Backreaction observed for first time in water tank black hole simulation

February 01, 2021

Scientists have revealed new insights into the behaviour of black holes with research that demonstrates how a phenomenon called backreaction can be simulated.

The team from the University of Nottingham have used their simulation of a black hole, involving a specially designed water tank, for this latest research published in Physical Review Letters. This study is the first to demonstrate that the evolution of black holes resulting from the fields surrounding them can be simulated in a laboratory experiment.

The researchers used a water tank simulator consisting of a draining vortex, like the one that forms when you pull the plug in the bath. This mimics a black hole since a wave which comes too close to the drain gets dragged down the plug hole, unable to escape. Systems like these have grown increasingly popular over the past decade as a means to test gravitational phenomena in a controlled laboratory environment. In particular, Hawking radiation has been observed in an analogue black hole experiment involving quantum optics.

Using this technique the researchers showed for the first time that when waves are sent into an analogue 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 come close to the drain, they effectively push more water down the plug hole causing the total amount of water contained in the tank to decrease. This results in a change in the water height, which in the simulation corresponds to a change in the properties of the black hole.

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

What was really striking for us is that the backreaction is large enough that it causes the water height across the entire system to drop so much that you can see it by eye! This was really unexpected. Our study paves the way to experimentally probing interactions between waves and the spacetimes they move through. For example, this type of interaction will be crucial for investigating black hole evaporation in the laboratory."

Black hole research at the University of Nottingham has recently received a £4.3 million funding boost for a three-year project that aims to provide 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 be using a new state laboratory to set up a novel hybrid superfluid optomechanical system to mimic quantum black hole processes in the laboratory.
-end-


University of Nottingham

Related Black Hole Articles from Brightsurf:

Black hole or no black hole: On the outcome of neutron star collisions
A new study lead by GSI scientists and international colleagues investigates black-hole formation in neutron star mergers.

The black hole always chirps twice: New clues deciphering the shape of black holes
A team of gravitational-wave scientists led by the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) reveal that when two black holes collide and merge, the remnant black hole 'chirps' not once, but multiple times, emitting gravitational waves--intense ripples in the fabric space and time--that inform us about its shape.

Wobbling shadow of the M87 black hole
New analysis from the Event Horizon Telescope (EHT) Collaboration reveals the behavior of the supermassive black hole in the center of the M87 galaxy across multiple years, indicating the crescent-like shadow feature appears to be wobbling.

How to have a blast like a black hole
Scientists at Osaka University have created magnetized-plasma conditions similar to those near a black hole using very intense laser pulses.

Black hole collision may have exploded with light
Astronomers have seen what appears to the first light ever detected from a black hole merger.

Black hole's heart still beating
The first confirmed heartbeat of a supermassive black hole is still going strong more than ten years after first being observed.

Black hole team discovers path to razor-sharp black hole images
A team of researchers have published new calculations that predict a striking and intricate substructure within black hole images from extreme gravitational light bending.

Planets around a black hole?
Theoreticians in two different fields defied the common knowledge that planets orbit stars like the Sun.

Black hole mergers: Cooking with gas
Gravitational wave detectors are finding black hole mergers in the universe at the rate of one per week.

Going against the flow around a supermassive black hole
At the center of a galaxy called NGC 1068, a supermassive black hole hides within a thick doughnut-shaped cloud of dust and gas.

Read More: Black Hole News and Black Hole Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.