摘要:

Digging techniques designed to protect the “scientific integrity” of a test tunnel at the US Department of Energy's Yucca Mountain project exposed more than a thousand workers to dangerous silica dust between 1992 and 1996, according to a DOE safety official. As many as 1500 workers may have been exposed to the dust, which can cause silicosis, a progressive and potentially fatal lung disease.

ISSN:0031-9228    

DOI:10.1063/1.1768668

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The Gallium Neutrino Observatory (GNO) is the price that Italy's underground lab is paying to get back on its feet after a small chemical spill nearly two years ago.

ISSN:0031-9228    

DOI:10.1063/1.1768669

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

As a physics student at the Norwegian Institute of Technology (now the Norwegian University of Science and Technology), Fred Kavli financed his studies with money from an earlier business venture. As teenagers, he and his brother had made wooden briquettes for automotive fuel during World War II.

ISSN:0031-9228    

DOI:10.1063/1.1768670

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

“Physics can't explain the existence of as simple a thing as a pair of spectacles,” says George Ellis, a cosmologist and the 2004 winner of the Templeton Prize. Founded three decades ago by global investor John Templeton, the prize “honors and encourages… breakthroughs to expand human perceptions of divinity and to help in the acceleration of divine creativity.” By design, the prize purse exceeds that of the Nobel Prizes; this year it is about $1.4 million.

ISSN:0031-9228    

DOI:10.1063/1.1768671

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2408555

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Like all wave phenomena, light has mechanical properties. Johannes Kepler suggested that comet tails always point away from the Sun because light carries linear momentum. In 1905, John Poynting developed the theory of electromagnetic radiation pressure and momentum density and, in 1921, Albert Einstein showed that Planck's blackbody law and the motion of molecules in a radiation field could be explained if the linear momentum of a photon isℏk.(The wave numberk = 2&pgr;/&lgr;andℏ = h/2&pgr;,where &lgr; is the wavelength andhis Planck's constant.) In modern times, light's linear momentum has been directly exploited for trapping and cooling atoms and molecules.

ISSN:0031-9228    

DOI:10.1063/1.1768672

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

How do you define the temperature of an electron gas? Like particles in general, electrons in a metal prefer to occupy energy levels in a way that minimizes their total energy. As fermions, they obey the Pauli exclusion principle and at zero temperature completely fill all the states below the Fermi energy. At nonzero temperatures, some electrons are found above the Fermi level by an amountkBT,the thermal energy of the system. More quantitatively, electrons at a particular temperature occupy energy levels with a probability given by the Fermi–Dirac distributionf(E) = 1/[1+exp(E/kBT)].Electrons reach this distribution by inelastic scattering—exchanging energy between themselves or with the surrounding crystal lattice.

ISSN:0031-9228    

DOI:10.1063/1.1768673

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

A couple of years ago I was visited by a Slimy Galactic Superoctopus—a being from outer space who, for the occasion, had taken on a female human appearance. Were it not for her spaceship in my garden and a few other details, I would have said she was just a pleasant young woman, very intelligent and pretty. She told me her name was Pallas. She had been writing a galactic PhD thesis on the nature of human mathematics, and we had long discussions on that and other topics. Then Pallas had to pass her exams and she disappeared into the darkness of space. I had little hope of seeing her again. But once more, her tall, white, silent spaceship stood in my garden, and when we met at the garden door, it was as if she had never been away.

ISSN:0031-9228    

DOI:10.1063/1.1768674

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1768675

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1768676

出版商:AIP    

年代:1904

数据来源: AIP