ISSN:0031-9228    

DOI:10.1063/1.2409334

出版商:AIP    

年代:1902

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1506735

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

The 1 July issue ofPhysical Review Lettersreports an important result from the Sudbury Neutrino Observatory (SNO), 2 km underground in an Ontario nickel mine. This much‐anticipated paper describes the first direct measurement of the total flux of neutrinos (above the detector's energy threshold) arriving from the core of the Sun, irrespective of any “flavor” metamorphoses along the way. And that total flux turns out to be in excellent agreement with the neutrino output predicted by the so‐called standard solar model (SSM).

ISSN:0031-9228    

DOI:10.1063/1.1506736

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

For the past two years, the sun has been shining brightly on researchers from Bell Labs, Lucent Technologies, who have come up with a method to endow many organic materials with unexpected and exciting properties. A dark cloud now looms over these researchers because of apparent similarities among figures that they published in different papers, reporting on different experiments. As soon as outside scientists called these similarities to the attention of Bell Labs management, Cherry Murray, senior vice president of physical‐sciences research, appointed a special committee to explore whether the figures are evidence of scientific misconduct. The committee, headed by Malcolm Beasley of Stanford University, hopes to complete its inquiry by summer's end.

ISSN:0031-9228    

DOI:10.1063/1.1506737

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

Though superseded for most applications by the solid‐state transistor, the venerable vacuum tube boasts one big advantage over its younger usurper: power. Free of stuff between its electrodes, a vacuum tube can operate at currents that would ohmically toast a transistor's semiconducting innards. Vacuum tubes remain the technology of choice for high‐power amplifiers, magnetrons, and klystrons.

ISSN:0031-9228    

DOI:10.1063/1.1506738

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

A strophysicists have been studying gamma‐ray bursts (GRBs) for more than 30 years, but they still don't fully understand the cataclysmic cosmic processes that give rise to these brief showers of energetic gamma rays. One technique for learning about the explosions (see also page 24 in this issue) is to study the emissions of the x‐ray, optical, or radio afterglows that follow the GRBs: Afterglows can reveal details of the temperature, ionization, composition, and other features of the material illuminated by the bursts.

ISSN:0031-9228    

DOI:10.1063/1.1506739

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

University of Chicago astrophysicist Michael Turner was hustling through the Washington, DC, power structure in mid‐April with the fervor of a lobbyist with a hot issue. As the driving force behind the just‐released National Research Council reportConnecting Quarks with the Cosmos: Eleven Science Questions for the New Century, Turner had the critical task of championing the study. After more than two years of overseeing the writing of the report, Turner was charged with convincing the Washington officials who control the federal science purse strings that the study was worth supporting.

ISSN:0031-9228    

DOI:10.1063/1.1506740

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

In the fall of 1999 while attending a meeting of the National Research Council's Board on Physics and Astronomy, NASA Director Daniel Goldin listened to what board members later described as a “stimulating session” on research at the intersection of physics and astronomy. At the end of the meeting, he asked board members if they could assess the science opportunities in this interdisciplinary area and develop a plan for turning the opportunities into reality. In March 2000, thanks to Goldin's request, several officials with NSF, the Department of Energy, and NASA formed the Committee on the Physics of the Universe to conduct the study.

ISSN:0031-9228    

DOI:10.1063/1.1506741

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

Triggered by a satellite signal, the telescope slews across the sky and zeroes in on a gamma‐ray burst, capturing the explosion's optical emissions within seconds. That, at least, is the plan. So far, though, it has played out like that just once, on 23 January 1999. The tantalizing GRB990123 has stoked scientists' enthusiasm, and several experiments using small, ground‐based, robotic telescopes to tackle big questions about gamma‐ray bursts are in the works.

ISSN:0031-9228    

DOI:10.1063/1.1506742

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

A new bird of prey is scanning the skies in New Mexico: RAPTOR (Rapid Telescopes for Optical Response), a binocular robotic telescope developed by scientists at Los Alamos National Laboratory, hunts for optical transients. One of its eyes is at the lab and the other is located 38 km to the west at Fenton Hill Observatory.

ISSN:0031-9228    

DOI:10.1063/1.1506743

出版商:AIP    

年代:1902

数据来源: AIP