摘要:

Prepared at the request of the AAPT Committee on Resource Letters; supported by a grant from the National Science Foundation.This is one of a series of Resource Letters on different topics, intended to guide college physicists to some of the literature and other teaching aids that may help them improve course contents in specified fields of physics. No Resource Letter is meant to be exhaustive and complete; in time there may be more than one letter on some of the main subjects of interest. Comments and suggestions concerning the content and arrangement of letters as well as suggestions for future topics will be welcomed. Please send such communications to Professor Joel Gordon, Chairman, Resource Letter Committee, Department of Physics, Amherst College, Amherst, Massachusetts.Notation:The letterEafter the item number means that the reference should be mainly useful forelementarycourses. In view of the complexity of the subjectelementarywill normally imply junior courses. The letterIindicates intermediate (senior and first-year graduates) andAindicates advanced (second-year graduates and students beginning research in Physics). An asterisk indicates items particularly recommended for introductory study.Additional copies:Available from American Institute of Physics, 335 East 45 Street, New York, New York 10017. When ordering, request Resource Letter SP-1 and enclose a stamped return envelope.

ISSN:0002-9505    

DOI:10.1119/1.1975017

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

The classic equation describing diffusion,δn/δt = D∇2n, is not consistent with the principles of special relativity. Specifically, its solutions permit the diffusive flow of particles to proceed at speeds in excess of the speed of light. A careful derivation, proceeding from the covariant form of the Boltzmann equation, results in a diffusion equation which exhibits the correct causal behavior. This equation assumes a particularly simple form,v−1(δ2n/δt2) + (δn/δt) = D∇2n, when the collision frequency for momentum transfer,v, is independent of particle speed. The general solution for diffusion in one dimension is presented, revealing the causal character of the diffusive flow.

ISSN:0002-9505    

DOI:10.1119/1.1975019

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

The one-dimensional nearest-neighbor Ising model, in the presence of a uniform external magnetic field, is solved using a difference equation technique. The approach involves neither combinatorial analyses nor matrix methods, and can be understood with a minimal knowledge of difference equations. The cases with periodic boundary conditions and with no boundary constraints are treated with equal ease. Similarly, the one-dimensional nearest-neighbor fluid is solved with the aid of difference equation techniques. Some difference-equation theory and the conventional matrix Ising model solutions are outlined in appendixes.

ISSN:0002-9505    

DOI:10.1119/1.1975021

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

It is shown that charge conservation is not necessary in deriving the displacement current in Ampere's law.

ISSN:0002-9505    

DOI:10.1119/1.1975023

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

The approach to radiative equilibrium of a system of free electrons in a background medium whose index of refraction is larger than unity is studied in the light of the basic principles of elementary nonrelativistic quantum theory. It is shown that the radiative equilibrium arises as a consequence of a balance between Čerenkov emission (spontaneous plus the induced emission) and absorption of photons by the uniformly moving electrons. A coupled pair of equations, one describing the time evolution of the photon distribution function and the other describing the time evolution of the electron distribution function, is thus derived. The equation for the time rate of change of the electron distribution function reduces, in the classical limit, to a Fokker-Planck equation.

ISSN:0002-9505    

DOI:10.1119/1.1975025

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A simple tuned circuit amplifier which can be readily constructed by advanced undergraduate physics students is used as a spectrum analyzer. A repetitive square voltage waveform is analyzed using this device. The main motivation for the development of the simple spectrum analyzer is to demonstrate physically the reality of the existance of the Fourier components of a repetitive waveform.

ISSN:0002-9505    

DOI:10.1119/1.1975027

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A review is given in elementary terms of the diffraction of waves from helices, with special reference to the structure of DNA. The essential features of the experimental results are discussed.

ISSN:0002-9505    

DOI:10.1119/1.1975029

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A physical science course centered around physical oceanography, which was taught to nonscience majors, is described. A very high level of interest was shown by the students. Most of the topics covered in conventional physical science courses can be covered in such a course but in a manner more enjoyable to the student.

ISSN:0002-9505    

DOI:10.1119/1.1975031

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

An application of Feynman-type diagrams in a simple one-particle problem is offered as a pedagogical prop for setting the stage for the diagrammatic representation of serious perturbation calculations. This example is useful to the student, since it brings out several features that will be involved in the applications of diagrams to more sophisticated problems. Important aspects of this application are: (1) It is shown how the rules for combining probability amplitudes can be used; (2) a technique for introducing an external field (which can cause transition among states) is described; and (3) some of the language used in diagrammatic representations is introduced. The concept of dressing a particle is only partially developed.

ISSN:0002-9505    

DOI:10.1119/1.1975033

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A physicist's educated intuition indicates that the presence of some readily analyzed forces in a gas reduces one's uncertainty about the actual state of affairs at the molecular level below the corresponding uncertainty in the absence of such forces. There ought to be a connection with at least one of the entropylike expressions appearing in statistical mechanics. A simple proof is given that, in the classical limit, the presence of any forces (represented by potentials dependent on particle positions only) does reduce the Gibbs entropy below its value, at the same temperature, in the absence of such forces. This may be taken as support for an interpretation of the Gibbs entropy as a measure of one's uncertainty about the actual microscopic situation, given the information typically available.

ISSN:0002-9505    

DOI:10.1119/1.1975035

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP