Oppenheimer is a movie devoted to two related stories – how, under the scientific direction of Robert Oppenheimer the US produced an atom bomb in time to be used against Japan at in the Second World War, and how after that achievement Oppenheimer, by now the Director of the Institute for Advanced Studies in Princeton had his security clearance revoked and was removed from advising the US government on nuclear weapons work.
Australian (and British) viewers will benefit from knowing about the role which Mark Oliphant (then in Birmingham) played behind the scenes in getting the atomic project going.
The movie was exciting and kept you on the edge of your seat. One expects that movies distort or omit historical or scientific facts, in the effort to produce a good spectacle and a good story. As I was enjoying the story, and the spectacle, I found myself becoming more and more annoyed by these distortions and omissions.
The critical fact which was omitted was that the determination that an atomic bomb could be constructed in a small enough package to be delivered by air was made in Britain, and that information was provided to the US early in 1941, but initially the US did not act on it. Mark Oliphant late in 1941, forcefully reminded the US of those discoveries and work started. Without the British action it is unlikely that the atomic bomb would have been available before the Allied invasion of Japan.
The distortion which I found irritating was the prominence given to the 1939 work of Oppenheimer, with his PhD student H. Snyder on black holes. This paper had no impact on the work on the production of the atom bomb. Perhaps it was introduced into the movie to provide an excuse for the endless and irrelevant images of stars and galaxies. Artistic licence – yes, but very annoying to me.
When the process of nuclear fission was discovered in 1938 in Germany and elucidated and explained in Europe and the US in 1939, the possibility of a nuclear fission bomb was obvious to many physicists. It was not immediately apparent what the dimensions of such a bomb would be, whether it could be readily delivered by air or not. The famous 1941 letter (composed by Szilard) from Einstein to President Roosevelt was not able to hint at the answer, and the Uranium Commission set up by the President to investigate concentrated its activity on the possible use of nuclear reactors to power submarines.
Oliphant’s heroic efforts are generally felt to be the “catalyst” that finally pushed the American bomb effort over the top
The breakthrough was made by Rudolf Peierls and Otto Frisch, two Jewish refugees working at the Department of Physics at the University of Birmingham. Mark Oliphant, the Head of the Physics Department had arranged jobs for them. Oliphant had a large group working on radar. That work was secret and Peierls and Frisch, being German aliens were not allowed to join the secret war work. Instead, they worked together on the calculation of how large a Uranium bomb would be, and what effects it would have. Peierls hand typed the now famous Peierls Frisch Memorandum and handed it to Oliphant. The now unclassified memorandum is available from several sources, one of which points out they make an error and instead of their estimate that 600 gram of uranium 235 would make a bomb, the correct estimate is 18 Kg.
Oliphant passed the memorandum to those responsible for considering the likely use of Uranium in the war, and the MAUD committee was set up to verify and work through the implications of the Peierls Frisch memorandum. The report is now unclassified and is available here. They recognised that the Atomic Bomb was feasible with Uranium in which the Uranium 235 isotope was enriched, but that the resources required for program were far beyond what the British could afford. Although the US was not yet in the war, the report of the MAUD committee was shared with the US early in 1941, but no response had been received.
Oliphant flew to the United States in late August 1941 in an unheated bomber to ostensibly consult about the radar program but was actually charged with inquiring why the United States was ignoring the MAUD Committee’s findings. Oliphant stated the following: “The minutes and reports had been sent to Lyman Briggs (Director of the Uranium Committee) and we were puzzled to receive virtually no comment. I called on Briggs in Washington, only to find out that this inarticulate and unimpressive man had put the reports in his safe and had not shown them to members of his committee. I was amazed and distressed.”
Histories differ on the extent to which Oliphant’s intervention speeded up the production of the Bomb, and whether or not it would have been ready to use before the invasion of Japan
Oliphant then met with the Uranium Committee. Samuel K. Allison was a new committee member, a talented experimentalist and a protégé of Arthur Compton at the University of Chicago. Oliphant “came to a meeting,” Allison recalls, “and said ‘bomb’ in no uncertain terms. He told us we must concentrate every effort on the bomb and said we had no right to work on power plants or anything but the bomb. The bomb would cost 25 million dollars, he said, and Britain didn’t have the money or the manpower, so it was up to us.” Allison was surprised that Briggs had kept the committee in the dark.
To further champion his cause, Oliphant contacted Ernest O. Lawrence at the University of California at Berkeley. After visiting with Lawrence and receiving his support, Oliphant visited with both James B. Conant and Vannevar Bush and then went to see Enrico Fermi before returning to Birmingham, England.
Oliphant’s heroic efforts are generally felt to be the “catalyst” that finally pushed the American bomb effort over the top.
As described in Wizards of Oz {Bret Mason 2022, New South Publishing, Sydney ISBN 9781742237459}, the visit to Lawrence, who had been a colleague of Oliphant at Cambridge was prompted by Oliphant’s frustration with the lack of action by the Uranium Committee and the apparent lack of understanding by Conant and Bush that a bomb was possible. Note that the visits were not in the order described in the official US history quoted above. Oliphant was not authorised to visit Lawrence, who did not have the necessary security clearance, but Oliphant flew to Berkeley. Oliphant described the work of the Maud Committee in detail, persuading Lawrence that the atomic bomb could and must be built, by the US. Oppenheimer joined them during the conversation. Oliphant wrote detailed letters to both Oppenheimer and Lawrence. All were concerned about the lack of action in the US and the need for speed because the basic physics behind the atom bomb had been developed before the war in Germany.
Histories differ on the extent to which Oliphant’s intervention speeded up the production of the Bomb, and whether or not it would have been ready to use before the invasion of Japan. In general US histories suggest that, although speeded up it was not enough to change the outcome of the war, and British histories suggest that it was critical. The October 1945 issue of Reviews of Modern Physics contains the US and British histories, work it out for yourself. Groves said that “without active and continuing British interest there would probably been no atomic bomb to drop on Hiroshima” but downplayed their scientific input. As the US repeated the British scientific work and developed the plutonium bomb in spite of that route being put on the shelf by the MAUD committee, that can be understood. Left open is the question of when it would have been started without the British input, and Oliphant’s push.
“If Congress knew the true history of the atomic energy project, I have no doubt that it would create a special medal to be given to meddling foreigners for distinguished services, and Dr. [Mark] Oliphant would be the first to receive one.” – Leo Szilard; speaking after the war and referring to Britain’s “manipulation” of America’s government officials to put the bomb effort on a “fast track.” From the US Nuclear Museum of Science and History.
The US Congress did establish such a medal, the Medal of Freedom, and it was received by Peierls and Frisch in 1947, but not Oliphant. He was to be the only meddling foreigner to be awarded the Medal of Freedom with Gold Palm, but he had been described as an “Australian Citizen” and the award was referred to the Australian Government for approval, which had decided that such awards should not be awarded to civilians and did not approve. In 1947 there were no Australian Citizens. Australians were a British Subjects. Had he been correctly described he would have received the medal. [Wizards of Oz p 322]
Australian and British viewers of the movie Oppenheimer should be aware British Science and Mark Oliphant’s personal persuasion made a vital part in the timely production of atomic bomb in 1945.
[Part of the text was adapted from the U.S. Department of Energy’s official Manhattan Project history: F. G. Gosling, The Manhattan Project: Making the Atomic Bomb (DOE/MA-0001; Washington: History Division, Department of Energy, January 1999), 9.].