摘要:

Growing mold in a bathtub is not usually known to attract students to physics, but it did start Donald Kerr, deputy director for science and technology at the Central Intelligence Agency, on a career path to science. As a young boy, Kerr was introduced to mold when he met a bacteriologist while on a family vacation to Cape Cod, Massachusetts. That chance encounter led Kerr to a PhD in plasma physics from Cornell University in 1966.

ISSN:0031-9228    

DOI:10.1063/1.1650063

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Commonalities between plasma behavior in lab experiments and as‐trophysical objects are what scientists plan to explore and exploit with the Center for Magnetic Self‐Organization in Laboratory and Astrophysical Plasmas, while the nuclear reactions that power stellar processes are the focus of the Joint Institute for Nuclear Astrophysics (JINA). NSF's two newest Physics Frontier Centers (see PHYSICSTODAY, November 2001, page 28) got started in the fall; each virtual center brings together experimenters, theorists, and computational scientists from several institutions.

ISSN:0031-9228    

DOI:10.1063/1.1650064

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1650065

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1650066

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

For more than four decades, the US has devoted substantial resources to developing antiballistic‐missile systems. During most of that period, effort was focused on developing systems that would defend against the thousands of intercontinental ballistic missiles (ICBMs) fielded by the Soviet Union. Recently, attention has shifted to systems that could counter ICBMs that North Korea or Iran might deploy. Although neither country currently has ICBMs, the US intelligence community projects that they are likely to develop or acquire them within 10 to 15 years.

ISSN:0031-9228    

DOI:10.1063/1.1650067

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

To excel in physics research in Africa is to conquer Mount Everest without the aid of additional oxygen. In a continent that lacks the infrastructure of research laboratories, technical support, and so forth, relatively few physicists have managed to perform at levels competitive with the best in the world.

ISSN:0031-9228    

DOI:10.1063/1.1650068

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

In solid‐state physics, the phenomenon of localization is usually perceived as arising fromextrinsicdisorder that breaks the discrete translational invariance of the perfect crystal lattice. Familiar examples include the localized vibrational phonon modes around impurities or defects (such as atomic vacancies or interstitial atoms) in crystals and Anderson localization of electrons in disordered media. The usual perception among solid‐state researchers is that, in perfect lattices—those free of extrinsic defects—phonons and electrons exist only in extended, plane wave states. That notion extends to any periodic structure, such as a photonic crystal or a periodic array of optical waveguides. Such firmly entrenched perceptions were severely jolted in the late 1980s by the discovery thatintrinsiclocalized modes (ILMs), also known as discrete breathers (DBs), are, in fact, typical excitations in perfectly periodic but strongly nonlinear systems.

ISSN:0031-9228    

DOI:10.1063/1.1650069

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1650070

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1650071

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1650072

出版商:AIP    

年代:1904

数据来源: AIP