# Four Physicists

After my Matric (Class X) I became increasingly interested in science history especially Nobel Prize winners in physics. I got photocopied the list of physics Nobel Prize winners from an encyclopaedia. I read some books on science history also. My father brought a physics book from a library. In that book were the sketches of all the Nobel Prize winners in physics upto that point. I asked one of my friend, now Dr Bilal Saeed, to make sketches of four physicists whom I liked for me. He made them for me. I kept these sketches for a long time. The four physicists were Albert Einstein, Richard Phillips Feynman, Lev Davidovich Landau and Murray Gell-Mann. From this site I came to know that all were Jews. I knew about two of them being Jews. Here are brief biographies of my favorite physicists.

### Albert Einstein

Albert Einstein was born at Ulm, Germany, on March 14, 1879. He entered the Swiss Federal Institute of Technology in Zürich at the age of 17, and on graduating became a Swiss citizen. He was unable to find a teaching post, he accepted a position as technical assistant in the Swiss Patent Office. In 1905 he obtained his doctor’s degree. It was while at the Patent Office that he produced the three papers published in 1905, covering Brownian motion, the photoelectric effect and special relativity.

The first of his papers of 1905 considered the Brownian motion that was discovered in 1828. Einstein’s calculations provided the most direct evidence for the existence of molecules. The next paper by Einstein tackled the photoelectric effect by considering the nature of electromagnetic radiation. Einstein assumed that light energy could only be transferred in packets. This was pivotal in establishing quantum theory within physics. He received the 1921 Nobel Prize in Physics “for his services to theoretical physics, and especially for his discovery of the law of the photoelectric effect”. Finally, Einstein set out the special theory of relativity in his third paper. Einstein correctly proposed that the speed of light is the same in all frames of reference. He put forward the principle of relativity, that all physical laws are the same in all frames of reference in uniform motion with respect to one another. He derived mass–energy equivalence formula $E = mc^2$ which has been dubbed “the world’s most famous equation”.

In 1909 he became Professor Extraordinary at Zurich, in 1911 Professor of Theoretical Physics at Prague, returning to Zurich in the following year to fill a similar post. In 1914 he was appointed Director of the Kaiser Wilhelm Physical Institute and Professor in the University of Berlin. He became a German citizen in 1914. He was in California when Hitler came to power in 1933. He never returned to Germany,resigning his position and taking up a post at the Institute of Advanced Study, Princeton. He became a United States citizen in 1940 and retired from his post in 1945. He helped initiate the Allied efforts to make an atomic bomb (the Manhattan project) by warning Roosevelt, the American president. In 1952 Einstein was offered, and sensibly declined, the presidency of Israel. He collaborated with Dr. Chaim Weizmann in establishing the Hebrew University of Jerusalem. He was also active in promoting nuclear disarmament after the Second World War.

From 1907 Einstein sought to extend relativity theory to frames of reference which are being accelerated with respect to one another. In 1915 he had published the general theory of relativity in complete form, using Riemannian geometry. Mass was taken to distort the ‘flatness’ of space-time and so to give rise to bodies in space moving along curved paths about one another. During the 1920s and 1930s Einstein engaged in debate over quantum theory, rejecting Born’s introduction of probability (‘God may be subtle, but He is not malicious’). He also sought to find a unified theory of electromagnetic and gravitational fields but without success.

He led a simple life, with sailing and music as his main relaxations. He married Mileva Maric in 1903 and they had a daughter and two sons; their marriage was dissolved in 1919 and in the same year he married his cousin, Elsa Löwenthal, who died in 1936. He died on April 18, 1955 at Princeton, New Jersey.

### Richard Phillips Feynman

Richard P Feynman was born in New York City on the 11th May 1918. He studied at the Massachusetts Institute of Technology where he obtained his B.Sc. in 1939 and at Princeton University where he obtained his Ph.D. in 1942.He was the architect of the modern space-time diagram formulation of quantum electrodynamics (QED), the theory that describes the quantum interaction of electrons with electromagnetic fields. He developed a widely used pictorial representation scheme for the mathematical expressions governing the behaviour of subatomic particles, which later became known as Feynman diagrams. For this work he shared the 1965 Nobel Prize in physics with Julian S Schwinger and Sin-Itiro Tomonaga. During his lifetime, Feynman became one of the best-known scientists in the world.

During World War II, he joined the Manhattan Project to build the atomic bomb, working first at Princeton, New Jersey, then at Los Alamos. He became the youngest group leader in the theoretical division, headed by Hans A Bethe, with whom he devised the formula for predicting the energy yield of a nuclear explosive. From 1945 to 1950, Feynman was at Cornell University as professor of theoretical physics. In 1950, Feynman accepted a professorship of theoretical physics at the California Institute of Technology, where he remained for the rest of his life. In the early 1950s, he provided a quantum mechanical explanation for the Soviet physicist Lev D Landau’s theory of super fluidity. This helped with the problem of superconductivity; however, the solution eluded Feynman. It was solved with the BCS theory of superconductivity, proposed by John Bardeen, Leon Neil Cooper, and John Robert Schrieffer.In 1958, Feynman contributed to the theory of nuclear interactions with Murray Gell-Mann. He invented a theory of partons, or hypothetical hard particles inside the nucleus of the atom, that helped lead to the theory of quarks. Between 1963 and 1965, he published his classic textbook based on his introductory physics course “The Feynman Lectures on Physics.” As of 2005, “The Feynman Lectures on Physics” has sold over 1.5 million copies in English, an estimated 1 million copies in Russian, and an estimated half million copies in other languages.

He was a member of the panel that investigated the Space Shuttle Challenger disaster. In addition to his work in theoretical physics, Feynman has been credited with pioneering the field of quantum computing, and introducing the concept of nanotechnology. He also had a deep interest in biology, and was a friend of the geneticist and microbiologist Esther Lederberg, who developed replica plating and discovered bacteriophage lambda. Feynman developed two rare forms of cancer, Liposarcoma and Waldenström’s macroglobulinemia, dying shortly after a final attempt at surgery for the former on February 15, 1988, aged 69. His last recorded words are noted as “I’d hate to die twice. It’s so boring.”

### Lev Davidovich Landau

Lev Davidovich Landau was born on January 22, 1908 to Jewish parents in Baku, in what was then the Russian Empire. Landau’s father was an engineer with the local oil industry and his mother was a doctor who did research in physiology. Landau was a mathematical prodigy and finished his secondary studies at age 13. Too
young to attend university, he studied physics and chemistry at the Baku Economical Technical School for a year before enrolling in Leningrad State University. After graduating from the Physical Department of Leningrad University at the age of 19, he began his scientific career at the Leningrad Physico-Technical Institute. The years 1929 – 1931 he spent abroad working in Germany, Switzerland, England and, especially, in Copenhagen under Niels Bohr. From then on he became a disciple of Bohr, whose work would have a powerful impact on his subsequent research, which involved applying the quantum paradigm to all realms of theoretical physics. Landau was a brilliant theorist whose research and teaching raised theoretical physics in the Soviet Union to new levels. The range of his discoveries influenced all branches of theoretical physics, from fluid mechanics to quantum field theory. His theoretical explanation of why liquid helium is a super fluid earned him the 1962 Nobel Prize in physics.

In 1930, Landau published a quantum theoretical study on the behavior of free electrons in a magnetic field that drew him instant international recognition. During 1932 – 1937 he was head of the Theoretical Department of the Ukrainian Physico-Technical Institute at Kharkov. Under his leadership, it became the center of theoretical physics in the Soviet Union. In 1937, Landau left Kharkov for Moscow to become head of the Theory Division of Institute of Physical Problems and teach at Moscow University. During the Great Purge, Landau was arrested on April 27, 1938 and held in an NKVD prison until his release on April 29, 1939, after his colleague Pyotr Kapitsa, an experimental low-temperature physicist, wrote a letter to Joseph Stalin, personally vouching for Landau’s behaviour.

The “Course of Theoretical Physics” is a ten-volume series of books covering theoretical physics that was initiated by Lev Landau and written in collaboration with his student Evgeny Lifshitz starting in the late 1930s. Generations of physicists, both in Russia and around the world, have been educated in physics through this series. In 1962 he received, jointly with E.M. Lifshitz, the Lenin Science Prize for their “Course of Theoretical Physics.” Landau developed a comprehensive exam called the “Theoretical Minimum” which students were expected to pass before admission to the school. The exam covered all aspects of theoretical physics, and between 1934 and 1961 only 43 candidates passed. Landau kept a list of names of physicists which he ranked on a logarithmic scale of productivity ranging from 0 to 5. The highest ranking, 0.5, was assigned to Albert Einstein. A rank of 1 was awarded to “historical giants” Isaac Newton, Eugene Wigner, and the founding fathers of quantum mechanics, Niels Bohr, Werner Heisenberg, Paul Dirac and Erwin Schrödinger. Landau ranked himself as a 2.5 but later promoted himself to a 2.

In 1962, the year he won the Nobel Prize, Landau was in a car accident that left him unconscious for six weeks. Several times doctors declared him clinically dead. Although he did regain consciousness and lived for another six years, he was never again capable of creative work. He died in Moscow on April 1, 1968.

### Murray Gell-Mann

Murray Gell-Mann was born on 15th September 1929, in New York City. He obtained his B.Sc. at Yale University in 1948, and his Ph.D. in 1951 at the Massachusetts Institute of Technology. He was a postdoctoral fellow at the Institute for Advanced Study in 1951, and a visiting research professor at the University of Illinois at Urbana–Champaign from 1952 to 1953. He was a visiting associate professor at Columbia University and an associate professor at the University of Chicago in 1954-55 before moving to the California Institute of Technology, where he taught from 1955 until he retired in 1993. He was awarded a Nobel Prize in physics in 1969 for his contributions and discoveries concerning the classification of elementary particles and their interactions. He is currently the Robert Andrews Millikan Professor of Theoretical Physics Emeritus at Caltech as well as a University Professor in the Physics and Astronomy Department of the University of New Mexico in Albuquerque, New Mexico and the Presidential Professor of Physics and Medicine at the University of Southern California.

At 24, Gell-Mann made a major contribution to the theory of elementary particles by introducing the concept of ‘strangeness’, a new quantum number which must be conserved in any so-called ‘strong’ nuclear interaction event. In 1953, Gell-Mann published a series of papers predicting specific, as yet undiscovered new particles, as well as other particles he insisted could not be discovered. His timing could not have been better. Successive experiments confirmed each of his positive predictions and did not contradict the negative ones. His “eightfold way” theory described the nuclear force in terms of a new fundamental quantity called strangeness, which obeyed a new kind of symmetry principle (called Unitary Symmetry SU[3]). This new theory presupposed a more basic elementary particle, which Gell-Mann called a quark, hidden inside the protons and neutrons of the nucleus. On the basis of this insight, he was able to impose order on the chaos of the particle zoo that was created by the discovery, in high-energy particle accelerator experiments, of some 100 excited states of particles associated with the atomic nucleus. Six types of quark are now recognized. Five were detected indirectly after 1964, but the sixth (‘top’) quark eluded detection until 1995.

Gell-Mann married Marcia Southwick in 1992, after the death of his first wife, J. Margaret Dow (d. 1981), whom he married in 1955. His children are Elizabeth Sarah Gell-Mann (b. 1956) and Nicholas Webster Gell-Mann (b. 1963); and he has a stepson, Nicholas Southwick Levis (b. 1978).