ISSN:0031-9228    

DOI:10.1063/1.3035175

出版商:AIP    

年代:1968

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3035145

出版商:AIP    

年代:1968

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3035147

出版商:AIP    

年代:1968

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3035148

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Good new use for bad old guns; How about decimal time?; Does anybody here know d'Abro?; Acoustics at Hastings; The Omphalosceptic.

ISSN:0031-9228    

DOI:10.1063/1.3035149

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

BY NOW THEREcan hardly be a physicist who has not been jolted by the challenge of the information explosion. Some men have been so overcome that they have given up subscribing toThe Physical Reviewfor lack of shelf space. The widespread concern about this challenge has been reflected in a number of recent articles inPHYSICS TODAYand in similar discussions in magazines of other fields and other countries. Among the great bulk of physicists diverse attitudes prevail: Some remain happy in a speciality narrow enough so that they can feel “in the swim” if they keep in touch with a few colleagues and read a highly specialized journal; others rationalize with the comment that most of the literature is garbage anyway; a few pin their hopes on the vast improvements being made by their documentalist colleagues in the science of indexing and retrieval.

ISSN:0031-9228    

DOI:10.1063/1.3035150

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

FROM TIME IMMEMORIALpeople must have been curious to know what keeps the sun shining. The first scientific attempt at an explanation was by Helmholtz about one hundred years ago, and was based on the force most familiar to physicists at the time, gravitation. When a gram of matter falls to the sun's surface it gets a potential energyEpot = −GM/R = −1.91×1015 erg/gm (1)whereM = 1.99×1033 gmis the sun's mass,R = 6.96×1010 cmits radius, andG = 6.67×10−8the gravitational constant. A similar energy was set free when the sun was assembled from intersellar gas or dust in the dim past; actually somewhat more, because most of the sun's material is located closer to its center, and therefore has a numerically larger potential energy. One‐half of the energy set free is transformed into kinetic energy according to the well‐known virial theorem of mechanics. This will permit us later to estimate the temperature in the sun. The other half of the potential energy is radiated away. We know that at present the sun radiates&egr; = 1.96 erg/gm sec (2)Therefore, if gravitation supplies the energy, there is enough energy available to supply the radiation for about1015 secwhich is about 30 million years.

ISSN:0031-9228    

DOI:10.1063/1.3035151

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

RECENTLY THE VALUEof pure research to the US nation has come into question. Although the federal government has steadily increased its support of pure research since the Second World War, attempts to determine the value of pure‐research activities to the national economy have been inconclusive. Project Hindsight concluded that very little basic research carried on in university laboratories had contributed to the development of weapons systems since the war and implied that consequently there was little point in the Defense Department's continued support of pure research in universities. On the other hand, those individuals who support increased funding of pure research by the federal government point out that the nation's most rapidly growing industries are those that have invested most heavily in research, with the implied conclusion that an investment in pure research will result in an expanded national economy.

ISSN:0031-9228    

DOI:10.1063/1.3035152

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

To CLARIFY MY TOPICI quote theConcise Oxford Dictionarydefinition of the word “Philistine”: “one of an alien warlike people in South Palestine who harassed the Israelites; (facetiously) an enemy into whose hands one may fall, e.g. bailiff, critic,et cetera; (in German universities) a nonstudent; an outsider; (or, in general) an uncultured person, one whose interests are material and commonplace.” I shall use the word in the sense of an outsider or, I might say, a nonphysicist. Thus, a rewording of the subject for purposes of clarification would be “How to live with nonphysicists.” There are, of course, many classes of nonphysicist, but I shall have space to refer to only a few of the principal types.

ISSN:0031-9228    

DOI:10.1063/1.3035153

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

“DON'T TRUSTanyone over 30!” This slogan—so disheartening to the elderly but sincere teacher—indicates that youth has at last realized what older generations have long known: The hope of the future lies with young idealists who have not yet found it expedient to accommodate. Although it is important to encourage youthful enthusiasms that lead to social improvements, it is also essential that the energies of our students be channeled toward constructive activities that serve as preparation for useful and responsible roles in society.

ISSN:0031-9228    

DOI:10.1063/1.3035154

出版商:AIP    

年代:1968

数据来源: AIP