ISSN:0031-9228    

DOI:10.1063/1.2815070

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2815071

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2815072

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

At the Soviet Union's Chernobyl nuclear power plant, the plume of smoke is gone, but a cloud of uncertainty still obscures the cause of the severe accident there. That accident, which began early on Saturday, 26 April, caused an intense fire that lasted many days, melted unknown quantities of reactor fuel and released into the environment a large fraction of the reactor's inventory of volatile radioactive fission products (including perhaps a million times more iodine‐131 than came from Three Mile Island). On 11 May Soviet officials reported that they had stabilized the reactor and had successfully prevented the core from melting through the bottom of the containment building. Although the crisis is past, formidable tasks lie ahead. These chores include entombing the severely damaged core; isolating or decontaminating an area more than 30 km in radius around the plant, from which about 100 000 people have been evacuated; monitoring radiation levels over far more extensive areas; and determining the cause of the accident to prevent repetitions elsewhere.

ISSN:0031-9228    

DOI:10.1063/1.2815073

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The Superconducting Super Collider, if it is built before the end of the century, will certainly be the largest scientific instrument in the world. But whether its circumference should be 100 miles, or a mere 50 miles, has been a bone of some contention. The design energy is not at issue: SSC is to be an ultra‐highenergy proton‐proton storage‐ring collider with countercirculating beams of 20‐TeV protons providing p–p collisions at 40 TeV in the center of mass. The radius of the gargantuan storage ring required to keep these protons going round in circles varies inversely as the strength of the superconducting bending magnets one chooses to make up the ring.

ISSN:0031-9228    

DOI:10.1063/1.2815074

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We discuss the unity of physics with a kind of nostalgia, for our field today is so patently diverse. We hear this diversity in the cacophony of our meeting halls, in the differing languages of theorists and experimenters, of rheologists and astrophysicists. The sheer numbers of physicists and of the papers we publish—one every few minutes—overwhelm us. Diversity has even been institutionalized: Our American Physical Society is now organized into a dozen disparate divisions, and physicists have organized many physics societies outside APS. One would expect one of the clearest expressions of the unity of physics to lie in the teaching of physics, but even that enterprise has its separate American Association of Physics Teachers. And didn't we establish the American Institute of Physics, of which APS is but one of ten members, because of theneedfor unity in physics?

ISSN:0031-9228    

DOI:10.1063/1.881034

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The past century has seen major advances in diffraction gratings, motivated by pressure for new and better data in two rather distinct fields: laboratory spectroscopy—aimed at understanding atomic structure and testing quantum theory—and astrophysical spectroscopy—aimed at understanding objects ranging from the Sun and stars to faint sources at the limit of detection. In this historical account I trace some of the hard‐won gains in the technology of the ruling machines that produce the gratings, and I touch on the role that larger and higher‐quality gratings have played in scientific advances. I focus on the work at the Mount Wilson Observatory, where I directed the diffraction‐grating laboratory from 1948 to 1963, but I do so with full recognition of the important contributions made at numerous other laboratories, especially those at The Johns Hopkins University, the Massachusetts Institute of Technology and the Bausch & Lomb Optical Company.

ISSN:0031-9228    

DOI:10.1063/1.881035

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2815075

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2815076

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2815077

出版商:AIP    

年代:1986

数据来源: AIP