Manhattan Project: People > Scientists > Robert Serber

ROBERT SERBER

(Physicist, Los Alamos Theoretical Division)
People > Scientists

Robert Serber was born on March 14, 1909, in Philadelphia, into a relatively comfortable Jewish family. On the advice of his uncle who was chief engineer at the Atlantic Refining Company, he enrolled in 1926 at Lehigh University in Bethlehem, Pennsylvania, and majored in engineering physics. He decided to pursue graduate education in 1930 and earned a position at the University of Wisconsin at Madison, working with physicist and future Nobel Prize winner John Van Vleck. Here he trained as a theoretical physicist. He married Charlotte Leof, the youngest daughter of a left-leaning, politically active Philadelphia family, a year before taking his Ph.D. in 1934. He was awarded a National Research Council postdoctoral fellowship, which, on the advice of Van Vleck, he decided to do with Eugene Wigner at Princeton University. On his way to Princeton, however, he attended a conference at the University of Michigan and heard a lecture by Robert Oppenheimer. So impressed was he by the youthful professor, only five years his senior, that Serber decided to go to the University of California at Berkeley to study with the group of young physicists gathered around Oppenheimer. In the following years, Oppenheimer became Serber's mentor a nd close personal and professional friend. In 1936, Serber became Oppenheimer's chief research assistant. In 1938, he was offered an assistant professorship at the University of Illinois at Urbana. His initial inclination was to stay at Berkeley with Oppenheimer, but the physicist and future Nobel Prize winner Isadore I. Rabi persuaded him that real jobs for Jewish students were rare and that he should "cut the umbilical cord" to Oppenheimer. The student and his mentor, nonetheless, remained in close contact, corresponding weekly.

In December 1941, a few weeks after the attack on Pearl Harbor, Oppenheimer drove down from Chicago to Urbana and recruited Serber to leave his academic post at Illinois and return to Berkeley to commence work on the bomb project as a theoretical physicist. The Serbers arrived back at Berkeley in April 1942, taking up residence in a spare room above Oppenheimer's garage. By late spring 1942, Oppenheimer was coordinating weapon theory and fast neutron research for the bomb project. In May, he wrote Ernest Lawrence that with "three experienced men" it would be possible to solve the theoretical problems of building a bomb. His short list of experienced theorists included Serber, along with Van Vleck, Edward Teller, and Hans Bethe. Oppenheimer assembled a group of theoreticians to review the status of the program, first for two days in June in Chicago at the Met Lab, and then for a more extended period at Berkeley in July. Serber presented calculations indicating that a gun-type device was feasible, and the group concluded that there were no major gaps in theory. As Serber would later note,

By summer things were pretty well in hand. The uncertainties were in the experimental figures, the cross sections, the number of neutrons per fission and whatnot. But they didn't seem large enough to make a difference between failure and success. They might determine whether the bomb would be a little bigger or a little smaller.

Serber remained in Berkeley after the July 1942 conference, continuing his bomb project research working out of Oppenheimer's office. Serber later noted that during this period he and Oppenheimer "were the Los Alamos project so far as theory was concerned." When Oppenheimer was tasked to be the director of the new weapons laboratory at Los Alamos, Serber assisted as part of the initial planning group setting up the lab, first at Berkeley and then after mid-March 1943 at the site itself. One of the first tasks was a series of lectures to indoctrinate the incoming scientific personnel. The talks, delivered in five days in early April by Serber, whose particular strength was to synthesize vast amounts of information and articulate it to others, reviewed comprehensively the nuclear physcs background and the current state of knowledge on the atomic bomb. Notes from Serber's lectures became a classic text on the basic technical issues facing Manhattan Project scientists. The text would be typed up as The Los Alamos Primer and passed out to new recruits.

At Los Alamos, Serber worked under Bethe in the Theoretical Division (T Division) and headed group T-2 studying the gun-type device and neutron diffusion, the way neutrons would distribute themselves in a critical mass. He developed a mathematical method with Robert Wilson, called the Serber-Wilson method, that was the primary means for performing criticality calculations for the bomb. Oppenheimer appointed Charlotte Serber as head of the Library Division. She was the only female division leader at the lab. Security personnel, based on investigations primarily of Charlotte's family, recommended in 1943 that both Serbers be removed from the bomb project, but the recommendations were not implemented.

After the Trinity test in July 1945, Serber went to Tinian Island in the Pacific as a member of the team that would assemble the weapons to be dropped on Japan. He was designated as the operator of the Fastax camera on the observer plane to record the blast for the Nagasaki drop. While gathering his gear in the dark from the supply tent, however, he picked up by mistake an extra life raft instead of a parachute. As the plane was at the end of the runway ready to take off, the pilot called for a parachute check. Since Serber did not have one, he was put off the plane, even though his camera was the only reason for the flight. After the Japanese surrender, Serber was a member of the initial team sent to Hiroshima and Nagasaki to measure radiation damage and the physical effects of the bomb.

After the war, Serber returned to Berkeley where Oppenheimer unsuccessfully sought a position for him in the Physics Department. Instead, Serber joined Lawrence's Radiation Laboratory as head of the Theoretical Division working on particle physics and building accelerators. He often substituted for Oppenheimer teaching his classes when he was away, however, and in May 1947, when Oppenheimer left Berkeley and went to Princeton, Serber fully took over his teaching duties. He was involved in weapons work intermittently. He returned to Los Alamos only once for a three-day secret conference on the hydrogen bomb (the Super) in 1946. Security issues continued to plague the Serbers. Charlotte was denied a clearance at the Radiation Laboratory in 1946 where she sought a position as librarian. Robert in August 1948 faced a Personnel Security Board hearing into his "character, associations and loyalty." He retained his clearance, but, as he later wrote, he "found the experience humiliating and frightening, and resented having been put through it." In 1951, he took a position at Columbia University where Rabi was and not far from Oppenheimer at Princeton. Serber would remain at Columbia for the rest of his career. He also spent one day a week and some summers over a twenty-year period at the Brookhaven National Laboratory on Long Island researching various topics. In addition, he served as consultant and advisor to Argonne National Laboratory, the Fermi National Accelerator Laboratory, and the Stanford Linear Accelerator Laboratory. Serber died in 1997.

Sources and notes for this page

The text for this page is original to the Department of Energy's Office of History and Heritage Resources. Major sources consulted include the following. Richard G. Hewlett and Oscar E. Anderson, Jr., The New World, 1939-1946: Volume I, A History of the United States Atomic Energy Commission (Washington: U.S. Atomic Energy Commission, 1972), 104, 232, 235, 242, 321; Lillian Hoddeson et al., Critical Assembly: A Technical History of Los Alamos During the Oppenheimer Years, 1943-1945 (New York: Cambridge University Press, 1993), 42-45, 54-56, 68-75, 157, 179, 246, 344-45, 397; Robert P. Crease, Robert Serber, 1909-1997: A Biographical Memoir (Washington: National Academy of Sciences, 2008), 3-12, 14-16, "cut the umbilical cord" quote p. 9, "found the experience…" quote p. 14; "were the Los Alamos Project…" quote in Serber obituary, New York Times, June 2, 1997; Interview of Robert Serber by Charles Weiner and Gloria Lubkin on February 10, 1967, Niels Bohr Library & Archives, American Institute of Physics (AIP), College Park, Maryland; Interview of Robert Serber by Anne Fitzpatrick on November 26, 1996, Niels Bohr Library & Archives, AIP, College Park, Maryland; "The Los Alamos Primer," LA-1. no date, declassified December 19, 1963; Robert Serber, The Los Alamos Primer: The First Lectures on How to Build An Atomic Bomb, annotated by Robert Serber, ed. Richard Rhodes (Berkeley: University of California Press, 1992), xxiii-xxxiii, "By summer things…" quote p. xxx. See also, Serber's published memoirs with Robert P. Crease, Peace and War: Reminisces of a Life on the Frontiers of Science (New York: Columbia University Press, 1998. The Los Alamos security badge photo is courtesy of the Los Alamos National Laboratory. Both the pictures of Serber with Luis Alvarez, Robert Oppenheimer and Willy Fowler and the shot of Serber at the blackboard appear courtesy Lawrence Berkeley National Laboratory. The Los Alamos Primer was converted into a PDF by Los Alamos National Laboratory.