YES coupons pay $1 if Gravitational waves are detected at a gravitational wave observatory before 1/1/2003 GMT. Detection must be certain at the 95% confidence level according to physicists and astronomers in the year 2003 or before. This will be judged on the basis of preprints and papers published in the year 2003 or before. Indirect detection by, for example, observation of effects gravitational waves have on the cosmic microwave background or interstellar gas does not count as a YES.
Information: Gravitational waves are waves in space-time geometry predicted by Einstein's General Theory of Relativity. Possible sources of detectable gravitational waves include supernova, neutron star collisions, black hole collisions and the big bang. A Gravitational Wave observatory with prospects for detection of gravitational waves before 2003 is the American LIGO: The Laser Interferometer Gravitational-Wave Observatory. LIGO is being built in two parts. Construction of the Washington LIGO began in 1992 and it is scheduled to begin gravitational wave searches in 1998. Construction of the second LIGO in Louisiana began in June 1995. GEO and VIRGO are other planned gravitational wave observatories in Europe. There are a number of others some of which have been operational for years.
For more information on some of the observatories:
Judgement will be based on the above URls and on information available from established scientific newsmedia. In cases of ambiguity intent takes precedence over wording. The judge is a trained physicist (Dr. rer. nat.).