J. Robert Oppenheimer

J. Robert Oppenheimer (1904-1967) was an American theoretical physicist[3][2] who is often called the "father of the atomic bomb" for leading the Manhattan Project, the program that developed the first nuclear weapon during World War II[7]. Born Julius Robert Oppenheimer on April 22, 1904, in New York City[5], he became one of the most influential and controversial figures in 20th-century science and politics.

Early Life and Education

Oppenheimer grew up in a Manhattan apartment adorned with paintings by van Gogh, Cézanne, and Gauguin. His father, Julius Oppenheimer, was a German immigrant who worked in his family's textile importing business. His mother, Ella Friedman, was a painter whose family had been in New York for generations[5]. Oppenheimer's family was part of the Ethical Culture Society, an outgrowth of American Reform Judaism founded and led at the time by Dr. Felix Adler. The progressive society placed an emphasis on social justice, civic responsibility, and secular humanism[2].

Dr. Adler also founded the Ethical Culture School, where Oppenheimer enrolled in September 1911. His academic prowess was apparent very early on, and by the age of 10, Oppenheimer was studying minerals, physics, and chemistry[2]. His correspondence with the New York Mineralogical Club was so advanced that the Society invited him to deliver a lecture—not realizing that Robert was a twelve-year-old boy[2]. He graduated as valedictorian of his high school class in 1921, but fell ill with a near-fatal case of dysentery and was forced to postpone enrolling at Harvard[2].

At Harvard, Oppenheimer studied mathematics and science, philosophy and Eastern religion, and French and English literature. He was admitted to graduate standing in physics in his first year as an undergraduate on the basis of independent study[5]. He graduated summa cum laude in 1925 and went to England to conduct research at Cambridge University's Cavendish Laboratory, working under J.J. Thomson[8]. In 1926, Oppenheimer went to the University of Göttingen to study under Max Born, obtaining his Ph.D. at the age of 22[8].

Academic Career

There, he published many important contributions to the then newly developed quantum theory, most notably a famous paper on the so-called Born-Oppenheimer approximation, which separates nuclear motion from electronic motion in the mathematical treatment of molecules[8]. He accepted an assistant professorship in physics at the University of California, Berkeley, and maintained a joint appointment with California Institute of Technology. In the ensuing 13 years, he "commuted" between the two universities, and many of his associates and students commuted with him[8].

Oppenheimer became credited with being a founding father of the American school of theoretical physics. He did important research in astrophysics, nuclear physics, spectroscopy and quantum field theory. He made important contributions to the theory of cosmic ray showers, and did work that eventually led toward descriptions of quantum tunneling. In the 1930s, he was the first to write papers suggesting the existence of what we today call black holes[8].

Manhattan Project Leadership

In the spring of 1941, the Roosevelt Administration received a British report on atomic bombs, prompting them to create the S-1 Committee of military and academic personnel to focus on an atomic bomb building project. Robert Oppenheimer was made S-1's "Coordinator of Rapid Rupture" to direct fast-neutron research[4]. Oppenheimer organized a secret seminar of theoretical physicists to make the basic outline for atomic bomb design. Participant Hans Bethe said, "I could see the tremendous intellectual power of Oppenheimer who was the unquestioned leader of the group."[4]

In August 1942 the U.S. Army was given the responsibility of organizing the efforts of British and U.S. physicists to seek a way to harness nuclear energy for military purposes, an effort that became known as the Manhattan Project. Oppenheimer was instructed to establish and administer a laboratory to carry out this assignment[1]. General Leslie R. Groves asked J. Robert Oppenheimer to head Project Y, planned to be the new central laboratory for weapon physics research and design. Vannevar Bush approves Oppenheimer's appointment in meeting with Oppenheimer and General Groves[2].

General Groves and Oppenheimer visit the Los Alamos, NM mesa in New Mexico and select it for "Site Y."[2] Oppenheimer, Groves, and Berkeley physicist Edwin McMillian inspected Jemez Springs, New Mexico, as a potential site for the laboratory but rejected the location in a deep canyon. Groves asked Oppenheimer if there was somewhere else in the area appropriate for the secret laboratory. Oppenheimer suggested the Los Alamos Ranch School[4].

Oppenheimer led the scientific end of the Manhattan Project in Los Alamos, New Mexico, beginning in 1942. The project, which grew from a few hundred people to more than 6,000 by 1945, was populated by many scientists who had escaped fascist regimes in Europe[7]. Their mission was to explore a newly documented fission process involving uranium-235, with which they hoped to make a nuclear bomb before Adolf Hitler could develop one. The project was initially allotted $6,000 by the U.S. government, but by the time the work culminated in 1945, the budget had grown to $2 billion[7].

Trinity Test

J. Robert Oppenheimer, Director of the Los Alamos Laboratory during the Manhattan Project, called the site "Trinity." The Trinity name stuck and became the site's official code name. It was a reference to a poem by John Donne, a writer cherished by Oppenheimer as well as his former lover Jean Tatlock[11].

The Trinity test was the detonation of the first atomic bomb, a plutonium implosion device called Gadget, at 5:29:45 am on July 16, 1945, at the Alamogordo air base in New Mexico[16]. Emitting as much energy as 21,000 tons of TNT and creating a fireball that measured roughly 2,000 feet in diameter, the first successful test of an atomic bomb, known as the Trinity Test, forever changed the history of the world[14].

J. Robert Oppenheimer (in 1965): "We knew the world would not be the same. A few people laughed, a few people cried, most people were silent. I remembered the line from the Hindu scripture, the Bhagavad-Gita. Vishnu is trying to persuade the Prince that he should do his duty and to impress him takes on his multi-armed form and says, 'Now, I am become Death, the destroyer of worlds.' I suppose we all felt that one way or another."[17]

Post-War Activities and Opposition to Hydrogen Bomb

In a speech before leaving Project Y he warned of the dangers of wars fought with atomic bombs, which he called "a most terrible weapon." In October 1945, Oppenheimer met with President Truman to advocate for international control of atomic weapons but aggravated Truman. Truman later described Oppenheimer as a "cry-baby scientist."[4]

After the war, Oppenheimer was appointed Chairman of the General Advisory Committee to the Atomic Energy Commission (AEC), serving from 1947 to 1952. It was in this role that he voiced strong opposition to the development of the hydrogen bomb[8]. For another key period of his life, from 1947–66, Oppenheimer served as the Director of the Institute for Advanced Study, which is the longest tenure of any IAS Director thus far[5].

Security Clearance Revocation

J. Robert Oppenheimer security hearing, 1954 government hearing that resulted in the revocation of J. Robert Oppenheimer's security clearance and the end of his tenure as an adviser to the highest echelons of the U.S. government[21]. On December 23, 1953, Maj. Gen. Kenneth Nichols, general manager of the AEC, sent a letter to Oppenheimer detailing charges that he was a security risk. Oppenheimer replied with a 43-page document on March 4, 1954; in it, he formally requested a hearing before the AEC's personnel security board[21].

The panel began hearings on April 12, 1954, and announced its decision on May 27. The three members were unanimous in declaring that Oppenheimer was a loyal citizen of the United States and discreet in the handling of atomic secrets. However, the majority of the board—Gray and Morgan—voted against the reinstatement of Oppenheimer as a consultant to the commission. The majority declared that they found his conduct and associations reflected a serious disregard for the requirements of the security system. They also criticized his lack of enthusiasm for the hydrogen bomb program[21].

The AEC issued its decision and opinions on June 29, 1954, with a vote of 4 to 1 to revoke Oppenheimer's security clearance, citing "fundamental defects of character", and Communist associations "far beyond the tolerable limits of prudence and self-restraint which are to be expected of one holding the high positions" he had held since 1942[24]. With his security clearance revoked, Oppenheimer was cut off from restricted information he needed to continue his work, and his career essentially came to an abrupt halt[23].

Scientific Community Response and Later Years

The results of the hearing provoked outrage within the scientific community. Oppenheimer was seen as a martyr to McCarthyism[22]. Protests over the handling of the Oppenheimer case were lodged with the commission by almost 500 members of the scientific staff of the Los Alamos Laboratory and 214 members of the Argonne National Laboratory. On July 5, 1954, the Federation of American Scientists urged Pres. Dwight D. Eisenhower to appoint a special board to review the security regulations of the federal government[21].

Prior to John F. Kennedy's assassination in 1963, the president announced Oppenheimer would receive the Enrico Fermi Award for his achievements in physics. President Lyndon B. Johnson presented him the award that December[7]. Oppenheimer retired from the Institute in 1966 and died of throat cancer on February 18, 1967[8].

Historical Vindication

Now, almost 70 years later, the United States Department of Energy has reversed the decision, stating the trial was a "flawed process that violated the Commission's own regulations." What's more, a review of the historical evidence shows the 1954 decision was less born out of genuine national security concerns than it was a product of the AEC's disagreement with Oppenheimer on nuclear weapons policy[23]. In 1954, the Atomic Energy Commission revoked Dr. Oppenheimer's security clearance through a flawed process that violated the Commission's own regulations. As time has passed, more evidence has come to light of the bias and unfairness of the process that Dr. Oppenheimer was subjected to while the evidence of his loyalty and love of country have only been further affirmed[27].