# Trinity, 16 July 1945: The First Atomic Bomb Test > What happened at the Trinity test? Explore the Manhattan Project’s first nuclear explosion, the people behind it, and the difference between a successful test and its human consequences. Canonical URL: https://aristotree.com/sam_r84/trinity-16-july-1945-the-first-atomic-bomb-test Language: en Creator: sam_r84 Last modified: 2026-10-08T11:16:05.541Z Concepts: 15 Relationships: 29 This is a public, user-curated knowledge graph. Follow the cited sources when verifying claims. ## Concepts ### Hanford Site Hanford produced plutonium for the Manhattan Project. Plutonium produced at Hanford was used in the Fat Man bomb. Topics: history Sources: - https://en.wikipedia.org/wiki/Hanford_Site - https://en.wikipedia.org/wiki/Hanford_Site?action=history - https://creativecommons.org/licenses/by-sa/4.0/ - https://www.energy.gov/lm/trinity-site-worlds-first-nuclear-explosion ### McDonald Ranch House The Trinity device’s nuclear components were assembled at the McDonald Ranch House near the test site. The Manhattan Project used the ranch house during preparations for Trinity. Topics: history Sources: - https://en.wikipedia.org/wiki/McDonald_Ranch_House - https://en.wikipedia.org/wiki/McDonald_Ranch_House?action=history - https://creativecommons.org/licenses/by-sa/4.0/ - https://www.energy.gov/lm/trinity-site-worlds-first-nuclear-explosion ### Donald Hornig Hornig worked on instrumentation for the Trinity test directed by Bainbridge. Hornig was a Los Alamos scientist during the Manhattan Project. Topics: history Sources: - https://en.wikipedia.org/wiki/Donald_Hornig - https://en.wikipedia.org/wiki/Donald_Hornig?action=history - https://creativecommons.org/licenses/by-sa/4.0/ - https://www.energy.gov/lm/trinity-site-worlds-first-nuclear-explosion ### George Kistiakowsky Kistiakowsky led explosives research at Los Alamos during development of the Trinity device. Kistiakowsky worked under Oppenheimer’s scientific leadership in the Manhattan Project. Topics: history Sources: - https://en.wikipedia.org/wiki/George_Kistiakowsky - https://en.wikipedia.org/wiki/George_Kistiakowsky?action=history - https://creativecommons.org/licenses/by-sa/4.0/ - https://www.energy.gov/lm/trinity-site-worlds-first-nuclear-explosion ### Norris Bradbury Bradbury worked at Los Alamos and supervised the final assembly of the Trinity device. Bradbury succeeded Oppenheimer as director of Los Alamos after the war. Topics: history Sources: - https://en.wikipedia.org/wiki/Norris_Bradbury - https://en.wikipedia.org/wiki/Norris_Bradbury?action=history - https://creativecommons.org/licenses/by-sa/4.0/ - https://www.energy.gov/lm/trinity-site-worlds-first-nuclear-explosion ### Project Y The Los Alamos Laboratory, also known as Project Y, was a secret scientific laboratory established by the Manhattan Project and overseen by the University of California during World War II. It was operated in partnership with the United States Army. Topics: history, historical episode Sources: - https://en.wikipedia.org/wiki/Project_Y - https://en.wikipedia.org/wiki/Project_Y?action=history - https://creativecommons.org/licenses/by-sa/4.0/ ### Fat Man "Fat Man" was the design of the nuclear weapon the United States used for seven of the first eight nuclear weapons ever detonated in history. It is also the most powerful design to ever be used in warfare. Topics: history, historical episode Sources: - https://en.wikipedia.org/wiki/Fat_Man - https://en.wikipedia.org/wiki/Fat_Man?action=history - https://creativecommons.org/licenses/by-sa/4.0/ ### J. Robert Oppenheimer J. Robert Oppenheimer was an American theoretical physicist who served as the director of the Manhattan Project's Los Alamos Laboratory during World War II. Topics: history, historical episode Sources: - https://en.wikipedia.org/wiki/J._Robert_Oppenheimer - https://en.wikipedia.org/wiki/J._Robert_Oppenheimer?action=history - https://creativecommons.org/licenses/by-sa/4.0/ ### Kenneth Bainbridge Kenneth Tompkins Bainbridge was an American physicist at Harvard University who worked on cyclotron research. His accurate measurements of mass differences between nuclear isotopes allowed him to confirm Albert Einstein's mass–energy equivalence concept. Topics: history, historical episode Sources: - https://en.wikipedia.org/wiki/Kenneth_Bainbridge - https://en.wikipedia.org/wiki/Kenneth_Bainbridge?action=history - https://creativecommons.org/licenses/by-sa/4.0/ ### Trinitite Trinitite, also known as atomsite or Alamogordo glass, is the glassy residue left on the desert floor after the plutonium-based Trinity nuclear bomb test on July 16, 1945, near Alamogordo, New Mexico. Topics: history, historical episode Sources: - https://en.wikipedia.org/wiki/Trinitite - https://en.wikipedia.org/wiki/Trinitite?action=history - https://creativecommons.org/licenses/by-sa/4.0/ ### Leslie Groves Leslie Richard Groves Jr. Topics: history, historical episode Sources: - https://en.wikipedia.org/wiki/Leslie_Groves - https://en.wikipedia.org/wiki/Leslie_Groves?action=history - https://creativecommons.org/licenses/by-sa/4.0/ ### Manhattan Project The Manhattan Project was a research and development program undertaken during World War II to produce the first nuclear weapons. It was led by the United States in collaboration with the United Kingdom and Canada. Topics: history, historical episode Sources: - https://en.wikipedia.org/wiki/Manhattan_Project - https://en.wikipedia.org/wiki/Manhattan_Project?action=history - https://creativecommons.org/licenses/by-sa/4.0/ ### Enrico Fermi Enrico Fermi was an Italian and naturalized-American physicist, renowned for being the creator of the world's first artificial nuclear reactor, Chicago Pile-1, and a member of the Manhattan Project. Topics: history, historical episode Sources: - https://en.wikipedia.org/wiki/Enrico_Fermi - https://en.wikipedia.org/wiki/Enrico_Fermi?action=history - https://creativecommons.org/licenses/by-sa/4.0/ ### Downwinders Downwinders were individuals and communities, in the United States, in the intermountain West between the Cascade and Rocky Mountain ranges primarily in Arizona, Nevada, New Mexico, and Utah but also in Oregon, Washington, and Idaho who were exposed to radioactive contamination or nuclear fallout from Topics: history, historical episode Sources: - https://en.wikipedia.org/wiki/Downwinders - https://en.wikipedia.org/wiki/Downwinders?action=history - https://creativecommons.org/licenses/by-sa/4.0/ ### Trinity, 16 July 1945: The First Atomic Bomb Test What happened at the Trinity test? Explore the Manhattan Project’s first nuclear explosion, the people behind it, and the difference between a successful test and its human consequences. Topics: history, historical episode Sources: - https://en.wikipedia.org/wiki/Trinity_(nuclear_test) - https://en.wikipedia.org/wiki/Trinity_(nuclear_test)?action=history - https://creativecommons.org/licenses/by-sa/4.0/ - https://www.energy.gov/lm/trinity-site-worlds-first-nuclear-explosion ## Relationships - Norris Bradbury — related_to → McDonald Ranch House: Assembly at the ranch house - Hanford Site — related_to → Fat Man: Supplied plutonium for Fat Man - Hanford Site — related_to → Manhattan Project: Produced project plutonium - McDonald Ranch House — related_to → Manhattan Project: Manhattan Project test facility - McDonald Ranch House — related_to → Trinity, 16 July 1945: The First Atomic Bomb Test: Assembly site for the test - Donald Hornig — related_to → Project Y: Los Alamos scientist - Donald Hornig — related_to → Kenneth Bainbridge: Worked on test instrumentation - George Kistiakowsky — related_to → J. Robert Oppenheimer: Scientific leadership colleague - George Kistiakowsky — related_to → Project Y: Led explosives research - Norris Bradbury — related_to → J. Robert Oppenheimer: Succeeded Oppenheimer - Norris Bradbury — related_to → Project Y: Led device assembly work - Manhattan Project — related_to → Downwinders: Test exposed nearby communities - Kenneth Bainbridge — related_to → Trinitite: Test produced this glass - Leslie Groves — related_to → J. Robert Oppenheimer: Oversaw scientific director - Project Y — related_to → Manhattan Project: Project research laboratory - Enrico Fermi — related_to → Manhattan Project: Contributed to the project - Project Y — related_to → Fat Man: Developed plutonium design - Kenneth Bainbridge — related_to → J. Robert Oppenheimer: Worked under scientific director - Leslie Groves — related_to → Manhattan Project: Led the military project - J. Robert Oppenheimer — related_to → Project Y: Directed the laboratory - Trinity, 16 July 1945: The First Atomic Bomb Test — related_to → Downwinders: Communities exposed to fallout - Trinity, 16 July 1945: The First Atomic Bomb Test — related_to → Trinitite: Glass formed at test site - Trinity, 16 July 1945: The First Atomic Bomb Test — related_to → Fat Man: Used a related design - Trinity, 16 July 1945: The First Atomic Bomb Test — related_to → Enrico Fermi: Observed the explosion - Trinity, 16 July 1945: The First Atomic Bomb Test — related_to → Project Y: Designed the device - Trinity, 16 July 1945: The First Atomic Bomb Test — related_to → Manhattan Project: Organized bomb development - Trinity, 16 July 1945: The First Atomic Bomb Test — related_to → Kenneth Bainbridge: Directed the test - Trinity, 16 July 1945: The First Atomic Bomb Test — related_to → Leslie Groves: Military project leader - Trinity, 16 July 1945: The First Atomic Bomb Test — related_to → J. Robert Oppenheimer: Scientific director