A laboratory-controlled superfluid vortex is helping physicists learn more about the behavior of black holes.
The vortex generated by helium cooled to just a fraction above absolute zero mimics the gravitational environment of these objects so precisely that it gives an unprecedented look at how space-time around them is pulled and distorted.
“Using superfluid helium has allowed us to study small surface waves in greater detail and precision than our previous experiments in water.” explains physicist Patrick Savantara from the University of Nottingham in the UK, who led the research.
“Because the viscosity of superfluid helium is so small, we were able to carefully investigate its interaction with the superfluid cyclone and compare the results with our own theoretical predictions.”
Black holes are quite possibly the strangest and most extreme objects in the entire universe that contains very strange things. It is also difficult to study. They do not emit any radiation that we can detect; We can only see light from the space directly surrounding them. But we have some very good theoretical studies that can describe their observed behavior quite accurately.
One way we can learn more about them is to create analogues of black holes. These are experiments that can recreate the theory of black holes to elucidate other aspects of their behavior. One analogue type of black hole is a vortex or vortex.
Any matter that gets close enough to the black hole starts swirling around it, then falls on it, like water swirling and gurgling down a drain.
This comparison is so apt that scientists have built water vortexes to study black hole behavior. However, Savantara and his colleagues wanted to take this a step further, using ultrafluid helium.
This is a helium isotope – helium-4 – that has been cooled to -271°C (-456°F), just above Absolute zero. At this very cold temperature, the bosons in helium-4 slow down enough to interfere and behave like a single superatom—a viscous fluid, or superfluid.
The team used the unusual quantum properties of helium-4 superfluid to generate a kind of “quantum tornado.”
“Superfluid helium contains small objects called quantum vortices, which tend to spread apart from each other.” “Svančara says. “In our setup, we were able to confine tens of thousands of these quanta into a compact body resembling a mini-tornado, achieving a vortex flow of record strength in the world of quantum fluids.”
By studying this tornado, researchers were able to identify similarities between the vortex flow and the effect of a rotating black hole on the curved spacetime around it. In particular, researchers observed standing waves similar to a black hole Restricted countriesThe excitation is similar to a newly formed black hole.
And this is just the beginning. Now that the researchers have proven that their experiment works the way they intended, the vortex is poised to open up a new field of black hole science.
“When we first noticed clear signatures of black hole physics in our initial research Analog experiment back in 2017It was a fascinating moment to understand some strange phenomena that are often difficult, if not impossible, to study otherwise. says physicist Silke Weinfurtner From the University of Nottingham.
“Now, with our most sophisticated experiment, we have taken this research to the next level, which may eventually lead us to predict how quantum fields behave in curved space-time around astrophysical black holes.”
The research was published in nature.
