Date of Birth: 09/10/1892
Place of birth: Worcester
Citizenship: United States
K. worked for years a teacher of physics at the University of Minnesota and then served two years as a research engineer in Pittsburgh "Westinghouse Lamp Company." There he was involved in the development and construction of lamps containing sodium vapor, and after the United States entered the First World War, helped to create aircraft instruments for the Signal Corps. While working in the company "Westinghouse" he went on to study X-rays, which subsequently led to his discovery of the effect named after him.
Fascinated by pure science, K. in 1919 he received a scholarship from the National Research Council and spent a year at the Cavendish Laboratory at Cambridge University. It was an exciting time: K. witnessed the first experiments of Ernest Rutherford on the splitting of the atom, which he later called the decisive factor in their academic life. Since there were Cavendish high X-ray unit, K. studied the scattering and absorption of gamma rays, which are high-energy X-rays emitted by radioactive nuclei. He noticed that the scattered radiation is easily absorbed by the substance than the primary radiation (rays that bombard the target), but neither he nor his colleagues at Cambridge could not explain this phenomenon using the laws of classical physics.
During the first two decades of the XX century. Physics gradually came to realize that classical physics is unable to explain the events that occur at the atomic level or intraatomic. Max Planck, Albert Einstein, Niels Bohr and others developed a new theory to explain some of subatomic phenomena, based on the radical assumption that energy is quantized, ie, that energy can be transferred only in discrete portions, or quanta. Quantum theory has been very useful to explain the phenomena previously seemed mysterious, and it allowed Bohr to build the most compelling of all the proposed models of the atom. However, quantum theory was not in its original form to deal with the analysis of the more common problems, and the majority of physicists are not convinced of its fundamental importance. Between 1910 and 1920. K together with other physicists, who studied the interaction of matter and energy, continued to look for the classic explanation of his experimental results.
Back in 1920 in the United States, K. headed the Physics Department of the University of Washington in St. Louis (Missouri), where he performed his most famous experiments. With the help of X-ray spectrometer HS Bragg, he made accurate measurements of the wavelength of X-rays scattered by the target. K. found that scattered radiation can be of two kinds: one wavelength coincides with the length of the primary radiation and the other has a greater wavelength. The increase in wavelength, which became known as the Compton effect was proportional to the scattering angle. Again, the results did not respond K. explanation within the framework of classical physics, but this time he made a decisive step by referring to the quantum theory. He found that an increase in the wavelength can be explained by considering the X-rays as particles with values ??of energy and momentum, predicted by quantum theory. The X-ray beam - "energy particle," or quantum - colliding with electron donating part of its energy to an electron target; consequently, after particle collision has less energy at a frequency that corresponds to - or greater wavelength - radiation. The new discovery K. consistent with his earlier discovery, where they talked about the fact that the scattered gamma rays are absorbed by the material is easier than primary gamma rays; a low-energy (longer wavelength) radiation is absorbed more easily than high-energy (shorter wavelength).
Since the light, like X-rays, is a form of electromagnetic radiation, the Compton effect was a strong argument in support of the nominated in 1905, Einstein`s hypothesis that light has properties not only the waves, but also particles. Corpuscular properties of electromagnetic radiation manifested in the interaction of the primary X-rays and electrons, while the wave properties detected in detecting the scattered rays - the action of the spectrometer can only be explained by considering the X-rays as waves.
K. published his results in 1923, and that same year he became a professor at the University of Chicago. He has suggested that as a result of the scattering of X-rays, electrons, which happened this scattering of atoms emitted at a high speed. Such recoil electrons as they are called K, were discovered and experimentally verified later in the same year CH.T.R. Wilson, whose invention of the condensing chamber allowed to observe the tracks of electrically charged particles.
K. The results caused a stir among physicists, but its quantum interpretation was accepted immediately, because it is contrary to the ideas of JJ Thompson. American physicist William Doohan opposed K. theory and tried to show that the data K may be associated with other effects. K., Doohan and other physicists have conducted additional experiments, and in 1924, Duane withdrew their objections, convinced that its own measurements in excellent agreement with the theory of K. Recognition of the Compton effect was an important incentive for the development of quantum mechanics, a complicated mathematical treatment of quantum theory deep and far-reaching applications in physics and chemistry.
In the 20-ies. K. held other important studies of X-rays. For example, in 1922, he has shown that the X-rays are totally reflected from smooth surfaces such as glass or metal, thus demonstrating that the X-rays behave in a similar light. In 1925, Karl and his colleagues got this effect by using a grating spectrometer, which allowed to divide the scattered X-rays in the components with the appropriate wavelengths. Their work laid the foundation for the study of X-rays as a branch of optics, and one that would bring K reputation as an outstanding scientist.
K. received in 1927 the Nobel Prize in Physics "for the discovery of the effect named after him." He shared the award with CH.T.R. Wilson. Introducing the winners, Kai Sigban of the Royal Swedish Academy of Sciences said that the Compton effect "is now so important that no nuclear theory can not be accepted in the future if it does not agree with him and does not follow the laws established by its discoverer."
After receiving the award K. engaged in the development of experimental methods for investigating the distribution of electrons in atoms. Together with the X-ray energy measurement Kai Sigbanom this work formed the basis of the subsequent theories of atomic structure. Experimental studies K. also made contributions to the understanding of the magnetic properties of ferromagnetic materials such as iron.
In the early 30-ies. K. interested in cosmic rays (radiation incident on the earth from outer space), since the interaction of gamma rays and electrons in cosmic rays provides an important example of the Compton effect. Between 1931 and 1933. he led expeditions to many parts of the world to get the data on cosmic rays. He received further confirmed on the basis of the information in the 20-ies. Jacob Clay`s conclusions about the change in the intensity of cosmic rays as a function of latitude. K. correctly explained the change by showing that, contrary to prevailing opinion of the cosmic rays are influenced by the magnetic field of the Earth and consist, at least in part, of the charged particles.
In 1941, K. headed the Physics Department, and became dean of the Physical Sciences Division of the University of Chicago. In the same year, he headed a committee of the National Academy of Sciences, created in order to study the possible use of nuclear energy for military purposes. A favorable review of this group led to the approval of the Manhattan Project. From 1942 to 1945 K. was a director of one of the units of this project, known as the Metallurgical Laboratory. Here, the first nuclear reactor was built under the direction of Enrico Fermi. Later K. supervised the construction of the Oak Ridge National Laboratory in Tennessee, which was engaged in uranium-235 separation from the more common uranium-238.
When Karl was offered in 1945 to lead the University of Washington, he decided to accept the offer and leave Chicago, but a new post and meant for him the end of the research. After retiring from his post as head of the university in 1954, he was professor emeritus of physics at Washington University. With this post he left in 1961, suggesting to divide his time between the University of Washington, Worcester College and the University of California at Berkeley.
In 1916, K. married Betty Charity Mc Kloska, they had two sons. Throughout his life his wife was his faithful companion in work, and during the Second World War it at his insistence even got access to secret work on a par with them. Man bright and outstanding, K. was able to ignite the enthusiasm in his students and colleagues. Sincerely religious, he headed Leymenskoe missionary movement from 1934 to 1948 and participated actively in the work of the National Conference of Christians and Jews. He died of a cerebral hemorrhage March 15, 1962 in Berkeley (CA).
Among the numerous awards K. can specify Rumford Medal of the American Academy of Arts and Sciences (1927), Hughes Medal of the Royal Society (1940), Medal of the Franklin Franklin Institute (1940) and the medal "For merits" of the United States Government ( 1946). He received honorary degrees from many universities, including Yale, Princeton and Harvard. K. was a member of the American Association for the Advancement of Science, the American Philosophical Society, the American Physical Society, the US National Academy of Sciences and New York Academy of Sciences, and a member of more than 20 foreign scientific societies.