摘要:

The evolution of the Balmer Series has not been well understood because of peculiar historical circumstances. Upon review of earlier publications of spectroscopy, an analysis of Balmer's papers, and a study of biographical information on Balmer, a clearer picture results. Much of the background information used by the mathematician Balmer was conveyed by the physicist Hagenbach and can be traced to a contemporary textbook by the spectroscopist Kayser, published one year prior to Balmer's historic lecture. Since Balmer did not describe all of his mathematical steps, they were reconstructed, using Balmer's own statements as much as possible. Balmer's success in establishing the series is connected with his ability in handling graphic methods of analysis; he referred to such analysis in his earlier paper, later published a geometrical construction of the hydrogen-line series and a text on projective geometry.

ISSN:0002-9505    

DOI:10.1119/1.1973077

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

A presentation is given, in its simplest and most useful form for applications to physics, of the permutation symbol approach to elementary vector analysis. It is hoped that the availability of such a presentation will encourage wider use of the method in introductory and intermediate college courses in physics and engineering.

ISSN:0002-9505    

DOI:10.1119/1.1973078

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

Vector differential operations can be introduced through their physical definitions which are independent of coordinate systems. It is shown how the components of the gradient of a scalar function and the curl of a vector can be calculated directly form their physical definitions.

ISSN:0002-9505    

DOI:10.1119/1.1973079

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

The term “Newtonian particle” is introduced to designate the ultimate entities of which gross bodies are assumed to be constituted in Newton's mechanics. It is shown that the principle of mass-additivity can be validated more convincingly in that system if the mutual forces between pairs of Newtonian particles are noncentral than if these forces are central forces. On the basis of this conclusion the action and reaction pairs of the third law are identified as wrench-pairs rather than simple force-pairs.

ISSN:0002-9505    

DOI:10.1119/1.1973080

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

A suggestion by Feynman that the Lamb-shift energy can be obtained from the changes in zero-point energy due to the presence of the atoms involved is worked through in detail for the Bethe nonrelativistic contribution to the energy shift. The self energy of a free electron is obtained in the same way and is equivalent to the state independent shift due to thee2A2/2m2term in the normal perturbation methods.

ISSN:0002-9505    

DOI:10.1119/1.1973082

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

The standard introductory course for the science and engineering students is too often completely crammed with formulas and problems and gives the beginning student no idea whatsoever of the excitement of physics, and of its philosophy, history, and research frontier. Several new introductory courses have made a fresh start and attenpted to introduce the excitement of research physics. However, very little effort has been expended on the other problem, that of making the beginning student aware of the philosophy and history of physics. This objective can be accomplished by a series of selected readings in the original literature and in the literature of the philosophy of physics. The author of this paper has experimented for several years with collateral reading of this nature in the introductory course and the results have been excellent.

ISSN:0002-9505    

DOI:10.1119/1.1973083

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

It is proved that the maximum amount of energy that can be extracted from an electromagnetic field by a small detector is given by the time integral of the squared-vector potential. It is further shown that a discussion of less than perfect detectors leads quite naturally to the concept of self-coherence.

ISSN:0002-9505    

DOI:10.1119/1.1973084

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

The scalar-indexed Warren-Cowley order parameters for the perfectly orderedCu3Auand CuZn alloys are calculated with the aid of Waring's theorem from number theory. Cowley and Klein have incorrectly reported these parameters forCu3Auas being one for even-order shells (of neighbors) and−13for odd-order shells. We show that these parameters are equal to one for those shells with radiusd(2k)12,k ≠ 4a(8b + 7), and−13for those shells with radiusd(2k + 1)12, wherea,b,kare nonnegative integers anddis the radius of the first shell in the fcc lattice. For the ordered form of CuZn (beta brass), we find that the order parameters are one for those shells with radiusd(k)12,k ≠ 4a(8b + 7), and minus one for those shells with radius(d/2)(8k − 5)12, wherea,bare nonnegative integers,kis a positive integer, anddis the nearest distance between two like atoms. Five theorems proved in this paper are the basis for the preceding results and are also useful in the study of point defects in cubic crystals and in the study of ionic crystals. Formulas are given for the radii of the shells of lattice points about given points, both lattice and interstitial points, in cubic lattices.

ISSN:0002-9505    

DOI:10.1119/1.1973085

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1973087

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1973088

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP