J. Robert Oppenheimer

J. Robert Oppenheimer (born Julius Robert Oppenheimer /ˈɒpənhaɪmər/ OP-ən-hy-mər; April 22, 1904 – February 18, 1967) was an American <a href="/facts/Theoretical_physics/Cs2Y12rQ">theoretical physicist</a> who served as the director of the <a href="/facts/Manhattan_Project/gtg8yRK2">Manhattan Project</a>'s <a href="/facts/Los_Alamos_Laboratory/8eL6rj8N">Los Alamos Laboratory</a> during <a href="/facts/World_War_II/2efV5L1U">World War II</a>. He is often called the "father of the <a href="/facts/Atomic_bomb/QVdBcMdm">atomic bomb</a>" for his role in overseeing the development of the first nuclear weapons.
Born in New York City, Oppenheimer obtained a degree in chemistry from <a href="/facts/Harvard_University/Lhy9L1cx">Harvard University</a> in 1925 and a <a href="/facts/Dr._rer._nat./tD7Lw14h">doctorate</a> in physics from the <a href="/facts/University_of_G%25C3%25B6ttingen/UTUodvX1">University of Göttingen</a> in Germany in 1927, studying under <a href="/facts/Max_Born/6VnUDWhA">Max Born</a>. After research at other institutions, he joined the physics faculty at the <a href="/facts/University_of_California%2c_Berkeley/MXVEjklr">University of California, Berkeley</a>, where he was made a full professor in 1936. Oppenheimer made significant contributions to physics in the fields of <a href="/facts/Quantum_mechanics/BRc3Mzgr">quantum mechanics</a> and <a href="/facts/Nuclear_physics/fzQbt1aF">nuclear physics</a>, including the <a href="/facts/Born%25E2%2580%2593Oppenheimer_approximation/hxlUcBrX">Born–Oppenheimer approximation</a> for molecular <a href="/facts/Wave_function/KgM5ykjY">wave functions</a>; work on the theory of <a href="/facts/Positron/HgV4zBzA">positrons</a>, <a href="/facts/Quantum_electrodynamics/zPteAr6G">quantum electrodynamics</a>, and <a href="/facts/Quantum_field_theory/VoewsNJV">quantum field theory</a>; and the <a href="/facts/Oppenheimer%25E2%2580%2593Phillips_process/Im2IDPEN">Oppenheimer–Phillips process</a> in <a href="/facts/Nuclear_fusion/hP0gLDqj">nuclear fusion</a>. With his students, he also made major contributions to <a href="/facts/Astrophysics/krFPRWLA">astrophysics</a>, including the theory of <a href="/facts/Cosmic_ray/uxCVdTKd">cosmic ray</a> showers, and the theory of <a href="/facts/Neutron_star/4enfoxBA">neutron stars</a> and <a href="/facts/Black_hole/1r2lmkcF">black holes</a>.
In 1942, Oppenheimer was recruited to work on the Manhattan Project, and in 1943 was appointed director of the project's Los Alamos Laboratory in <a href="/facts/New_Mexico/wosJCGaW">New Mexico</a>, tasked with developing the first nuclear weapons. His leadership and scientific expertise were instrumental in the project's success, and on July 16, 1945, he was present at the first test of the atomic bomb, <a href="/facts/Trinity_(nuclear_test)/0aHtpyUN">Trinity</a>. In August 1945, the weapons were used on <a href="/facts/Empire_of_Japan/gMpNKg2W">Japan</a> in the <a href="/facts/Atomic_bombings_of_Hiroshima_and_Nagasaki/fRpj8aJA">atomic bombings of Hiroshima and Nagasaki</a>, to date the only uses of nuclear weapons in conflict.
In 1947, Oppenheimer was appointed director of the <a href="/facts/Institute_for_Advanced_Study/jQQCURKt">Institute for Advanced Study</a> in Princeton, New Jersey, and chairman of the General Advisory Committee of the new <a href="/facts/United_States_Atomic_Energy_Commission/7VXrvVJ9">United States Atomic Energy Commission</a> (AEC). He lobbied for international control of <a href="/facts/Nuclear_power/jzSyvxSn">nuclear power</a> and weapons in order to avert <a href="/facts/Nuclear_arms_race/2IabKwkf">an arms race</a> with the <a href="/facts/Soviet_Union/m7wWsPto">Soviet Union</a>, and later opposed the development of the <a href="/facts/Hydrogen_bomb/T9zFe3H0">hydrogen bomb</a>, partly on ethical grounds. During the <a href="/facts/Second_Red_Scare/sv21SjjU">Second Red Scare</a>, his stances, together with his past associations with the <a href="/facts/Communist_Party_USA/HzjqxVkv">Communist Party USA</a>, led to an <a href="/facts/Oppenheimer_security_clearance_hearing/aQw8GpVr">AEC security hearing</a> in 1954 and the revocation of his <a href="/facts/United_States_security_clearance/veKtcudb">security clearance</a>. He continued to lecture, write, and work in physics, and in 1963 received the <a href="/facts/Enrico_Fermi_Award/RduNp6M5">Enrico Fermi Award</a> for contributions to theoretical physics. On December 16, 2022, <a href="/facts/United_States_Secretary_of_Energy/sU3Usc8s">United States secretary of energy</a> <a href="/facts/Jennifer_Granholm/neQhhMQ4">Jennifer Granholm</a> <a href="/facts/Vacated_judgment/RFxjqkYI">vacated</a> the 1954 decision, saying it had been the result of a "flawed process" and affirming that Oppenheimer had been loyal.

J. Robert Oppenheimer open-in-new

J. Robert Oppenheimer