Sources of gravity waves

The discovery of many possible sources of gravitational radiation, such as neutron stars, compact x-ray sources, rapidly rotating binary novae and the violent events occurring in quasars and galactic nuclei, has opened a new era of general-relativity physics. In the 1960's nearly all workers in the field considered the detection of gravitational radiation "exceedingly unlikely." From this pessimistic estimate the balance of opinion has shifted to the optimistic view that gravitational radiation, a crucial prediction of Einstein's general theory of relativity, is now within reach of current experimental techniques.