ISSN:0002-9505    

DOI:10.1119/1.1807213

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

The great post‐Newtonian revolution in physical science culminated with Einstein’s general theory of relativity in the second decade of our century, and with the establishment of the quantum theory in the third decade. The responses of literature over the past half century to these changes in world view have served as stimulating examples of cultural interchange. The novels of Thomas Pynchon, William Gaddis, Robert Coover, Joseph McElroy, Don DeLillo, and Robert Pirsig make use of the new physics as metaphor for three traditional activities of novelists: examining order and disorder, questioning cause and effect, and seeking unity in the human and physical universes.

ISSN:0002-9505    

DOI:10.1119/1.11804

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

A theory concerning the orbital spacing patterns in the solar system, more intriguing than many of the traditional topics to our general studies astronomy students and useful pedagogically since it is accessible to such students in quantitative as well as qualitative terms, is presented. The orbital distributions of the planets and major satellite systems are fitted with a Bode‐type form. The Saturnian system requires vacant orbitals if the best fit is to have an accuracy comparable to that obtained for the other systems. One pattern of vacant orbitals is shown to be consistent with what would be expected if Titan produced resonant perturbations on the forming satellite system.

ISSN:0002-9505    

DOI:10.1119/1.11805

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

The fraction of the kinetic energy of the wind impinging on its area, that a wind turbine can convert to useful power, has been shown by Betz in an idealized laminar‐flow model to have an upper limit of 16/27 or 59%. The limit is here simply rederived and it is shown how deviations from the idealized model, involving rotational kinetic energy of the downwind stream and turbulent mixing from outside the boundaries of the idealized stream, can either increase or decrease the power available. The limit is thus not a strict upper limit in practice.

ISSN:0002-9505    

DOI:10.1119/1.11807

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

A familiar theorem involving a balance between net torque and rate of change of angular momentum in the electromagnetic field is rederived. This version of the theorem includes the intrinsic torques exerted by the fields on the polarized medium. It is seen that these terms lead naturally to the expression for the intrinsic angular momentum carried by a localized pulse of electromagnetic radiation. In the present treatment the expressions for the external and intrinsic angular momenta arise naturally as separate entities, in contrast to standard treatments, in which both arise out of what is evidently only the external angular momentum.

ISSN:0002-9505    

DOI:10.1119/1.11808

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

It is shown that Einstein’s final unified field theory, the relativistic theory of the nonsymmetric field, is identical to a theory Einstein proposed in 1925.

ISSN:0002-9505    

DOI:10.1119/1.11809

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

A method to simulate the dispersive properties of various media is described. We have used it to demonstrate to an Electromagnetic Theory class, the dispersion of a pulsed electromagnetic wave propagating in an unbounded dielectric medium. In addition, the characteristics of the electromagnetic precursors (Sommerfeld and Brillouin) have also been demonstrated.

ISSN:0002-9505    

DOI:10.1119/1.11811

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

Standard clocks at rest in (i) a rigidly hyperbolically accelerated reference frame, (ii) on a rotating disk, and (iii) on the surface of the earth are considered. Special relativity is sufficient to predict the behavior of the clocks in cases (i) and (ii). In case (iii), however, gravitational effects are important, which is taken account of by use of the principle of equivalence. It is concluded that in cases (i) and (ii) clocks connected along a line in the direction of the acceleration do not maintain Einstein synchronization. As to the rate of standard clocks on the surface of the earth, the drifts caused by the rotating motion of the earth and the deviation of the earth’s surface from a sphere cancel each other. On the geoid this cancellation is exact. This means that the synchronization of clocks at every position at the mean sea level, no matter how far apart on the earth they are located, is not destroyed by these effects. Owing to tidal effects clocks on the earth at different positions in the solar gravitational field do not maintain their synchronization. This effect is several orders of magnitude less than the above ones.

ISSN:0002-9505    

DOI:10.1119/1.11812

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

In order to understand in detail how the representations of the rotation group are constructed from products of the spin‐1/2 representation, a clear distinction must be maintained between three related but conceptually different quantities: a vector in an abstract vector space, its components in some chosen basis, and its representatives. The rotation group provides an example that these are indeed different concepts, and that paradoxes result if they are confused.

ISSN:0002-9505    

DOI:10.1119/1.11813

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

We describe the numerical methods of relaxation and over‐relaxation for solving Laplace’s equation for a system of conductors. These methods are quite tractable nowadays using only modest sized computers. Several simple (analytically solvable) though moderately complicated (arising from experimental situations) examples of their use are given.

ISSN:0002-9505    

DOI:10.1119/1.11802

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP