Congratulations to the Laser Interferometer Gravitational-Wave Observatory for confirmation of Albert Einstein’s prediction of the existence of gravitational waves.
Dr. Bill Unruh, UBC Professor of Physics and Astronomy, elaborates:
Just to follow up, this morning the LIGO collaboration announced that they have seen a gravity wave signal at both the detectors at Hanford Wash, and at Livingston Louisiana. The signal was strong enough that it was well above noise even in the raw data. With matched filter analysis then assign a S/N ratio of 25 to the signal. The best fit filter gives the source to be a pair of black holes (29 and 36 solar mass, with about +- 15% uncertainty for 90% confidence) at a distance of about z=.09. In the process of inspiral about 3 solar mass was converted into gravity waves (ie a conversion efficiency of “mass” to energy of about 5%).
Because only two detectors were operational (in an engineering comissioning run in preparation for a science run– also the Virgo detector in Italy is still being finally prepared) the location on the sky of the source is very imprecise.
This is the first observation on earth of the gravity waves (their effect has been seen previously on the energy loss of the various binary pulsars, the first of which won the Nobel prize for Hulse and Taylor) This is a direct detection of the expected effect of such waves on an instrument on earth. It is also the first observation of a binary black hole system.
William G. Unruh | Canadian Institute for| Tel: +1(604)822-3273
Physics&Astronomy | Advanced Research | Fax: +1(604)822-5324
UBC, Vancouver,BC | Program in Cosmology | unruh@physics.ubc.ca
Canada V6T 1Z1 | and Gravity | www.theory.physics.ubc.ca/