From: GARAVELLI@NBRF.GEORGETOWN.EDU
Newsgroups: bionet.info-theory
Subject: Washington Philosophical Society --- 2000th Meeting
Date: 6 Oct 92 17:12:07 GMT
Distribution: bionet


                    The Philosophical Society of Washington
                                  Founded 1871

                                 2000th Meeting
                      Friday, October 23, 1992, at 8:15 pm

                   John Wesley Powell Auditorium, Cosmos Club
                     (Entrance at 2170 Florida Avenue, NW)

                              Virginia L. Trimble
                             University of Maryland

                          The Universe You Don't See:
                    The Existence and Nature of Dark Matter

A wide range of astronomical observations demonstrate that 90% or more of the
mass that contributes to the gravitational forces in the universe does not emit
its fair share of light.  This rises to 99% if one assumes that the total
density is sufficient to reverse the expansion of the universe in the distant
future.  The nature of this dark matter is exceedingly uncertain.  Calculations
of nuclear reaction rates in the early dense state ("Big Bang") strongly limit
the amount of ordinary matter (made of atoms with nuclei of protons and
neutrons) to about 10% of the closure density.  A very wide range of
alternatives has been suggested, and laboratory experiments may eventually
distinguish among them.

Ms. Trimble received her PhD in Astronomy from the California Institute of
Technology in 1968.  Her research has encompassed many topics of astrophysics
such as binary stars, open clusters, supernova remnants, and dark matter. 
Throughout her career, she has served on the boards of various professional
societies including the American Physical Society and the American Association
for the Advancement of Science as well as on the editorial boards of various
scientific journals.  She is currently a Professor at the University of
California, Irvine, a Visiting Professor at the University of  Maryland, and an
editor or editorial board member of six journals including "The Scientist" and
"Astrophysical Journal".

    Willard Grant             Eloise Moore Agger            Mary Enig         
      President                  Program Chair           Membership Chair     
 (202) 659-2320 (day)         Bethesda, MD  20814     (301) 572-4914 (evening)
(202) 362-9708 (evening)        (301) 652-7325

Network inquiries to:  John S. Garavelli
                       GARAVELLI@GUNBRF.BITNET
                       GARAVELLI@NBRF.GEORGETOWN.EDU

                    Non-members are welcome at all meetings
                          Appropriate Attire Required

Notice:  Parking at the Cosmos Club is limited to members of the Club and their
guests.  The Cosmos Club is within easy walking distance of the Dupont Metro
stop (Q Street exit), the Connecticut Avenue bus routes (L2, L4), and the
Massachusetts Avenue bus routes (N2, N4).

                    The Philosophical Society of Washington
                     First Half 1992-1993 Season Schedule

September 11	Susumu Sato, National Institutes of Health
		Application of the Superconducting Quantum Interference
		Device (SQUID) Magnetometer in Biomedical Research

October 2	Ayub Ommaya, Neurosurgon
		I Feel Therefore I Am: The Biology of Emotion

October 23	Virginia Trimble, University of Maryland
		The Universe You Don't See:
		The Existence and Nature of Dark Matter

November 6	Colin Cox, Johns Hopkins University
		X Marks the Spot:  Hubble Telescope Research

November 20	Fernand D. Bedard, National Security Agency
		Superconductivity:  Who Cares?

December 4	Michael Slesinger, Office of Naval Research
		Chaos and Fractals: Past and Future

December 18	Teed Rockwell, Philosopher
		Beyond Determinism and Indignity:
		A Reinterpretation of Operant Conditioning

January 8	Retiring President's Address 

All meetings start at 8:15 p.m., with the exception of the Retiring President's
Address, which begins at 8:30 p.m.  Meetings are followed by a Social Hour with
beer and cider.  Non-Members Welcome