Robert Oppenheimer (left), Leslie Groves (center) and Robert Sproul (right) at the ceremony to present the Los Alamos Laboratory with the Army-Navy "E" Award at the Fuller Lodge on 16 October 1945
The Trinity test of the Manhattan Project on 16 July 1945 was the first detonation of a nuclear weapon.
Stanisław Ulam
In nuclear fission, the atomic nucleus of a heavy element splits into two or more light ones when a neutron is captured. If more neutrons are emitted, a nuclear chain reaction becomes possible.
Enrico Fermi, John R. Dunning, and Dana P. Mitchell in front of the cyclotron in the basement of Pupin Hall at Columbia University
Stanisław Ulam
In nuclear fusion, the nuclei of light elements are fused to create a heavier element.
March 1940 meeting at Berkeley, California: Ernest O. Lawrence, Arthur H. Compton, Vannevar Bush, James B. Conant, Karl T. Compton, and Alfred L. Loomis
The Scottish Café's building now houses the Universal Bank in Lviv, Ukraine.
Map of Los Alamos site, New Mexico, 1943–45
Different fission bomb assembly methods explored during the July 1942 conference
Ulam's ID badge photo from Los Alamos
Four-family apartment units at Los Alamos
Manhattan Project Organization Chart, 1 May 1946
Stan Ulam holding the FERMIAC
The Technical Area at Los Alamos. There was a perimeter fence around the entire site, but also an inner fence shown here around the Technical Area.
Oppenheimer and Groves at the remains of the Trinity test in September 1945, two months after the test blast and just after the end of World War II. The white overshoes prevented fallout from sticking to the soles of their shoes.
Ivy Mike, the first full test of the Teller–Ulam design (a staged fusion bomb), with a yield of 10.4 megatons on 1 November 1952
The main gate at Los Alamos
Groves confers with James Chadwick, the head of the British Mission.
The Sausage device of Mike nuclear test (yield 10.4 Mt) on Enewetak Atoll. The test was part of the Operation Ivy. The Sausage was the first true H-Bomb ever tested, meaning the first thermonuclear device built upon the Teller-Ulam principles of staged radiation implosion.
Passage between buildings A and B in the Technical Area
Shift change at the Y-12 uranium enrichment facility at the Clinton Engineer Works in Oak Ridge, Tennessee, on 11 August 1945. By May 1945, 82,000 people were employed at the Clinton Engineer Works. Photograph by the Manhattan District photographer Ed Westcott.
An artist's conception of the NASA reference design for the Project Orion spacecraft powered by nuclear propulsion
Isidor Isaac Rabi, Dorothy McKibbin, Robert Oppenheimer and Victor Weisskopf at Oppenheimer's home in Los Alamos in 1944
Physicists at a Manhattan District-sponsored colloquium at the Los Alamos Laboratory on the Super in April 1946. In the front row are Norris Bradbury, John Manley, Enrico Fermi and J. (Jerome) M. B. Kellogg (1905-1981). Robert Oppenheimer, in dark coat, is behind Manley; to Oppenheimer's left is Richard Feynman. The Army officer on the left is Colonel Oliver Haywood.
When the positive integers are arrayed along the Ulam spiral, prime numbers, represented by dots, tend to collect along diagonal lines.
A row of Thin Man casings. Fat Man casings are visible in the background. The tow truck was used by the 216th Army Air Forces Base Unit to move them.
Map of Los Alamos site, New Mexico, 1943–45
An animation demonstrating the lucky number sieve. The numbers in red are lucky numbers
A ring of electrorefined plutonium. It has a purity of 99.96%, weighs 5.3 kg, and is about 11 cm in diameter. It is enough plutonium for one bomb core. The ring shape helps with criticality safety.
Hanford workers collect their paychecks at the Western Union office.
Plutonium has six allotropes at ambient pressure: alpha (α), beta (β), gamma (γ), delta (δ), delta prime (δ'), & epsilon (ε)
The majority of the uranium used in the Manhattan Project came from the Shinkolobwe mine in Belgian Congo.
Explosive lenses are used to compress a fissile core inside an implosion-type nuclear weapon.
Oak Ridge hosted several uranium separation technologies. The Y-12 electromagnetic separation plant is in the upper right. The K-25 and K-27 gaseous diffusion plants are in the lower left, near the S-50 thermal diffusion plant. The X-10 was for plutonium production.
An implosion-type nuclear bomb. In the center is the neutron initiator (red). It is surrounded by the plutonium hemispheres. There is a small air gap (white, not in the original Fat Man design) and then the uranium tamper. Around that is the aluminium pusher (purple). This is encased in the explosive lenses (gold). Colors are the same as in the diagram opposite.
Alpha I racetrack at Y-12
Norris Bradbury, group leader for bomb assembly, stands next to the partially assembled Gadget atop the Trinity test tower. Later, he became the director of Los Alamos vice Oppenheimer.
Calutron Girls were young women who monitored calutron control panels at Y-12. Gladys Owens, seated in the foreground, was unaware of what she had been involved in.
A Little Boy unit on Tinian connected to test equipment, possibly to test or charge components within the device
Oak Ridge K-25 plant
Water Boiler
The S-50 plant is the dark building to the upper left behind the Oak Ridge powerhouse (with smoke stacks).
The April 1946 colloquium on the Super. In the front row are (left to right) Norris Bradbury, John Manley, Enrico Fermi and J. M. B. Kellogg. Robert Oppenheimer, in dark coat, is behind Manley; to Oppenheimer's left is Richard Feynman. The Army officer on the left is Colonel Oliver Haywood.
Workers load uranium slugs into the X-10 Graphite Reactor.
Herbert Lehr and Harry Daghlian loading the assembled tamper plug containing the plutonium pit and initiator into a sedan for transport from the McDonald Ranch House to the Trinity shot tower
Aerial view of Hanford B-Reactor site, June 1944
The explosives of "the gadget" were raised to the top of the tower for the final assembly.
Map of the Hanford Site. Railroads flank the plants to the north and south. Reactors are the three northernmost red squares, along the Columbia River. The separation plants are the lower two red squares from the grouping south of the reactors. The bottom red square is the 300 area.
Deak Parsons (right) supervises loading the Little Boy bomb into the B-29 Enola Gay. Norman Ramsey is on his left, with his back to the camera.
A row of Thin Man casings. Fat Man casings are visible in the background.
Fat Man bomb, with liquid asphalt sealant sprayed on the casing's seams, is readied on Tinian.
An implosion-type nuclear bomb
Remote handling of a kilocurie source of radiolanthanum for a RaLa Experiment at Los Alamos
Remote handling of a kilocurie source of radiolanthanum for a RaLa Experiment at Los Alamos
Bradbury (left) examines plans for new laboratory sites and permanent housing with Leslie Groves of the Armed Forces Special Weapons Project (center) and Eric Jette (right) in April 1947; Colonel Lyle E. Seeman stands behind Bradbury, second from the left.
The explosives of "the gadget" were raised to the top of the tower for the final assembly.
The Trinity test of the Manhattan Project was the first detonation of a nuclear weapon.
Major General Leslie R. Groves, Jr., speaks to service personnel Oak Ridge Tennessee in August 1945.
A billboard encouraging secrecy among Oak Ridge workers
Security poster, warning office workers to close drawers and put documents in safes when not being used
Allied soldiers dismantle the German experimental nuclear reactor at Haigerloch.
Silverplate B-29 Straight Flush. The tail code of the 444th Bombardment Group is painted on for security reasons.
Little Boy explodes over Hiroshima, Japan, 6 August 1945 (left);
Fat Man explodes over Nagasaki, Japan, 9 August 1945 (right).
Presentation of the Army–Navy "E" Award at Los Alamos on 16 October 1945. Standing, left to right: J. Robert Oppenheimer, unidentified, unidentified, Kenneth Nichols, Leslie Groves, Robert Gordon Sproul, William Sterling Parsons.
President Harry S. Truman signs the Atomic Energy Act of 1946, establishing the United States Atomic Energy Commission.
The Lake Ontario Ordnance Works (LOOW) near Niagara Falls became a principal repository for Manhattan Project waste for the Eastern United States. All of the radioactive materials stored at the LOOW site—including thorium, uranium, and the world's largest concentration of radium-226—were buried in an "Interim Waste Containment Structure" (in the foreground) in 1991.
A "bomb" (pressure vessel) containing uranium halide and sacrificial metal, probably magnesium, being lowered into a furnace
After the reaction, the interior of a bomb coated with remnant slag
A uranium metal "biscuit" from the reduction reaction

The Los Alamos Laboratory, also known as Project Y, was a secret laboratory established by the Manhattan Project and operated by the University of California during World War II.

- Project Y

He participated in the Manhattan Project, originated the Teller–Ulam design of thermonuclear weapons, discovered the concept of the cellular automaton, invented the Monte Carlo method of computation, and suggested nuclear pulse propulsion.

- Stanislaw Ulam

Nuclear physicist Robert Oppenheimer was the director of the Los Alamos Laboratory that designed the actual bombs.

- Manhattan Project

In October 1943, he received an invitation from Hans Bethe to join the Manhattan Project at the secret Los Alamos Laboratory in New Mexico.

- Stanislaw Ulam

Nonetheless, in February 1944, Teller added Stanislaw Ulam, Jane Roberg, Geoffrey Chew, and Harold and Mary Argo to his T-1 Group.

- Project Y

At the University of Wisconsin–Madison, Stanislaw Ulam gave one of his students, Joan Hinton, an exam early, so she could leave to do war work.

- Manhattan Project
Robert Oppenheimer (left), Leslie Groves (center) and Robert Sproul (right) at the ceremony to present the Los Alamos Laboratory with the Army-Navy "E" Award at the Fuller Lodge on 16 October 1945

6 related topics with Alpha

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Edward Teller

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Hungarian-American theoretical physicist who is known colloquially as "the father of the hydrogen bomb" (see the Teller–Ulam design), although he did not care for the title, considering it to be in poor taste.

Hungarian-American theoretical physicist who is known colloquially as "the father of the hydrogen bomb" (see the Teller–Ulam design), although he did not care for the title, considering it to be in poor taste.

Teller in his youth
Teller's ID badge photo from Los Alamos
Physicists at a Manhattan District-sponsored colloquium at Los Alamos on the Super in April 1946. In the front row are (left to right) Norris Bradbury, John Manley, Enrico Fermi and J. M. B. Kellogg. Robert Oppenheimer, in dark coat, is behind Manley; to Oppenheimer's left is Richard Feynman. The Army officer on the left is Colonel Oliver Haywood.
The Teller–Ulam design kept the fission and fusion fuel physically separated from one another, and used X-rays from the primary device "reflected" off the surrounding casing to compress the secondary.
The 10.4 Mt "Ivy Mike" shot of 1952 appeared to vindicate Teller's long-time advocacy for the hydrogen bomb.
Teller testified about J. Robert Oppenheimer in 1954.
One of the Chariot schemes involved chaining five thermonuclear devices to create the artificial harbor.
Teller became a major lobbying force of the Strategic Defense Initiative to President Ronald Reagan in the 1980s.
Edward Teller in his later years
Appearing on British television discussion After Dark in 1987

Teller was an early member of the Manhattan Project, charged with developing the first atomic bomb.

In early 1943, the Los Alamos Laboratory was established in Los Alamos, New Mexico to design an atomic bomb, with Oppenheimer as its director.

It included Stanislaw Ulam, Jane Roberg, Geoffrey Chew, Harold and Mary Argo, and Maria Goeppert-Mayer.

J. Robert Oppenheimer, c. 1944

J. Robert Oppenheimer

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American theoretical physicist.

American theoretical physicist.

J. Robert Oppenheimer, c. 1944
Heike Kamerlingh Onnes' Laboratory in Leiden, Netherlands, 1926. Oppenheimer is in the middle row, second from the left.
The University of California, Berkeley, where Oppenheimer taught from 1929 to 1943
Physicists Albert Einstein and Oppenheimer conferring circa 1950
Oppenheimer's ID badge from the Los Alamos Laboratory
Presentation of the Army-Navy "E" Award at Los Alamos on October 16, 1945. Oppenheimer (left) gave his farewell speech as director on this occasion. Robert Gordon Sproul right, in suit, accepted the award on behalf of the University of California from Leslie Groves (center).
A group of physicists at the 1946 Los Alamos colloquium on the Super. In the front row are Norris Bradbury, John Manley, Enrico Fermi and J.M.B. Kellogg. Behind Manley is Oppenheimer (wearing jacket and tie), and to his left is Richard Feynman. The army colonel on the far left is Oliver Haywood. In the third row between Haywood and Oppenheimer is Edward Teller.
The Trinity test of the Manhattan Project was the first detonation of a nuclear device.
Oppenheimer's Van Gogh, Enclosed Field with Rising Sun (1889).
Institute for Advanced Study in Princeton, New Jersey
Oppenheimer in 1946 with his trademark cigarette
President Dwight D. Eisenhower receives a report from Lewis L. Strauss, Chairman of the Atomic Energy Commission, on the Operation Castle hydrogen bomb tests in the Pacific, March 30, 1954. Strauss pressed for Oppenheimer's security clearance to be revoked.
Oppenheimer's former colleague, physicist Edward Teller, testified on behalf of the government at Oppenheimer's security hearing in 1954.
Oppenheimer Beach, in Saint John, U.S. Virgin Islands
Award of honorary degrees at Harvard to Oppenheimer (left), George C. Marshall (third from left) and Omar N. Bradley (fifth from left). The President of Harvard University, James B. Conant, sits between Marshall and Bradley. June 5, 1947
Oppenheimer and Leslie Groves in September 1945 at the remains of the Trinity test in New Mexico. The white canvas overshoes prevented fallout from sticking to the soles of their shoes.
J. Robert Oppenheimer giving a speech during a 1966 visit to Israel

A professor of physics at the University of California, Berkeley, Oppenheimer was the wartime head of the Los Alamos Laboratory and is often credited as the "father of the atomic bomb" for his role in the Manhattan Project – the World War II undertaking that developed the first nuclear weapons.

In 1951, Edward Teller and mathematician Stanislaw Ulam developed what became known as the Teller-Ulam design for a hydrogen bomb.

Fermi in 1943

Enrico Fermi

3 links

Italian (later naturalized American) physicist and the creator of the world's first nuclear reactor, the Chicago Pile-1.

Italian (later naturalized American) physicist and the creator of the world's first nuclear reactor, the Chicago Pile-1.

Fermi in 1943
Fermi was born in Rome at Via Gaeta 19.
Plaque at Fermi's birthplace
Enrico Fermi as a student in Pisa
A light cone is a three-dimensional surface of all possible light rays arriving at and departing from a point in spacetime. Here, it is depicted with one spatial dimension suppressed. The timeline is the vertical axis.
Fermi and his research group (the Via Panisperna boys) in the courtyard of Rome University's Physics Institute in Via Panisperna, c. undefined 1934. From left to right: Oscar D'Agostino, Emilio Segrè, Edoardo Amaldi, Franco Rasetti and Fermi
Enrico Fermi between Franco Rasetti (left) and Emilio Segrè in academic dress
Beta decay. A neutron decays into a proton, and an electron is emitted. In order for the total energy in the system to remain the same, Pauli and Fermi postulated that a neutrino (\bar{\nu}_e) was also emitted.
Diagram of Chicago Pile-1, the first nuclear reactor to achieve a self-sustaining chain reaction. Designed by Fermi, it consisted of uranium and uranium oxide in a cubic lattice embedded in graphite.
Fermi's ID photo from Los Alamos
Ernest O. Lawrence, Fermi, and Isidor Isaac Rabi
The FERMIAC, an analog computer invented by Fermi to study neutron transport
Laura and Enrico Fermi at the Institute for Nuclear Studies, Los Alamos, 1954
Fermi's grave in Chicago
The sign at Enrico Fermi Street in Rome
Memorial plaque in the Basilica Santa Croce, Florence. Italy

He emigrated to the United States, where he worked on the Manhattan Project during World War II.

At Los Alamos, he headed F Division, part of which worked on Edward Teller's thermonuclear "Super" bomb.

Along with Stanislaw Ulam, he calculated that not only would the amount of tritium needed for Teller's model of a thermonuclear weapon be prohibitive, but a fusion reaction could still not be assured to propagate even with this large quantity of tritium.

John von Neumann in the 1940s

John von Neumann

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Hungarian-American mathematician, physicist, computer scientist, engineer and polymath.

Hungarian-American mathematician, physicist, computer scientist, engineer and polymath.

John von Neumann in the 1940s
Von Neumann's birthplace, at 16 Báthory Street, Budapest. Since 1968, it has housed the John von Neumann Computer Society.
Excerpt from the university calendars for 1928 and 1928/29 of the Friedrich-Wilhelms-Universität Berlin announcing Neumann's lectures on the theory of functions II, axiomatic set theory and mathematical logic, the mathematical colloquium, review of recent work in quantum mechanics, special functions of mathematical physics and Hilbert's proof theory. He also lectured on the theory of relativity, set theory, integral equations and analysis of infinitely many variables.
Von Neumann's gravestone
History of approaches that led to NBG set theory
Flow chart from von Neumann's "Planning and coding of problems for an electronic computing instrument," published in 1947.
The first implementation of von Neumann's self-reproducing universal constructor. Three generations of machine are shown: the second has nearly finished constructing the third. The lines running to the right are the tapes of genetic instructions, which are copied along with the body of the machines.
A simple configuration in von Neumann's cellular automaton. A binary signal is passed repeatedly around the blue wire loop, using excited and quiescent ordinary transmission states. A confluent cell duplicates the signal onto a length of red wire consisting of special transmission states. The signal passes down this wire and constructs a new cell at the end. This particular signal (1011) codes for an east-directed special transmission state, thus extending the red wire by one cell each time. During construction, the new cell passes through several sensitised states, directed by the binary sequence.
Von Neumann's wartime Los Alamos ID badge photo
Implosion mechanism
Operation Redwing nuclear test in July 1956
The von Neumann crater, on the far side of the Moon.

During World War II, von Neumann worked on the Manhattan Project with theoretical physicist Edward Teller, mathematician Stanislaw Ulam and others, problem-solving key steps in the nuclear physics involved in thermonuclear reactions and the hydrogen bomb.

The involvement included frequent trips by train to the project's secret research facilities at the Los Alamos Laboratory in a remote part of New Mexico.

The first nuclear explosive devices, cumbersome and inefficient, provided the basic design building blocks of all future weapons. Pictured is the Gadget device being prepared for the first nuclear test, Trinity.

Nuclear weapon design

2 links

A fourth type, pure fusion weapons, are a theoretical possibility.

A fourth type, pure fusion weapons, are a theoretical possibility.

The first nuclear explosive devices, cumbersome and inefficient, provided the basic design building blocks of all future weapons. Pictured is the Gadget device being prepared for the first nuclear test, Trinity.
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Diagram of a gun-type fission weapon
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Flash X-Ray images of the converging shock waves formed during a test of the high explosive lens system.
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Ivy Mike, the first two-stage thermonuclear detonation, 10.4 megatons, November 1, 1952.
Bassoon, the prototype for a 9.3-megaton clean bomb or a 25-megaton dirty bomb. Dirty version shown here, before its 1956 test. The two attachments on the left are light pipes; see below for elaboration.
centre
Subsidence Craters at Yucca Flat, Nevada Test Site.
A diagram of the Green Grass warhead's steel ball safety device, shown left, filled (safe) and right, empty (live). The steel balls were emptied into a hopper underneath the aircraft before flight, and could be re-inserted using a funnel by rotating the bomb on its trolley and raising the hopper.

The series of RaLa Experiment tests of implosion-type fission weapon design concepts, carried out from July 1944 through February 1945 at the Los Alamos Laboratory and a remote site 14.3 km (9 miles) east of it in Bayo Canyon, proved the practicality of the implosion design for a fission device, with the February 1945 tests positively determining its usability for the final Trinity/Fat Man plutonium implosion design.

The design breakthrough came in January 1951, when Edward Teller and Stanislaw Ulam invented radiation implosion – for nearly three decades known publicly only as the Teller-Ulam H-bomb secret.

The Y-12 plant in Oak Ridge, Tennessee, where mass spectrometers called calutrons had enriched uranium for the Manhattan Project, was redesigned to make secondaries.

David Hawkins' Los Alamos ID badge

David Hawkins (philosopher)

0 links

Professor whose interests included the philosophy of science, mathematics, economics, childhood science education, and ethics.

Professor whose interests included the philosophy of science, mathematics, economics, childhood science education, and ethics.

David Hawkins' Los Alamos ID badge

He was also an administrative assistant at the Manhattan Project's Los Alamos Laboratory and later one of its official historians.

Hawkins saw his role as that of a go-between, mediating between the civilian scientists and the military leadership at Los Alamos, but he also found a kindred spirit in the Polish mathematician Stan Ulam, who was working in Edward Teller's "Super" Group.