ISSN:0002-9505    

DOI:10.1119/1.16767

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16769

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16770

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16771

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

In modern physics the vacuum is not a tranquil void but a quantum state with fluctuations having observable consequences. The present concept of the vacuum has its roots in the zero‐point energy of harmonic oscillators and the electromagnetic field, and arose before the development of the formalism of quantum mechanics. This article discusses these roots in the blackbody research of Planck and Einstein in 1912–1913, and the relation to Bose–Einstein statistics and the first indication of wave–particle duality uncovered by Einstein’s fluctuation formula. Also considered are the Einstein–Stern theory of specific heats, which invoked zero‐point energy in a way which turned out to be incorrect, and the experimental implications of zero‐point energy recognized by Mulliken and Debye in vibrational spectroscopy and x‐ray diffraction.

ISSN:0002-9505    

DOI:10.1119/1.16772

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

It is shown very simply that for any two observables represented by Hermitian operators that do not commute, there is a state for which there is no joint probability distribution for the two observables.

ISSN:0002-9505    

DOI:10.1119/1.16773

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

Randomness is a fundamental but elusive concept in mathematics and physics. Even for the elementary case of a random binary sequence, a generally accepted and operational definition is lacking. However, when ensembles are used for the foundation of probability theory, randomness has to be identified with uncorrelatedness, a neglected notion that yet solves many puzzles surrounding randomness. In any single sequence, a definite amount of correlation is unavoidable. At best, the remaining correlations are of high order or cover a large distance. This is the case for properly defined well‐tempered pseudorandom sequences. Reliable algorithms for the generation of pseudorandom bits at rates of 1 GHz result.

ISSN:0002-9505    

DOI:10.1119/1.16747

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

Strong laser perturbation of an atom with fine or hyperfine structure is analyzed in the context of a level‐crossing experiment. The effect of sufficiently powerful, detuned, and/or spectrally broad light is to produce ‘‘hyperfine uncoupling,’’ which can be regarded as the optical Back–Goudsmit effect. It is easily understood in terms of an analogy between the level‐crossing effect and double‐slit experiment.

ISSN:0002-9505    

DOI:10.1119/1.16748

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

A historical introduction to the issues raised by the Casimir effect is provided, putting special emphasis on the experiments which attempt to test this and related phenomena. The classical and modern quantum interpretations are explained, and an account of the existing calculation methods is given. The discussion is illustrated with an example of the zeta‐function regularization procedure.

ISSN:0002-9505    

DOI:10.1119/1.16749

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

For pedagogical purposes, and also to provide a simple schema wherein ideas and methods may quickly be tried out, a toy version of the interacting boson model (IBM) is developed in two dimensions.

ISSN:0002-9505    

DOI:10.1119/1.16750

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP