When helium is cooled to just above absolute zero, it transitions to a superfluid state. In this unique condition, the typical rules of physics are bent - viscosity vanishes, allowing the superfluid to flow without losing any kinetic energy. This means that when set in motion, it can keep moving in a loop endlessly without additional energy inputs.
This study was led by a team from the University of Nottingham, in collaboration with researchers from King's College London and Newcastle University. Their efforts have birthed a novel experimental setup for probing the mysteries of black holes. The vortex created within the superfluid helium offers a precise analog to the environments surrounding black holes, granting scientists unprecedented insight into their interaction with the cosmos.
The findings and details of this innovative study have been documented in the "Nature" journal ([DOI: 10.1038/s41586-024-07176-8](https://dx.doi.org/10.1038/s41586-024-07176-8)).
**Quantum Tornado**
"In our experiments, superfluid helium's exceptionally low viscosity enabled us to observe the interactions between surface waves and the quantum tornado in much finer detail than before," shared Patrik Svancara from the University of Nottingham, the study's lead researcher.
The project commenced with the creation of a specialized cooling system capable of storing superfluid helium. By cooling it down to -456 degrees Fahrenheit, the helium displayed extraordinary quantum behaviors. Unlike other superfluid substances where creating vortices can be challenging, helium's unique properties allow for the formation of stable, powerful vortices.
Svancara highlighted the role of quantum vortices, microscopic whirls within the superfluid that usually drift apart. "We managed to confine tens of thousands of these quantum vortices, creating a compact, tornado-like flow of unparalleled strength," he explained.
**Exploring Black Holes**
Black holes are celestial objects of immense mass, from which, past a certain proximity (the event horizon), not even light can escape due to their strong gravitational pull. This characteristic makes them invisible and difficult to study directly. Scientists infer their presence and properties by observing their effects on nearby matter and light.
The team noticed striking parallels between the movement of their quantum vortices and the way rotating black holes interact with spacetime. This finding paves the way for new methods of simulating black holes to study their environmental interactions more effectively.
"Discovering clear indicators of black hole physics in our 2017 experiments was a pivotal moment in our efforts to unravel some of the universe's most enigmatic phenomena," stated Professor Silke Weinfurtner, a contributing author. "Our advanced experimental design now offers a deeper understanding of how quantum fields operate in the curved spacetime surrounding astrophysical black holes."
Source: University of Nottingham, photo by Leonardo Solidoro
