Scientists searching for gravitational waves, an elusive form of radiation predicted
by Albert Einstein, will gather at a three-day meeting entitled “The Astrophysics of
Gravitational Wave Sources,” at the University of Maryland, College Park, beginning today
and continuing through Saturday, April 26, 2003.

The meeting will blend recent observations of black holes and other potential
sources of gravitational waves with theoretical predictions, new computer
modeling, and proposed gravitational wave detectors. The meeting is sponsored by
NASA, the National Science Foundation and Penn State, and is organized by NASA
Goddard Space Flight Center in Greenbelt, Md.

According to Einstein’s theory of general relativity, gravitational waves are ripples
in the four-dimensional fabric of space-time created by massive objects in motion
or undergoing an extreme event. The waves hardly interact with matter, however,
altering the distance of objects as far apart as the Earth and the Moon by less than
the width of an atom.

While scientists have yet to directly detect gravitational waves, Russell Hulse and
Joseph Taylor won the 1993 Nobel Prize in Physics for indirect detection of
gravitational waves from two pulsars in a close orbit. A new generation of
detectors and fervent interest among scientists may lead to direct detection in the
coming years.

Featured presentations at the April gravitational wave meeting include:

* First results from Laser Interferometer Gravitational Wave Observatory (LIGO), which has established upper limits on the frequency of neutron star mergers (a source of gravitational radiation) in the Milky Way and Andromeda galaxies.

* New observations of gamma-ray bursts and predictions of the gravitational waves expected to be produced by these cataclysmic events.

* New observations of other key sources of gravitational radiation, such as pulsars, black holes, neutron stars and supernovae.

* Update on the Laser Interferometer Space Antenna (LISA) project, a proposed space-based mission to complement LIGO by detecting gravitational waves at a different range of frequencies.

Gravitational wave astronomy is poised to open a new observational window on the Universe through both ground-based, high-frequency detectors (LIGO and LIGO II) and space-based, low-frequency detectors (LISA), according Dr. Joan Centrella, a theoretical astrophysicist in the Goddard Laboratory for High Energy Astrophysics and chair of the meeting. She said that gravitational wave detectors will provide an unprecedented look at astrophysical systems previously viewed almost exclusively through electromagnetic ‘eyes,’ such as optical, X-ray, and radio telescopes.

Furthermore, because gravitational waves hardly interact with matter, they carry information from the heart of black hole mergers and other catastrophic events often enshrouded in dust, which blocks light. Background gravitational waves may still be reverberating from the Big Bang itself 13.7 billion years ago.

Members of the working press and freelance science writers are welcome to attend. Please contact William Steigerwald of NASA Goddard Public Affairs. Media must present their credentials at the meeting registration desk for free registration. Credentials include: a press card, a membership card from NASW or a regional affiliate of NASW, or prior agreement from Goddard Public Affairs.

For more information about the meeting, including location and schedule, refer to:

http://astrogravs.gsfc.nasa.gov/docs/agws_workshop/program.html.