How Fast Is Black Hole Equator?

The fastest spinning black holes have equators rotating at 290,000 km/s — 99% the speed of light. Black hole spin literally drags space itself around with them through 'frame dragging' — a prediction of general relativity confirmed by observation.

Black holes have only three measurable properties from the outside: mass, charge, and spin. Everything else about what fell in is fundamentally lost.

• Drags space itself along with it
• This effect is called frame-dragging