A spinning black hole is one of the most extreme objects in the universe — a gravitational monster whose rotation energy can, in theory, be tapped. But how do you test that theory when black holes are millions of light-years away? Physicists at the City University of New York (CUNY) have found a clever answer: build a stationary device that mimics the impossible rotation speeds of a black hole using synthetic motion, and watch the energy extraction happen in real time on a lab bench.
The experiment, published in July 2026, successfully demonstrated the Penrose superradiance effect — a phenomenon first proposed by physicist Roger Penrose in 1969. Penrose suggested that if a particle enters a spinning black hole's ergosphere (the region just outside the event horizon where spacetime itself is dragged along), the particle could split in two: one half falls into the black hole while the other escapes with more energy than the original particle carried in. The physicist Yakov Zel'dovich later extended this idea to electromagnetic waves, predicting that waves could be amplified by interacting with a rapidly rotating object.
The CUNY team, led by researchers at the university's Advanced Science Research Center, built a tabletop resonator circuit — essentially a specially designed loop of conductive material — that never physically rotates. Instead, they used electronic components to create what they call "synthetic rotation": the electromagnetic field inside the device behaves as though it is spinning at speeds far beyond what physical rotation could achieve. When electromagnetic waves of the correct frequency were introduced into the system, they emerged significantly amplified, recording a gain of 7.8 decibels — clear experimental evidence of superradiance.
Because the device does not actually spin, the researchers avoided the immense engineering challenge of rotating anything near the speeds needed for the Penrose effect (which approach the speed of light). The synthetic rotation technique is the key breakthrough that transformed a 57-year-old theoretical prediction into a controllable laboratory observation.
Confirms a fundamental prediction of general relativity. While Penrose's theory has been widely accepted by physicists, direct experimental confirmation has been elusive because the conditions required — extreme rotation, strong gravity — exist only around black holes. This experiment provides the first clear laboratory evidence that the energy extraction mechanism works as predicted.
Potential applications in energy harvesting. Superradiance is not just an astrophysical curiosity. The same principle could one day be used to design highly efficient energy-harvesting devices that capture energy from rotating systems or wave fields. The synthetic rotation technique opens a new avenue for studying wave amplification and energy transfer in controlled settings.
A new tool for quantum physics. The ability to create and study superradiance on a tabletop gives physicists a platform to explore related quantum effects, such as Hawking radiation (the theoretical emission of particles by black holes) and vacuum fluctuations, without needing to travel to space.