Black hole ripples could help pin down expansion of universe

The echoes of light from jets launched from black holes offers a new way to pin down the distance to these exotic objects and to study a largely unobserved population in the center of the Galaxy. It could also even help determine the rate of expansion of the universe. The technique, developed by a team at the University of Newcastle and tested on the archetype black hole Cygnus X-1, was presented by postgraduate researcher and team member Patrick O’Neill at the National Astronomy Meeting in Cardiff.