摘要:

A general solution for the differential equation for the stream function in axial symmetric flow is derived. It is shown how the general form of the stream function is related to the solution for the potential function and a table of functions is given by use of which equations for the stream function may be written down if the potential function is known and vice versa. By use of the table a stream-function pattern is worked out from a known potential function. The tabulated functions satisy “Cauchy-Riemann-type” of relations for axial symmetry.

ISSN:0002-9505    

DOI:10.1119/1.1972156

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

Looking at souvenirs from Galileo, physicists often wonder, “Who was the real Galileo?” What was his place in science? in philosophy? in history? in public affairs? A brief review is made here of the nature of historical evidence and its applicability to two famous Galileo incidents: the swinging lamp of Pisa and the leaning tower of Pisa. Some attention is given also to the question of historical myth, particularly in the case of Galileo. The author emphasizes Galileo's contributions to modern physics rather than his indebtedness to ancient philosophy. Galileo is first considered as a public figure; on the one hand, as a prominent person and, on the other hand, as a propagandist for the Copernican theory and for a phenomenological outlook. Galileo is regarded as a person, with particular concern for the “inevitability” of the celebrated Galileo case. The author, however, deals with Galileo as a physicist. His scientific approach is examined in terms of his experiential viewpoint, of his own behavior as an observer and a measurer, and of his role as a mathematical physicist, with particular interest in his use of models. Finally, Galileo's contributions to dynamics are reviewed: namely, his growing understanding of the first law of motion and his inklings as to the second law, with respect to acceleration but even more important with reference to role of the medium, as well as the relation of the projectile and tidal phenomena to Newton's first two corollaries. The author concludes that Galileo, the physicist, can rightly be regarded as the founder of dynamics.

ISSN:0002-9505    

DOI:10.1119/1.1972162

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

An experiment is described in which students of general science make many independent measurements of resistance and perform a statistical analysis on the accumulated data. The results are compared with the normal distribution curve. The values of various precision indices are determined and the significance of such statistical facts examined. Mention is made of the need for a similar kind of experiment that would use multifactorial analysis and correlation techniques.

ISSN:0002-9505    

DOI:10.1119/1.1972166

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

Remarks made by the Chairman of the Committee on Awards for 1965 during the presentation ceremony of the Oersted Medal to Philip Morrison in recognition of his notable contributions to the teaching of physics.

ISSN:0002-9505    

DOI:10.1119/1.1972169

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1972171

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

In many physical relationships involving the Laplacian of a function, it proves useful to interpret the Laplacian as a measure of thelocal anomalyof that function. This little used, but often very illuminating interpretation, due originally to Maxwell, is illustrated with a number of examples drawn from mathematical physics.

ISSN:0002-9505    

DOI:10.1119/1.1972175

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

A potential and field diagram is given for introducing elementary students to these concepts by means of a semirealistic gravitational example. Problems involving rocket and satellite motion can be solved by use of the diagram, and open-ended questions about the sun's influence are raised.

ISSN:0002-9505    

DOI:10.1119/1.1972183

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

TheEuclideanandEinsteingeodesics are defined for a two-dimensional space-time surface. Both are shown to approach the same classical law of gravitational acceleration, and to preserve the equivalence principle. However, only the Einstein geodesic allows a local time to be defined in such a way that the local velocity of light is constant. The conical surface is discussed and the connection is made between it and the frame of the uniformly accelerated relativistic rocket. Coordinate transformations are discussed to the extent that it is established that the shape of the two-dimensional surface embedded in a Euclidean three-space depends on the choice of coordinate frame.

ISSN:0002-9505    

DOI:10.1119/1.1972189

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

The time-dependent behavior of an isolated system consisting of many spins in a solid lattice is studied. An interaction of the formBjkσjxσkxis assumed between any pair(j, k)of spins. The system is treated without making any approximations; it is one of the few many-body systems whose time-evolution can be treated exactly. The behavior is fully determined by the initial density matrix and the distribution of valuesBjk. By considering a variety of distributions for theBjk, and a variety of initial density matrices, one finds cases (initial random phasing and particular continuous spectra) where the system relaxes monotonically to a metastable equilibrium; in other cases (coherent initial state or nearest-neighbor coupling only) the system oscillates indefinitely without relaxation; in still other cases (initial random phasing andN → ∞) the system relaxes in an oscillatory way to the metastable equilibrium.

ISSN:0002-9505    

DOI:10.1119/1.1972193

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

A review of canonical transformations in quantum mechanics is outlined with a view toward their use in the solution of specific problems. Several typical problems are worked out by the method of canonical transformations to emphasize the utility of this approach. In this way one may obtain an insight into the nature and limitation of the connection that exists between the canonical transformations of classical mechanics and the unitary transformations of quantum mechanics. The purpose of this paper is to achieve certain expository and pedagogical objectives, and no original contribution to the theory is intended.

ISSN:0002-9505    

DOI:10.1119/1.1972198

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP