摘要:

Editor’snote: This is a reprint (slightly edited) of a paper of the same title that appeared in the bookPhysicsandOurWorld:ASymposiuminHonorofVictorF.Weisskopf, published by the American Institute of Physics (1976). The personal tone of the original talk has been preserved in the paper, which was itself a slightly edited transcript of a tape. The figures reproduce transparencies used in the talk. The demonstration involved a tall rectangular transparent vessel of corn syrup, projected by an overhead projector turned on its side. Some essential hand waving could not be reproduced.

ISSN:0002-9505    

DOI:10.1119/1.10903

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

The tippe top displays the unexpected behavior of inverting itself when it is spun upon a flat surface. In the process its center of mass rises. Several explanations of this behavior have been offered in the literature. Here, in the light of a historical perspective, physical arguments are presented which support the contention that the influence of sliding friction is the key to the understanding of the top’s behavior. Then, a rigorous analysis of the top’s mechanics is offered, together with computer‐generated solutions of the equations of motion.

ISSN:0002-9505    

DOI:10.1119/1.10926

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

Because of its exceptional significance in the history of great ideas in science, Einstein’s first paper on relativity, especially its first part, deserves a more careful translation into English than presently exists. A new and annotated translation of this first part is presented here, together with a brief discussion of certain aspects of Einstein’s paper.

ISSN:0002-9505    

DOI:10.1119/1.10927

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

In a paper entitled ’’An Operator Calculus Having Applications in Quantum Electrodynamics’’ [Phys. Rev. 84, 108 (1951)], Feynman gives techniques and theorems for working with ordered operators. We believe that the entire development, because of its direct involvement in the transition from the Heisenberg–Schrödinger to Feynman’s path‐integral formulation of quantum mechanics, is of general interest. We aim to make these less appreciated early techniques of Feynman more accessible to the general physicist.

ISSN:0002-9505    

DOI:10.1119/1.10929

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

Protein and virus x‐ray crystallography is an ideal interdisciplinary topic for a molecular biophysics or physical biochemistry course. X‐ray diffraction theory is the domain of physics; chemical techniques are used to isolate proteins and viruses and elucidate mechanisms for active‐state geometries; the biological sciences provide the experimental subject, life‐sustaining macromolecules. The crystallography lectures are outlined, briefly discussed, and rigorously referenced. Further topics for a molecular biophysics course as well as available texts are given.

ISSN:0002-9505    

DOI:10.1119/1.10901

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

An experiment is described which investigates the hyperfine structure of the 63S1and 53P0,1,2excited levels of cadmium. The nuclear spin of the odd isotopes and the hyperfine constants for the levels are derived.

ISSN:0002-9505    

DOI:10.1119/1.10902

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

A pedagogical method is described for measurement of the coefficient of restitution for collisions between a bouncing ball and a horizontal surface. Indirect measurement using only the sound made by the bouncing ball facilitates the rapid collection of data, allowing introductory laboratory students more time to concentrate on theory, method, data reduction, analysis, and the physical implications of their results. The coefficient of restitution is found to decrease systematically with increasing relative approach speed.

ISSN:0002-9505    

DOI:10.1119/1.10904

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

Novel experiments are described which, using unsophisticated apparatus, permit adequate measurement of the elastic constants of material available in the form of a thin flexible strip. The accuracy attainable is limited, as in standard methods, by the measurement of the thickness of the material. This quantity appears in the calculations raised to the third power in the measurement of both Young’s modulus and the shear modulus.

ISSN:0002-9505    

DOI:10.1119/1.10905

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

An elementary method for the calculation of the momentum autocorrelation function of a particle in a one‐dimensional box is presented.

ISSN:0002-9505    

DOI:10.1119/1.10906

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

The method of the perturbation expansion illustrated by Landau and Lifshitz in their textbook on mechanics is extended to higher orders. The validity of the method is established by the problem of a particle moving in the central force fieldf(r) =−k/r2+2C/r3.

ISSN:0002-9505    

DOI:10.1119/1.10907

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP