George Gamow was a Ukrainian-American theoretical physicist and cosmologist, who worked with many of the pioneers of quantum theory. He is perhaps best known for his discovery of alpha decay via quantum tunnelling, and for his work on the radioactive decay of the atomic nucleus, including an early “liquid drop” model of the atom. His predictions of cosmic microwave background radiation and his explanation of the present levels of hydrogen and helium in the universe both lent important theoretical support to the Big Bang theory. However, he also published important papers on star formation, stellar nucleosynthesis and genetics/DNA.
Georgiy Antonovich Gamov was born on 4 March 1904 in Odessa in the Russian Empire (now in Ukraine) to ethnic Russian parents, both of whom were teachers. His mother died when he was 9 years old and he was brought up by his father. His education at the local gymnasium was often interrupted by shelling during the First World War, so he was to a large extent self-taught.
His education continued at the Novorossiya University in Odessa from 1922 to 1923, and then at the University of Leningrad from 1923, where he studied optics and, later, cosmology. He studied for a time under Alexander Friedmann before Friedmann’s untimely death in 1925. At Leningrad, Gamow became friends with two other students of theoretical physics, Lev Landau and Dmitri Ivanenko, and the three (known as “The Three Musketeers”) met regularly to discuss and analyze the ground-breaking papers on quantum mechanics which were being published during those years.
On gaining his PhD from the University of Leningrad in 1928, he worked on quantum theory at the University of Göttingen in Germany, where his research into the atomic nucleus provided the basis for his doctorate. He was invited to Niels Bohr’s Institute for Theoretical Physics at the University of Copenhagen from 1928 to 1931, with a break in 1929 to work with Ernest Rutherford at the Cavendish Laboratory, Cambridge. He continued to study the atomic nucleus, and was the first to propose a “liquid drop” model of the atom (which treats the nucleus of an atom as a drop of incompressible nuclear fluid) which Neils Bohr and John Wheeler later went on to develop. He also worked on stellar physics with Robert Atkinson and Fritz Houtermans.
In 1928, Gamow described the theory of the alpha decay of a nucleus via quantum tunnelling, the first successful explanation of the behaviour of radioactive elements using quantum theory. According to classical physics, it takes an enormous amount of energy to pull apart the nucleus of an atom, and particles are confined to the nucleus because of the high energy requirement to escape the very strong potential. In quantum mechanics, however, there is a finite probability that the particle can “tunnel” through the potential and escape (alpha decay), as Gamow demonstrated from first principles through a relationship between the half-life of the particle and the energy of the emission.
After his time in Copenhagen, Gamow returned to the USSR and worked at a number of Soviet establishments before deciding to flee Russia due to the increased oppression. His first two attempts in 1932 to defect with his wife, fellow physicist Lyubov Vokhminzeva, by kayaking 250 kilometres across the Black Sea to Turkey, and then from Murmansk to Norway, were both foiled by poor weather. Eventually, the two successfully defected while attending the 1933 Solvay Conference for physicists in Brussels, Belgium.
They moved to the United States in 1934, and Gamow began working as Professor of Physics at George Washington University in Washington DC, where he remained until 1954. During this time, he collaborated with Edward Teller, and the two published some important joint papers, including one on beta decay in 1936, and one on a theory of the internal structures of red giant stars in 1942. He became a naturalized American in 1940.
In 1948, Gamow and his student Ralph Alpher produced an important paper on cosmogony entitled "The Origin of Chemical Elements", which outlined how the present levels of hydrogen and helium in the universe (which between them 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 the presence of other elements heavier than helium was explained later by Fred Hoyle, who was actually an opponent of the Big Bang theory.
In the same paper, Gamow made an estimate of the strength of residual cosmic microwave background radiation (CMB), predicting that the afterglow of the Big Bang would have cooled after billions of years, filling the universe with a radiation about five degrees above absolute zero. This prediction was only proved by the accidental discovery of CMB (with a temperature 2.7 degrees above absolute zero) by Arno Penzias and Robert Wilson in 1965, considered one of the most important substantiations of the Big Bang theory.
In the 1950s, after the discovery of the structure of DNA in 1953 by Francis Crick and James Watson, Gamow turned his attention to biochemistry and genetics, and 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. Although flawed, his work was important in helping Crick and Watson to enumerate the twenty amino acids which are common to most proteins.
Gamow was a highly successful science writer, and managed to convey the excitement of the revolution in physics and other scientific topics of interest to the common reader. In 1956, he was awarded the Kalinga Prize by UNESCO for his work in popularizing science through his “Mr. Tompkins...” series of books, as well as “One Two Three...Infinity” and other works.
Gamow remained at George Washington University until 1954, then worked briefly at the University of California, Berkeley from 1954 to 1956, and then at the University of Colorado at Boulder from 1956 to 1968.
He gradually developed an excessive drinking habit which may well have precipitated his death on 19 August 1968, at age 64, in Boulder, Colorado. He was buried in Boulder’s Green Mountain Cemetery.