Gamow, George

(b. Odessa, Russia, 4 March 1904; d. Boulder, Colorado, 20 August 1968)

physics.

Gamow’s father, Anton Gamow, taught Russian language and literature. Gamow was an outstanding student at the Odessa Normal School (1914–1920) but, owing to the turbulent political conditions of the time, his early education in general was rather sporadic. In 1922 he enrolled in the PhysicoMathematical Faculty of Novorossysky University, but within a year he transferred to the University of Petrograd (Leningrad). There, in 1925, he carried out experimental researches on optical glasses and briefly studied relativistic cosmology under A. A. Friedmann before his attention was drawn to the exciting and profound discoveries being made in quantum theory in Europe: his first publication (1926) involved an attempt to consider Erwin Schrödinger’s wave function as the fifth dimension (the other four being the usual spatial and temporal dimensions).

In the summer of 1928, the year he received his Ph. D., Gamow traveled to Göttingen, where he made his first major contribution to physics; his theory of nuclear α decay. Ernest Rutherford had found (1927) that RaC α particles incident on uranium cannot penetrate the nucleus, although their energy is roughly double that of α particles emitted by uranium. Gamow immediately recognized that the apparent paradox vanished if the emitted α particles were “tunneling through” the nuclear potential barrier—a characteristic wave mechanical effect. Quantitative calculations proved that the empirically established relationship between the nuclear decay constant and the energy of the emitted α particles (the Geiger-Nuttall law) could be completely understood. This same conclusion was reached virtually simultaneously (see Nature, 122 [22 Sept. 1928]) by R. W. Gurney and E. U. Condon at Princeton University.

Niels Bohr, impressed by Gamow’s achievement offered him a Carlsberg fellowship to enable him to spend 1928–1929 at his Copenhagen Institute of Theoretical Physics, where Gamow continued to study problems in theoretical nuclear physics—for example, the parameters governing the yield of protons in α-bombardment reactions. In addition, through correspondence and personal contact with F. A. Houtermans and Robert Atkinson, he helped make pioneering contributions to the theory of thermonuclear reaction rates in stellar interiors. In the fall of 1929, after a visit to the Soviet Union” Gamow went to the Cavendish Laboratory at Cambridge on a Rockefeller fellowship. There he recognized that Heinz Pose’s recent results on the α bombardment of aluminum indicated that the α particles were undergoing nuclear resonance. Later in the year Rutherford asked Gamow to estimate the energy required to split the nucleus by means of artificially accelerated protons and, encouraged by the result, set J. D. Cockcroft and Ernest Walton to work on the construction of the accelerator, with well-known results.

In 1930–1931 Gamow received further fellowship aid to return to Bohr’s institute in Copenhagen, where a major part of his time was devoted to preparing a paper on the quantum theory of nuclear structure, which he had been invited to deliver at Rome in October 1931, to the first International Congress on Nuclear Physics. After returning to the Soviet Union to renew his visa in the spring of 1931 he was denied permission to attend the Rome conference. Gamow spent the next two years as professor of physics at the University of Leningrad; then he and his wife, Lyubov Vokhminzeva, whom he had married in 1931, were permitted to attend the Solvay Conference at Brussels—an opportunity they took to leave the Soviet Union for good. After the conference was over, they spent successive two-month periods in Paris at the Pierre Curie Institute, in Cambridge at the Cavendish Laboratory, and in Copenhagen at Bohr’s institute, before going to the University of Michigan. In the fall of 1934 Gamow was appointed professor of physics at George Washington University in Washington, D.C. He remained at George Washington University until 1956, when he transferred to the University of Colorado. At the same time, after twenty-five years of married, he and his wife were divorced; two years later he married Barbara Perkins.

Soon after accepting his position at George Washington University, Gamow persuaded Edward Teller to join him. By mid-1936 they had jointly discovered what is now known as the Gamow-Teller selection rule for β decay—Gamow’s last major contribution to “pure” nuclear theory. Subsequently he concerned himself largely with applying nuclear physics to astronomical phenomena. Early in 1938, for example, he used his knowledge his knowledge of nuclear reactions to interpret stellar evolution, that is, the Hertzsprung— Russell diagram and the mass-luminosity relation. At about the same time he organized a conference on thermonuclear reactions, the discussions at which contributed significantly to Hans Bethe’s discovery of the carbon cycle. In 1939 Gamow and Teller, both of whom were strong advocates of the expanding-universe theory, traced the origin of the great nebulae to the formation of ancient stellar condensations which subsequently began separating from each other; in addition, they investigated the energy production in red giants. In 1940–1941 Gamow and M. Schoenberg explicated the role of neutrino emission in the production of the rapid and tremendously large increase in luminosity associated with novae and supernovae (exploding stars).

Concurrently, Gamow was establishing his reputation among nonscientists as one of the most talented and creative popularizers of science of all time. His first book-length venture, the well-known Mr. Tompkins in Wonderland, grew out of a popular article on relativity entitled “A Toy Universe” which he wrote in 1937’but which was rejected by Harper’s Magazine and several other magazines. Not until C. P. Snow, then editor of Discovery. read it, published it, and solicited more was Gamow’s career launched. In all, Gamow wrote almost thirty books, most of which were of a popular nature and most of which he illustrated himself. In 1956 his popular writings brought him the UNESCO Kalinga Prize and a lecture tour to India and Japan.

During World War II, Gamow served as a consultant to the Division of High Explosives in the Bureau of Ordnance of the U.S. Navy Department, studying, for example, the propagation of shock and detontation waves in various conventional explosives. Immediately after the war he went as an observer to the Bikini atomic bomb test contributed to the theory of war games for the U.S. Army, and (after gaining top Security clearance in 1948) worked with Teller and Stanislaw Ulam on the hydrogen bomb project at Los Alamos.

Yet Gamow’s, thoughts were never far from relativity and cosmology. In 1948 he predicted that all matter in the universe is in a state of general rotation about some distant center; at the same time he began developing his ideas on the origin and frequency distribution of the chemical elements, postulating that before the “big bang” there existed a primordial state of matter, (“ylem”) consisting of neutrons and their decay products, protons and electrons, mixed together in a sea of high-energy radiation—the basic ingredients necessary for the formation of deuterons and heavier, and heavier nuclei as the universe subsequently expanded. Most of the detailed theoretical calculations were carried out by R. Alpher (assisted by R. Herman), which resulted in the well-know Alpher-Bethe-Gamow letter in Physical Review of 1 April 1948—Bethe’s name, in one of Gamow’s more famous jokes, being added gratuitously to conform to the Greek alphabet. This work also led to the prediction of a residual blackbody radiation spectrum, the remnant from the primordial “big bang” corresponding to few degrees Kelvin. This radiation was first detected in early 1965 by A. A. Penzias and R. W. Wilson; much more definite evidence was found the following year by P. G. Roll and D. T. Wilkinson (in experiments initiated by R. R. Dicke and P. J. E. Peebles) at Princeton University. Cosmological questions concerned Gamow to the end, one of his last investigations being on the possible inconstancy of the gravitational constant and the charge or the electron.

In early 1954, less than a year after J. D. Watson and Francis Crick discovered the double helical structure of DNA, Gamow recognized that the information contained in the four different kinds of nucleotides (adenine, thymine, guanine, cytosine) constituting the DNA chains could be translated into the sequence of twenty amino acids which form protein molecules by counting all possible triplets one can form from four different quantities. This remarkable way in which Gamow could rapidly enter a more or less unfamiliar field at the forefront of its activity and make a highly creative contribution to it, often far more by intuition than by calculation, led Ulam to characterize his work as “perhaps the last example of amateurism in scientific work on a grand scale.” It earned him membership in a number of professional societies—American Physical Society, Washington Philosophical Society, International Astronomical Union, American Astronomical Society, U.S. National Academy of Sciences, Royal Danish Academy of Sciences and Letters—as well as an overseas fellowship in Churchill College, Cambridge.

Gamow was a tremendously prolific writer, having roughly 140 technical and popular articles, in addition to his many books, to his credit. (On the negative side, his historical writings, which like most of his books are of a basically “popular” character, are of marginal value;) He was tall, fair-haired, blue-eyed, and possessed a legendary sense of humor. He was very widely traveled, greatly enjoyed reading and memorizing poetry, spoke six languages (all dialects of “Gamowian”), and loved collecting photographs and other memorabilia.

BIBLIOGRAPHY

I. Original Works. A bibliography of Gamow’s scientific and popular writings is included in his autobiography, My world line (New York, 1970). The most important scientific papers consulted and referred to in text are the following; “Zur Wellentheorie der Materic,” in Zeitschrift Für Physik, 39 (1926), 865–868, written with D. D. Ivanenko; “Zur Quantentheorie des Atomkernes,” ibid, 51 (1928), 204–212 “Selection Rules for the β-Disintegration,” in Physical Review, 49 (1936), 895–899, written with E. Teller; “Nuclear Energy Sources and Stellar Evolution,” ibid., 53 (1938), 595–604; “The Expanding Universe and the Orgin of the Great Nebulae,” in Nature, 143 (1939), 116–117, 375, written with E. Teller; “On the Origin of Great Nebulae,” in Physical Review, 53 (1939), 654–657, written with E. Teller; “Energy Production in red Giants,” ibid., 719, written with E. Teller; “The Possible Role, of Neutrinos in Stellar Evolution”, ibid., 58 (1940) 117, written with M. Schoenberg; “Neutrino Theory of Stellar Collapse,” ibid., 59 (1941), 539–547, written with M. Scoenberg; Rotaning Universe?” in Nature, 158 (1946), 549; “The Origin of Chemical Elements,” in physical Review, 73 (1948), 803–804, written with R. A. Alpher and H. Bethe; “Possible Relation Between Deoxyribonucleic Acid and Protein Structures,” in Nature, 173 (1954), 318; “Statistical Correlation of Protein and Ribonucleic Acid Composition, “in Proceedings of the National Academy Of Science of the United States of America, 41 (1955), 1011–1019, written with M. YČas; and “History of the Universe,” in Science, 158 (1967), 766–769.

II. Secondry Literature. See American Men of Science; Current Biography, 1951; Physics To-day, 21 (1968), 101–102; and Nature, 220 (1968), 723, See also P. G. Roll and D. T. Wilkinson, “Measurement of Cosmic Background Radiation at 3.2-cm. Wavelength,” in Annals of Physics, 44 (1967), 289–321.

Roger H. Stuewer.

George Gamow

The Russian-American physicist George Gamow (1904-1968) made important contributions to nuclear physics. He also did significant work in the fields of astrophysics and biology and wrote books popularizing science.

George Gamow was born in Odessa, Russia, on March 4, 1904. He became interested in physics at an early age, and when he was 18 he enrolled in the physico-mathematical faculty at Novorossia University in Odessa. After a year he transferred to the University of Leningrad, from which he eventually received a Ph.D. in 1928. That summer he visited the university in Göttingen, Germany. His work impressed the Danish physicist Niels Bohr so much that he was invited to be a fellow of theoretical physics at the University of Copenhagen. He remained in Denmark for one year, then spent the next year studying with Ernest Rutherford at the Cavendish Laboratory in England. He subsequently returned to the University of Copenhagen for another year.

In 1931 Gamow accepted the position of professor of physics at the University of Leningrad. After denying him permission to leave the country for two years, the Soviet government allowed him and his wife, Lynbov Vokhminzeva, to attend the 1933 Solvay Congress in Belgium; he took this opportunity to leave the Soviet Union forever. He spent the rest of the year at various scientific institutions all over Europe and was appointed professor of physics at the George Washington University in Washington, D.C., in 1934. Gamow remained there until 1956, when he transferred to the University of Colorado and divorced his wife. He married Barbara Perkins in 1958, and they remained in Colorado until his death in 1968. His career was extremely diverse: he delved into nuclear physics, astrophysics, biology, and writing.

Gamow's first major contribution to nuclear physics took place in Göttingen. He was intrigued by an unusual phenomenon that Rutherford had reported as a result of an alpha particle scattering experiment. When a uranium sample is bombarded with alpha particles (positively charged particles composed, like helium nuclei, of two protons and two neutrons), the particles are repelled by the electrostatic force exerted on them by the uranium nuclei, which are also positively charged. However, a uranium nucleus already contains alpha particles, and these remain there for a long time because the repulsive force exerted by a nucleus on alpha particles is overcome by the attractive force of the strong nuclear interactions at very close distances. The classical theories of physics maintained that the particles could never leave the nucleus because of the barrier that is created at the distance where the repulsive force becomes an attractive one. What puzzled Rutherford was that some alpha particles do leak out of the nucleus, though very slowly.

Gamow applied the new wave mechanics theories to this problem. In wave mechanics, the motion of particles is determined by "pilot waves," which are waves that can penetrate through any barrier. He showed that the alpha particles were in a sense "riding" on the pilot waves, enabling them to "tunnel" out through the barrier. This theory explained not only Rutherford's puzzle but also the relationship between the alpha particles emitted by different radioactive substances and the half-lives of the substances.

Gamow's second major contribution to nuclear physics was in the form of the Gamow-Teller selection rule for beta decay, a process whereby the nucleus of a radioactive atom emits an electron, thereby transforming itself into a different atom. In his theory of beta decay, Enrico Fermi had said that the electron leaves the nucleus straight out along the radius vector. Working with Edward Teller, Gamow showed that the electron could escape just as easily by moving in a hyperbolic trajectory. This discovery brought considerable insight into the magnetic interaction between the electron and the nucleus.

After this work Gamow turned his attention towards the application of nuclear physics to astrophysics. There had been previous, unsuccessful attempts to explain the abundance of nuclei in the cosmos in terms of thermodynamic equilibrium conditions. One of the problems with this approach was that the conditions for the formation of heavier nuclei were not the same as those for the formation of lighter nuclei. Gamow advocated the theory of the big bang and the expanding universe as a means of resolving the problem. He theorized that before the bang there was a fundamental state of matter he called "ylem" that consisted of a mixture of neutrons, electrons, and protons held together in a ball of high energy radiation. This ball then exploded and began to expand, allowing the fundamental particles to combine and form nuclei, and, eventually, elements—this is a process known as nucleo synthesis. He suggested that because such a universe was continually expanding, and hence changing, there would be sufficiently diverse conditions for elements of all different atomic weights to form in a non-equilibrium process. This theory also led Gamow to predict that there should be a certain level of remnant radiation from the big bang. This radiation was discovered accidentally almost 20 years later by researchers at Bell labs.

In 1954 Gamow turned to the field of biology, building on the work done by Francis Crick and James Watson on the helical structure of DNA (deoxyribonucleic acid). Gamow's work was in genetic coding theory, which deals with the way information is transferred in the genes. He used combinatorial mathematics to show that it was possible to establish the validity of certain proposed coding schemes by studying known sequences of amino acids.

Gamow also wrote many books popularizing science in an entertaining, innovative manner. This achievement won him the UNESCO Kalinga Award in 1956. He was a member of numerous scientific societies, among them the American Physical Society, the Washington Philosophical Society, the International Astronomical Union, and the Royal Danish Academy of Sciences and Letters.

Further Reading

Among the many books Gamow wrote to explain science to the layman are the well-known Mr. Tompkins books. Mr. Tompkins in Wonderland (1940) explains the theory of relativity, and Mr. Tompkins Explores the Atom (1944) discusses modern theories of the atom. He wrote several books on cosmology, including The Moon (1953) and a trilogy published in 1955 composed of The Birth and Death of the Sun, Biography of the Earth, and The Creation of the Universe. He had also been working on an autobiography, My World Line, at the time of his death. Incomplete, the book was published post-humously in 1970. □

Gamow, George (1904–68) US nuclear physicist, b. Russia. He developed the Big Bang theory and explained (with Ralph Alpher and Hans Bethe) the abundance of chemical elements in the universe. In molecular biology, Gamow deduced the triplet code (codon) of bases in DNA. With Edward Teller, he established the Gamow-Teller theory of beta decay.

George Gamow

1904-1968

Russian-born American physicist who made important contributions to cosmology, nuclear physics, and molecular biology. Gamow was codeveloper of the Alpher-Bethe-Gamow "big bang" theory of the universe's origin, which explained the observed abundance of lighter elements. He later concluded that heavier elements formed in the center of stars. He independently developed alpha decay theory and suggested how DNA governed protein synthesis. Gamow was a great popularizer of physics and widely known for his Mr. Tompkins books.