摘要:

The American Institute of Physics is a not‐for‐profit membership corporation chartered in New York State in 1931 for the purpose of promoting the advancement and diffusion of the knowledge of physics and its application to human welfare. Leading societies in the field of physics and astronomy are its members. AIP's activities include providing services to its Member Societies in the publishing, fiscal, and educational areas, as well as other services which can best be performed by one operating agency rather than dispersed among the constituent societies.

ISSN:0031-9228    

DOI:10.1063/1.2814839

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2814840

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2814841

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2814842

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Ever since Yakir Aharonov and David Bohm pointed out, in 1959, that electrons propagating around a magnetic field through a field‐free vacuum should exhibit a quite surprising interference effect, its experimental and theoretical investigation has been contributing to our understanding of the fundamental character of the quantum theory. The recent appearance of this Aharonov–Bohm effect in a rather different context may eventually have a profound effect on our view of the solid state on a “mesoscopic” scale—between the microscopic and the truly macroscopic.

ISSN:0031-9228    

DOI:10.1063/1.2814843

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Hubble's celebrated constant, which relates the recessional velocities of galaxies to their distances, is perhaps the most important number in extragalactic astronomy. Using it, along with their favorite models, astronomers and cosmologists derive the age of the universe, estimate its size, calculate the luminosity of quasars and much more. Unfortunately, astronomers are far from agreeing on a value for Hubble's constant. Some believe thatH0is about 50 km/sec Mpc; others think it is closer to 100 km/sec Mpc. Depending on the details of the cosmological model chosen, this can lead to a discrepancy of a factor of 2—ten billion years or so—in the age of the universe.

ISSN:0031-9228    

DOI:10.1063/1.2814844

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

In my view of the evolution of solidstate physics, the 1970s were the decade of bulk phenomena. We made enormous strides in understanding crystals—we mapped their energy bands, developed clever computational schemes and became experimentally and theoretically adept at characterizing solid crystals. At the same time, we developed the tools to study surfaces, and we continue to make amazing progress in this area, as Shuk Y. Tong explained in a recent article (PHYSICS TODAY, August 1984, page 50).

ISSN:0031-9228    

DOI:10.1063/1.881062

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

It is a pleasure to write about Theodore von Ka´rma´n. I am somewhat concerned, however, as I consider the audience for this article, many of whom are also fluid dynamicists: I can imagine quite a few old friends who knew von Ka´rma´n—perhaps as well as I—saying, “Oh, that isn't the way it really was.” Well, I can only say that what I am going to write about is the way I remember it. (There must be some kind of “statute of limitations” that says that when you get to a certain age—and I suppose I have—you're entitled to tell it the way you remember it, and let the chips fall where they may.)

ISSN:0031-9228    

DOI:10.1063/1.881063

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

About 400 research facilities officially classified as Federal laboratories employ nearly 185 000 of the nation's scientists and engineers and account for roughly $18 billion per year—a third of all Federal R&D funding in fiscal 1985. Most of this support went to a relatively few large centers devoted to energy and weapons research, highenergy physics experiments, medical programs and space science and exploration. Besides the multipurpose national labs such as Sandia, Argonne, Los Alamos and the National Bureau of Standards, which perform a broad range of R&D activities, the full roster includes a diversity of installations, including the Boll Weevil Research Laboratory; the National Radio Astronomy Observatory; the Insect Attractant, Behavior and Basic Biology Center; the FBI Laboratory; and even the National Zoo. Despite the contributions of the Federal labs, how they can enrich the nation's R&D enterprise with “public technology” has been a subject of concern in Washington for decades.

ISSN:0031-9228    

DOI:10.1063/1.881064

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2814845

出版商:AIP    

年代:1986

数据来源: AIP