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S. Mahadevan in his Editorial, Resonance, July 2004 | |
The year 2004 is the birth centenary of George Gamow, a highly creative scientist and who by his superb popular writings made abstract concepts of science accessible to millions of laypersons or the uninitiated ones. Gamow was a first class physicist. However, Gamow’s attitude to physics was larger than life. He was particularly known for finding the right scientific problems for research and introducing conceptual simplicity to them. Gamow was a pioneer in theoretical investigations of atomic nuclei. He proposed a so-called nuclear fluid model of the nucleus. Gamow’s model of alpha decay (a form of radioactive decay) represented the first application of quantum mechanics to the study of nuclear structure. He also described beta decay (another form of radioactive decay). Gamow’s interests were not confined within the bounds of physics. His ideas influenced research in a variety of topics. Gamow made important advances in both cosmology and molecular biology. He studied the structure and evolution of stars and creation of elements. He showed how the collision of nuclei in the interior of the Sun could produce the nuclear reactions that produce the energy. Gamow was a major expounder of the ‘Big Bang’ theory of the origin of the universe. He suggested how DNA might provide the code for protein synthesis. Gamow is regarded as one of the greatest science popularisers of all time. George Gamow (his original name in Russian was George Antonovich Gamow) was born on March 04, 1904 in Odessa, Russia (now in Ukrain). His father was a school teacher. Astronomy fascinated Gamow since his early school years. He used to patiently examine the starry sky through a little telescope presented by his father. During 1923-29 he studied optics and cosmology at the University of Leningrad (St Petersburg). Before joining the University of Leningrad, Gamow had spent a year (1922-23) at the Novorossia University in his hometown, Odessa. In 1926 Gamow attended summer-school in Gottingen in Germany. During his PhD work Gamow explained the then mysterious phenomenon of natural radioactivity as well as Rutherford’s experiments on the induced transformation of light elements by applying the newly developed quantum theory. In 1928 he received his PhD degree from the University of Leningrad. After receiving his PhD Gamow went to work at the Institute of Theoretical Physics in Copenhagen, where Niels Bohr (1885-1962) became very interested in his work. Bohr offered Gamow a one-year scholarship (1929-30) from the Royal Danish Academy. While working there Gamow proposed a hypothesis that the atomic nuclei can be treated as little droplets of so-called nuclear fluid. In this model, called the liquid drop model of the nucleus, neutrons and protons behave like the molecules in a drop of liquid. John Archibald Wheeler (1911- ) and Niels Bohr adopted this model for explaining the process of nuclear fission. Wheeler and Bohr proposed that the spherical nucleus may get distorted into dumb-bell shape and when sufficient energy is acquired by the nucleus, say, by absorption of a neutron, the nucleus splits into two fragments. And in this process energy is released. These discoveries led to today’s theory of fusion and fission. During 1929-30 Gamow worked in Cambridge University with Ernest Rutherford (1871-1937) as Rockefeller Fellow. In 1931 Gamow was asked to return to the erstwhile Soviet Union to join as Master of Research at the Academy of Science in Leningrad. In those days Joseph Stalin (1879-1953) was in power. Gamow and his wife wanted to leave USSR. In their first attempt to escape from Russia, they planned to go to Turkey by crossing the Black Sea. They undertook this journey of 270 km on a small boat (kayak). After continuing their journey for 36 hours they had to abandon it because of bad weather. They came back. Gamow somehow could convince that they were carrying out some experiments on the boat. After making a few more unsuccessful attempts they finally got a chance to realize their goal. In 1933 Gamow was permitted by the authorities to attend the Solvay Congress in Brussels. Gamow’s wife Lyubov Vokhminzeva was also allowed to go as his Secretary. They did not return to the Soviet Union. After getting an invitation for lecturing at the University of Michigan, Gamow and his wife left for USA in 1934. While in USA, he was offered a professorship at the George Washington University. For excepting the offer he put forward three conditions; His first condition was that the university also appoint a colleague of his choice to work with him in the physics department. His choice was Edward Teller (1908- ), who was then working at Birbeck College in London. His second condition was the support of Cloyd Heck Marvin, the president of the university, and Merle Antony Tuve (1901-82), Director of the accelerator laboratory at the Carnegie Institution of Washington, in organizing a conference on theoretical physics to be held annually in Washington under the joint auspices of the university and the Carnegie Institution. The third condition was that his initially appointment in the George Washington University be described as Visiting Professor. The conditions were accepted by the University authorities. In his early years at the George Washington University, Gamow’s collaboration with Edward Teller on the theory of beta decay (that is emission of electrons from the nucleus) led to the formulation of the so-called “Gamow-Teller Selection Rule for Beta Emission”. Among his other research works carried out while working at the George Washington University were: the theory of the internal structure of red giant stars, the theory of so-called Urca process (jointly with Mario Schoenberg) and the theory of the origin of chemical elements by the process of successive neutron capture, jointly with Ralph Asher Alpher (1921- ). The beta decay or the emission of an electron from the nucleus is accompanied by the emission of a neutrino. When a nucleus captures an electron an antineutrino is emitted. Gamow proposed that when these processes take place in the interior of stars the resulting neutrinos and antinutrinos escape, and matter in the stellar interior can rapidly loose energy. Gamow called this process `Urca process’ after a casino in Rio de Jeneiro where the customers lose money easily. In 1948 Gamow and his colleague Ralph Alpher wrote a paper about the Big Bang theory and how matter originated. Gamow proposed that the matter of the universe originally existed in a primordial state called the “Ylem”. Helium and perhaps other elements formed from the “Ylem” shortly after the Big Bang had started the Univers’s exapansion. The Big Bang theory was originally proposed by Absbe Georges Edouard Lemaitre (1894-1966). In his last years Gamow started working in biology. He made a major contribution to the problem of how the order of the four different kinds of bases (adenine, cytosine, thymine and guanine) in DNA chains could control the synthesis of proteins from amino acids. He proposed that short sequences of the bases could form a ‘code’ capable of carrying necessary information for the synthesis of proteins. As there are only twenty amino acids that make up all the proteins, the code must consist of blocks of three bases because then only it will have a vocabulary of sufficient instructions. It cannot be one base for one amino acid because then there will be only four amino acids. If two bases code for one amino acid then they could produce only 4x4 = 16 amino acids. So it would therefore need a sequence of three bases to code for one amino acid, with a capacity of 4x4x4 =64 words, which was more than adequate for the construction of all proteins. Gamow’s coding scheme generated a great deal of interest among scientists working in the concerned fields. His great innovation was the introduction of mathematical reasoning to the coding problem without going into much biochemical details. For regular exchange of ideas on the coding problem Gamow formed the so-called RNA Tie Club consisting of 20 hand-picked scientists corresponding to the 20 amino acids. Each member of the Tie club was given the nickname of an amino acid , and all were presented with a diagrammed tie and tiepin made to Gamow’s specifications. Though the members were located in different parts of the world, the Tie Club brought physical scientists and biologists together to work on one of the most challenging problems in modern science. The concept of code for transferring genetic information was casually mentioned by Watson and Crick in a 1953 article. However, this was first publicly articulated in an article published in late 1954 by Gamow, Martynas Ycas and Alexander Rich. By 1960 it was shown that Gamow’s central idea was correct. In 1956 Gamow joined the University of Colorado as Professor and stayed there till his death. Besides his excellent research contributions in physics, cosmology and biology, Gamow wrote a number of important textbooks:
Perhaps to many Gamow is known only as a popular science writer. His popular science writings have influenced millions in all parts of the world. His keen sense of humour is very much evident in his popular science writings. His books will remain as classics in the history of science popularization. Gamow is regarded as one of the most successful writers of all time. He wrote many books and most of these are still in print. Through these beautiful written books Gamow successfully conveyed much of the excitement of the revolution in physics that he lived through and other scientific topics of interest. Gamow himself prepared the illustrations for his books. Thus the illustrations added a new dimension. They complemented what he intended to convey in text. Wherever it was essential he used mathematics. The popular science books written by Gamow are listed below:
His books have been translated into many languages. In 1956 Gamow was awarded the Kalinga Prize by UNESCO—the only international award given for science popularization. Commenting on Gamow’s writings C.S.Yoganand wrote: “There have been many great scientists – I don’t need to give examples! – and many popular science writers – Isaac Asimov’s is perhaps one of the names that comes to mind immediately. But Gamow belong to that rare species of first class scientists who are also first class science communicators. It is hard to name another from the same species... A distinguishing feature of Gamow’s writings, indeed of his life itself, is universality. They represent science as a whole. Importantly, he does not avoid mathematics if and when necessary unlike most of the ‘popular science writers”. References
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Sunday, January 3, 2010
George Gamow - Scientist and Science Populariser
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