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1. |
Physics Update |
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Physics Today,
Volume 50,
Issue 12,
1997,
Page 9-9
Benjamin P. Stein,
Phillip F. Schewe,
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PDF (325KB)
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ISSN:0031-9228
DOI:10.1063/1.2806741
出版商:AIP
年代:1997
数据来源: AIP
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2. |
How Should Physicists, Biologists Work Together? The ‘Harness the Hubris’ Debate Continues |
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Physics Today,
Volume 50,
Issue 12,
1997,
Page 11-1495
Jay S. Huebner,
Eric Jakobsson,
Hans G. Dam,
V. Adrian Parsegian,
Robert H. Austin,
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PDF (1228KB)
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ISSN:0031-9228
DOI:10.1063/1.881621
出版商:AIP
年代:1997
数据来源: AIP
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3. |
Work on Atom Trapping and Cooling Gets a Warm Reception in Stockholm |
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Physics Today,
Volume 50,
Issue 12,
1997,
Page 17-19
Barbara Goss Levi,
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PDF (942KB)
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摘要:
This month, Steven Chu, Claude Cohen‐Tannoudji and William Phillips will doff their laboratory clothes and don white tie and tails to receive the 1997 Nobel Prize in Physics in Stockholm. The Royal Swedish Academy of Sciences selected these three “for the development of methods to cool and trap atoms with laser light.” Thanks to these methods, neutral atoms have now been slowed to speeds below a few centimeters per second, corresponding, for helium atoms, totemperatures of a few hundred nanokelvin. To bring atoms to such a crawl, the researchers broke not one but two barriers originally thought to limit the temperatures to which atoms could be cooled.
ISSN:0031-9228
DOI:10.1063/1.881626
出版商:AIP
年代:1997
数据来源: AIP
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4. |
Optical Frequency Measurement is Getting a Lot More Precise |
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Physics Today,
Volume 50,
Issue 12,
1997,
Page 19-21
Bertram Schwarzschild,
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PDF (935KB)
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摘要:
At the Max Planck Institute for Quantum Optics in the Munich suburb of Garching, Theodor Hansch and colleagues have measured the ultraviolet transition frequency between the 1S and 2S states of atomic hydrogen to be2.466 061 413 187 34(84)×1015 Hz.With an uncertainty of only 3 parts in1013,this result exceeds the accuracy of the best previous measurement of the 1S‐2S transition by two orders of magnitude. It is, in fact, the most accurate measurement to date of any frequency in the visible or ultraviolet. It's so accurate that simply repeating the measurement a year from now would provide a better and more direct verification (or falsification) of the constancy of the fine‐structure constant over cosmological time than any astrophysical data we have.
ISSN:0031-9228
DOI:10.1063/1.881627
出版商:AIP
年代:1997
数据来源: AIP
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5. |
New Results Suggest X‐Ray Emission is a Common Property of Comets |
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Physics Today,
Volume 50,
Issue 12,
1997,
Page 21-23
Charles Day,
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PDF (816KB)
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摘要:
Comets—dubbed “dirty snowballs” by comet guru Fred Whipple—are among the last celestial bodies you'd expect to emit x rays, which typically come from matter at least as hot as106 K.But last year, to the surprise of astronomers, Carey Lisse (University of Maryland) and Mike Mumma (NASA's Goddard Space Flight Center) discovered faint x‐ray emission from comet Hyakutake. They observed the photogenic comet with the ROSAT satellite as the comet flew by Earth in March 1996. That same month, Mumma and Vladimir Krasnopolsky (Catholic University of America) detected the comet with the Extreme Ultraviolet Explorer (EUVE) satellite.
ISSN:0031-9228
DOI:10.1063/1.882046
出版商:AIP
年代:1997
数据来源: AIP
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6. |
Ancient Stardust in the Laboratory |
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Physics Today,
Volume 50,
Issue 12,
1997,
Page 26-32
Thomas J. Bernatowicz,
Robert M. Walker,
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PDF (2050KB)
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摘要:
Amazingly, individual grains of dust from stars that existed before the Sun was born have made their way to Earth in meteorites. When subjected to a battery of cutting‐edge laboratory techniques, these tiny grains provide thrilling new insights into such topics as the dynamics of supernova explosions, the age and chemical evolution of the Galaxy, fundamental nuclear physics and processes in the outer envelopes of stars. The path from dust grain to astrophysical insight is the subject of this article.
ISSN:0031-9228
DOI:10.1063/1.882049
出版商:AIP
年代:1997
数据来源: AIP
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7. |
The Foundation of the Silicon Age |
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Physics Today,
Volume 50,
Issue 12,
1997,
Page 34-39
Ian M. Ross,
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摘要:
IfPHYSICS TODAYhad been launched just one year earlier—in 1947 rather than 1948—it might have begun life by soliciting a number of articles to commemorate the 50th anniversary of the discovery of the electron by J. J. Thomson. That 1897 event could surely have qualified as the start of the electronics discipline and the industry that followed. It was the new understanding of the properties of the electron that created the field of electronics and that, combined with our developing capability in the electrical, magnetic and mechanical arts, made possible a rich array of new products and services.
ISSN:0031-9228
DOI:10.1063/1.881628
出版商:AIP
年代:1997
数据来源: AIP
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8. |
The Moses of Silicon Valley |
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Physics Today,
Volume 50,
Issue 12,
1997,
Page 42-47
Michael Riordan,
Lillian Hoddeson,
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PDF (1636KB)
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摘要:
Forty years ago the southern part of the San Francisco Bay area was predominantly an agricultural valley filled with apricot orchards. Today this region is the bustling high‐technology capital of the world—envied by governments around the globe for its creativity and productivity. How did this remarkable technological transformation occur? And why is Silicon Valley located southeast of San Francisco rather than in, say, northern New Jersey, the Boston area or near Dallas?
ISSN:0031-9228
DOI:10.1063/1.881629
出版商:AIP
年代:1997
数据来源: AIP
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9. |
With Republicans and Science Societies in the Lead, Congress May Try to Double R&D Budget by 2008 |
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Physics Today,
Volume 50,
Issue 12,
1997,
Page 49-50
Irwin Goodwin,
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PDF (662KB)
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ISSN:0031-9228
DOI:10.1063/1.881630
出版商:AIP
年代:1997
数据来源: AIP
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10. |
US Formally Rejects Leaked Claim that Russia Violated CTBT with Test |
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Physics Today,
Volume 50,
Issue 12,
1997,
Page 50-51
Irwin Goodwin,
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PDF (729KB)
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ISSN:0031-9228
DOI:10.1063/1.882048
出版商:AIP
年代:1997
数据来源: AIP
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