The Making of the Atomic Bomb

One of the 20th century’s premier physics intellects, perhaps second only to Einstein, Bohr was large and athletic but also unassuming and soft spoken. He discovered the basic structure of atomic electron orbits and developed the idea of complementarity, whereby subatomic items can be treated simultaneously as particles and waves. Bohr established a physics institute in Denmark, where he helped advance physics and assisted many young scientists with their careers. During World War II, Bohr worked with the Swedish government to help thousands of Danish Jews escape to Sweden. Bohr was deeply concerned that the development of atomic weapons would lead to a deadly arms race; during World War II, he met with Roosevelt and Churchill to discuss his ideas about nuclear arms treaties. 

Brilliant, tormented with self-doubt, drawn to the romance of Marxism, Oppenheimer was one of the great physicists of the 20th century. At first working at the University of California at Berkeley with Glenn Seaborg on the cyclotron, Oppenheimer reached a career high point as director of the Los Alamos project to build the first atomic weapons. He believed, with Bohr, that nuclear bombs should be regulated by an international body, but his Communist sympathies got him into trouble with officials. 

Considered the father of nuclear physics, Rutherford discovered radon, figured out the half-life of radiation, identified alpha and beta particles, and revealed that every atom contains a nucleus. He won a Nobel Prize, ironically in chemistry. Rutherford ran the Cavendish Laboratory at Cambridge at a time when world-changing discoveries were made there. Eleven of his students went on to win Nobel Prizes, an unmatched record. Many of his protégés became involved in the atomic bomb projects in England and the US. 

General Groves, who managed the building of the Pentagon in 1941, ran the Manhattan Project from September 1942 until its completion in 1947. Tough-minded and decisive, Groves accomplished things quickly and cheaply; he knew how to deal with soldiers, politicians, administrators, and scientists. Against the advice of those suspicious of Oppenheimer’s loyalties, Groves chose the Berkeley scientist to run the new Los Alamos lab. Along with that institution, Groves built the Oak Ridge U235 plant and the Hanford plutonium complex. His efforts bore fruit with the completion of the atomic bomb project and the weapon’s use at the end of the Second World War. 

Italian physicist Fermi was so good at science that, in college, he taught his own professors. In the 1930s, his team discovered atomic fission and numerous isotopes; he won the Nobel Prize in 1938. Escaping anti-Semitic Italy, Fermi brought his family to the US, where he constructed the first working atomic reactor pile at the University of Chicago in December 1942. Fermi worked on the science team at Los Alamos that developed the atomic bomb.

A Hungarian physicist, Szilard realized the potential of atomic fission as an energy source and worried that atomic bombs may be possible. At the outset of the Second World War, Szilard got Einstein to write a letter to President Roosevelt that warned of catastrophe if Hitler were to obtain nuclear weapons. The letter inspired the US effort to build a bomb. Though he fully supported the atomic bomb project as a pushback to Hitler, Szilard also campaigned for openness among nuclear scientists and public awareness of the dangers of nuclear weaponry. These views got him into trouble with the authorities, who were suspicious about his motives. Szilard had to give up his scientific patents to the US in order to be accepted into the Manhattan Project. 

Compton discovered that X-rays, when bounced off graphite, reflected at a lower wavelength, proving Einstein’s 1905 postulate that the rays, and related forms of energy such as light, are particles as well as waves. His Compton Effect won him the 1927 Nobel Prize in physics. Compton was a religious man who nevertheless renounced his Mennonite pacifism in view of the Nazi danger. In 1941, he was pulled from his work as a University of Chicago physics professor to lead a review of nuclear weapons research. He became a high-level administrator in the Manhattan Project and helped Fermi assemble the first reactor pile at the University of Chicago in 1942. Later, Compton helped develop the breeding of plutonium for use in atomic bombs. 

Colonel Tibbets, one of the bomber pilots to fly the first US daylight raid against German-occupied Europe, was chosen to train the crews who would drop atomic bombs on Japan. Tibbets assembled a battalion in the Utah desert, where crews practiced in the new B-29 Superfortress bombers. On August 6, 1945, Tibbets piloted a dozen-man crew in a B-29 named for his mother, “Enola Gay,” that transported the Little Boy atomic bomb from the Pacific island of Tinian to a deadly appointment with the Japanese southern port city of Hiroshima. 

The second woman to get a PhD from the University of Vienna, Meitner partnered with Otto Hahn to make critical discoveries in particle physics, including the fission of uranium. During the Hitler years, Hahn won the Nobel Prize for their work while Meitner, a Jew, was left out; scientists later honored her by naming an element, meitnerium, after her. 

Hitler’s extreme hatred of the Jews defined the early years of his rule over Germany, when he oversaw the passage of 400 laws that restricted Jewish life, including a rule that forbade Jews from teaching at state institutions, which caused a mass exodus of physicists from Germany. These great minds would turn around and work for countries fighting the Nazis during World War II, helping them to defeat Hitler.

Arguably the most famous scientist in history, Einstein in the early 1900s made several important discoveries—the explanation for Brownian motion, the photelectric effect, special and general relativity—and won a Nobel Prize. His work revamped the nature of space and time, and he contributed to the beginnings of quantum mechanics, thereby changing our understanding both of the microscopic and the cosmic. During World War II, the normally pacifistic Einstein convinced Roosevelt to launch a crash program to develop an atom bomb before Hitler or the Japanese did so.