As anyone who's ever seen a science fiction movie knows, whipping up a black hole in a laboratory doesn't seem like such a good idea.
But that didn't stop researchers in England who wanted to see if they could create something in the lab that would serve as a black hole analog and give them greater insights into the way spacetime curves near the galactic gravity gobblers.
So researchers from the University of Nottingham (UN), King's College London, and Newcastle University turned to vortices in fluids, which can, in some ways, mimic the way matter swirls around a black hole in space.
In particular, they decided to see if they could improve upon a previous method invented at UN's Black Hole Laboratory in which a vortex in a specially designed water bath shed light on a particular phenomenon known to occur around black holes known as superradiance. (You can watch that experiment in the following video from UN.)
In this case, they used superfluid helium chilled down to an icy -271 °C (-456 °F). Superfluids are fluids with near zero viscosity.
"Using superfluid helium has allowed us to study tiny surface waves in greater detail and accuracy than with our previous experiments in water," said Patrik Svancara from the School of Mathematical Sciences at the University of Nottingham, who was the lead author on the study. "As the viscosity of superfluid helium is extremely small, we were able to meticulously investigate their interaction with the superfluid tornado and compare the findings with our own theoretical projections."
At the temperature to which the superfluid helium was chilled, it begins to exhibit quantum properties, which can cause it to become unstable. However thanks to a custom-made chamber, the research team was able to contain the fluid and mitigate the quantum effects.
"Superfluid helium contains tiny objects called quantum vortices, which tend to spread apart from each other," said Svancara. "In our set-up, we've managed to confine tens of thousands of these quanta in a compact object resembling a small tornado, achieving a vortex flow with record-breaking strength in the realm of quantum fluids."
By measuring the wave dynamics on the surface of this superchilled superfluid, the team was able to conclude that the system mimicked gravitational conditions that were the same as those found near rotating black holes. The hope is that the setup will help the team gain even greater insights into black holes which, despite ongoing discoveries, still hold a multitude of mysteries for astrophysicists.
"When we first observed clear signatures of black hole physics in our initial analog experiment back in 2017, it was a breakthrough moment for understanding some of the bizarre phenomena that are often challenging, if not impossible, to study otherwise," said Silke Weinfurtner, who leads the work in the Black Hole Laboratory. "Now, with our more sophisticated experiment, we have taken this research to the next level, which could eventually lead us to predict how quantum fields behave in curved spacetimes around astrophysical black holes."
The research has been published in the journal Nature.
Source: University of Nottingham
