Gravity is one of the four fundamental forces of nature.Gravity is the force that structures the universe - it shapes space and alters time - but gravity is still shrouded in mystery. The existence of tiny gravitational ripples in the fabric of space is a direct prediction of Einstein's theory of space, time and gravitation known as his General Theory of Relativity. Gravitational waves pass directly through any object they encounter and cause everything including space itself to alternately stretch and shrink in different directions, but only by an infinitesimal amount. They cause things to vibrate as do sound waves. Space should be full of gravity wave 'sounds': intense drum beats from the collision of black holes; chirrups like bird calls when neutron stars and black holes spiral together; pure tones from rapidly rotating neutron stars and continuous murmurs from the big bang itself. Vast amounts of gravitational energy are thought to be out there and passing through us all the time.
Scientists aim to detect the new gravitational spectrum to enable humanity to directly 'listen' to black holes and the birth of the universe itself.The first generation of detectors were based on giant bars of metal designed to vibrate in response to gravitational waves. Five of these were built around the world - one of them at the University of Western Australia. Today, large teams of physicists, engineers, mathematicians, computer programmers and technicians are testing and developing a new generation of detectors based on devices called Laser Interferometers. These devices use high power lasers, supermirrors, advanced vibration isolators and state-of-the-art digital techniques. Today we are at a point where the upcoming detectors are certain to detect known powerful signals produced when superdense neutron stars spiral together and merge to create a black hole.