When we left off on the last blog, we learned that Edward Teller joined with Enrico Fermi and introduced the idea for a Super to Oppenheimer at Los Alamos, when they both worked for Oppenheimer in the Manhattan Project. When the war ended, Oppenheimer canceled the Super project, and Teller left Los Alamos to join Fermi in his new Institute for Nuclear Science in Chicago. (While at Fermi’s institute, Teller teamed with Maria Mayer (neé Göppert) for a short while. Mayer later won the Nobel Prize in physics for her research on the structure of the nucleus.)
Meanwhile, Norris Bradbury had replaced Oppenheimer as the director of Los Alamos, and he offered Teller a contract to continue work on the Super, and he ordered a review of the program with the Super Conference of 1946, which was attended by Soviet spy Klaus Fuchs. We’ll pick up the story from there.
Oppenheimer was a dominant figure in the culture of Los Alamos, even after he left there to rejoin Lawrence at the Rad Lab, and then to become the director of the Institute for Advanced Study at Princeton. So, it is understandable that Oppenheimer’s opposition to doing thermonuclear research would have an effect on the culture at Los Alamos, and Teller found it a little difficult to recruit physicists to join his Super project. To help keep his project on track, Teller recruited an acquaintance of his, George Gamow (pronounced Gam-off), to work with him on the Super.
Gamow was a character—another icon of quantum physics. He was born a Ukrainian in the city of Odessa, when it was part of the Russian empire. Tall and gangly, as can be seen in that photo of him with Nobel laureate Wolfgang Pauli, which I’ve chosen to illustrate this blog, Gamow had an effervescent sense of humor. He was a visionary, in the sense that he could look at an equation and envision how it represented reality, and in that way he could come up with a law of physics. His ability to do this was legendary.
Barely out of university, he was able to explain the physics behind the radiation discovered by Marie Curie, with his so-called “tunneling effect,” where he mathematically showed how an alpha particle could escape a nucleus by tunneling out. (Readers who are former students of mine from our days at West Point are probably now feeling nausea set in out of memories of listening to me in class, so I’m going to stop with the physics for now.) Later, he switched his interest to the cosmos and used his vivid imagination to describe the beginning of the universe as a Big Bang—a phrase since stolen by television.
Teller and Gamow were fellows together at Niels Bohr’s institute in Copenhagen, where they became fast friends. When Gamow secured a position as a professor of physics at George Washington University, he procured a physics position for Teller so he too could reach America. It was only natural then, that Teller would call up his friend Gamow and ask him to come to Los Alamos and help design the Super. (In this excerpt we are also introduced to Stanislaw Ulam. We’ll learn more about Ulam in a later blog.) Please enjoy this latest blog, “The Super: Onset of a Thermonuclear Age,” which includes highlights from my upcoming book, From Berkeley to Berlin:
Despite his feelings about the efficacy of a Super, Bradbury kept the program going. In 1947, he offered Teller, who had joined Fermi in Chicago, a consulting agreement, and Teller went back to Los Alamos full-time to lead the Super program. His new group included a mathematician from his Manhattan Project team, Stanislaw Ulam. Since he was having trouble recruiting members to his team, Teller reached out and asked a friend of his, George Gamow, a physics professor at George Washington University, to join him. With Gamow’s arrival, Bradbury formed an oversight group composed of Teller, Gamow, and Ulam, called the “Director’s Committee,” to become the theoretical core for the Super program. The two physicists and mathematician were a potent team.
Stanislaw Ulam, born in Poland, had come to America at the behest of the Hungarian-born mathematician John von Neumann, to be a fellow at Harvard, where coincidently, he met and befriended David Griggs. Von Neumann vouched for Ulam to join the Manhattan Project, and throughout his early years at LASL, he remained with the Super program.
The third prominent figure of the Director’s Committee was George Gamow. A slender man full of good humor, he was six feet three inches tall with blond hair and youthful looks. He had a quirky way of visualizing and explaining physics phenomena: Gamow is widely credited with coining the phrase “big bang theory” to describe the beginning of the universe. As a young man, the Ukrainian physicist twice attempted to escape the Soviet Union by paddling away in a kayak with his wife, once in the Arctic Ocean and once in the Black Sea—both attempts were thwarted by adverse weather. He finally succeeded in escaping when, in 1933, he was invited to the Solvay Conference in Brussels. He got permission to have his wife join him, and when the conference ended, Marie Curie offered him employment at her institute in France. In 1934, he became a fellow at Niels Bohr’s Institute for Theoretical Physics in Copenhagen, where he met Teller; from there, he accepted a position as a professor at George Washington University and departed for America.
It is interesting to note that the members of the Director’s Committee came from Eastern Europe. They had all seen what life was like under a Communist regime, which made them ardent anti-Communists. They were passionate about developing a thermonuclear weapon before Stalin’s Soviet Union could. They were a parallel to eminent Manhattan Project physicists like J. Robert Oppenheimer, Hans Bethe, and Enrico Fermi, who had lived in Western Europe and experienced life under a Fascist regime, and who were passionate to develop an atomic bomb before Hitler’s Nazis could.
To give ions enough kinetic energy to fuse together, or to put it in another way, to get to high temperatures, Teller’s team had to design a Super that could duplicate an environment like that inside the center of a star, where temperatures can reach 27 million degrees Fahrenheit. Almost all of the energy in the center of a star is carried by photons—particles of light. High temperatures stay constant because, with thousands of miles of matter blocking their escape routes, photons cannot easily escape the star. (It can take hundreds of thousands of years for a photon created in the center of the Sun to escape and reach the Earth.) There is plenty of time for energetic nuclei to collide and fuse.
On the other hand, the Super is vastly smaller than a star, so photons readily escape and carry away energy, which lowers the temperature. As the temperature drops, it falls to levels below what is needed for thermonuclear reactions to occur. The problem facing Teller’s physicists was when an atomic blast raised the temperature of the Super to high temperatures, there would be only millionths of a second to get the nuclei to fuse. This was a race between nuclei fusing and photons escaping the device. Teller often looked to Fermi for guidance on this, for Fermi was an expert in this kind of science. Between August 2 and October 9, 1945, Fermi had delivered a series of six lectures at Los Alamos that established the conditions needed for a thermonuclear device to work.
The three members of the Director’s Committee dove in and tackled the challenge of designing a Super. They explored different ideas for starting thermonuclear ignition, with some schemes carrying exotic names, like Gamow’s “Cat’s Tail” and Ulam’s “Jet Fuse.” Teller and Gamow co-wrote a document in January 1950 in which they laid out in greater detail the design parameters needed for the Super—that document became the basis for the design of the Classic Super.
Gamow had an intense energy he could apply to a problem, with new and exotic ideas continually popping out of his head. His vivid imagination allowed him to visualize the laws of physics, giving him an electric effect on his fellow physicists. As Ulam observed, “Gamow possessed this ability to see analogies between models for physical theories to an almost uncanny degree. In our ever-more-complicated and perhaps over-sophisticated uses of mathematics, it was wonderful to see how far he could go using intuitive pictures and analogies from historical or even artistic comparison.” Somehow, these three talented scientists would have to design a Super that worked.
Although he stayed in the background, Lawrence remained a constant presence to the scientists working on the Super—why would he stay interested their research? He was growing wary of the onset of Communist aggression in Eastern Europe and the spread of Communism into mainland Asia. Something stirred within him that he had last felt when he learned nuclear fission had been discovered in Berlin.