. Szilard preferred to work behind the scenes, advising others on how to save the world: he advised not only Einstein and fellow scientists, but also U.S presidents and Senators, and two Soviet premiers.
In this talk I will describe how the lives and careers of Albert Einstein and Leo Szilard converged, first in Berlin, then here in Princeton.
For background, Einstein was born in Ulm, Germany, in 1879. He was educated in Munich, and in Zurich, Switzerland, and became a technical assistant at the Swiss Patent Office in Bern. Einstein received his doctorate in 1905, and that year he proposed that mass and energy are equivalent. For this insight he’s forever associated with the formula E=mc2. After teaching in Zurich and Prague, he became a professor of physics at the University of Berlin in 1914.
Leo Szilard was born in Budapest, Hungary, in 1898, and he studied engineering there until the fascist Horthy regime took power in 1919 — then he fled to Berlin to continue his education.
In Berlin, Szilard was drawn to the thriving field of physics, and discovered its center to be a weekly colloquium at the University attended by such Nobel laureates as Einstein, Max Planck, Max von Laue, and James Franck. The 22-year-old Szilard was undaunted by this illustrious gathering, and when enrolling to take a course from Planck, Szilard told the distinguished professor, “I only want to know the facts of physics. I will make up the theories myself.”
Soon Szilard took to walking Einstein home from the colloquia, and the two struck up a friendship that thrived on their pleasures of freewheeling conversation and lateral thinking. Both were non-observant Jews who enjoyed discussing philosophy – especially Spinoza — and cosmology and physics. They also enjoyed sharing jokes about rabbis who are confronted with tough questions and give improbable answers.
Two boys knock on a rabbi’s door. His wife lets them in, and they ask the rabbi to help them resolve a dispute. The first boy gives his interpretation of a Talmudic text. “You’re right,” the rabbi says. But when the second boy states his argument, the rabbi says, “You’re right.” The rabbi’s wife objects. “How can you say that he’s right, and also that he’s right?” “You know,” the rabbi says, “I think you’re also right.”
In 1921, Szilard asked Einstein to teach a seminar on statistical mechanics for a few friends. These were fellow Hungarians Dennis Gabor, Eugene Wigner, and John von Neumann. Gabor would later earn a Nobel Prize in Physics for inventing holography and Wigner for atomic theory and the principles of symmetry. Von Neumann would develop game theory and the modern computer. 1921 was also the first year Einstein visited the United States, and he came here to Princeton to lecture at the University.
In a more practical collaboration, during the 1920s Szilard and Einstein shared 20 joint patents when designing electromagnetic pumps for household refrigerators. Impractical and too noisy at the time, their concept became essential in the 1950s and 1960s to run another Szilard invention, the breeder reactor: a nuclear power plant designed to make more fuel than it consumes.
During more than a decade in Berlin, Einstein and Szilard formed an enduring friendship that put them at ease together. At one lecture by Einstein, Szilard interrupted to say, “But, Herr Professor, what you have now said is just nonsense.” To this Einstein paused, thought for a second, and smiled. To other interruptions by Szilard he often replied, “Yes, yes. You are quite right.” For his part, Einstein criticized Szilard for being “too clever” with his many schemes to save the world, and for having too much faith in human reason.
In 1928, Szilard and von Neumann formed a group to study modern economics, and at Berlin University that summer the two gave a course on New Ideas on Quantum Theory. Later that year they taught Quantum Mechanics, and Szilard published his doctoral thesis. It applied the concept of entropy to information, the basis for what became “cybernetics” or “information theory.” In 1930, Szilard and von Neumann taught New Work in Theoretical Physics, their final course together.
John von Neumann first came to Princeton University in 1929, as a visiting
professor for one term. He then spent a term here each year until 1933, when he accepted appointment as the youngest professor at the Institute for Advanced Study. It’s difficult for we mortals to appreciate just how brilliant von Neumann was. As a boy, for amusement he divided two seven-digit numbers by each other in his head, and any book chapter he read he could then recite word for word.
His compatriot Eugene Wigner joined the Princeton Physics Department in 1930, and Szilard may well have accompanied his two Hungarian friends in 1931, when he was invited by the University to spend a year developing “mathematical physics.” Szilard declined that offer, but visited here for a month in 1932 before returning to Berlin, where he worked with AEG on refrigerators and taught at the University.
Szilard was considered a candidate for the Institute in 1932, but Einstein declined to recommend him because he believed Szilard’s talents were in “technical science and experimental physics” and not in “mathematical physics.”
In 1933, Einstein became a professor at the Institute and Szilard fled Germany. In London that fall, Szilard realized two concepts that would change the course of physics and world affairs: the “nuclear chain reaction” and the “critical mass” needed to create and sustain it. Szilard expected that nuclear power might replace coal and oil as energy fuels. But he also feared nuclear bombs could destroy the world. After filing a patent for these concepts in 1934, he had it made a military secret lest German scientists also see this awesome possibility.
But it would be five years later, here in Princeton, before Szilard finally realized how his frightful ideas might just work. He was visiting Wigner in January 1939 when the eminent Danish physicist Niels Bohr came to the University. Bohr reported that a month earlier, in Berlin, German scientists had split or “fissioned” the Uranium atom. Szilard had named Uranium in his 1934 patent, and now saw its potential for nuclear bombs.
Then a guest scholar at Columbia, Szilard enlisted the Nobel laureate Enrico Fermi and others in his research, and in July of 1939 he and Fermi co-designed the world’s first nuclear reactor. With Wigner at the wheel — Szilard never learned to drive a car – the two tracked down Einstein at his summer cottage on Long Island, and there told him about how nuclear chain reactions might work. How E=mc2 could make bombs.
Einstein’s response: “I haven’t thought of that at all.” Einstein had been immersed in a search for a Unified Field Theory, but he trusted Szilard’s instincts and agreed to sign a letter warning President Franklin D. Roosevelt about German nuclear weapons research, which by that time had already been assigned to the army. (American research would not shift to the army for another three years.)
Einstein and Szilard were both pacifists, but their fear that Hitler could have the A-bomb led them to try to start an American program that – if successful – might be a deterrent.
Two days after drafting the letter to FDR, Szilard, thought to reach an even higher power. He wrote out his own version of the Ten Commandments. Institute professor Freeman Dyson used these commandments as epigraphs in his 1992 book From Eros to Gaia. One was, “Do not destroy what you cannot create.” Another was, “Let your acts be directed toward a worthy goal. But do not ask if they will reach it: They are to be models and examples, not means to an end.” In place of “Honor thy father and thy mother,” Szilard wrote: “Honor children. Listen reverently to their words and speak to them with infinite love.”
Einstein’s letter prompted FDR to create a Uranium Committee, and at its first meeting in October 1939 Szilard, Wigner, and fellow Hungarian Edward Teller met skeptical military officers who grudgingly agreed to grant them $6,000.
But by the following spring, no money had arrived at Columbia for the Szilard-Fermi research, so Szilard visited Einstein for a second letter to FDR in March 1940. This time he warned the president that if money weren’t forthcoming, Szilard just might publish his self-censored research on nuclear chain reactions: in effect, pressuring the federal government to pay up or else.
A month later, Szilard was back at Einstein’s house for a third letter to FDR, this time urging that “large scale experiments” should be funded.
After the war, Einstein said he had “really only acted as a mailbox” for Szilard, but besides sending letters to the White House he played another decisive role to advance the A-bomb when the U.S. Army nearly denied Fermi and Szilard security clearances. Investigators who based their conclusions about these “enemy aliens” on “highly reliable sources,” drew the paradoxical conclusions that Fermi, a refugee from Italian fascism, was “undoubtedly a Fascist” and that Szilard, in terror of the Nazis, was “very pro-German.” The Army decided of each that “employment of this person on secret work is not recommended.” At the time, the only “secret work” in the U.S. was in the heads of Fermi and Szilard.
But when pressured by the White House, FBI Director J. Edgar Hoover sent agents here to interview Einstein (whose pacifist views would later cause his own loyalty to be questioned). Einstein vouched for Szilard – freeing, at last, the money essential for chain-reaction research at Columbia. Had Fermi and Szilard not received funding in November 1940, their pioneering atomic research would have ceased. In all probability, their nuclear reactor would not have worked by December 1942, and A-bombs would not have been ready by August 1945.
Einstein played no other part in the U.S. effort to beat Germany to the A-bomb, and when the U.S. Army took over with the code-named “Manhattan Project” in June 1942 Szilard and other scientists were engaged in a huge industrial enterprise. Ironically, the same month that the U.S. militarized and scaled up it’s nuclear work, June 1942, the German scientists admitted they could not create a weapon before war’s end, and their budget and efforts were cut.
A debate persists about why the Germans failed to make an A-bomb, but in one important matter the evidence is clear. Both German and American scientists first tried to use graphite as a “moderator” to slow down neutrons – that gives them a better chance of hitting uranium atoms to sustain a chain reaction. But only Szilard realized they needed pure graphite because the commercial-grade contained boron, which absorbed neutrons and choked-off the reaction. He ordered pure graphite for his experiments with Fermi, and they ultimately succeeded.
When the Germans failed, they abandoned graphite as their moderator and switched to heavy water. This they could only obtain from a hydroelectric plant in Norway, and once the Allies destroyed that supply, Germany’s chances for success vanished. After the war, Wigner said, If the Manhattan Project could have run on ideas alone we would have only needed Leo Szilard.
Within the Manhattan Project the Hungarians Szilard, von Neumann, Wigner, and Teller were called “The Martians” because they were all super-humanly intelligent and spoke an un-earthly language. All four were born in the same district in Budapest, and you’ll find a map of their landing sites on the easel outside.
I know you Princetonians have some experience with Martians, thanks to Grover’s Mill and the 1938 radio broadcast by Orson Welles. But you can boast about hosting actual Martians. The first to land here was von Neumann in 1929, and the last was John Kemeny. Also born in Budapest, Kemeny came to Princeton University in 1943, worked during the war at Los Alamos with Princeton physicist Richard Feynman, and when a graduate student Kemeny was Einstein’s mathematics assistant. Coming out of the Institute one day, Kemeny and Einstein met von Neumann. “You have made the wrong kind of computer,” Einstein told von Neumann. “Why don’t you invent a computer that would help me in my work? I don’t need a numerical computer.” Kemeny went on to design just such a computer language, “Beginner’s All-purpose Symbolic Instruction Code” or BASIC. He was later President of Dartmouth and chaired the President’s Commission to study the nuclear-plant accident at Three Mile Island.
In March 1945, as the Allies neared victory in Europe, Szilard came here to ask Einstein for a fourth letter to FDR – this one to urge that Cabinet members hear Szilard’s warning about a post-war nuclear arms race with Russia. FDR died before seeing that letter, and when Szilard took it to the Truman White House in May 1945 he was sent to visit James F. Byrnes, who was about to be named Secretary of State. Byrnes dismissed Szilard’s plea to demonstrate the A-bomb, and told him that using it on Japanese cities might make the Russians “more manageable” after the war.
In June 1945, Szilard helped Manhattan Project colleagues in Chicago to draft the Franck Committee Report that urged an A-bomb demonstration. And in July, he drafted and sent to President Truman, a petition – signed by 155 Manhattan Project scientists – questioning the bomb’s use. To undermine this, Project director Gen. Leslie Groves, polled his scientists, and was miffed when 83% of them favored a demonstration.
When Einstein learned about the bombing of Hiroshima he said, “Ach! The world is not ready for it.” Szilard’s reaction was “a sense of relief” – at last he could alert politicians and the public to his fears of a nuclear arms race. But when Szilard tried to publicize his petition, General Groves had it classified “Secret” and it was not published until 1963. (In Szilard’s view, the most powerful weapon to result from the Manhattan Project wasn’t the A-bomb; it was the “SECRET” stamp.)
“When I visited Einstein at Princeton shortly after the bomb was dropped at Hiroshima and Nagasaki,” Szilard later recalled, “our conversation turned back six years to the visit on Long Island when we discussed the letter he might write to the President. ‘You see now,’ Einstein said to me, ‘that the ancient Chinese were right. It is not possible to foresee the results of what you do. The only wise thing to do is to take no action — to take absolutely no action.'”
But Einstein soon changed his mind, and took several actions. He became a co-founder of The Bulletin of the Atomic Scientists, a magazine by Manhattan Project veterans to educate the public about the perils of the bomb. In March 1946, Einstein and Szilard joined fellow scientists to publish One World or None, a book warning about nuclear proliferation and urging its control by a world government.
Einstein and Szilard worked together again in the spring of 1946 when they founded the Emergency Committee of Atomic Scientists, with Einstein as chairman. The scientists met at the Nassau Tavern, and at the Institute for Advanced Study. In a public statement, drafted by Szilard and Nobel laureate Harold Urey, Einstein warned of mankind’s “drift toward unparalleled catastrophe” because of nuclear weapons.
In June 1946, Szilard went to Hollywood to confer on an MGM film about the bomb, The Beginning or the End, and he spent many days re-writing the script about his meeting with Einstein and their letter to FDR. Einstein and Szilard worried that their role in beginning the atomic age should be portrayed accurately, and the studio accepted some script changes. But MGM president Louis B. Mayer reminded Einstein: “It must be realized that dramatic truth is just as compelling a requirement on us as veritable truth is on a scientist.” The film won an Oscar, for its explosive special effects.
Szilard Einstein played themselves before cameras in July 1946 when, on the back porch of Einstein’s Mercer Street house, they reenacted for a “March of Time” newsreel how they had drafted their 1939 letter to FDR. Then, seated in Einstein’s study with Urey they discussed an Emergency Committee statement warning about nuclear weapons.
Einstein’s life in Princeton was relaxed, marked by his daily walk to the Institute, and home again, often with the mathematician Kurt Godel. “I live like a bear in my cave,” Einstein wrote his friend Max Born, “and really feel more at home than ever before in my eventful life.” He enjoyed playing the violin with friends, but seldom attended social events.
By contrast, two other Institute colleagues became famous around town for their sociability. From his earliest days in Princeton, von Neumann seemed always to be throwing lavish and noisy parties at his home, often with waiters in white jackets serving drinks. Von Neumann and Institute director J. Robert Oppenheimer were renowned hosts, and, if they had their way, the Manhattan Project may well have been renamed the Martini Project as both made a science of mixing and consuming the drink.
Szilard actually became a Princetonian for a few years in the early 1950s when he moved into Drumthwacket on Stockton Street, now the New Jersey governor’s mansion but then the home of Abram and Margaret Spanel. Szilard was attracted to Spanel for his original and sometimes whimsical solutions to the world’s problems — which he published in paid ads in the New York Times and Herald Tribune. Spanel was an inventor with more than 2,000 patents, and headed the International Laytex Corporation, maker of the popular Playtex Bra. Both Szilard and Spanel tried to watch their weight, and for this purpose Szilard designed them a pencil-shaped pocket calorie counter.
When living at Drumthwacket, Szilard often caught the train to New York with Spanel, the two constantly chatting about world affairs and possible political solutions. Szilard also enjoyed the friendly company of Spanel’s vivacious wife, Margaret, who often hosted Sunday lunches at their mansion. After one lunch, Mrs. Spanel recalled, Szilard entered the living room for coffee and found William Welch seated in the lotus position by the fireplace. Welch was a yoga enthusiast and a disciple of the Russian-Greek mystic Gurdjieff, whom many considered a fraud. Welch looked up from his pose, eyed Szilard’s girth, and said loudly: “I bet you can’t do this, Dr. Szilard.” Glaring down at Welch, Szilard replied: “There are those who think the important thing about the Buddha is the way he sat. There are others who think the important thing about the Buddha is the way he thought.”
At many a lunch, Szilard was joined by his fellow Martians, von Neumann and Wigner, and the three old friends stood about delighting in conversations so brisk that one would start a sentence, another would add to it, and the third would give it a surprising and stunning conclusion.
After World War II, Szilard shifted from physics to arms control and biology. Operating as an “intellectual bumblebee” among scientists in America and Europe, he is credited with a theory on negative feedback regulation of enzyme activity that won others the Nobel Prize. Szilard also founded the country’s first political action committee for arms control, the Council for a Livable World, which thrives today. And he helped found the Salk Institute for Biological Studies in La Jolla, CA, where he was a fellow until his death in 1964.
In 1955, just a week before Einstein died, he signed a manifesto with British philosopher and peace activist Bertrand Russell, calling on scientists worldwide to renounce work on weapons of mass destruction. This manifesto led, in 1957, to the creation of the Pugwash Conferences on Science and World Affairs, a movement of scientists who meet privately to seek arms control and disarmament – then encourage their participants to speak directly to their countries’ leaders and policymakers. Szilard was a founding member, and through his Pugwash contacts managed to arrange a private meeting in New York in 1960 with Soviet premier Nikita Khrushchev, at which he agreed to the proposed Moscow-Washington Hotline.
The Pugwash Conferences received the 1995 Nobel Peace Prize for their arms-control efforts, and the movement today includes Student Pugwash chapters on campuses throughout the world. There was a chapter here, encouraging young people to probe the reasons for scientific advancement and the implications of technology on the everyday lives of citizens. So, in a way, the spirits of both Einstein and Szilard were kept alive here in town — an inspiration for the next generation of scientists.
WILLIAM LANOUETTE is the author of Genius in the Shadows: A Biography of Leo Szilard, The Man Behind the Bomb. His research for that book led him to interview many illustrious Princetonians. His book—and his talk tonight—reveal the enduring friendship of Einstein and Szilard, especially through their many interactions here in town.
Bill has had a professional career as both a writer and a policy analyst specializing in the interplay between science and politics—most notably, the history of nuclear weapons and nuclear power.
His doctoral thesis at the London School of Economics studied the use and abuse of scientific information by American and British legislators. From 1991 to 2006, he was Senior Analyst for energy and science issues at the U.S. Government Accountability Office, the investigative agency of Congress.
Before GAO, he was a reporter for Newsweek, a writer for The National Observer (a Dow-Jones weekly newspaper) and for National Journal. He has been Washington Correspondent for The Bulletin of the Atomic Scientists, and has written freelance articles for The Atlantic Monthly, The Economist, The New York Herald Tribune, Scientific American, Smithsonian, and The Washington Post. firstname.lastname@example.org