ISSN:0031-9228    

DOI:10.1063/1.2409951

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1570753

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1570754

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1570756

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1570757

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

After 36 years of solar neutrino experiments, the inescapable conclusion is that a large fraction of the electron neutrinos(&ngr;e)produced by nuclear processes in the Sun's core are metamorphosing into other neutrino varieties somewhere en route to the detectors on Earth (see PHYSICSTODAY, December 2002, page 16). The cause is very likely neutrino oscillation, resulting from the existence of three putative neutrino mass eigen‐states with three different masses. But until recently, the data have allowed considerable latitude in the oscillation parameters, leaving open a variety of possible mechanisms as the neutrinos traverse solar and terrestrial matter as well as 150 million kilometers of vacuum.

ISSN:0031-9228    

DOI:10.1063/1.1570758

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

A cluster of galaxies looks different at optical and x‐ray wavelengths. In the optical band, you see the galaxies themselves—typically about a hundred—in orbit about the cluster's center of mass. In x rays, you can still see the biggest galaxies, but the smaller ones are lost against a bright background of diffuse plasma that fills intracluster space.

ISSN:0031-9228    

DOI:10.1063/1.1570759

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

A simple equation, the Navier–Stokes, completely describes a fluid's flow. A single parameter, the Reynolds number, flags a flow as smooth or turbulent. But a true understanding of turbulence—one that would furnish accurate predictions of a hurricane's path or a car's drag—remains out of reach.

ISSN:0031-9228    

DOI:10.1063/1.1570760

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Office of Science and Technology Policy Director John Marburger stepped before a crowd of Washington insiders gathered for the early February unveiling of the administration's fiscal year 2004 research and development budget proposal and noted, with a slight smile, that “some astute observers may have noticed that many of the 2003 appropriations bills have not passed in Congress.” Then came the understatement: “That makes it difficult to make comparisons [with the 2004 proposal].”

ISSN:0031-9228    

DOI:10.1063/1.1570761

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

This year's “for women in science” awards by cosmetics giant L'Ore´al and the United Nations Educational, Scientific and Cultural Organization (UNESCO) recognize lifetime achievements by women in condensed matter sciences. The awards are in their fifth year, but this is the first time they've rewarded work in the physical sciences. The awards were also increased fivefold this year, with five women from five continents each receiving $100 000.

ISSN:0031-9228    

DOI:10.1063/1.1570763

出版商:AIP    

年代:1903

数据来源: AIP