AS he enters his tenth decade, Edward Teller continues questing after knowledge and innovation. Time recently cited his suggestion of sending a robot spacecraft to rendezvous with asteroid XF11, first thought to be on a collision path with Earth. The idea was to get information about the composition and strength of passing asteroids so as to understand how best to destroy or divert them. Teller for some time has been interested in outer space and has been concerned with the possibility of catastrophes caused by asteroids, comets, or other near-Earth objects. In fact, he and his colleagues have studied ways to deflect or destroy such objects with nuclear explosions. Prolific in his ideas and determined in his pursuit of scientific truth, Teller has promoted scientific studies far ahead of their time, studies that often have profoundly affected the direction of science and technology.
While making notable contributions to science, Teller has also involved himself in myriad causes. He has promoted science education to develop strong scientists and engineers for the future; he has advocated openness in sharing scientific information; he has been at the forefront of developing safe nuclear energy for civilian use; and he has developed advanced technologies to defend U.S. national security.
That last cause has, of course, brought Teller both credit and controversy. It has endowed him with a larger-than-life presence in the scientific pantheon and has forever tagged him as the "father of the hydrogen bomb." Nevertheless, it is not the sum of his work; a better symbol of his work is Lawrence Livermore National Laboratory, the institution Teller fought for and cites as his proudest achievement. Founded as a second weapons laboratory, it has also been, as Teller intended, a world-class science research institution that has made many scientific innovations while serving the nation's security interests. The work at Livermore demonstrates just how comprehensive Teller science has been.

Doing Pure Science
Throughout his career, Teller has been a participant in the development of nuclear theory; he has helped shape the nature of nuclear physics research. Trained in chemical physics and spectroscopy, he cast his research net across a broad range of physics subfields. He began with atomic and molecular physics and broadened his expertise with nuclear physics, plasma physics, astrophysics, and statistical mechanics.
In 1925, when Teller graduated from gymnasium in Hungary and entered university in Germany, it was a time of revolution and extraordinary breakthroughs in physics. Einstein had turned the scientific world on its head with his theory of relativity. Then Niels Bohr came along and invented the early quantum theory-the radical insight that electrons circling atomic nuclei were jumping from orbit to orbit without heed to the space in between-and revolutionized the scientific understanding of atoms and molecules. Bohr's theory started to explain the stability of atoms, how combinations of neutral atoms could form chemical bonds, and why atoms of a particular element could form only limited numbers of bonds. Teller, fascinated by quantum mechanics, changed from studying chemical engineering-which he was doing at the behest of his father-and went to the University of Leipzig to study physics under Werner Heisenberg, an important contributor to modern quantum mechanics theory. Heisenberg's uncertainty principle held that subatomic particles are governed not by causality but by probability.

As Heisenberg's student, Teller obtained his Ph.D. in 1930 in theoretical physics. The same year, he published his first paper, "Hydrogen Molecular Ion," the result of his application of quantum mechanics to the chemical bond of the positively charged hydrogen molecule. Teller exactly calculated the energy levels in an excited hydrogen molecular ion and thereby explained the properties and behavior of the hydrogen molecule. A mathematics prodigy, Teller was the right person for solving the involved mathematics problem of how one electron spins around two nuclei. That work was one of the earliest descriptions and still is a widely held view of the molecule today.
During the 1930s, Teller continued working on electron structure in molecular physics at the University of Göttingen. With Heisenberg in 1933, Teller wrote another significant paper, which extended the Franck-Condon principle to symmetry-breaking transitions among the nuclei in a polyatomic molecule. In 1939, this idea was applied to absorption spectra of benzene, explaining an anomalous band in the ultraviolet.
A series of collaborations with his students and colleagues led to a 1937 paper coauthored with Emil Jahn on the Jahn-Teller effect, a statement about the role of electron energy levels in determining the shape of molecules with more than two atoms. Although the proof was purely mathematical and its predictions were not verified experimentally until 1952, it remains one of Teller's most significant and enduring contributions. Because of the effect's value in spectroscopy, calculating chemical reactivity, and determining crystal structure, its significance extends through all of modern chemistry.
Teller had meanwhile fled Germany in 1933, going first to Copenhagen, then London. In 1935, he accepted a position at George Washington University, where he continued his work in chemical physics. His most significant result in the late 1930s centered on the theory of the physical adsorption of gases on surfaces. Named the BET theory after the initials of its creators Brunauer, Emmett, and Teller, it still plays a major role in calculations for such industrial processes as catalysis of chemical reactions.
At George Washington, Teller began a fruitful collaboration in nuclear physics and astrophysics with the distinguished physicist George Gamow. Their first publication appeared the same year Teller arrived and led to the definition of Gamow-Teller transitions, a still-important extension of the theory of beta decay. The beta decay theory describes the radioactive transformation of an atom as the nucleus emits or absorbs an electron or positron, changing its atomic number by one without altering its mass number. The Gamow- Teller theory provides rules for classifying subatomic particle behavior in radioactive decay. With this work, Teller, who had been pondering the activity of the electron spinning around the atom, found himself delving into the very heart of the atom, the nucleus. Teller and others' prewar research in nuclear physics produced significant theoretical results on the forces holding nuclei together, the forces between nucleons, models of the atomic nucleus, and neutron scattering in molecular gases and crystal lattices.

Developing Nuclear Weapons
In 1939, at the Washington Conference on Theoretical Physics convened annually by George Gamow, attendees received some startling news: the German scientists Otto Hahn and Fritz Strassman had discovered fission. Bombarding uranium with neutrons, they had split the nucleus and released a great amount of energy.
That announcement was to be the opening salvo leading to the Manhattan Project and the development of the atomic bomb. Scientists at the conference wondered whether a splitting nucleus would release enough additional neutrons to start a fission chain reaction that would release a large amount of energy. Two months following the conference, Leo Szilard, a Hungarian colleague and friend of Teller's, confirmed the feasibility of such a chain reaction in his laboratory. A way had been found to make a bomb of great power out of a small amount of fissionable material, and Teller would play a role in it.
The following events are well recounted in history books: Szilard and Teller convinced Einstein to sign a letter to President Roosevelt about an atom-bomb-building project; America entered the war, which galvanized bomb research; the top-secret Manhattan Project enlisted an elite band of scientists to work on the bomb in the remote mountains of Los Alamos; and work culminated in 1945, with the explosion of the world's first atomic bomb.

Teller was present throughout the critical points in the development of the atomic bomb. He obtained initial federal funding for chain-reaction research, performing experiments by the fall of 1941 with Leo Szilard and Enrico Fermi at Columbia University. Their work led to the first controlled nuclear reaction.
Early in the war, atomic research intensified and was consolidated at the University of Chicago's Metallurgical Laboratory, where Teller was a part of the theoretical group and worked on the first nuclear reactor. There, the feasibility of releasing significant nuclear energy was confirmed. The Manhattan Project to produce the bomb began, and scientists took off for the mountains of New Mexico.
Once Teller had settled his family in Los Alamos in April 1943, one of his early responsibilities was to indoctrinate incoming scientists about the project. He also worked on implosion calculations, helping John von Neumann to develop ways to calculate the critical mass and nuclear efficiency of various bomb designs. He devised the implosion approach used in the first atomic bomb.
But even as he was involved with the work on the fission weapon, Teller, always thinking ahead, was pondering a fusion bomb, one that worked not by splitting heavy nuclei but by uniting light nuclei. The same process that powers the sun and the stars, fusion involves hydrogen, whose nuclei are the simplest in nature and have the lowest electrical charge. Hydrogen nuclei also have the least repulsion of each other, so the nuclei fuse at lower temperatures. Scientists knew that fusion theoretically could release more energy per unit mass than fission.
With suggestions from Fermi, Teller had conceptualized a fusion weapon, in which a fission bomb would be used to heat a mass of deuterium (a heavy form of hydrogen) to start a fusion reaction. The concept stalled initially when Teller thought his calculations indicated the unlikelihood of a fission weapon producing the hundreds of millions of degrees of temperature needed to trigger significant fusion. But Manhattan Project colleague Emil Konopinski revisited these calculations with him, and they concluded that the concept probably would work. The thermonuclear superbomb became a secondary endeavor during the Manhattan Project.
The end of the war diminished the government's interest in weapon development, so research work at Los Alamos shrank significantly, as did funds for nuclear testing and research. However, work on the "super" was revived upon the discovery that the Soviet Union, now an adversary of the U.S., had detonated an atomic bomb. A faction of the scientific community, including Teller, felt that it would only be a matter of time before the Soviets developed a hydrogen bomb. To maintain the balance of power, it was imperative for the U.S. to develop a hydrogen bomb first. A majority of the scientific community had doubts about the morality or the practicality of developing such a bomb, but pressure to build it mounted with the discovery that Manhattan Project scientist Klaus Fuchs had passed nuclear secrets-including concepts for a hydrogen bomb-to the Soviets. On January 31, 1950, President Truman gave the go-ahead to intensify the pursuit of the fusion hydrogen bomb. (See box below.)
Back at Los Alamos, scientists were trying to solve a critical problem of propagating a fusion reaction initiated by a fission bomb through a cylinder of liquid deuterium. The breakthrough came when Teller invented the radiation implosion concept, which was described by Teller and Los Alamos colleague Stanislaw Ulam in one of the most famous documents produced during 40 years of weapons research, but not widely read because of its security classification. In the radiation implosion concept, the fusion fuel is first compressed. This makes possible the ignition and effective burn of fusion fuel. Radiation is channeled from the exploding primary fission bomb to the secondary fusion device, causing it to implode and compress its fusion fuel.
The "Mike" thermonuclear device based on this radiation implosion concept was exploded on Eniwetok atoll on October 31, 1952. In this first test, cryogenic deuterium fuel was used. Later, solid lithium-deuterium fuel was used.

Developing the H-Bomb

In the fall of 1941, Enrico Fermi suggested that a fission bomb be used to heat a mass of deuterium to a temperature where the thermonuclear fusion of two deuterium atoms will proceed rapidly. I came up with a counter argument: that the needed temperature would be so high that most energy will appear as useless radiation rather than usable kinetic energy of the nuclei. Fermi agreed to my objection.
A few months later, I attempted to finalize my argument on the deuterium-plus-deuterium reaction. We did not succeed. Emil Konopinski, my collaborator, suggested (correctly) that tritium in a deuterium-plus-tritium reaction might react much faster than deuterium-plus-deuterium. I, in turn, proposed that the thermonuclear reaction might proceed before a lot of radiation is emitted and an equilibrium with radiation is established.
During this work, Oppenheimer invited us to participate in a discussion at Berkeley about the problems of explosives using nuclear energy. Oppenheimer mentioned the possibility of a hydrogen bomb to Arthur Compton (head of the whole Chicago project), arguing that the fission and fusion bomb problems required a new laboratory, which was established in March 1943.
In Los Alamos, difficulties connected with the fission bomb soon required the whole available effort. But working with a small group, I could give continued attention to the hydrogen bomb. It turned out that it is quite difficult to postpone radiation equilibrium and obtain sufficient time for thermonuclear reactions. But it still seemed quite promising to obtain a hydrogen bomb in this manner.
With the end of the Second World War, strong feelings developed against continuing the work. I returned to pure physics in Chicago for the next few years, which personally I found more attractive.
In 1949, I returned as a visitor to Los Alamos with the main purpose to continue the improvement of the fission bomb. But in the summer, the Soviets exploded a copy of our fission bomb. The question arose whether work on the hydrogen bomb should be given new emphasis. This possibility was strongly supported by Ernest Lawrence. On the other hand, the Scientific Advisory Board (SAB) advised unanimously against such a project. In Los Alamos, Ulam and Everett made further calculations. They came up with results of improved quality, which, however, were negative on the feasibility of their approach to H-bombs.
By the end of 1950, I had the novel and positive answer. Because of the wartime work, we knew how to strongly compress the thermonuclear fuel, and, in the compressed fuel, radiation would be less important and would not inhibit the reaction. The Los Alamos administration discouraged new approaches, so for the time being I restricted myself to a few private discussions. One of these occurred between Ulam and myself in February 1951. Ulam suggested compression, for which I was fully prepared. I knew how to accomplish it, and I knew how it would help. I put all this down in a joint report, which Ulam signed but failed to support in subsequent discussions.
I took the opportunity of an SAB meeting (spring 1951) to present the plan for "an equilibrium hydrogen bomb," in which compressed fuel would be used. I gained the unanimous support of the SAB.
At that time, progress at Los Alamos had been assured, and I felt that it would be better for me to start work at an additional laboratory. This possibility materialized (with the essential help of Ernest Lawrence) in Livermore. In 1952, in the early days of Livermore, the first hydrogen bomb was successfully exploded. The detailed thermo-nuclear design was furnished by John Wheeler and collaborators.
An important application of the hydrogen bomb came through a plan for placing such explosives in rockets carried by submarines. This development made it impossible for the Soviets to attack the United States and prevent retaliation. Indeed, rocket-delivered explosives are hard to shoot down, and the submarines that carry them are hard to locate. The proposal I made succeeded because of the excellent work of John Foster at Livermore, who designed a small and efficient primary fission bomb, and Carl Haussmann, who designed a small and efficient secondary hydrogen bomb. The resulting nuclear explosives were more than ten times as powerful as those used during the Second World War, but the use of thermonuclear reactions made them flexible enough to become practical explosives carried by submarines.
-- Edward Teller, June 1998

Building an Institution
What would become Lawrence Livermore National Laboratory was established just a few weeks before the Mike test, on September 2, 1952. It was the result of vigorous efforts by Teller, who believed that a friendly competitor of the Los Alamos laboratory would accelerate the development of thermonuclear weapons and fuel scientific accomplishment. Teller was greatly assisted by Ernest Lawrence, who also came up with a suitable site. The Livermore laboratory began life as a branch of the University of California Radiation Laboratory (now the Ernest Orlando Lawrence Berkeley National Laboratory).
Lawrence Livermore is stamped with Teller's vision and ideas. Throughout the 45 years of its existence, Teller has been its guiding presence.

Champion of Safe Reactors
Nuclear fission was discovered just before the beginning of World War II, which explains why its first application was as a weapon. But it has the potential for many civilian uses. Teller has long been a champion of nuclear energy for peaceful uses, particularly as an alternative to other sources of energy. To that end, he has made many fundamental contributions to the design of safe and reliable nuclear reactors for generating power.
In 1947, Edward Teller became the first chairman of the Atomic Energy Commission's Committee on Reactor Safeguards. The committee was originally formed to review, evaluate, and advise the AEC of the hazards of reactor operations. The committee's charter was later expanded to include all aspects of reactor safety.
Teller, an engaging and energetic chairman, led the committee as it incorporated many improvements. The committee innovated such safety features as containment structures and methods for flooding the reactor in an emergency, promoted training of reactor operators while advocating system designs that lowered dependence on human factors, and devised systematic rules for reactor siting that took into account the nearby population and the reactor's power level.
In the early years of reactor technology, few techniques and little information existed for evaluating reactor safety. Probabilistic safety analysis techniques had not been developed, and human tolerances to radiation and ingestion of plutonium were not well known. Under Teller's guidance, the committee developed the concept of designing safety features into reactors to prevent the "worst possible accident." Over time, this concept evolved to today's "design basis accident," which considers accident probabilities in setting design safety standards. In 1956, Teller led a study that culminated in the design of an inherently safe reactor. The TRIGA (Test, Research, Isotopes-General Atomics) reactor was invented that summer, the result of a Teller idea and his articulate advocacy of peaceful nuclear applications at the 1955 Conference on Peaceful Uses of Atomic Energy in Geneva. Some 60 TRIGA reactors were later built around the world.
Teller's study group developed a special reactor material system with an automatic mechanism to stabilize power output at a safe value and thus prevent dangerous overheating. The TRIGA design has led to many important and varied uses in nuclear education, research, and medicine.

Nuclear Power as Servant
When President Eisenhower gave the famous "Atoms for Peace" speech at the U.N., about adapting atomic-bomb technology to peaceful uses, the idea resonated with Teller. He took the theme further in a keynote speech to the Joint AEC Weapons Laboratory Symposium on Nonmilitary Uses of Nuclear and Thermonuclear Explosions, held in Livermore in February 1957, where he led an effort to stimulate new ideas in civilian nuclear applications. The conference led to the initiation of the Plowshare Program in June 1957 to explore the feasibility of using nuclear explosions for applications such as earth moving, power production, and breeding fissile materials such as plutonium.

Teller wholeheartedly endorsed the program and, through his writings and public talks, acquainted others with the range of Plowshare ideas and explained the physics and chemistry at their basis. Unfortunately, his enthusiasm for the project was at odds with the public's rising concerns about the environmental impact of nuclear power. Ultimately, Plowshare lost to such concerns. Even so, the program studies and experiments yielded many achievements, including:
  • The first view of the phenomenology of an underground nuclear explosion and subsequent information derived from it has proved useful for other underground investigations and nuclear tests.
  • The most complete environmental study to date for excavating a small harbor at a remote site in Alaska with nuclear explosions. This work became a model for the modern environmental impact statement.
  • Development of a family of nuclear excavation explosives that had TNT-equivalent yields from 1 kiloton to over 100 kilotons and that would release only a relatively low quantity of fission products into the atmosphere. These "clean" nuclear explosives would have been used to excavate a new Panama Canal, had that project gone forward.
  • Demonstrations of fracturing low-permeability rocks with nuclear explosions and, later, the design of a special nuclear explosive for this purpose, leading to increased natural gas production.

  • Legacy of X-Ray Lasers
    The Lawrence Livermore program to research nuclear-pumped x-ray laser systems accelerated after President Reagan's "Star Wars" speech to introduce the Strategic Defense Initiative (SDI) in 1983. Teller thought such a laser system would provide a shield for the United States against Soviet missiles. He championed the x-ray laser effort and numerous other R&D activities, including guided antimissile missiles called Brilliant Pebbles. (See box below).

    Strategic Defense Initiative: The Next Stop

    It is widely believed that the rapid development of weapons of mass destruction is the main danger humanity confronts. An extreme consequence of this belief is that new scientific knowledge is considered dangerous and must be limited.
    I strongly believe that the main danger lies in human intentions and not in the ability to bring about mass destruction. An important example is the history of the wars of Genghis Khan-in particular, the destruction of Persia by the Mongols. More than half the population of the defeated country was killed, and Persia, the present-day Iran, has never recovered its great historic importance.
    I believe that the most important part of the present danger is due to the situation that the world has become smaller and more interactive, and catastrophes may occur with unprecedented rapidity.
    The United States, which is losing the remnants of its isolation, is a particularly important component in this change. The technical cause of this change lies primarily in the development and worldwide proliferation of missiles. They may carry weapons of mass destruction such as nuclear explosives or poisons (chemical or biological), but even if they carry no more than high explosives, they are already a terrible and sudden danger to stability.
    My attempts to do something about this situation go back to the visit of Ronald Reagan, freshly elected governor of California, to the Livermore Laboratory. Reagan listened with an active interest to receive novel information of our attempts (in 1967) at missile defense. He asked a few relevant questions and then left without stating clearly whether and to what extent he agreed.
    That answer came in 1983 when Reagan gave a remarkable after-dinner speech to a mixed audience of which I was a part. With a delay of sixteen years, he unambiguously stated that missile defense was possible, necessary, and urgent. In that regard, he gave the Livermore initiative his full support. But how to do it? Reagan suggested that defense, if ever possible, should not utilize nuclear explosives.
    In this new situation, my good friend, Lowell Wood, took the strong initiative of advocating first x-ray lasers and later "Brilliant Pebbles." The latter (and final) proposal consisted in destroying the attacking missile by a direct collision with a small guided defensive object. The defensive object should actually be a satellite already in orbit. Lowell and others in our Laboratory continued to develop this concept. Having helped and supported this effort, I am convinced that it is realistic particularly with the continuing great advancement in computing capability. An important part of the development was and remains the specification that the aggressive missile should be destroyed soon after it has been launched. This necessitates continuing surveillance of our globe by satellites and an international understanding that unannounced missiles or missiles in unannounced orbits should be promptly destroyed. This, in turn, would make safety from rapid attack a worldwide benefit.
    Such an effect has been strongly supported by Presidents Reagan and Bush. Unfortunately, efforts toward missile defense continue at present mostly in connection with defending our armed forces on their missions abroad. The American people (together with all other people in the world) should have such a defense that, indeed, necessitates defensive measures against dangerous launches even before it is obvious who will be attacked. We give priority to the defense of our armed forces, whose needs as an organization must obviously be satisfied. Unfortunately, the need to defend our homeland may, in political practice, be deemphasized by denying the possibility or, at any rate, the urgency of such a defense.
    What has been stated here does not describe my only technical activity nor the only strongly needed technical-military development. It appears to me that it stands out as a matter that has been in the public eye for a couple of decades and where there seems to be a necessity for change in emphasis in the immediate future.
    -- Edward Teller, May 1998

    Some experts believe the SDI helped to bring about major changes in world politics, including the end of the Cold War. The destruction of the Berlin Wall and the collapse of the Soviet Union changed defense priorities. The program for developing the x-ray laser into an antiballistic missile system was eliminated. But the SDI program produced a better understanding of the physics of x-ray lasers and new computer codes for modeling plasmas. It has also resulted in:
  • A laboratory x-ray laser for biological imaging. Coupling x-ray lasers with x-ray microscopes, Livermore scientists can create three-dimensional holograms of living organisms, which enable them to study how DNA is organized inside a sperm cell.
  • Advanced materials such as aerogel and SEAgel. As a target for the x-ray laser, these materials can be doped with other materials. Their very low densities have spurred numerous commercial uses, such as thermal insulation and encapsulating material for timed-release medication.
  • Radiographic diagnostic techniques to detect flaws in SDI components and spinoff methods for detecting flaws in artificial heart valves.

  • Good Luck Wish
    During his 90th birthday celebration on January 15, 1998, Teller spoke about his latest science interests. He acknowledged that biology is the major field of opportunity for young, would-be scientists, although quantum mechanics is still the field he would choose for himself, "for things that are explainable."
    While x-ray lasers did not head his latest to-do list, he did bring up the larger issue of planetary defense and the future of physics. He said, "I see planetary defense as a very interesting contribution not to the preservation of life, but to the further understanding of the evolution of life."

    Speaking to an audience of 400 on his birthday, Teller strongly stated that he believes Livermore's National Ignition Facility now under construction will succeed in achieving fusion energy, and a new branch of physics will develop in which ultrahigh pressures from lasers will be used to change electron structures.
    "All of planetary physics and much of astrophysics may well depend on the findings of NIF," he said. To his audience, many of whom will be instrumental in achieving the lofty goal, Teller said with a smile, "Good luck."
    -- Gloria Wilt, with Bart Hacker

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