SETI Physics News Update.431


Larry Klaes (lklaes@bbn.com)
Thu, 03 Jun 1999 10:18:12 -0400


>Date: Wed, 2 Jun 1999 10:45:56 -0400 (EDT) >From: AIP listserver <physnews@aip.org> >To: physnews-mailing@aip.org >Subject: update.431 > > >PHYSICS NEWS UPDATE >The American Institute of Physics Bulletin of Physics News >Number 431 June 2, 1999 by Phillip F. Schewe and Ben Stein > >THIRD-HARMONIC MICROSCOPE. Imaging biological >samples often involves telling apart one wet thing from another. A >relatively new way of gaining the needed contrast is to exploit the >nonlinear optical features of the sample itself by using a process in >which a high-power laser beam can, when it is brought to a tight >focus in certain media, generate subsidiary light waves at twice the >original frequency (second harmonic), three times the frequency >(third harmonic), and so on. If the detector is sensitive to just the >third harmonic radiation, say, then by scanning the laser focus >across the face of the sample, an image can be built up with a >spatial resolution as small as the focal size. Jeff Squier at UC San >Diego (619-534-0290, jsquier@chem.ucsd.edu) and his colleagues >have used this scheme to produce the first 3-dimensional third- >harmonic image of a living system. (Paper JTuA2, May 25, at the >electro-optics and quantum electronics meeting in Baltimore; see >figure at www.aip.org/physnews/graphics.) > >METHANE DWARFS is the name for a new type of celestial >object. Actually they are a subclass of brown dwarf. With a mass >of less than 80 times that of Jupiter, Brown dwarfs cannot sustain >the fusion reactions that burn in our sun. At this week's meeting in >Chicago of the American Astronomical Society, Zlatan Tsvetanov >and Wei Zheng of Johns Hopkins University reported seeing >several very red objects very like one observed (Gliese 229B) in >1995. The new objects, glimpsed with the Sloan Digital Sky >Survey telescope, are red not because their spectrum has been red >shifted owing to great distance, but because they are nearby and >very cool. In fact they are cool enough to permit the presence of >methane, which normally dissociates amid the heat of stars and >even in other, warmer, brown dwarfs. (Fermilab press release, 31 >May; www.aas.org/meetings/aas194/program/index.html) > >PH.D. PHYSICISTS IN THE U.S. REPORTED A MEDIAN >SALARY OF $70,000 in 1998, an increase of 8 percent over the >past two years, and salary gaps appear to be narrowing between >physicists with master's ($57,000) and bachelor's degrees >($54,000). This information comes from approximately 9,250 >respondents to an American Institute of Physics survey of members >belonging to its ten member societies. Moreover, the >unemployment rate of the respondents is 0.7%, the lowest this >decade. However, physics master's recipients who teach at high >schools reported only a 3 percent increase in their salary, not >keeping up with the pace of inflation. The highest median salary >belongs to those in the healthcare industry ($87,500). Although >median salaries differed across employment sectors for >respondents in their early- and mid-career, those working in many >sectors reach a median salary of $90,000-100,000 after 25 years of >experience, especially when one considers supplemental income, >such as consulting and summer teaching often done by physicists >with 9-10 month contracts at colleges and universities. ("1998 >Salaries: Society Membership Survey," issued in April by the AIP >Education and Employment Statistics Division; single copies can >be ordered by going to www.aip.org/statistics/; reporters seeking >more information should contact Amanda Benedict, >abenedic@aip.org, 301-209-3388) >



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