摘要:

A great deal of insight can be obtained into the infrared divergence problem in quantum electrodynamics by consideration of a simple model in which the electromagnetic field is quantized but the electric current is treated classically. It is not necessary to use box normalization.

ISSN:0002-9505    

DOI:10.1119/1.1970929

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

In an introductory paper, the vortex sponge was shown to be governed, in restricted cases, by Maxwell's free-space equations. In the present paper, analogs to electric and magnetic energies and Poynting's theorem are derived by simple mechanical considerations. Rotational stability, suggested originally by MacCullagh as a fundamental property of a luminiferous ether, turns out to be a quality of the medium, as do the stresses introduced by Faraday and Maxwell to explain the mechanical actions of electric and magnetic fields. A rudimentary model for the electrostatic field is suggested on this basis. A conventional definition of charge and the laws of Coulomb and Biot complete Maxwell's equations for cases including charges and currents. A model of the magnetic field based on the bulk rotation and the Faraday-Maxwell stresses, combined with the laws of Coulomb and Biot, permits the inference of the Lorentz force. Although numerous gaps occur in the treatment, it seems not unlikely that the vortex sponge has the qualities described by the electromagnetic field equations as well as the mechanical attributes required for a model of these fields.

ISSN:0002-9505    

DOI:10.1119/1.1970931

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

A simple, concise method is presented for deriving any desired thermodynamic first derivative in terms of a minimal basic set. The method is given in detail for a two-degree-of-freedom system, specifically a homogeneous fluid. The variables involved, including thermodynamic potentials, are briefly reviewed and the Maxwell relations derived. Differentials of all variables are expressed in terms of those ofpandTwith the use of a basic set of three partial derivatives. A four-step method is then stated for deriving any desired first derivative from these expressions; three examples are presented as illustrations. The Jacobian formalism is given for comparison at appropriate points, but not otherwise used. Finally, a natural, straightforward extension of the method to anN-degree-of-freedom system is outlined.

ISSN:0002-9505    

DOI:10.1119/1.1970933

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

A review is made of the historical background of the Special Theory of Relativity with particular attention to the theoretical contributions of Henri Poincaré. The primary aims are to show the synthetic aspects of Einstein's original paper on relativity and to clarify the logic of his fundamental innovations.

ISSN:0002-9505    

DOI:10.1119/1.1970936

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

A simple furnace has been constructed for growing large metal crystals. Single crystals of aluminum which are conical in shape, 2 in. in diameter at the base and 5 in. in height have been produced.

ISSN:0002-9505    

DOI:10.1119/1.1970938

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

The authors give some personal recollections of their participation in the experiments of Rutherford and Chadwick on the disintegration of light elements by impact of alpha particles in the 1920's.

ISSN:0002-9505    

DOI:10.1119/1.1970940

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

In order to explain energy equipartition in terms of temperature changes, the equipartition theorem is restated to incorporate the kinetic-theory definition of temperature. This procedure emphasizes the role of energy changes in a system and thereby promotes a clearer understanding of, and the need for, the quantum partition case.

ISSN:0002-9505    

DOI:10.1119/1.1970942

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

The importance of finding general solutions to the Hamilton-Jacobi equation is emphasized. The procedure for doing so is presented together with examples of its use.

ISSN:0002-9505    

DOI:10.1119/1.1970943

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

The study of a few idealizations of plasma oscillations, such as the electrostatic, electromagnetic, and hydromagnetic modes illustrate the behavior of vibrations in a plasma. The dispersion relations for each type are derived here and their significance is discussed. Further consideration is given to electrostatic modes of interacting streams with a brief mention of instability growth and decay.

ISSN:0002-9505    

DOI:10.1119/1.1970945

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP

摘要:

This paper describes a method for determiningγfor gases by measuring the velocity of sound in a closed resonance tube with fixed ends. Air, nitrogen, helium, carbon dioxide, normal hydrogen, and parahydrogen were studied at temperatures between 77°K and 373°K. Inexpensive ceramic transistor radio earphones were used as both exciter and detector. The exciter was driven by a variable frequency audio oscillator in the range 50–3000 cps and the output voltage of the detector was amplified and observed on an oscilloscope. The measured values ofγare accurate to about 1%. This accuracy, and the simplicity of the experiment, combine to offer a good experiment for the undergraduate laboratory.

ISSN:0002-9505    

DOI:10.1119/1.1970946

出版商:American Association of Physics Teachers    

年代:1964

数据来源: AIP