Accreting black holes can spin in the opposite direction of their surrounding disk, affecting energy emission and jet formation. This counter-rotation influences the black hole’s efficiency in converting matter to energy.
It matters because it informs models of accretion physics and black hole growth.
It also impacts predictions for gravitational wave signals during mergers.
Some black holes spin opposite to their accretion disks, twisting physics in unexpected ways.
[NASA, nasa.gov]