Black holes aren’t frozen: they spin rapidly, dragging space itself along, as predicted by Einstein’s theory. The first model of a non-rotating hole was built by Karl Schwarzschild, but reality is more dynamic. Infalling gas forms a scorching disk, where plasma accelerates to near light speed and emits radio waves. As light travels through the magnetized medium, it becomes polarized: its waves oscillate in a single plane, like compass needles following the field lines.

By linking radio telescopes into a virtual antenna the size of Earth, astronomers captured this radiation from two supermassive giants — M87* and Sagittarius A*. Comparison with computer simulations revealed that magnetic fields near the hole’s edge are twisted into spirals, and it is these that launch plasma jets flying thousands of light-years, like projectiles from a magnetic sling.

But the biggest surprise: a rotating hole can transfer its spin energy through these fields — a mechanism discovered by Penrose. Thus the abyss turns into an engine powering the jets. The hole’s mass bends the light itself (gravitational lensing), while frame-dragging adds further distortions. Understanding these effects refines spin measurements and the shape of gravitational waves from black hole mergers.