Scientists Mimic Black Hole Evolution in Bathtub-Like Experiment

The black hole simulation strongly resembled the vortex that forms when yanking the plug in a bath.
Chris Young
The photo credit line may appear like thisUniversity of Nottingham

Scientists from the University of Nottingham revealed new insights into the behavior of black holes via a simulation of one of the space giants in a water tank.

The research team's new paper, published in Physical Review Lettersdetails how they simulated a phenomenon called backreaction.

In doing so, theirs is the first study to demonstrate how the evolution of black holes, based on their surrounding fields, can be simulated in a laboratory.

The researchers used a tank simulator consisting of a draining vortex to mimic a black hole. Much in the same way water drains when you empty a bath, any wave that comes too close to the drain is inescapably dragged down the plughole. 

Using this technique, the researchers showed that when waves are sent into an analog black hole, the properties of the black hole can change significantly.

The reason for this is surprisingly simple: when waves come close to the drain, they effectively push more water down the plughole causing the total amount of water contained in the tank to decrease. 

This results in a change in water height, which corresponds to a change in the properties of the black hole, as per the observable rules of the researchers' simulation.

Analog black holes are 'intrinsically backreacting systems'

"For a long time, it was unclear whether the backreaction would lead to any measurable changes in analog systems where the fluid flow is driven, for example, using a water pump. We have demonstrated that analog black holes, like their gravitational counterparts, are intrinsically backreacting systems," lead author Dr. Sam Patrick, from the University of Nottingham School of Mathematical Sciences, explains in a press release

"We showed that waves moving in a draining bathtub push water down the plug hole, modifying significantly the drain speed and consequently changing the effective gravitational pull of the analog black hole," he continues.

The researchers say their findings will be pivotal for future experiments. For example, this type of interaction will be "crucial for investigating black hole evaporation in the laboratory," Dr. Patrick explains. 

The University of Nottingham recently received a £4.3 million ($5.8 million) funding boost for black hole research: the research team aims to use quantum simulators to mimic the conditions of the early universe and, in doing so, uncover mysteries of the cosmos.