Laboratory experiment using water tank simulation to demonstrate back reaction. Credit: University of Nottingham
Scientists have revealed new insights into the behavior of black holes with research demonstrating how a phenomenon called backlash can be simulated.
The University of Nottingham team used their simulation of a black hole, which involves a specially designed water tank, for this latest research conducted in Physical overview letters. This study is the first to show that the evolution of black holes due to the surrounding fields can be simulated in a laboratory experiment.
The researchers use a water tank simulator that consists of a draining vortex, like the shape when you pull the plug into the bath. It mimics a black hole, as a wave that gets too close to the drain is dragged into the drain and cannot escape. Systems like these have become increasingly popular over the past decade as a way to test gravitational phenomena in a controlled laboratory environment. In particular, Hawking radiation was observed in an analog black hole experiment with quantum optics.
Using this technique, the researchers showed for the first time that when the waves are sent to an analog black hole, the properties of the black hole itself can change significantly. The mechanism underlying this effect in their particular experiment has a remarkably simple explanation. When waves get close to the drain, it effectively pushes more water into the drain so that the total amount of water in the tank decreases. This results in a change in water level, which in the simulation corresponds to a change in the properties of the black hole.
Lead author, postdoctoral researcher, dr. Sam Patrick, of the University of Nottingham School of Mathematical Sciences, explains: ‘It has long been unclear whether the backlash would lead to measurable changes in analog systems where the fluid flow is powered, for example using a water pump. We have shown that analog black holes, like their gravitational counterparts, are intrinsically back-responsive systems. We have shown that waves moving in a draining bath push water into the drain, significantly changing the drain speed and consequently changing the effective gravity of the analog black hole.
What was striking to us was that the back reaction is large enough so that it lowers the water level over the entire system so that you can see it with the naked eye! It was really unexpected. Our study paves the way for experimentally investigating interactions between waves and the space times in which they move. This type of interaction will, for example, be crucial for the investigation of the evaporation of black holes in the laboratory. ”
Black Hole Research at the University of Nottingham recently received a £ 4.3 million boost for a three-year project aimed at providing further insights into the physics of the early universe and black holes.
The research team will use quantum simulators to mimic the extreme conditions of the early universe and black holes. The Nottingham team will use a new state laboratory to set up a new hybrid superfluid optomechanical system to mimic quantum processes in the laboratory.
Reference: “Backreaction in an Analogue Black Hole Experiment” by Sam Patrick, Harry Goodhew, Cisco Gooding and Silke Weinfurtner, January 29, 2021, Physical overview letters.
DOI: 10.1103 / PhysRevLett.126.041105