TLDR: "The discovery that the black hole in RX J1131-1231 is spinning at over half the speed of light suggests that this black hole has grown via mergers, rather than pulling material in from different directions."
TLDR: "The discovery that the black hole in RX J1131-1231 is spinning at over half the speed of light suggests that this black hole has grown via mergers, rather than pulling material in from different directions."