Weinberg (Weinberg), Steven( The American physicist, Nobel Prize in Physics, 1979)
Comments for Weinberg (Weinberg), Steven
Biography Weinberg (Weinberg), Steven
genus. May 3, 1933
American physicist Steven Weinberg was born in New York, the son of Eva (nee Israel) Weinberg and Frederick Weinberg, court stenographer. His early interest in science was stimulated and encouraged his father in science-oriented school in the Bronx, where one of his teachers was Sheldon L. Glashow. For sixteen years interests in. focused on theoretical physics.
Received in 1954. bachelor's degree from Cornell University,. worked for the Institute for Theoretical Physics in Copenhagen (now the Niels Bohr Institute). Back in the U.S., he in 1957, Mr.. received his doctorate from Princeton University, and the thesis was devoted to applications to renormalization, and the mathematical technique, an important place in his later works.
After defending his doctoral dissertation in. from 1957. worked at Columbia University and then taught at the University of California at Berkeley until 1969, when he became a lecturer at the Massachusetts Institute of Technology. In 1973, Mr.. he moved to Harvard University as professor of physics, having inherited the post from Julius C. Schwinger. Simultaneously, he served as chief scientific officer at the Smithsonian Astrophysical Observatory.
. As he indicated in his own report, his interests were very broad, including the 'great variety of themes - vysokoenergicheskoe behavior of Feynman diagrams (named after Richard P
. Feiniana), neutral current weak interactions, symmetry breaking, scattering theory, the physics of muons, etc. - those are often chosen simply because they wanted their own understanding in some areas of physics'. In his most famous study, he tried to unify the fundamental forces of nature.
At the beginning of the XIX century. physics reduced the forces acting in nature, the three of gravity, electricity, magnetism. In the 1870's. Scottish physicist James Clerk Maxwell found that electricity and magnetism are not independent forces, and represent different aspects of force, now known as electromagnetism. Maxwell was able to show, . that light is an electromagnetic phenomenon, . and determine its speed, . predict the existence of radio waves, and to encourage further research to find a deep principle, . to encompass all the forces of nature.,
. After the discovery of the atomic nucleus in the XX century
. scientists had to add two additional forces: the strong interaction and weak interaction of the strong interaction holds together the protons and neutrons that make up the atomic nucleus. In contrast, the weak interaction, instead of holding the particles together, separates them, as, for example, it is the radioactive emission of beta rays (electrons). Unlike gravity and electromagnetism, which operate at unlimited distances, the strong interaction does not apply for the core-mantle boundary. Weak interaction extends to even smaller area. According to V., Glashow and Abdus Salam, the electromagnetic and weak forces are different aspects of a single 'electroweak' force.
. With the help of the concept, called the gauge symmetry, Glashow first tried to unite electromagnetism with the weak force (weak interaction) in 1960
. There are several types of symmetries, including the mirror symmetry (like a pair of gloves) and the charge symmetry (the interaction force between two particles carrying electric charge, will not change if the particles exchange their charges). Symmetry, . due to gauge invariance, . deals with the mathematical values, . absolute value of which (as opposed to relative) does not affect the physical interaction, . so that the origin can be changed, . without changing any of the observed values.,
. While the term 'gauge symmetry' was introduced in 1920, this concept can be traced in earlier works
. Indeed, Maxwell's theory of electromagnetism can be interpreted as the application of this principle of symmetry. Conclusions of Maxwell's theory remains the same, no matter from what point of counting the value of the voltage. For such a point is usually chosen the one which corresponds, to use an electrical engineer, the potential of the Earth. Absolute value of electric potential plays no role; voltage is the potential difference at two points for one of them can take the point of the Earth. Trying to apply the principle of gauge symmetry to the more complex physics of strong interactions, Chen Ning Yang and Robert L. Mills in 1954. have progressed towards the establishment of a unified concept of forces in nature, which has contributed and the work of Glashow, in. and Salama.
New promotion occurred in 19601. When Glashow suggested the existence of four particles, serving as carriers of electromagnetism and the weak interaction. One of them, the photon (or quantum of light), was already known as a carrier of electromagnetic energy. Three other particles (which now are called bosons-W +, W-and Z0) serve as mediators in weak interactions. Because the carrier particles had no mass, weak interactions should, according to the theory of Glashow, in an unlimited distances, which obviously contradicts the experimental data. To cope with this difficulty, Glashow postulated large masses of bosons W +, W-and Z0, but now the theory predicts that some of the weak interaction should be carried out with infinite power.
. Using a gauge theory, as Glashow, in
. proposed in 1967. unified theory. His decision, which depends on a mechanism known as spontaneous symmetry breaking, is that the photon is still considered to have no mass, whereas the remaining three particles have mass. According to this theory, electromagnetic and weak forces are identical with the extremely high energies. Under these conditions, the mass of the W and Z bosons have little effect on the process, since the massive particles are easily formed from the available energy (in the theory of relativity, Albert Einstein established the equivalence of mass and energy). Thus, the exchange of W-and Z-bosons in accuracy is the same as the exchange photon, and the forces of the weak interaction is as strong as the electromagnetic. However, at lower energies W and Z particles are formed rarely, so that the weak interactions become less frequent and occur at smaller distances than electromagnetic. As the earthly world of physics exists at relatively low energies, the difference between these two forces appears more than their similarities.
A year later, after in. reported on his theory, Abdus Salam independently of him suggested a similar theory. Their ideas did not attract much attention until 1971, when the Netherlands physicist Gerhard Hooft used a mathematical technique called renormalization and proposed Julius C. Schwinger and Tomonaga Itiro, which allowed him and other researchers to complete the study of unified forces of nature. The theory of gauge symmetry, developed by Glashow, in. and Salam, found dramatic confirmation in 1973, when they were discovered weak neutral currents in the experiments conducted in the laboratories of the National Accelerator. Farm near Chicago and at CERN (European Organization for Nuclear Research) near Geneva. In 1983. W-and Z-bosons were discovered at CERN by Carlo Rubbia and his colleagues
V., Glashow and Salam were awarded in 1979. Nobel Prize in Physics "for his contribution to the unified theory of weak and electromagnetic interactions between elementary particles, including the prediction of weak neutral currents'. In his Nobel lecture in. spoke about the symmetries, or regularity, manifested in the laws of nature. "We can study the matter only at low temperatures, where, it seems, the symmetry is spontaneously broken, so that nature does not look simple or single ... But, watching the long and hard, we can identify the forms of symmetry, which, though broken, are precisely the principles that govern all nuclear phenomena '.
Since 1982, Mr.. V. has served as professor of the University of Texas at Austin. He was a consultant to the Institute for Defense Studies (1960 ... 1973) and the Agency for Disarmament and Arms Control United States (1971 1973). In addition to work on elementary particles and field theory, including quantum theory and general relativity, he showed great interest in astronomy and astrophysics.
In. Goldwasser and Louise were married in 1954, they have a daughter. In his leisure he likes to study medieval history.
In. won J. Robert Oppenheimer University of Miami (1973), Danny Heineman Prize (1977) American Physical Society and the Elliott Cresson Medal Franklinovskogo Institute (1979). He is a member of the U.S. National Academy of Sciences. American Physical Society, American Astronomical Society, Royal Society of London and the American Academy Middle. He has an honorary degree from Knox College, Chicago, Rochester, Yale, New York University and Clark University.