摘要:

The progress of science may be said to depend largely on our asking the most appropriate questions and hoping that the same kind of imagination that led to the questions will provide clues to the answers. There was a time, not so long ago, when it was felt that all possible appropriate fundamental questions about sound had been raised and that the answers indeed were all found in Lord Rayleigh's famousTheory of Sound. It was believed to be sure that there were hosts of engineering applications of acoustics to be explored, but that these would not turn up anything fundamentally new. This view is no longer held by those who have followed trends in acoustics during the past quarter century. Both as an active branch of physics and as a subject fundamental to modern engineering, acoustics poses many unsolved problems of fundamental character. Some of these indeed have been suggested by the very advances in instrumentation made possible through acoustical engineering. For it is only through such instrumentation that we can now work with sounds of the very high intensity and high frequency which produce curious and unexplained effects in matter under extreme conditions of temperature and pressure. At the same time it is also through experimental facilities of this kind that we can begin to study more effectively the influence of sound on human beings and other organisms, and this too immediately raises hosts of questions. Through the fertile interplay of theory and application, acoustics is in a particularly strategic position to suggest problems whose solution will cast new light on both the properties of matter and the interaction of sound and man.

ISSN:0031-9228    

DOI:10.1063/1.3062502

出版商:AIP    

年代:1958

数据来源: AIP

摘要:

The national laboratory as an adjunct to research activity is emerging during our lifetimes as an essential element of scientific progress. Consequently, it seems worthwhile to examine the roles and the special characteristics of the national laboratory that differentiate it from the traditional laboratories of the universities and other establishments conducting undirected and fundamental scientific research. I shall not, however, refer to the outstanding engineering, applied, and generally directed research activities that are often conducted by these national laboratories, since these activities have much in common with the general industrial research carried on throughout the whole fabric of American scientific life.

ISSN:0031-9228    

DOI:10.1063/1.3062503

出版商:AIP    

年代:1958

数据来源: AIP

摘要:

Since the Fourth International (Paris) Conference on Low‐Temperature Physics in 1955, precision low‐temperature research has been plagued by havingtwostandard scales for temperature in the range 1 to 5.2 °K. These are the helium vapor‐pressure scales of J. R. Clement (the 55E Scale), and of H. van Dijk and M. Durieux (the L55 Scale). The differences between these scales (Fig. 1) are within the experimental uncertainties of the measurements on which the scales are based. A reliable decision as to which of these two scales is superior to the other calls for a study and reevaluation of all the data on which the scales are based. The original orrawexperimental data from which published values for the vapor pressure, and calorimetric and state properties of helium were calculated should be recalculated using the presentbestvalues for physical constants and related properties of helium. The magnitude of this reevaluation may be better appreciated when it is realized that the temperature scales used by the original investigators are in error and have to be corrected for, but that these corrections cannot be determined until the ultimate objective,thestandard scale, has been determined. This is a big, though possible, undertaking. There are real difficulties, however, because some investigators have not published sufficient data for a complete reevaluation of their work. Then the personal judgment of the reevaluator becomes important. Difficulties of this kind seemed to be blocking agreement of Clement and van Dijk on a single helium vapor‐pressure scale of temperatures.

ISSN:0031-9228    

DOI:10.1063/1.3062505

出版商:AIP    

年代:1958

数据来源: AIP

摘要:

The week of December 16, 1957, was a busy one for physicists in the Stanford area, with no less than three major meetings taking place: a symposium on magnetohydrodynamics, a conference on nuclear sizes, and, finally, the regular west coast winter meeting of the American Physical Society. Of these, the first‐mentioned was sponsored by the Lockheed Missile Systems Division and took place at its Palo Alto research laboratory adjacent to the Stanford campus. About 200 delegates, many of whom attended an initial symposium held there on the same subject in December 1956, participated in the more recent meeting. Considering the growing popularity of the field and the challenging nature of the material, an annual meeting dedicated to magnetohydrodynamics may be a worthwhile venture for several years to come.

ISSN:0031-9228    

DOI:10.1063/1.3062507

出版商:AIP    

年代:1958

数据来源: AIP

摘要:

PHYSICISTS interested in employment opportunities in industry, the government, or educational institutions are invited to register with the AIP Placement Service, which is planning to arrange interviews between job applicants and personnel recruiters at the Hotel Shoreham in Washington, D.C., during the annual spring meeting of the American Physical Society.

ISSN:0031-9228    

DOI:10.1063/1.3062512

出版商:AIP    

年代:1958

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3062516

出版商:AIP    

年代:1958

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3062519

出版商:AIP    

年代:1958

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3062520

出版商:AIP    

年代:1958

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3062523

出版商:AIP    

年代:1958

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3062524

出版商:AIP    

年代:1958

数据来源: AIP