Research Fellows Directory
Dr Silke Weinfurtner
University of Nottingham
Extracting energy from rotating systems
Black holes are bizarre objects. Everything entering their event horizon stays forever trapped. Yet, black holes are also able to give energy away. This energy powers gamma-ray bursts, and sometimes entire galaxies. Some decades ago, an energy extraction mechanism from black holes was hypothesized by Russian scientist Yakov Zeldovich. This mechanism, known as superradiance, consists in shining a beam of light on a black hole. Under appropriate conditions, the beam is reflected off with higher intensity!
But this is all theoretical work, and performing experiments on actual black holes is impossible, for the time being... What we now propose is that a similar effect takes place also in other, more familiar, contexts. We propose a feasible experimental setup using a water vortex flow in the center of a water tank. By carefully setting up the water flow, large amplifications can be obtained. Our findings offer the first experimental realisation of rotational superradiance, stimulating new research in General Relativity, Fluid Dynamics and Acoustics.