摘要:

The use of physics for demographic analyses is not a form of alchemy. A brief reflection on the use of abstract structures to organize knowledge suggests a commonness to both social and physical science. Population distribution is examined using the structure of thermodynamics.

ISSN:0002-9505    

DOI:10.1119/1.1976139

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

Many entities in physics have both particlelike and wavelike properties. In representing the particlelike properties physicists usually use words ending in -ON. The originators of the concept underlying the particle nature, and the coiners of the name are discussed for the following “particles”: boson, electron, exciton, fermion, magnon, neutron, phonon, photon, plasmon, polariton, polaron, proton, and roton.

ISSN:0002-9505    

DOI:10.1119/1.1976141

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

Circular white light fringes are seen when a dispersing medium is placed in one arm of a Michelson interferometer. A formula for the number of fringes as a function of the bandwidth of the source and the dispersion of the medium is obtained which agrees well with experiment. The phenomenon has been made into a student experiment on wave groups.

ISSN:0002-9505    

DOI:10.1119/1.1976143

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

The standard quantum mechanical problem of scattering of an incident plane wave by a rectangular potential barrier in one dimension is examined from a point of view which emphasizes the multiple-scattering contributions to the reflected and transmitted, waves. This approach is used to gain insight into the phenomenon of resonant scattering of a wave packet by a potential barrier.

ISSN:0002-9505    

DOI:10.1119/1.1976145

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

A computer simulation of a two-dimensional ideal gas has been studied in order to observe the time development of the speed distribution function. The results described here are effective in demonstrating to naturally skeptical freshmen that the Maxwell-Boltzmann distribution indeed occurs in nature. The results are also useful to demonstrate the statistical nature of the second law of thermodynamics.

ISSN:0002-9505    

DOI:10.1119/1.1976147

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

Introductory physics courses are typically specialized in that they are designed for a very specific audience; physics majors, premeds, liberal arts students, etc. The categories are numerous. Further, these courses are usually highly structured with homework assignments, laboratories, and lectures establishing the cadence. The majority of students respond by progressing in lock-step fashion through the course. In this course at tne University of Missouri—St. Louis, there is no specialized audience and there is no cadence—more correctly, the cadence is drastically muted. The students supply the rhythm as the learning of physics is made an individual matter. A variety of learning devices are made available, and the student opts those that hold promise for him. No attempt is made to survey the subject of physics; rather, two major topics form the subject content. One of these topics is developed in a quasihistorical fashion to give the student some feel for physics in its verb sense. The conceptual structure of physics is sweepingly potent and alluringly intelligible—this course is designed to convey these facts.

ISSN:0002-9505    

DOI:10.1119/1.1976149

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

The known expression for the Doppler frequency shift may be used in the derivation of the relation for interference-intensity patterns in Young's modified double-slit arrangement with a monochromatic source. Alternately, the statement that the interference-fringe maxima formed in the observation plane must move downward as a density gradient ahead of a collimating lens moves upward are sufficient to establish Doppler's law for the effect of velocity on frequency shift. The theoretical result has actually been confirmed by Schwar and Weinberg in experiments that were designed to demonstrate the use of schlieren interferometry with a laser source in velocity measurements on flames.

ISSN:0002-9505    

DOI:10.1119/1.1976151

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

This paper describes an experimental use of computer terminals for instructional purposes in a university-level general physics course over a 2-yr period. Programs have been written to simulate physical problems otherwise difficult for the student to investigate. The student specifies all of the important parameters and observes the calculated result which can be displayed in graphical form. Prior to the simulated experiment, a tutorial series of questions in a multiple choice format is used to familiarize the student with the problem and to help him make an intelligent parameter selection. Similar questions can be used to guide the analysis of the results after the calculations and to allow him to repeat the simulation with variations of any or all parameters. In the particular example given here, the student can launch a satellite into orbit with his own choice of parameters. The program ensures that be cannot consider physically meaningless values. The results of computer managed instruction (CMI) programs, student reactions to them, estimates of their cost and the present and future impact of the computer on our physics curriculum are discussed.

ISSN:0002-9505    

DOI:10.1119/1.1976153

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

The local field model introduced by Bloembergen, Purcell, and Pound is shown by direct calculation in a specific case to produce a Gaussian local field distribution which shape is often characteristic of nuclear magnetic resonance lines in solids. That this result is obtained is shown to be due to the fact that the binomial distribution describes the local field distribution of a system of spin12particles provided they are more or less uniformly distributed in space and that there is a sufficiently large number of them. In the limit of a large number of spins this distribution is known to become Gaussian in shape so that the local field model can be said to predict a Gaussian line shape under rather general conditions.

ISSN:0002-9505    

DOI:10.1119/1.1976155

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

Integrals of powers of the energy over the Bose-Einstein and Fermi-Dirac distributions are special cases of Lerch's zeta function. As a consequence, various results for these integrals follow directly from results recorded in the mathematical literature on special functions. The low-temperature series for the Fermi-Dirac case is considered as an example and derived from results recorded in the Bateman project. Alternative rigorous derivations of this series, useful for classroom presentation, are also given.

ISSN:0002-9505    

DOI:10.1119/1.1976157

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP