Trinity (nuclear test)
Trinity was the code name of the first detonation of a nuclear weapon, conducted by the United States Army at 5:29 a.m. MWT[a] (11:29:21 GMT) on July 16, 1945, as part of the Manhattan Project. The test was of an implosion-design plutonium bomb, nicknamed the "gadget", of the same design as the Fat Man bomb later detonated over Nagasaki, Japan, on August 9, 1945. Concerns about whether the complex Fat Man design would work led to a decision to conduct the first nuclear test. The code name "Trinity" was assigned by J. Robert Oppenheimer, the director of the Los Alamos Laboratory, inspired by the poetry of John Donne.
Trinity
United States
Trinity Site, New Mexico
July 16, 1945
25 kilotons of TNT (100 TJ)
36,480 acres (14,760 ha)
1945
July 16, 1945
October 15, 1966
December 21, 1965[2]
December 20, 1968
The test, both planned and directed by Kenneth Bainbridge, was conducted in the Jornada del Muerto desert about 35 miles (56 km) southeast of Socorro, New Mexico, on what was the Alamogordo Bombing and Gunnery Range (renamed the White Sands Proving Ground just before the test). The only structures originally in the immediate vicinity were the McDonald Ranch House and its ancillary buildings, which scientists used as a laboratory for testing bomb components.
Fears of a fizzle prompted construction of "Jumbo", a steel containment vessel that could contain the plutonium, allowing it to be recovered; but ultimately Jumbo was not used in the test. On May 7, 1945, a rehearsal was conducted, during which 108 short tons (98 t) of high explosive spiked with radioactive isotopes was detonated.
Some 425 people were present on the weekend of the Trinity test. Observers included Vannevar Bush, James Chadwick, James B. Conant, Thomas Farrell, Enrico Fermi, Hans Bethe, Richard Feynman, Isidor Isaac Rabi, Leslie Groves, Robert Oppenheimer, Frank Oppenheimer, Geoffrey Taylor, Richard Tolman, Edward Teller, and John von Neumann.
The Trinity bomb released the explosive energy of 25 kilotons of TNT (100 TJ) ± 2 kilotons of TNT (8.4 TJ), and a large cloud of fallout.
Thousands of people lived closer to the test than would have been allowed under guidelines adopted for subsequent tests, but no one living near the test was evacuated before or afterward.
The test site was declared a National Historic Landmark district in 1965, and listed on the National Register of Historic Places the following year.
Ground zero after the test
The Trinity explosion, 25 ms after detonation. The viewed fireball hemisphere's highest point in this image is about 200 metres (660 ft) high.
![An aerial photograph of the Trinity crater shortly after the test.[f]](http://upload.wikimedia.org/wikipedia/commons/thumb/0/01/Trinity_crater_%28annotated%29_2.jpg/385px-Trinity_crater_%28annotated%29_2.jpg)
Site today[edit]
In September 1953, about 650 people attended the first Trinity Site open house. Visitors to a Trinity Site open house are allowed to see the ground zero and McDonald Ranch House areas.[155] More than seventy years after the test, residual radiation at the site was about ten times higher than normal background radiation in the area. The amount of radioactive exposure received during a one-hour visit to the site is about half of the total radiation exposure which a U.S. adult receives on an average day from natural and medical sources.[156]
On December 21, 1965, the 51,500-acre (20,800 ha) Trinity Site was declared a National Historic Landmark district,[157][2] and on October 15, 1966, was listed on the National Register of Historic Places.[1] The landmark includes the base camp where the scientists and support group lived, ground zero where the bomb was placed for the explosion, and the McDonald ranch house, where the plutonium core to the bomb was assembled. One of the old instrumentation bunkers is visible beside the road just west of ground zero.[158] An inner oblong fence was added in 1967, and the corridor barbed wire fence that connects the outer fence to the inner one was completed in 1972.[159]
The Trinity monument, a rough-sided, lava-rock obelisk about 12 feet (3.7 m) high, marks the explosion's hypocenter.[155] It was erected in 1965 by Army personnel using local rocks taken from the western boundary of the range.[160]
A special tour of the site on July 16, 1995 (marking the 50th anniversary of the Trinity test) attracted 5,000 visitors.[161] Since then, the site has been open to the public on the first Saturdays of April and October.[162][163]
Visitors to the Trinity site in 1995 for the 50th anniversary
Trinity Site Historical Marker, 2008
Remnants of Jumbo, 2010
Closeup of plaque on obelisk, 2018
Sign warning against removal of trinitite, 2018
People gather around Ground Zero monument, 2018
Post World War II Fat Man casing
In popular culture[edit]
The Trinity test has been portrayed in various forms of media, including documentary films and dramatizations. In 1946, an 18-minute documentary titled Atomic Power was produced by Time Inc. under The March of Time banner and released theatrically. It featured many people involved with the project, including J. Robert Oppenheimer and Ernest Lawrence, as actors in recreations of real discussions and events that led up to the Trinity test.[164]: 291–296 In 1947, a docudrama titled The Beginning or the End chronicled the development of nuclear weapons and portrayed the Trinity test.[165][166]
In 1980, a television drama miniseries titled Oppenheimer, a co-production between the British Broadcasting Corporation and the American television station WGBH-TV, aired for seven episodes on BBC Two. The Trinity test is depicted in its fifth episode.[167] In early 1981, a documentary titled The Day After Trinity was released, focusing closely on the events of the Trinity test.[168]
In 1989, a feature film titled Fat Man and Little Boy depicted the Trinity test.[169] Two documentaries, Trinity and Beyond and The Bomb, were released in 1995 and 2015 respectively.[170][171]
The 2023 Christopher Nolan-directed blockbuster Oppenheimer prominently portrayed the Trinity test. Nolan cited the film's depiction of the test firing as one of its most important scenes, calling it "the fulcrum that the whole story turns on." Nolan avoided using computer-generated imagery for the re-enactment of the explosion, instead using practical effects.[172] The popularity of the film brought newfound attention to previous media depictions of the Trinity test, such as the 1981 documentary The Day After Trinity.[168]