Laue (Laue), Max von( German physicist, Nobel Prize in Physics, 1914)
Comments for Laue (Laue), Max von
Biography Laue (Laue), Max von
September 9, 1879, Mr.. - April 24, 1960
The German physicist Max Theodor Felix von Laue was born to a civil servant department of military courts Julius Laue and Minna nee Tserrener. Gentry prefix 'von' name acquired in 1913, when his father L. received hereditary nobility. By the nature of the father's family moved from place to place, so L. had to learn in many schools, but mainly secondary education he received in a Protestant school in Strasbourg. At the age of twelve L. became interested in physics, and his mother gave him the opportunity to attend 'Urania' - Berlin society, the popularization of science. The society arranged exhibitions of existing models of scientific instruments, experiments demonstrated, given to them for explanation.
After graduating in 1898. gymnasium L. began to study physics, chemistry and mathematics at the University of Strasbourg. Simultaneously, he held a one-year compulsory military service. At university his interest in physics lectures supported by Ferdinand Braun. Studied L. and the Universities of GÃ¶ttingen, Munich and Berlin. In 1903, Mr.. He led the Max Planck at Berlin University with honors defended his doctoral dissertation on the theory of interference of light in a plane-parallel plates. Interference is the interaction of intersecting light waves, damping or reinforcing each other, depending on the difference of their phases (states in the cycles of changes in the electric and magnetic fields). While working on his thesis, A. first became interested in physical optics.
The next two years L. held at the University of GÃ¶ttingen, and then passed the exam for teaching physics in secondary school. From 1905 to 1909. He was an assistant Planck Institute for Theoretical Physics in Berlin. During this period he tried to apply the concept of entropy to the fields of radiation and determine the thermodynamic sense of coherence of light waves. Entropy in thermodynamics is a physical property associated with changes in energy and the degree of equilibrium of the system. Coherent light waves indicates the existence of a strictly defined sustainable relationship between their phases, when the degree of agreement or a mismatch between their varying electromagnetic fields remains unchanged. Teamwork L. and Planck developed into a friendship, loyalty to which they are preserved for life. Having worked from 1906 to 1909. Assistant Professor (Visiting Professor) at the University of Berlin, L. moved to the Department of Physics, University of Munich to Arnold Sommerfeld. In Munich, L. lectured on optics and thermodynamics, Yves 1911. published the first detailed monograph on the former then-controversial theory of relativity of Albert Einstein.
The following year, L. was appointed to the chair of theoretical physics at Zurich University, where he spent two years before moving to University of Frankfurt. Much of the First World War L. worked at the University of WÃ¼rzburg Wilhelm Wien. There he engaged in research of electronic tubes used in telephone and wireless. In 1917, Mr.. L. was appointed deputy director of the Kaiser Wilhelm Physical Institute in Berlin, whose director was Einstein. Continuing to fulfill its mainly administrative duties at the institute, L. in 1919. accepted an invitation to take the post of professor of physics at Berlin University and remained so until 1943
Shortly after moving to Zurich L. interested in the problem which remained unresolved since the discovery of X-rays by Wilhelm Roentgen (1895): whether this radiation is a form of electromagnetic radiation with very short length volnyN While L. worked on the head of the wave optics for multi-volume 'Encyclopedia of Mathematical Sciences' (' Enzykiopadie der mathematischen Wissenschaften "). He needed to express mathematically the action of the diffraction grating on the light waves. Diffraction grating - a glass plate or mirror, which at a short distance from each other are shown equally spaced strokes (grooves), dividing the incident light into many individual sources. The secondary light waves, . originating from different parts of the diffraction grating, . have the same phase, . but get to the point of the screen, . travel different distances, . Since the propagation of light phase is repeated through the distance, . equal to the wavelength (eg, . through the distance between adjacent crests of ocean waves), . rays come to a point with different phases, depending on, . how many (integer and fraction) of wavelengths fit into their path traversed,
. As a result, the screen appears complicated pattern of light and dark stripes: bright, where the incoming wave is in phase and reinforce each other; dark - where incoming waves are in antiphase and canceled each other out. L. studied generalization of the mathematical description for two-dimensional diffraction grating with two families of strokes.
At the same time to the L. asked his colleague to help in the mathematical study of behavior of light waves in a crystal. It was assumed that the crystal is a three-dimensional lattice with atoms at the nodes, forming a recurrent right 'pattern'. L. failed to solve the problem, . which he was asked, . but it is interested in the question, . how would behave in the light waves, . if they were very short (much shorter, . than the wavelengths of visible light) compared with the distances between atoms in a crystal lattice,
. At the then existing level of knowledge has been widely assumed that the distances between atoms in crystal lattices is about 10 times greater than the expected wavelengths of X-rays. L. immediately suggested that if the X-ray emission is indeed electromagnetic waves, the crystal will act on it as a three-dimensional diffraction grating. From the crystal in different directions should rely on individual atoms scattered X-rays and give rise to the diffraction pattern, . consisting of bright dots, . where the rays come, . in-phase and therefore mutually reinforcing, . and dark areas, . where the rays converge, . in one way or another do not coincide in phase and thus extinguishing each other.,
. proposed an experiment that would confirm or refute the hypothesis put forward by him, and waiting until there are willing and related equipment, began to overcome some theoretical objections. In April 1912. Officer, University of Munich, Walter Frederick (Sommerfeld's assistant) and graduate student at the same university Paul Knipping was able to send to the crystal blue vitriol (copper sulfate), a narrow beam of X-rays and record the scattered radiation on the crystal on the photographic plate,
. Their first success was the diffraction pattern of dark dots, which they saw when the plate is shown (dark spots on the negative match big illumination). Now, these diffraction patterns are called lauegramm. Even if the incident X-rays consisted of a mixture of different wavelengths, the dark point of the radiation came from the same wavelength. This was further proof that the interference of electromagnetic waves. Relations between the phases of waves of different lengths are too complex to produce a clear diffraction pattern. But the presence of a mixture of radiation with a particular wavelength can selectively produce a clear diffraction pattern, easily distinguishable against the background. Inspired by the confirmation of his hypothesis, L. cope with all the mathematical difficulties. He found that to describe the diffraction by a two-dimensional lattice is necessary to repeat the calculations carried out in the case of scattering by a one-dimensional lattice.
. The derived equations enabled them to establish a correspondence between the experimentally observed lauegrammami, on the one hand and the reality of atoms in crystals and the wavelength of X-rays - on the other
. Thus L. opened a very promising area of research (X-ray crystallography), . in which X-rays used to determine the structure of crystals, . in crystals known structure - to determine the wavelengths of X-rays,
. Analysis of X-ray radiation emitted by the atoms (X-ray spectroscopy), was very important for understanding the structure of the atom. Einstein called the opening of L. 'one of the most beautiful in physics'.
'For the discovery of X-ray diffraction on crystals' L. was awarded the Nobel Prize in Physics 1914. Presenting the winner, G.D. Granqvist from the Royal Swedish Academy said: 'As a result, the opening of L. been conclusively established that the X-ray radiation is the light waves are very small length. In addition, it has led to the most important discoveries in the field of crystallography ... Opening of LA - continued Granqvist, - to determine the position of atoms in crystals and get a lot of useful information '.
Job A. formed the basis of many discoveries: the methods of X-ray crystallography, William L. Bragg, establishing the molecular structure of penicillin, Dorothy K. Hodgkin and amino acids by John K. Kendrew and Max Perutz. It has contributed to the further development of spectroscopy and solid state physics. Will improve his theory of interference of X-rays, L. investigated the interaction between atoms in the crystal and the incident electromagnetic radiation. At the end of his life he went to the theory of diffraction with an entirely new angle, considering the amplitudes of the waves instead of the traditional flow of energy. In 30-ies. L. participated in the work of Walter Meissner, led to the discovery of the effect of pushing a superconductor magnetic field.
At the Congress of Physicists, held at University of WÃ¼rzburg (1933), A. condemned the new National Socialist government of Adolf Hitler for the fact that it shifted the Albert Einstein from his post as director of the Kaiser Wilhelm Physical Institute in Berlin. He compared the persecution of Einstein with the persecution of Galileo in the XVII century. L. not only defended Einstein's relativity theory from the attacks of scientists supporting Nazism, such as Philipp von Lenard and Johannes Stark, but actively opposed the Admission Stark in the Prussian Academy of Sciences and Germany's association of researchers. Despite such active anti-Nazi speeches, L. throughout the Second World War were allowed to teach and engage in research activities.
Once in 1944. Berlin became subject to systematic bombing, L. translated the Kaiser Wilhelm Physical Institute in g. Hechingen (land Wurttemberg). The following year he was arrested by the Allies and with other German scientists sent to England. L. was allowed vernutsyavGermaniyuv1946 g. On his return he became acting director of the Max Planck Institute (formerly the Kaiser Wilhelm Institute) and professor of physics at the University of Gottingen. Occupying these positions and as consultant of the State Physical-Technical Institute in Berlin, L. played a major role in the revival of science post-war Germany. Since 1951, Mr.. and before the ensuing seven years later, the resignation of L. was director of the Institute of Physical Chemistry, Fritz Haber in Berlin.
In 1910,. L. married Magdalena Degan, they have a son and daughter. L. loved sailing, rock climbing, classical music. He was particularly fond of fast driving in a car or motorbike. April 8, 1960, heading for the meeting at Wannsee, he collided with motorcyclist and failed to get out of the machine tips over. Almost fully recovered from his injuries, L. died. He was buried in Gottingen, where rest Max Planck, Walther Nernst and other prominent German scientists.
In addition to the Nobel Prize, A. won many other awards, including the Max Planck medal Germanskogo Physical Society (1932) and Grand Cross of the Order "For Merit federal 'government of Germany (1953). He was an honorary doctor of Bonn, . Stuttgart, . Munich, . Berlin, . Manchester and the University of Chicago, . member of numerous scientific societies, . including American, . Germanskogo, . French Physical Society, . and the Vienna Academy of Sciences,
. In 1948, Mr.. L. was elected honorary president of the International Union of Crystallography, in 1953. an officer of the Order of the Legion of Honor.