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《Communications in Mathematical Physics》2001,219(1):1-3
Harry Lehmann was born in 1924 at Güstrow, Mecklenburg. After graduation from school in Rostock, the German army drafted him
in 1942 for service in North Africa, where he was taken prisoner of war by the American forces. He spent three years in a
prison camp in the United States; there he had the opportunity to study on his own, and to prepare for the university. When
he was released in 1946, he soon returned to his parents in Rostock and began to study physics, first at the University of
Rostock, then at the Humboldt University in East Berlin, obtaining his diploma with a thesis on experimental physics. In 1949
he became assistant of Friedrich Hund at the University of Jena, where he wrote his doctoral dissertation on classical electrodynamics.
When Hund moved to the University of Frankfurt, Lehmann served at Jena as acting professor, until Hund was replaced.
In the fall of 1952, Heisenberg offered Lehmann a position at the Max Planck Institute for Physics in G?ttingen. There he
joined an active group of young theorists from Germany and abroad who had come to collaborate with Heisenberg. After his initial
stay, he requested permission to extend his visit; but the authorities of the former German Democratic Republic never responded,
and so Harry Lehmann remained in the west. As a result it was not until 1976 that he could once again visit his parents in
Rostock.
A main topic of discussion in Heisenberg's institute was the method of renormalization, that had been developed in the United
States and Japan right after the war. This technique made it possible to compute measurable quantities of quantum electrodynamics,
and to compare them with experiments, even though divergent integrals entered intermediate stages of the calculations. Despite
the enormous success of renormalization theory, made evident by the high-precision agreement between theory and experiment,
many physicists of the older generation in Europe remained skeptical and were convinced that the infinities indicated a serious
deficiency of quantum field theory. Dirac, for instance, called renormalization theory “a sin against theoretical physics”.
On the other hand the younger theoretical physicists were quite enthusiastic. They considered it a challenge to reformulate
the theory in such a way that renormalization infinities never occur, either in the formulation of the principles, or in the
calculation of observable quantities. Harry Lehmann's publication on the properties of propagators [1] was an early decisive
step in this direction. From minimal assumptions he derived the main properties of propagators, and expressed the constants
of renormalization by integrals over finite quantities, even though those quantities diverged in perturbation theory.
He carried out a large part of his pioneering work in the 1950's, in collaboration with Kurt Symanzik and Wolfhart Zimmermann.
The shorthand designation LSZ is familiar to all elementary particle physicists up to this day. The LSZ-formalism and the
Lehmann representation are among the most important basic tools of the theory of elementary particles [2]. An important application
of this technique in scattering theory provides the relation between scattering amplitudes and time ordered correlation functions.
These were derived as an immediate consequence of the asymptotic behavior of field operators in the distant past and future.
In 1955 Harry Lehmann left Heisenberg's institute to visit Copenhagen as a member of the CERN Study Group, and in 1956 he
accepted a professorship at the University of Hamburg to become the successor to Wilhelm Lenz. He founded the theoretical
elementary particle physics group, and for thirty years, his strong personality determined the character of the II. Institut
für Theoretische Physik at Hamburg University. He became Professor Emeritus in 1986. He also advised the German Electron Synchrotron laboratory DESY and helped start its theory group by persuading
Kurt Symanzik to return there from New York. Many young scientists were strongly influenced by his personality, by his style
of discussion in seminars, by the conciseness of his insightful contributions to research, and by his views on physics in
general.
Harry Lehmann's interest in the theory of dispersion relations led to the beginning of his close collaboration with Res Jost.
In the case of equal mass scattering Jost and Lehmann found a representation for matrix elements of the commutator of two
field operators between energy-momentum eigenstates [3]. This representation was extended by Dyson to the general case of
unequal masses [4]. On the basis of the Dyson representation, Lehmann derived dispersion relations and other analytic properties
of the scattering amplitudes as a consequence of locality, relativistic invariance and conditions on the particle spectrum
[5]. These results are also valid for composite particles despite their internal structure, since only general properties
are used in the derivation which are independent of the dynamics of the system. Dispersion relations, therefore, provide an
experimental test for the principles of local quantum field theory.
Harry Lehmann remained active in research until the end of his life. He directed several NATO Advanced Study Institutes in
Cargèse (France). With K. Pohlmeyer he worked on field theories with non-polynomial Lagrangians. During his last years he
investigated symmetry breaking effects for the quark mass spectrum together with T. T. Wu.
Harry Lehmann's scientific merits were recognized in many ways. He received the Max Planck medal of the German Physical Society
1967 and he was made a Chevalier de la Legion d'Honneur on December 31, 1969. He was honoured in 1997 by the Dannie Heineman
Prize of the American Physical Society and the American Institute of Physics.
Harry Lehmann was an excellent speaker with the remarkable ability to communicate involved and difficult subjects understandably.
We remember him gratefully, in friendship, and with esteem for his scientific work. 相似文献
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R. J. Baxter 《Journal of statistical physics》2011,145(3):518-548
Lars Onsager announced in 1949 that he and Bruria Kaufman had proved a simple formula for the spontaneous magnetization of
the square-lattice Ising model, but did not publish their derivation. It was three years later when C.N. Yang published a
derivation in Physical Review. In 1971 Onsager gave some clues to his and Kaufman’s method, and there are copies of their
correspondence in 1950 now available on the Web and elsewhere. Here we review how the calculation appears to have developed,
and add a copy of a draft paper, almost certainly by Onsager and Kaufman, that obtains the result. 相似文献
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Simón Reif-Acherman 《Physics in Perspective (PIP)》2013,15(4):415-450
One century ago this year the Dutch experimental physicist Heike Kamerlingh Onnes (1853–1926) was awarded the Nobel Prize in Physics for his work in low-temperature physics, in particular for his production of liquid helium. I trace the route to his Nobel Prize within the context of his and his colleagues’ research in his laboratory at the University of Leiden, and in light of his nominators and the nominations he received in the five years 1909–1913. 相似文献
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B. G. Sidharth 《Foundations of Physics Letters》2006,19(5):499-500
The latest results from the Wilkinson Microwave Anisotropy Probe (WMAP) with regard to the Cosmic Microwave Background (CMB) throw up some intriguing results, and the question has been asked “Does this point to new physics?” We point out that indeed all this indicates new physics on the Planck scale. 相似文献
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Karl Hufbauer 《Physics in Perspective (PIP)》2012,14(4):421-470
I first show that Kuhn came to have doubts about physics soon after entering college but did not make up his mind to leave the discipline until 1947–1948 when a close association with Harvard’s President James B. Conant convinced him of the desirability of an alternative career in the history of science. I go on to maintain that it was realistic for Kuhn to prepare for such a career in essentially autodidactic ways both because he enjoyed Conant’s patronage and because he could expect that his credentials in physics would be an asset in this relatively young interdisciplinary specialty. I then suggest that it was through his work as a teacher, researcher, and journeyman gatekeeper in the history of science that Kuhn gradually came to identify with the field. Finally, I argue that his training in physics, his teaching of general-education courses, and his hopes of influencing current philosophy of science helped shape his early practice as a historian of science. By way of epilogue, I briefly consider Kuhn’s path from his tenuring at Berkeley in 1958 to the appearance of The Structure of Scientific Revolutions in 1962. 相似文献
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Preliminary results for the design,fabrication,and performance of a backside-illuminated avalanche drift detector 下载免费PDF全文
The detection of low-level light is a key technology in various experimental scientific studies. As a photon detector, the silicon photomultiplier (SiPM) has gradually become an alternative to the photomultiplier tube (PMT) in many applications in high-energy physics, astroparticle physics, and medical imaging because of its high photon detection efficiency (PDE), good resolution for single-photon detection, insensitivity to magnetic field, low operating voltage, compactness, and low cost. However, primarily because of the geometric fill factor, the PDE of most SiPMs is not very high; in particular, for those SiPMs with a high density of micro cells, the effective area is small, and the bandwidth of the light response is narrow. As a building block of the SiPM, the concept of the backside-illuminated avalanche drift detector (ADD) was first proposed by the Max Planck Institute of Germany eight years ago; the ADD is promising to have high PDE over the full energy range of optical photons, even ultraviolet light and X-ray light, and because the avalanche multiplication region is very small, the ADD is beneficial for the fabrication of large-area SiPMs. However, because of difficulties in design and fabrication, no significant progress had been made, and the concept had not yet been verified. In this paper, preliminary results in the design, fabrication, and performance of a backside-illuminated ADD are reported; the difficulties in and limitations to the backside-illuminated ADD are analyzed. 相似文献
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M. J. Crowe 《Physics in Perspective (PIP)》1999,1(1):54-64
The distinguished physicist and historian and philosopher of science Pierre Duhem (1861 - 1916) not only taught physics, but also worked out in his Aim and Structure of Physical Theory a philosophical analysis of physics. Duhem's analysis offers important suggestions about how physics progresses and also how physics should be taught. This essay suggests what advice Duhem would give persons involved in physics teaching about how physics should be presented. In particular, it discusses Duhem's insightful critique of what he called the Newtonian method. 相似文献
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著名物理学家海森伯曾于1929年访华,旋即被聘为中央研究院物理所名誉研究员,成为中国近代物理学史上第一个获此荣誉的外籍学者.文章对他来华的具体时间作出推断,述及其与早期中国物理学界某些人士的因缘. 相似文献
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Gustav Mie and the scattering and absorption of light by particles: Historic developments and basics
Helmuth Horvath 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(11):787-799
Gustav Mie was a professor of physics with a strong background in mathematics. After moving to the University of Greifswald in North-Eastern Germany he became acquainted with colloids, and one of his PhD students investigated the scattering and attenuation of light by gold colloids experimentally. Mie used his previously acquired knowledge of the Maxwell equations and solutions of very similar problems in the literature to concisely treat the theoretical problem of scattering and absorption of light by a small absorbing sphere. He also presented many numerical examples which completely explained all the effects that had been observed until then. Since all calculations were done by hand, Mie had to limit his theoretical results to three terms in infinite expansions, thus he only could treat particles smaller than 200 nm at visible wavelengths. Mie's paper had remained hardly noticed for the next 50 years, most likely because of the lack of computers. It experienced a revival later and up to now it has been referenced more than 4000 times, owing to the widespread use of Mie's approach in sciences such as astronomy, meteorology, fluid dynamics and many others.Gustav Mie did not consider his work on scattering of light by small particles as very important, since he just tried to explain the effects which his students had observed. He concentrated on hot topics in theoretic physics, e.g., the theory of matter. He wrote several textbooks, e.g., on relativity, gravitation theory, and electromagnetism, and all of them had run into several editions. 相似文献
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Michael Wiescher 《Physics in Perspective (PIP)》2017,19(1):3-59
This paper describes the life and scientific development of Arthur E. Haas, from his early career as young, ambitious Jewish-Austrian scientist at the University of Vienna to his later career in exile at the University of Notre Dame. Haas is known for his early contributions to quantum physics and as the author of several textbooks on topics of modern physics. During the last decade of his life, he turned his attention to cosmology. In 1935 he emigrated from Austria to the United States. There he assumed, on recommendation of Albert Einstein, a faculty position at the University of Notre Dame. He continued his work on cosmology and tried to establish relationships between the mass of the universe and the fundamental cosmological constants to develop concepts for the early universe. Together with Georges Lemaître he organized in 1938 the first international conference on cosmology, which drew more than one hundred attendants to Notre Dame. Haas died in February 1941 after suffering a stroke during a visit in Chicago. 相似文献
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介绍并赏析爱因斯坦对量子力学理论的发展起过重要推动作用的文章一篇.他利用带有动量及能量的光子的想象,引入自发辐射、诱发辐射及吸收3种跃迁概率,验证了分子的麦克斯韦-玻尔兹曼分布与辐射的普朗克分布之间的动量能量转移的动平衡.结合这一工作前后的物理学背景和发展,本文也着重阐明学术思想的发生和发展过程. 相似文献
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M. J. Nye 《Physics in Perspective (PIP)》1999,1(2):136-156
In 1948, the year in which P. M. S. Blackett received the Nobel Prize in physics, he published a highly controversial book on the military and political consequences of atomic energy. The book appeared in the United States under the sensationalist title Fear, War and the Bomb. Blackett had been a naval officer during the First World War, a veteran of Ernest Rutherford's Cavendish Laboratory and head of the physics department at Manchester in the interwar years, and he was a founder of operational research during the Second World War. Vilified in the British and American press in the 1940s and 1950s, he continued to contest prevailing nuclear weapons strategy, finding a more favorable reception for his arguments by the early 1960s. This paper examines the publication and reception of Blackett's views on atomic weapons, analyzing the risks to a physicist who writes about a subject other than physics, as well as the circumstances that might compel one to do so. 相似文献
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Demokrit – Planck A branch of physics exists closely linked to the constant h and associated with atomism. It is this h-physics that Planck originated. But atomism like existence of localized, charged particles with different masses does not follow from this physics, especially the charge quant. Hence Demokrit asserted more then quantum physics is competent to answer. 相似文献
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H. Ioannidou 《International Journal of Theoretical Physics》1983,22(12):1129-1139
A statistically founded derivation of the quanta of energy is presented, which yields the Planck formula for the mean energy of the blackbody radiation without making use of the quantum postulate. The derivation presupposes an ensemble of particles and leads to a statistical interpretation of the Planck constant, which is defined and discussed. By means of the proposed interpretation ofh and as an application of it, the quantum uncertainty relation is derived classically and results as a statistical inequality. On the whole this paper is compatible with the statistical ensemble interpretation of quantum mechanics. 相似文献
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Ruth Lewin Sime 《Physics in Perspective (PIP)》2006,8(1):3-51
As President of the Kaiser Wilhelm Society and its successor, the Max Planck Society, from 1946 until 1960, Otto Hahn (1879–1968)
sought to portray science under the Third Reich as a purely intellectual endeavor untainted by National Socialism. I outline
Hahn’s activities from 1933 into the postwar years, focusing on the contrast between his personal stance during the National
Socialist period, when he distinguished himself as an upright non-Nazi, and his postwar attitude, which was characterized
by suppression and denial of Germany’s recent past. Particular examples include Hahn’s efforts to help Jewish friends; his
testimony for colleagues involved in denazification and on trial in Nuremberg; his postwar relationships with émigré colleagues,
including Lise Meitner; and his misrepresentation of his wartime work in the Kaiser Wilhelm Institute for Chemistry. 相似文献
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Shaul Katzir 《Physics in Perspective (PIP)》2005,7(3):268-292
Henri Poincaré (1854–1912) developed a relativistic physics by elevating the empirical inability to detect absolute motion,
or motion relative to the ether, to the principle of relativity, and its mathematics ensured that it would be compatible with
that principle. Although Poincaré’s aim and theory were similar to those of Albert Einstein (1879–1955) in creating his special
theory of relativity, Poincaré’s relativistic physics should not be seen as an attempt to achieve Einstein’s theory but as
an independent endeavor. Poincaré was led to advance the principle of relativity as a consequence of his reflections on late
nineteenth-century electrodynamics; of his conviction that physics should be formulated as a physics of principles; of his
conventionalistic arguments on the nature of time and its measurement; and of his knowledge of the experimental failure to
detect absolute motion. The nonrelativistic theory of electrodynamics of Hendrik A.Lorentz (1853–1928) of 1904 provided the
means for Poincaré to elaborate a relativistic physics that embraced all known physical forces, including that of gravitation.
Poincaré did not assume any dynamical explanation of the Lorentz transformation, which followed from the principle of relativity,
and he did not seek to dismiss classical concepts, such as that of the ether, in his new relativistic physics.
Shaul Katzir teaches in the Graduate Program in History and Philosophy of Science, Bar Ilan University. 相似文献
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The Planck constant h is one of the most significant constants in quantum physics.Recently,the precision measurement of the value of h has been a hot issue due to its important role for the establishment of both a new SI and a revised fundamental physical constant system.Up to date,two approaches,the watt balance and counting atoms,have been employed to determine the Planck constant at a level of several parts in 108.In this paper,the principle and progress on precision measurement of the Planck constant using watt balance and counting atoms at national metrology institutes are reviewed.Further improvement in determining the Planck constant and possible developments of a revised physical constant system in future are discussed. 相似文献
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Jon M. Harkness 《Physics in Perspective (PIP)》2002,4(4):456-490
Otto H. Schmitt was born in St. Louis, Missouri, in 1913. As a youth, he displayed an affinity for electrical engineering
but also pursued a wide range of other interests. He applied his multi-disciplinary talents as an undergraduate and graduate
student at Washington University, where he worked in three departments: physics, zoology, and mathematics. For his doctoral
research, Schmitt designed and built an electronic device to mimic the propagation of action potentials along nerve fibers.
His most famous invention, now called the Schmitt trigger, arose from this early research. Schmitt spent most of his career
at the University of Minnesota, where he did pioneering work in biophysics and bioengineering. He also worked at national
and international levels to place biophysics and bioengineering on sound institutional footings. His years at Minnesota were
interrupted by World War II. During that conflict - and the initial months of the Cold War to follow - Schmitt carried out
defense-related research at the Airborne Instruments Laboratory in New York. Toward the end of his career at Minnesota, Schmitt
coined the term biomimetics. He died in 1998.
RID="*"
ID="*"Jon M. Harkness received his Ph.D. degree in the history of science from the University of Wisconsin in 1996. During
the spring of 2002, he is an adjunct assistant professor of the history of medicine at the University of Minnesota. 相似文献