George Gamow

From Wikipedia, the free encyclopedia

George Gamow
George Gamow
George Gamow
Born March 04, 1904
Odessa, Russian Empire
Died August 19, 1968
Nationality United States, Russia
Fields Physicist, Science writer
Known for Cosmic microwave background radiation, Quantum tunnelling, Big Bang

George Gamow (pronounced as IPA: [ˈgamof]) (March 4, 1904 – August 19, 1968) , born Georgiy Antonovich Gamov (Георгий Антонович Гамов), was a Russian Empire-born theoretical physicist and cosmologist. He discovered alpha decay via quantum tunneling and worked on radioactive decay of the atomic nucleus, star formation, stellar nucleosynthesis, big bang nucleosynthesis, nucleocosmogenesis and genetics.

Contents

[edit] Life and career

Gamow was born in the town of Odessa, Russian Empire (now in Ukraine) to ethnic Russian parents. He was educated at the Novorossiya University in Odessa (1922–23) and at the University of Leningrad (1923–1929). Gamow studied under Alexander Friedmann for some time in Leningrad, though Friedmann died in 1925. At the University Gamow made friends with two other students of theoretical physics, Lev Landau and Dimitri Dmitrievich. The three formed a group known as the Three Musketeers which met to discuss and analyze the ground-breaking papers on quantum mechanics published during those years.

On graduation, he worked on quantum theory in Göttingen, where his research into the atomic nucleus provided the basis for his doctorate. He then worked at the Theoretical Physics Institute of the University of Copenhagen, from 1928 to 1931, with a break to work with Ernest Rutherford at the Cavendish Laboratory, Cambridge. He continued to study the atomic nucleus (proposing the "liquid drop" model), but also worked on stellar physics with Robert Atkinson and Fritz Houtermans.

In the early 1900s, radioactive materials were known to have characteristic exponential decay rates or half lives. At the same time, radiation emissions were known to have certain characteristic energies. By 1928, Gamow had solved the theory of the alpha decay of a nucleus via tunnelling. Classically, the particle is confined to the nucleus because of the high energy requirement to escape the very strong potential. Also classically, it takes an enormous amount of energy to pull apart the nucleus. In quantum mechanics, however, there is a probability the particle can tunnel through the potential and escape. Gamow solved a model potential for the nucleus and derived a relationship between the half-life of the particle and the energy of the emission, known as the Geiger-Nuttall law.

Gamow then worked at a number of Soviet establishments before deciding to flee Russia because of increased oppression. His first two attempts to defect with his wife, Lyubov Vokhminzeva, were in 1932 and involved attempting to kayak: first a 250 kilometer paddle over the Black Sea to Turkey and then from Murmansk to Norway. Poor weather foiled both attempts. In 1933, the two tried a less dramatic approach--Gamow managed to obtain permission for himself and his wife (who was also a physicist) to attend the Solvay Conference for physicists in Brussels. The two attended and promptly defected. In 1934, they moved to the United States. He began working at The George Washington University in 1934, where he published articles with Edward Teller, Mario Schenberg and Ralph Alpher. Gamow became a naturalized American in 1940.

[edit] Big bang theory work

Gamow produced an important cosmogony paper with his student Ralph Alpher, which was published as "The Origin of Chemical Elements" (Physical Review, April 1, 1948). This paper became known as the Alpher-Bethe-Gamow theory. (Gamow had added the name of Hans Bethe, listed on the article as "H. Bethe, Cornell University, Ithaca, New York" (who had not had any role in the paper) to make a pun on the first three letters of the Greek alphabet, alpha beta gamma.)

The paper outlined how the present levels of hydrogen and helium in the universe (which are thought to make up over 99% of all matter) could be largely explained by reactions that occurred during the "big bang". This lent theoretical support to the big bang theory, although it did not explain the presence of elements heavier than helium (this was done later by Fred Hoyle).

In the paper, Gamow made an estimate of the strength of residual cosmic microwave background radiation (CMB). He predicted that the afterglow of big bang would have cooled down after billions of years, filling the universe with a radiation five degrees above absolute zero.

Gamow published another paper in the British journal Nature later in 1948, in which he developed equations for the mass and radius of a primordial galaxy (which typically contains about one hundred billion stars, each with a mass comparable with that of the sun).

Astronomers and scientists did not make any effort to detect this background radiation at that time, due to both a lack of interest and the immaturity of microwave observation. Consequently, Gamow's prediction in support of the big bang was not substantiated until 1964, when Arno Penzias and Robert Wilson made the accidental discovery for which they were awarded the Nobel Prize in physics in 1978. Their work determined that the universe's background radiation was 2.7 degrees above absolute zero, just 2.3 degrees lower than Gamow's 1948 prediction.

[edit] DNA and later career

Grave of George Gamow in Green Mountain Cemetery, Boulder, Colorado, USA
Grave of George Gamow in Green Mountain Cemetery, Boulder, Colorado, USA

After the discovery of the structure of DNA in 1953 by Francis Crick and James Watson, Gamow attempted to solve 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.[1] Crick has said[2] that Gamow's suggestions helped him in his own thinking about the problem. As related by Crick,[3] Gamow suggested that the twenty combinations of four DNA bases taken three at a time correspond to twenty amino acids used to form proteins. This led Crick and Watson to enumerate the twenty amino acids which are common to most proteins.

However the specific system proposed by Gamow (known as "Gamow's diamonds") was incorrect, as the triplets were supposed to be overlapping (so that in the sequence GGAC (for example), GGA could produce one amino acid and GAC another) and non-degenerate (meaning that each amino acid would correspond to one combination of three bases - in any order). Later protein sequencing work proved that this could not be the case; the true genetic code is non-overlapping and degenerate, and changing the order of a combination of bases does change the amino acid.

Gamow remained at George Washington University until 1954, then worked at University of California, Berkeley (1954), and University of Colorado at Boulder (1956–1968).

On August 19, 1968, George Gamow died at age 64 in Boulder, Colorado, and was buried there in Green Mountain Cemetery. The University of Colorado at Boulder Physics department tower is named after him.

The George Gamow Tower at the University of Colorado at Boulder
The George Gamow Tower at the University of Colorado at Boulder

[edit] Writings

Gamow was a highly successful science writer, with several of his books still in print. He conveyed the excitement of the revolution in physics and other scientific topics of interest to the common reader. Gamow himself prepared the illustrations for his books, which added a new dimension to and complemented what Gamow intended to convey in the text. Wherever it was essential, he used mathematics.

In 1956, he was awarded the Kalinga Prize by UNESCO for his work in popularizing science with his Mr. Tompkins... series of books (1939–1967), One Two Three ... Infinity, and other works.

Gamow was working on a textbook entitled Basic Theories in Modern Physics, with Richard Blade, but it was not completed before he died. He wrote a book entitled My World Line: An Informal Autobiography, which was published posthumously in 1970.

[edit] Books

[edit] Popular

  • The Birth and Death of the Sun (1940)
  • The Biography of the Earth (1941)
  • One, Two, Three...Infinity (1947), Viking Press (copyright renewed by Barbara Gamow, 1974), Dover Publications, ISBN 0-486-25664-2, illustrated by the author. Dedicated to his son, Igor Gamow ("who wanted to be a cowboy") The book winds from mathematics to biology, through physics, crystallography, and more.
  • The Moon (1953)
  • Puzzle-Math (1958) with Marvin Stern
  • Biography of Physics (1961)
  • Gravity (1962) Dover Publications, ISBN 0-486-42563-0. Profiles of Galileo, Newton, and Einstein
  • A Planet Called Earth (1963)
  • A Star Called the Sun (1964)
  • Thirty Years That Shook Physics: The Story of Quantum Theory, 1966, Dover Publications, ISBN 0-486-24895-X. Illustrated by the author and with period photographs, Gamow describes an insider's view of the development of quantum theory. Having worked with Niels Bohr and Ernest Rutherford, he not only can expound the theory, he supplies candid photos of Edward Teller on skis, Bohr on a motorcycle, Werner Heisenberg having a swim, and Enrico Fermi playing tennis. The finale is a dramatic playscript (also illustrated) of the history of atomic physics with the scientists cast in roles after the model of Goethe's Faust.
  • My World Line: An Informal Autobiography (1970) Viking Press, ISBN 0-670-50376-2

[edit] Mr. Tompkins series

  • Mr. Tompkins in Wonderland (1940) Originally published in serial form in Discovery magazine (UK) in 1938.
  • Mr. Tompkins Explores the Atom (1945)
  • Mr. Tompkins Learns the Facts of Life (1953), about biology
  • Mr. Tompkins in Paperback (1965), combines Mr. Tompkins in Wonderland with Mr. Tompkins Explores the Atom, Cambridge University Press, 1993 Canto edition with foreword by Roger Penrose, ISBN 0-521-44771-2. Creatively illustrated by the author, and complete with a scored musical composition ("The Cosmic Opera"), the book explains the principles of relativity and quantum theory in a fashion that is entertaining to young people and adults.
  • Mr. Tompkins Inside Himself (1967), A rewritten version of Mr. Tompkins Learns the Facts of Life gives a broader view of biology, including recent developments in molecular biology. It was coauthored by M. Ycas.

[edit] Science textbooks

  • The Constitution of Atomic Nuclei and Radioactivity (1931)
  • Structure of Atomic Nuclei and Nuclear Transformations (1937)
  • Atomic Energy in Cosmic and Human Life (1947)
  • Theory of Atomic Nucleus and Nuclear Energy Sources (1949) coauthor C. L. Critchfield
  • The Creation of the Universe (1952)
  • Matter, Earth and Sky (1958)
  • Physics: Foundations & Frontiers (1960) coauthor John M. Cleveland
  • The Atom and its Nucleus (1961)
  • Mr. Tompkins Gets Serious: The Essential George Gamow (2005) Pi Press, ISBN 0-13-187291-5. Incorporates material from Matter, Earth, and Sky and The Atom and Its Nucleus. Notwithstanding the title, this book is not part of the Mr. Tompkins series.

[edit] See also

[edit] References

  1. ^ Segrè, Gino (2000-03-30), “The Big Bang and the genetic code”, Nature 404 (6777): 437, doi:10.1038/35006517, <http://www.nature.com/cgi-taf/DynaPage.taf?file=nature/journal/v404/n6777/full/404437a0_r.html> 
  2. ^ DNA: An "Amateur" Makes a Real Contribution. Retrieved on 2007-07-11.
  3. ^ Crick, Francis "What Mad Pursuit" (Basic Books 1998), Chap.8 The Genetic Code

[edit] External links

Wikiquote has a collection of quotations related to: