https://resonance.is/super-massive-b...peed-of-light/

The fact that some black holes are now known to rotate at relativistic speeds also increases our understanding of the dynamics and physics of black holes. The extreme or relativistic speeds of rotation of the subatomic particles may be responsible for the dilated mass of the particles and the source of the extremely strong gravitational fields. The recent discovery of the relativistic speed of rotation of the matter on the outside of the black hole has added a greater understanding of the physics of black holes.