14 DAY TRIAL // The joint German-British Gravitational Wave Detector GEO600 has now entered an 18-month run of continuous measurement. Researchers are optimistic that they will be able to observe a never before seen phenomenon- the Gravitational Wave- which is one of the great untested predictions of Einstein's General Theory of Relativity. Gravitational Waves can be used to do "dark astronomy", studying those aspects of the Universe for which ordinary astronomy using light (and the rest of the electromagnetic spectrum) can provide limited information.
"If there is a supernova in our vicinity during the next couple of months, our chances of detecting and measuring the resulting gravitational waves are good. The first step towards gravitational wave astronomy has been taken, at last allowing us to observe the 96% of our universe which have been hidden to us up to now" says Prof. Dr. Karsten Danzmann, head of the International Centre for Gravitational Physics which is jointly run by the Max Planck Society and the University of Hannover. Data is taken in conjunction with the two US LIGO observatories.
The sensitivity of the GEO600 detector has been continuously improved since the start of test runs in 2002. "We could only reach out towards a small fraction of our own galaxy, the Milky Way, in those days. Today our sensitivity has increased by a factor of 3000 and we can detect events in distances many times greater than the distance between us and our galactic neighbour, the Andromeda Galaxy" Karsten Danzmann explains.
GEO600 is the most modern Michelson laser interferometer in the world. Its laser beams run in two underground vacuum tubes which are 600 m long. The GEO600 gravitational wave detector incorporates lasers of unmatched stability, absorption-free optics, a highly sophisticated vibration damping arrangement and an innovative signal enhancement system. The technology developed in Hannover will also be implemented in the next generation of the US LIGO observatories.
Professor Jim Hough of the Institute for Gravitational Research at the University of Glasgow adds he is "optimistic about the chances of a detection over the next eighteen months." When Ladbrokes offered odds of 500-1 against the detection of gravitational waves by 2010, Professor Hough was one of many who were quick to place their bet and the odds fell to 2-1 in days, before the book was closed. The bookmakers could well find themselves paying up in the next 18 months.
The direct measurement of gravitational waves is one of the most profound challenges of modern physics as it will allow us to observe the hitherto inaccessible and, at 96%, greater part of our universe. "We are very curious and eager to see what new insights we will gain. We are opening a wholly new chapter in the long history of astronomy with the direct observation of the 'dark side' of our universe Black Holes, Dark Matter and the reverberations of the Big Bang", says Prof. Danzmann.