Showing papers in "Physics Today in 1952"
TL;DR: The principle of relativity Relativistic mechanics Electromagnetic fields electromagnetic waves as discussed by the authors The propagation of light The field of moving charges Radiation of electromagnetic waves Particle in a gravitational field The gravitational field equation
Abstract: The principle of relativity Relativistic mechanics Electromagnetic fields Electromagnetic waves The propagation of light The field of moving charges Radiation of electromagnetic waves Particle in a gravitational field The gravitational field equation The field of gravitational bodies Gravitational waves Relativistic cosmology Index.
9,047 citations
1,112 citations
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87 citations
TL;DR: This is the first invited session of the American Physical Society devoted to the topic of radiation effects in solids—a field that has been an active one for nearly a decade, but it is safe to say that it will not be the last such session.
Abstract: As far as I am aware, this is the first invited session of the American Physical Society devoted to the topic of radiation effects in solids—a field that has been an active one for nearly a decade. I believe it is safe to say that it will not be the last such session. The long delay in this event arises, of course, from the fact that the field received its greatest stimulus from the wartime research in the field of atomic energy so that many aspects of it were classified at the start and will remain classified indefinitely in the future.
63 citations
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TL;DR: Onnes and Onnes as mentioned in this paper showed that the electrical resistance of a superconductor can be measured at a temperature just a few degrees above the absolute zero, and they concluded that the resistivity of superconductors must be immeasurably small.
Abstract: Ever since Kamerlingh‐Onnes discovered in 1911 that the electrical resistance of mercury abruptly vanished at a temperature just a few degrees above the absolute zero, the phenomenon of superconductivity has presented an intriguing challenge to physicists Subsequent experiments by Onnes and others definitely established that the resistivity of a superconductor, if at all finite, must be immeasurably small, and less than 10−20 ohm cm Consequently the superconductor is assumed to have zero resistance Onnes soon found that the superconducting property was not peculiar to mercury but was characteristic of a sizable group of metals Twentyone of the metallic elements are known to be superconductors as are innumerable alloys and intermetallic compounds The known superconductors are exhibited in Fig 1 and are seen to fall into definite areas of the periodic table None of the monovalent metals are observed to be superconducting, at least down to temperatures of the order of a few tenths of a degree absolute
27 citations
TL;DR: In this paper, the authors argue that science should make a connection between science and ethics, and that science can be seen as a way to prevent a suicidal use of scientific knowledge.
Abstract: Few echoes of the controversy over the nature of science will be found in this article. An earlier generation agonized over the question: “Does scientific inquiry tell us anything about values and moral obligations?” and reached a very skeptical conclusion. Fifteen years ago studies of the language and logic of science appeared to many scientists and philosophers to have settled the question: you could not logically leap from assertions about what is and what is possible to assertions about what ought to be. Then came war and the Manhattan project, and many who had accepted the divorce of science and ethics were frightened into reconsidering the matter. If science had nothing to say about values and duties, so much the worse for science. There ought to be a connection between science and ethics. Whatever the semantic difficulties, something needed to be done to prevent a suicidal use of scientific knowledge. Since 1945 there have been many conferences, many symposia, reconsidering the relation of fact to ...
10 citations
TL;DR: The recognition of the importance of scientific research to the development and maintenance of adequate national defense has affected the over-all program of the Department of Defense in many ways as mentioned in this paper, including the establishment of a number of agencies charged with the administration and coordination of research and development in scientific fields of particular interest to the departments in which they are located.
Abstract: Recognition of the importance of scientific research to the development and maintenance of adequate national defense has affected the over‐all program of the Department of Defense in many ways. One of these has been the establishment of a number of agencies charged with the administration and coordination of research and development in scientific fields of particular interest to the departments in which they are located. Several of these have been described in previous articles in this series.
TL;DR: The history of western thought since the seventeenth century leaves little doubt as to the practical validity of the method of controlled quantitative analysis discovered by Galileo, interpreted by Descartes, and variously generalized by Newton and Einstein this article.
Abstract: The history of western thought since the seventeenth century leaves little doubt as to the practical validity of the method of controlled quantitative analysis discovered by Galileo, interpreted by Descartes, and variously generalized by Newton and Einstein. The impact of its success on every level of human activity—religious, political, industrial, and educational (to mention only the more obvious ones)—has awakened the most diverse and even contradictory speculations as to the specific character of the science it yields and the precise intentions of those who engage in it. Often enough, one gathers the impression that these speculations are founded on an arbitrary and quite uncritical conception of the nature of modern science; a conception formulated in terms of what one thinks or wishes to think science is from its effects upon the extrascientific domain (which, in the present context, includes philosophy) rather than in terms of a patient and sustained critical analysis of its characteristic structure.
TL;DR: In addition to the research carried on in the University of Chicago's physics department, a substantial amount of physics research is pursued in the university's three research institutes: the Institute for the Study of Metals, Institute for Nuclear Studies, and the Institute of Radiobiology and Biophysics as discussed by the authors.
Abstract: In addition to the research carried on in the University of Chicago's physics department, a substantial amount of physics research is pursued in the University's three research institutes: the Institute for the Study of Metals, the Institute for Nuclear Studies, and the Institute of Radiobiology and Biophysics. Supported jointly by the University and by subscriptions from private industries, the institutes may essentially be regarded as a new experiment in education and science and in the relation of the two to industry. Their laboratories, representing a capital investment of over twenty million dollars, provide facilities beyond the means of any single department. The participation of staff members from many departments makes possible the fullest utilization of the new facilities. The institutes have a total academic and professional staff of about 150 persons and about 185 other employees.
TL;DR: As my nearly six years of service as Director of the National Bureau of Standards draw to a close, it seems that an important final part of that service would be to set down some over-all views concerning the scientific work of the Federal Government growing out of that experience.
Abstract: As my nearly six years of service as Director of the National Bureau of Standards draw to a close, it seems that an important final part of that service would be to set down some over‐all views concerning the scientific work of the Federal Government growing out of that experience. Our governmental institutions are so close to us that I had some experience with them before entering Federal service full‐time, especially during World War II, and likewise I expect to have association with such matters in the future while in private employment.
TL;DR: The helical focusing magnetic β-ray spectrometer was designed and constructed at the California Institute of Technology (CIT) in the early 1950s as mentioned in this paper. But it was only recently completed and made the first tests on it which indicate that it will meet all our expectations both as to high absolute accuracy and high luminosity and sensitivity to weak sources.
Abstract: The direct measurement of gamma‐rays only yields about half the picture in the study of nuclear energy levels. The other, and indeed to most physicists more familiar, half concerns the β‐rays, including in this term both the continuous β‐ray spectrum and the line spectrum by “conversion”, either internal or external. Ever since 1948, therefore, we have been much occupied with the design and construction along rather novel lines of a high precision helical focusing magnetic β‐ray spectrometer planned as a companion instrument to the crystal diffraction spectrometer as regards absolute precision and accuracy. We have only very recently completed this instrument and made the first tests on it which indicate that it will meet all our expectations both as to high absolute accuracy and high luminosity and sensitivity to weak sources.
The beta‐ray spectrometer discussed in the following pages has recently been completed at the California Institute of Technology. It is shown in cross section on the cover.
TL;DR: A detailed and comprehensive survey of physics in South America with the many ramifications in the economic, social, and political patterns of these countries cannot be undertaken with this experience and in this space.
Abstract: This report is based primarily on observations made during a three‐month trip to South America during the summer of 1951. Obviously, the task of presenting a complete and comprehensive survey of physics in South America with the many ramifications in the economic, social, and political patterns of these countries cannot be undertaken with this experience and in this space. However, the evidences of vigorous development in physics and other basic sciences in South America have been sufficiently impressive to me to warrant recording my impressions of some of the leading laboratories in the hope that they will be of interest to other physicists. I am certain that in a relatively few years physics in South America will have developed to such an extent that physicists here will not only find it of interest, but will find it scientifically imperative, to maintain close contact with their colleagues on the opposite side of the equator.
TL;DR: A recent survey article on high altitude laboratories has elicited so much correspondence that it was thought worth-while to present today's roster of such stations in tabular form as mentioned in this paper.
Abstract: A recent survey article on high altitude laboratories has elicited so much correspondence that it was thought worth‐while to present today's roster of such stations in tabular form. In the table below and on the map on p 30 several stations now in operation are listed in order of ascending geomagnetic latitude. In addition four stations at present under study are mentioned, one or more of which may be in operation in the near future. Omitted from this list are such well‐known observatories as Mt. Wilson, Mt. Palomar and others, since their elevation is not particularly high. Also omitted are such cities which may happen to lie at high elevations, as for example La Paz, Bolivia, at which no formally organized high altitude laboratories are known to this writer. Finally, we do not list any observatories in countries behind the Iron Curtain, but only those which will welcome scientists of all nations. The majority of the stations have electric power available usually via transmission lines from generating st...
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TL;DR: The physics of the solid state are known in 1900 as discussed by the authors and there were tentative theories of many of them, and very elaborate studies of the interrelations of them with crystal symmetry, leading up to the proper m...
Abstract: The physics of the solid state is nothing new. In 1900 it was as well realized as now that mechanics, heat, electricity, magnetism, optics, all have their solid‐state aspects. In mechanics we have elasticity, plasticity, elastic vibrations or sound. In heat we have specific heat, thermal expansion, heat conductivity. In electricity we have conductivity, dielectric constant. In magnetism we have paramagnetism, diamagnetism, ferromagnetism, the Hall effect. Optics involves the refractive index, optical absorption, double refraction, and so on. There are interrelations between different effects: Magnetostriction, the relation between magnetism and elasticity; pyroelectricity, the relation between heat and dielectric behavior; the Faraday effect, the relation between magnetism and optical double refraction; and a host of others. All these were known in 1900, there were tentative theories of many of them, and very elaborate studies of the interrelations of them with crystal symmetry, leading up to the proper m...
TL;DR: McMahon as mentioned in this paper has shown such real understanding of the basic conditions for scientific development and for advantageous application of the great potentialities of atomic energy, that we physicists have been largely responsible for creating the activity for whose wise handling in the national interest he has so great a responsibility.
Abstract: First may I add my greeting to Senator McMahon, and add my appreciation of his willingness to meet with us tonight. He and we have a strong bond in common. We physicists have been largely responsible for creating the activity for whose wise handling in the national interest he has so great a responsibility. And may I say, on the basis of several opportunities to see him in the discharge of these responsibilities, that we are very fortunate in having this aspect of our common interest in the hands of a man who has shown such real understanding of the basic conditions for scientific development and for advantageous application of the great potentialities of atomic energy.
TL;DR: The Atomic Energy Act of 1946 provides in Section 2(b) that there shall be a General Advisory Committee to advise the Commission on scientific and technical matters relating to materials, production, and research and development, to be composed of nine members, who shall be appointed from civilian life by the President as discussed by the authors.
Abstract: The Atomic Energy Act of 1946 provides in Section 2(b) that “There shall be a General Advisory Committee to advise the Commission on scientific and technical matters relating to materials, production, and research and development, to be composed of nine members, who shall be appointed from civilian life by the President.” The Act further directs that “The Committee shall designate one of its own members as Chairman. The Committee shall meet at least four times in every calendar year.” Beyond that, the Act does not specify how the Committee is to perform its advisory functions, how it is to obtain the information and analysis on which to base its advice, nor how to determine the issues to which it should direct its attention.