Scientists are claiming a stunning discovery in their quest to fully understand gravity. <br /> <br />They have observed the warping of space-time generated by the collision of two black holes more than a billion light-years from Earth. <br /> <br />The international team says the first detection of these gravitational waves will usher in a new era for astronomy. <br /> <br />One of the UK's foremost experts on black holes, Prof Stephen Hawking,
