Near a spinning black hole, spacetime itself rotates, dragging everything around it. This frame dragging, predicted by general relativity, forces matter in the accretion disk into tight, spiraling orbits and sets up extreme shear and rotation in the surrounding plasma.
As charged particles orbit in this plasma, they generate and amplify magnetic fields that thread the accretion disk and penetrate the event horizon region. In a rapidly rotating black hole, the ergosphere allows these magnetic field lines to tap into the hole’s rotational energy. The Blandford–Znajek mechanism describes how this process extracts energy and channels it along the spin axis.
Instead of all matter crossing the event horizon, some plasma is forced to follow these magnetic field lines. The fields act like rigid rails embedded in curved spacetime, collimating and accelerating particles to relativistic speeds along narrow jets. Strong magnetohydrodynamic forces and conservation of angular momentum keep the outflow focused, so material escapes along the poles while the rest continues inward and is accreted.
