NASA scientists and their international partners using the new Japanese Suzaku satellite have collected a startling new set of black hole observations, revealing details of twisted space and warped time never before seen with such precision. The observations include clocking the speed of a black hole’s spin rate and measuring the angle at which matter pours into the void, as well as evidence for a wall of X-ray light pulled back and flattened by gravity.
https://www.nasa.gov/centers/goddard/news/topstory/2006/spinning_blackhole.html