摘要:

The time‐energy uncertainty relation is reviewed and discussed from some elementary aspects. The relation is confirmed for a metastable system by a direct estimate of the uncertainties.

ISSN:0002-9505    

DOI:10.1119/1.13772

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

An advanced undergraduate laboratory experiment is described in which a standard two‐grid Franck–Hertz tube is used as a combined electron gun, drift space, and retarding potential analyzer. Electron energy spectra with a resolution better than 1 eV are obtained which show some of the energy‐loss features characteristic of mercury vapor.

ISSN:0002-9505    

DOI:10.1119/1.13773

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

The motion of planets and satellites is investigated by considering mainly the velocity vector, rather than the position. We introduce a convenient diagram in the velocity subspace to describe the orbital properties: semi‐major axis, eccentricity, pericenter and apocenter distances. Orbital changes resulting from the atmospheric drag or from any sudden modification of the velocity vector are easily inferred from the diagram. Sample applications are presented as well.

ISSN:0002-9505    

DOI:10.1119/1.13739

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

An acoustic signal from a cw source towed near the sea surface produces a Lloyd’s mirror type of pattern. The signal received on a six‐hydrophone moored array gives a record of this three‐dimensional pattern. A comparison of the observed data and calculated pattern using the characteristics of the ocean provides some insight into transmission in a region where the velocity is depth dependent.

ISSN:0002-9505    

DOI:10.1119/1.13740

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

The standard freshman kinetic theory of pressure would indicate the equation of statep=μ/nfor incoherent radiation in ann‐dimensional space. The validity of this can be demonstrated by two different methods—one using Maxwell’s equations to show the vanishing of the averaged trace of the stress energy tensor, the other following a statistical mechanical derivation. One use of the result is in the study of cosmological solutions to Einstein’s equations inndimensions.

ISSN:0002-9505    

DOI:10.1119/1.13741

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

A nonstandard method for determining solar temperature has been presented. This method is based on the comparison between the brightness of a commercially available incandescent lamp and the Sun. This comparison is quantitative, due to the well‐known properties of tungsten. Planck’s law too has a fundamental role in this comparison. A silicon cell with an interference filter which has a central wavelength of 600 nm is used to examine the two sources of light. A quite satisfactory value of the solar temperature—about 5700 K—has been obtained in this way, and some interesting points are raised in connection with the radiation constantc2of Planck’s law. The experiment may be considered as an advanced project concerning solar energy teaching or blackbody radiation theory.

ISSN:0002-9505    

DOI:10.1119/1.13742

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

Louis de Broglie’s original theory of matter waves has until very recently received relatively little treatment in the literature on history and foundations of physics. This paper attempts to clarify a number of aspects of de Broglie’s theory, as formulated primarily in his famous thesis, which still give rise to confusion or debate. To this end, a re‐examination is made of the scope and validity of the relativistic physics employed in de Broglie’s arguments concerning the existence of phase waves and their physical implications. Recent doubts concerning the soundness of de Broglie’s introduction of a wave group associated with the quantum are also analyzed in detail, and it is argued that the wave group indeed has a problematic, if minor, role in the overall theory.

ISSN:0002-9505    

DOI:10.1119/1.13743

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.13744

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.13745

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.13746

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP