🔭 Physicists Recreated a Black-Hole-Inspired Effect — in a Circuit With No Moving Parts

More than 50 years ago, Roger Penrose proposed that rotational energy could be extracted from a spinning black hole. Yakov Zel’dovich later predicted a wave version of the effect: an object rotating fast enough could transfer some of its energy to incoming waves, amplifying them.

The problem was speed. Reproducing the effect with electromagnetic waves would require rotation far beyond the limits of ordinary machinery.

Researchers at the CUNY Advanced Science Research Center have now bypassed that obstacle with a stationary radio-frequency circuit. It contains three coupled electronic resonators whose properties are modulated in a precisely timed sequence. Nothing physically rotates, but the traveling modulation pattern acts like ultrafast “synthetic rotation.”

Waves carrying the appropriate orbital angular momentum emerged amplified, with a reported net gain of up to 7.8 decibels. The experiment, published in Nature, demonstrates what the researchers call Floquet rotational superradiance.

There is no free energy involved. The additional energy comes from the external drive used to modulate the circuit — not from an actual black hole. The researchers also stress that this is not a one-to-one replica of Zel’dovich’s original rotating-object proposal, but a related effect combining rotational Doppler physics with parametric amplification.

Counterintuitively, ordinary losses in the circuit helped broaden the conditions under which amplification occurred.

The platform could provide a new way to study extreme rotational wave physics and may eventually inspire selective amplifiers, photonic devices and communication technologies.

What other seemingly impossible physical environments could be recreated using synthetic motion?

📄 Paper: https://www.nature.com/articles/s41586-026-10725-y

#Physics #BlackHoles #Superradiance #Metamaterials