David Bohm

David Bohm
Born	(1917-12-20)December 20, 1917 Wilkes-Barre, Pennsylvania, United States
Died	October 27, 1992(1992-10-27) (aged 74) London, England
Citizenship	American Brazilian British
Fields	Physics (theoretical)
Institutions	Manhattan Project Princeton University University of São Paulo Technion University of Bristol Birkbeck College, London
Alma mater	Pennsylvania State College California Institute of Technology University of California, Berkeley
Doctoral advisor	Robert Oppenheimer
Doctoral students	Y. Aharonov D. Pines J. Bub H. Bortoft M. Weinstein
Known for	Bohm-diffusion Bohm interpretation De Broglie–Bohm theory Hidden variable theory Bohm quantum potential Aharonov–Bohm effect Einstein–Podolsky–Rosen– Bohm paradox Holographic paradigm Holomovement Holonomic brain theory Bohm dialogue Bohm criterion Nonradiation condition Pilot wave Implicate and explicate order Random phase approximation Quantum decoherence Quantum mind
Influences	Albert Einstein Jiddu Krishnamurti
Influenced	John Stewart Bell
Notable awards	1991  Elliott Cresson Medal 1990  Royal Society fellowship

David Joseph Bohm FRS^[1] (December 20, 1917 – October 27, 1992) was an American scientist who has been described as one of the most significant theoretical physicists of the 20th century^[2] and who contributed innovative and unorthodox ideas to quantum theory, neuropsychology and the philosophy of mind.

Bohm advanced the view that quantum physics meant the old Cartesian model of reality – that there are two kinds of substance, the mental and the physical, that somehow interact – was too limited. To complement it, therefore, he developed a mathematical and physical theory of "implicate" and "explicate" order.^[3] He also believed that the working of the brain, at the cellular level, obeyed the mathematics of some quantum effects, and postulated that thought was distributed and non-localised in the way that quantum entities do not readily fit into our conventional model of space and time.^[4]

Bohm warned of the dangers of rampant reason and technology, advocating instead the need for genuine supportive dialogue which he claimed could broaden and unify conflicting and troublesome divisions in the social world. In this his epistemology mirrored his ontological viewpoint.^[5] Due to his youthful Communist affiliations, Bohm was targeted during the McCarthy era, prompting him to leave the United States. He pursued his scientific career in several countries, becoming first a Brazilian and then a British citizen.

His main concern has been with understanding the nature of reality in general and of consciousness in particular as a coherent whole, which according to Bohm is never static or complete but which is an unending process of movement and unfoldment.^[6]

Biography

Youth and college

Bohm was born in Wilkes-Barre, Pennsylvania, United States, to a Hungarian Jewish immigrant father Samuel Bohm^[7] and a Lithuanian Jewish mother. He was raised mainly by his father, a furniture-store owner and assistant of the local rabbi. Despite being raised in a Jewish family, he became an agnostic in his teenage years.^[8] Bohm attended Pennsylvania State College (now Pennsylvania State University), graduating in 1939, then the California Institute of Technology for a year. He then transferred to the theoretical physics group directed by Robert Oppenheimer at the University of California, Berkeley, where he obtained his doctorate.

Bohm lived in the same neighborhood as some of Oppenheimer's other graduate students (Giovanni Rossi Lomanitz, Joseph Weinberg, and Max Friedman) and with them became increasingly involved not only with physics, but with radical politics. Bohm became active in Communist and Communist-backed organizations including the Young Communist League, the Campus Committee to Fight Conscription, and the Committee for Peace Mobilization.

Work and doctorate

Manhattan Project contributions

During World War II, the Manhattan Project mobilized much of Berkeley's physics research in the effort to produce the first atomic bomb. Though Oppenheimer had asked Bohm to work with him at Los Alamos (the top-secret laboratory established in 1942 to design the atom bomb), the director of the Manhattan Project, General Leslie Groves, would not approve Bohm's security clearance, after evidence about his politics (Bohm's friend, Joseph Weinberg, had also been suspected of espionage).

Bohm remained in Berkeley, teaching physics, until he completed his Ph.D. in 1943, by an unusual circumstance. According to Peat (see reference below, p. 64), "the scattering calculations (of collisions of protons and deuterons) that he had completed proved useful to the Manhattan Project and were immediately classified. Without security clearance, Bohm was denied access to his own work; not only would he be barred from defending his thesis, he was not even allowed to write his own thesis in the first place!" To satisfy the university, Oppenheimer certified that Bohm had successfully completed the research. He later performed theoretical calculations for the Calutrons at the Y-12 facility in Oak Ridge, used to electromagnetically enrich uranium for use in the bomb dropped on Hiroshima in 1945.

McCarthyism and leaving the United States

After the war, Bohm became an assistant professor at Princeton University, where he worked closely with Albert Einstein. In May, 1949, the House Un-American Activities Committee called upon Bohm to testify before it— because of his previous ties to suspected Communists. Bohm, however, pleaded the Fifth amendment right to refuse to testify, and refused to give evidence against his colleagues.

In 1950, Bohm was charged for refusing to answer questions of the Committee and was arrested. He was acquitted in May, 1951, but Princeton University had already suspended him. After the acquittal, Bohm's colleagues sought to have him re-instated to Princeton, and Einstein reportedly wanted Bohm to serve as his assistant. The university did not renew his contract. His request to go to Manchester found support with Einstein, but was unsuccessful.^[9] Bohm then left for Brazil to assume a professorship of physics at the University of São Paulo at the invitation of Jayme Tiomno, and by recommendation of Einstein and Oppenheimer.

Quantum theory and Bohm-diffusion

The Bohmian trajectories for an electron going through the two-slit experiment. The similar pattern was also observed for single photons.^[10]

During his early period, Bohm made a number of significant contributions to physics, particularly to quantum mechanics and relativity theory. As a post-graduate at Berkeley, he developed a theory of plasmas, discovering the electron phenomenon known now as Bohm-diffusion.^[11] His first book, Quantum Theory published in 1951, was well received by Einstein, among others. However, Bohm became dissatisfied with the orthodox interpretation of quantum theory, which he had written about in that book. Starting from the realization that the WKB approximation of quantum mechanics leads to deterministic equations and convinced that a mere approximation could not turn a probabilistic theory into a deterministic theory, he doubted the inevitability of the conventional approach to quantum mechanics.^[12]

Bohm's aim was not to set out a deterministic, mechanical viewpoint, but rather to show that it was possible to attribute properties to an underlying reality, in contrast to the conventional approach.^[13] He began to develop his own interpretation (De Broglie–Bohm theory), the predictions of which agree perfectly with the nondeterministic quantum theory. He initially referred to his approach as a hidden variable theory, but later referred to it as ontological theory, reflecting his view that a stochastic process that would underlie the phenomena described by his theory may be found. Bohm and his colleague Basil Hiley later stated that they found their own choice of terms of an "interpretation in terms of hidden variables" to be too restrictive, in particular as their variables, position and momentum, "are not actually hidden".^[14]

Bohm's work and the EPR argument became the major factor motivating John Bell's inequality, which rules out local hidden variable theories; the full consequences of Bell's work are still being investigated.

Brazil

After his arrival in Brazil on October 10, 1951, the U.S. Consul in São Paulo had confiscated his passport, informing him he could retrieve it only to return to his country. This reportedly frightened Bohm,^[15] and significantly lowered his spirits, as he had hoped to travel to Europe. He applied for and received Brazilian citizenship, but due to then-Brazilian law he had to give up his U.S. citizenship and could retrieve it only decades later, in 1986, after pursuing a lawsuit.^[16]

At the University of São Paulo, Bohm worked on the causal theory that became the object of his publications in 1952. Jean-Pierre Vigier traveled to São Paulo, where he worked with Bohm for three months; Ralph Schiller (a student of cosmologist Peter Bergmann) was his assistant for two years; he worked with Tiomno and Walther Schützer; and Mario Bunge stayed to work with him for one year. He was in contact with Brazilian physicists Mário Schönberg, Jean Meyer, Leite Lopes, and had discussions on occasions with visitors to Brazil, including Richard Feynman, Isidor Rabi, Léon Rosenfeld, Carl Friedrich von Weizsäcker, Herbert Anderson, Donald Kerst, Marcos Moshinsky, Alejandro Medina, and the former assistant to Heisenberg, Guido Beck, who encouraged him in his work and helped him to obtain funding. The Brazilian CNPq explicitly supported his work on the causal theory and funded several researchers around Bohm. His work with Vigier was the beginning of a long-standing cooperation between the two and Louis De Broglie, in particular, on connections to the hydrodynamics model proposed by Madelung.^[17] Yet the causal theory met much resistance and skepticism, with many physicists holding the Copenhagen interpretation to be the only viable approach to quantum mechanics.^[16]

Bohm and Aharonov form of the EPR paradox

In 1955, Bohm relocated to Israel, where he spent two years working at the Technion at Haifa. Here he met Sarah ("Saral") Woolfson. The couple married in 1956.

In 1957, Bohm and his student Yakir Aharonov published a new version of the Einstein–Podolsky–Rosen (EPR) paradox, reformulating the original argument in terms of spin.^[18] It was this form of the EPR paradox that was discussed by John Stuart Bell in his famous paper of 1964.^[19]

Aharonov–Bohm effect

Schematic of double-slit experiment in which Aharonov–Bohm effect can be observed: electrons pass through two slits, interfering at an observation screen, with the interference pattern shifted when a magnetic field B is turned on in the cylindrical solenoid.

In 1957, Bohm relocated to the United Kingdom as a research fellow at the University of Bristol. In 1959, Bohm and Aharonov discovered the Aharonov–Bohm effect, showing how a magnetic field could affect a region of space in which the field had been shielded, although its vector potential did not vanish there. This showed for the first time that the magnetic vector potential, hitherto a mathematical convenience, could have real physical (quantum) effects. In 1961, Bohm was made Professor of Theoretical Physics at the University of London's Birkbeck College, where his collected papers are kept.

Implicate and explicate order

At Birkbeck College, much of the work of Bohm and Basil Hiley expanded on the notion of implicate, explicate and generative orders proposed by Bohm.^[3][20][21] In the view of Bohm and Hiley, "things, such as particles, objects, and indeed subjects" exist as "semi-autonomous quasi-local features" of an underlying activity. These features can be considered to be independent only up to a certain level of approximation in which certain criteria are fulfilled. In this picture, the classical limit for quantum phenomena, in terms of a condition that the action function is not much greater than Planck's constant, indicates one such criterion. They used the word "holomovement" for the activity in such orders.^[22]

Holonomic model of the brain

In a holographic reconstruction, each region of a photographic plate contains the whole image

In collaboration with Stanford neuroscientist Karl Pribram, Bohm was involved in the early development of the holonomic model of the functioning of the brain, a model for human cognition that is drastically different from conventionally accepted ideas.^[4] Bohm worked with Pribram on the theory that the brain operates in a manner similar to a hologram, in accordance with quantum mathematical principles and the characteristics of wave patterns.^[23]

Thought as a System

Bohm was alarmed by what he considered an increasing imbalance of not only man and nature, but among peoples, as well as within people, themselves. Bohm mused: "So one begins to wonder what is going to happen to the human race. Technology keeps on advancing with greater and greater power, either for good or for destruction." He goes on to ask:

What is the source of all this trouble? I'm saying that the source is basically in thought. Many people would think that such a statement is crazy, because thought is the one thing we have with which to solve our problems. That's part of our tradition. Yet it looks as if the thing we use to solve our problems with is the source of our problems. It's like going to the doctor and having him make you ill. In fact, in 20% of medical cases we do apparently have that going on. But in the case of thought, it's far over 20%.

In Bohm's view:

...the general tacit assumption in thought is that it's just telling you the way things are and that it's not doing anything – that 'you' are inside there, deciding what to do with the info. But you don't decide what to do with the info. Thought runs you. Thought, however, gives false info that you are running it, that you are the one who controls thought. Whereas actually thought is the one which controls each one of us.

Thought is creating divisions out of itself and then saying that they are there naturally. This is another major feature of thought: Thought doesn't know it is doing something and then it struggles against what it is doing. It doesn't want to know that it is doing it. And thought struggles against the results, trying to avoid those unpleasant results while keeping on with that way of thinking. That is what I call "sustained incoherence".

Bohm thus proposes in his book Thought as a System a pervasive, systematic nature of thought:

What I mean by "thought" is the whole thing – thought, felt, the body, the whole society sharing thoughts – it's all one process. It is essential for me not to break that up, because it's all one process; somebody else's thoughts become my thoughts, and vice versa. Therefore it would be wrong and misleading to break it up into my thoughts, your thoughts, my feelings, these feelings, those feelings... I would say that thought makes what is often called in modern language a system. A system means a set of connected things or parts. But the way people commonly use the word nowadays it means something all of whose parts are mutually interdependent – not only for their mutual action, but for their meaning and for their existence. A corporation is organized as a system – it has this department, that department, that department. They don't have any meaning separately; they only can function together. And also the body is a system. Society is a system in some sense. And so on.

Similarly, thought is a system. That system not only includes thoughts, "felts" and feelings, but it includes the state of the body; it includes the whole of society – as thought is passing back and forth between people in a process by which thought evolved from ancient times. A system is constantly engaged in a process of development, change, evolution and structure changes...although there are certain features of the system which become relatively fixed. We call this the structure.... Thought has been constantly evolving and we can't say when that structure began. But with the growth of civilization it has developed a great deal. It was probably very simple thought before civilization, and now it has become very complex and ramified and has much more incoherence than before.

Now, I say that this system has a fault in it – a "systematic fault". It is not a fault here, there or here, but it is a fault that is all throughout the system. Can you picture that? It is everywhere and nowhere. You may say "I see a problem here, so I will bring my thoughts to bear on this problem". But "my" thought is part of the system. It has the same fault as the fault I'm trying to look at, or a similar fault.

Thought is constantly creating problems that way and then trying to solve them. But as it tries to solve them it makes it worse because it doesn’t notice that it's creating them, and the more it thinks, the more problems it creates. (pp. 18–19)

Bohm views physical processes as determined by information of more and more subtle levels which interact, and does not limit this consideration to matter alone. In an article of 1990, A new theory of the relationship of mind and matter, he resumes his view that there exists a close link to mental processes: "the whole notion of active information suggests a rudimentary mind-like behaviour of matter". In his view, mental processes as well can be understood as representing levels of activity of increasing subtlety which act upon each other. He recalls that thought is intricately connected with physical reactions, as is known from everyday experience. Yet on the mental side, action as response to information need not be immediate; rather, in some cases at least, it can be mediated by "suspension" of physical action and the resulting train of thought.^[24]

Bohm suggests that the mental and the physical sides, which he sees as two "poles" of a unified whole, are closely interlinked and that "at each level, information is the bridge or link between the two sides". A relationship between the mental and matter may exist at indefinitely great levels of subtlety, while nonetheless each kind and level of mind may have a relative autonomy and stability. His article concludes with the statement that "knowledge of matter (as well as of mind) has changed in such a way as to support the approach that has been described here. To pursue this approach further might perhaps enable us to extend our knowledge of both poles into new domains".^[24]

Belief in the paranormal

Bohm held many beliefs in the paranormal. Martin Gardner gave an overview of these beliefs in the Skeptical Inquirer:

Bohm's creative work in physics is undisputable (sic), but in other fields he was almost as gullible as Conan Doyle. He was favorably impressed by Count Alfred Korzybski's Science and Sanity, with the morphogenic fields of Rupert Sheldrake, the orgone energy of Wilhelm Reich, and the marvels of parapsychology. For a while he took seriously Uri Geller's ability to bend keys and spoons, to move compasses, and produce clicks in a Geiger counter, all with his mind.^[25]

Bohm carried with him a key bent by Uri Geller as if it were a holy relic. When the key later disappeared, Bohm took this to be Geller's psychokinetic powers at work from a distance. When the key was found an hour later, he believed this to be another paranormal event! Bohm's close associate Basil Hiley at once recognized Geller as a charlatan. He often warned Bohm that if he appeared to endorse Geller it would damage their work. Bohm agreed to back away from Geller. As Hiley said to Peat, Bohm often had to be saved from idiots.^[25]

Gardner also mentions Bohm's belief in panpsychism, of which Bohm said "Even the electron is informed with a certain level of mind".^[26]

Bohm dialogue

To address societal problems during his later years, Bohm wrote a proposal for a solution that has become known as "Bohm Dialogue", in which equal status and "free space" form the most important prerequisites of communication and the appreciation of differing personal beliefs. An essential ingredient to this form of dialogue is that participants "suspend" immediate action or judgment and that they give themselves and each other the opportunity to become aware of the thought process itself. Bohm suggested that if these "dialogue groups" were experienced on a sufficiently wide scale, they could help overcome the isolation and fragmentation which Bohm observed was currently present in society.

Later years

Bohm continued his work in quantum physics past his retirement in 1987. His final work, the posthumously published The Undivided Universe: An Ontological Interpretation of Quantum Theory (1993), resulted from a decades-long collaboration with his colleague Basil Hiley. He also spoke to audiences across Europe and North America on the importance of dialogue as a form of sociotherapy, a concept he borrowed from London psychiatrist and practitioner of Group Analysis Patrick De Mare, and had a series of meetings with the Dalai Lama. He was elected Fellow of the Royal Society in 1990.^[1]

Near the end of his life, Bohm began to experience a recurrence of depression which he had suffered at earlier times in his life. He was admitted to the Maudsley Hospital in South London on 10 May 1991. His condition worsened and it was decided that the only treatment that might help him was electroconvulsive therapy. Bohm's wife consulted psychiatrist David Shainberg, Bohm's long-time friend and collaborator, who agreed that electroconvulsive treatments were probably his only option. Bohm showed improvement from the treatments and was released on 29 August. However, his depression returned and was treated with medication.^[27]

Bohm died after suffering a heart attack in Hendon, London, on 27 October 1992, aged 74. He had been traveling in a London taxicab on that day; after getting no response from the passenger in the back seat for a few seconds, the driver turned back and found that Bohm had collapsed.^[27]

Publications

• 1951. Quantum Theory, New York: Prentice Hall. 1989 reprint, New York: Dover, ISBN 0-486-65969-0
• 1957. Causality and Chance in Modern Physics, 1961 Harper edition reprinted in 1980 by Philadelphia: U of Pennsylvania Press, ISBN 0-8122-1002-6
• 1962. Quanta and Reality, A Symposium, with N. R. Hanson and Mary B. Hesse, from a BBC program published by the American Research Council
• 1965. The Special Theory of Relativity, New York: W.A. Benjamin.
• 1980. Wholeness and the Implicate Order, London: Routledge, ISBN 0-7100-0971-2, 1983 Ark paperback: ISBN 0-7448-0000-5, 2002 paperback: ISBN 0-415-28979-3
• 1985. Unfolding Meaning: A weekend of dialogue with David Bohm (Donald Factor, editor), Gloucestershire: Foundation House, ISBN 0-948325-00-3, 1987 Ark paperback: ISBN 0-7448-0064-1, 1996 Routledge paperback: ISBN 0-415-13638-5
• 1985. The Ending of Time, with Jiddu Krishnamurti, San Francisco: Harper, ISBN 0-06-064796-5.
• 1987. Science, Order, and Creativity, with F. David Peat. London: Routledge. 2nd ed. 2000. ISBN 0-415-17182-2.
• 1989. Meaning And Information, In: P. Pylkkänen (ed.): The Search for Meaning: The New Spirit in Science and Philosophy, Crucible, The Aquarian Press, 1989, ISBN 978-1-85274-061-0.
• 1991. Changing Consciousness: Exploring the Hidden Source of the Social, Political and Environmental Crises Facing our World (a dialogue of words and images), coauthor Mark Edwards, Harper San Francisco, ISBN 0-06-250072-4
• 1992. Thought as a System (transcript of seminar held in Ojai, California, from 30 November to 2 December 1990), London: Routledge. ISBN 0-415-11980-4.
• 1993. The Undivided Universe: An ontological interpretation of quantum theory, with B.J. Hiley, London: Routledge, ISBN 0-415-12185-X (final work)
• 1996. On Dialogue. editor Lee Nichol. London: Routledge, hardcover: ISBN 0-415-14911-8, paperback: ISBN 0-415-14912-6, 2004 edition: ISBN 0-415-33641-4
• 1998. On Creativity, editor Lee Nichol. London: Routledge, hardcover: ISBN 0-415-17395-7, paperback: ISBN 0-415-17396-5, 2004 edition: ISBN 0-415-33640-6
• 1999. Limits of Thought: Discussions, with Jiddu Krishnamurti, London: Routledge, ISBN 0-415-19398-2.
• 1999. Bohm-Biederman Correspondence: Creativity and Science, with Charles Biederman. editor Paavo Pylkkänen. ISBN 0-415-16225-4.
• 2002. The Essential David Bohm. editor Lee Nichol. London: Routledge, ISBN 0-415-26174-0. preface by the Dalai Lama

See also

• American philosophy
• Bohm sheath criterion
• List of American philosophers
• Orchestrated objective reduction
• Karl H. Pribram
• Quantum mind#David Bohm
• Quantum mysticism
• Random phase approximation
• The Holographic Universe

Notes

References

• "Bohm's Alternative to Quantum Mechanics", David Z. Albert, Scientific American (May, 1994)
• Brotherhood of the Bomb: The Tangled Lives and Loyalties of Robert Oppenheimer, Ernest Lawrence, and Edward Teller, Herken, Gregg, New York: Henry Holt (2002) ISBN 0-8050-6589-X (information on Bohm's work at Berkeley and his dealings with HUAC)
• Infinite Potential: the Life and Times of David Bohm, F. David Peat, Reading, Massachusetts: Addison Wesley (1997), ISBN 0-201-40635-7 DavidPeat.com
• Quantum Implications: Essays in Honour of David Bohm, (B.J. Hiley, F. David Peat, editors), London: Routledge (1987), ISBN 0-415-06960-2
• Thought as a System (transcript of seminar held in Ojai, California, from 30 November to 2 December 1990), London: Routledge. (1992) ISBN 0-415-11980-4.
• The Quantum Theory of Motion: an account of the de Broglie-Bohm Causal Interpretation of Quantum Mechanics, Peter R. Holland, Cambridge: Cambridge University Press. (2000) ISBN 0-521-48543-6.

Further reading

• William Keepin: A life of dialogue between science and spirit – David Bohm. In World Scriptures: Leland P. Stewart (ed.): Guidelines for a Unity-and-Diversity Global Civilization, World Scriptures Vol. 2, AuthorHouse, 2009, ISBN 978-1-4389-8086-7, pp. 5–13
• William Keepin: Lifework of David Bohm. River of Truth, Re-vision, vol. 16, no. 1, 1993, p. 32 (online at scribd)

External links

Wikiquote has quotations related to: David Bohm

• The David Bohm Society
• The Bohm Krishnamurti Project: Exploring the Legacy of the David Bohm and Jiddu Krishnamurti Relationship
• David Bohm's ideas about Dialogue
• the David_Bohm_Hub. Includes compilations of David Bohm's life and work in form of texts, audio, video, and pictures
• Thought Knowledge Perception Institute A non-partisan organization that aims to preserve and continue the work of David Bohm and others
• Lifework of David Bohm: River of Truth: Article by Will Keepin (PDF-version)
• Interview with David Bohm provided and conducted by F. David Peat along with John Briggs, first issued in Omni magazine, January 1987
• Archive of papers at Birkbeck College relating to David Bohm and David Bohm at the National Archives
• David Bohm at the Mathematics Genealogy Project
• Oral History interview transcript with David Bohm 8 May 1981, American Institute of Physics, Niels Bohr Library and Archives

Manhattan Project Timeline Sites Clinton Engineer Works Dayton Project Hanford Engineer Works Los Alamos National Laboratory Berkeley Radiation Laboratory Montreal Laboratory Inyokern Trinity Test Site Wendover Heavy water sites Administrators Vannevar Bush Arthur Compton James Conant Thomas Farrell Leslie Groves John Lansdale, Jr. Ernest Lawrence James Marshall Franklin Matthias Kenneth Nichols Robert Oppenheimer Deak Parsons William Purnell Paul Tibbets Charles Thomas Harold Urey Stafford L. Warren Roscoe Wilson Scientists Luis Alvarez Robert Bacher Hans Bethe Niels Bohr Norris Bradbury James Chadwick Charles Critchfield Enrico Fermi Richard Feynman Klaus Fuchs Maria Goeppert-Mayer George Kistiakowsky George Koval Mark Oliphant Norman Ramsey Bruno Rossi Glenn Seaborg Emilio Segrè Louis Slotin Henry DeWolf Smyth Edward Teller Stanisław Ulam Robert Wilson Leona Woods Operations Alsos Mission Bombings of Hiroshima and Nagasaki Project Alberta Operation Crossroads Operation Peppermint Silverplate 509th Composite Group Enola Gay Bockscar The Great Artiste Weapons Fat Man Little Boy Pumpkin bomb Thin Man Related topics Ames process Armed Forces Special Weapons Project Atomic Energy Act of 1946 British contribution Einstein–Szilárd letter Interim Committee Oppenheimer security hearing Plutonium RaLa Experiment S-1 Uranium Committee Smyth Report Uranium Manhattan Project