May 30, 2019

Scientists try to re-create the physics of a black hole

Image: Event Horizon Telescope Collaboration

A group of scientists are trying to mimic the physics of a black hole on a tiny scale to figure out how these massive and extreme objects work in deep space.

Details: A new study in the journal Nature details the creation and testing of this laboratory-based black hole that uses sound waves sent through a quantum substance known as Bose-Einstein condensate to test the underlying physics of these objects.

The big question: Stephen Hawking theorized that if two quantum particles appeared near a black hole, one could fall into its event horizon, and the other could escape, creating what’s now known as Hawking radiation.

  • Researchers may never be able to test this theory on a real black hole in space, so creating a laboratory analogue is as close as we can get.

What they found: The analogue black hole effectively used sound waves instead of light to mimic black hole physics.

  • One-half of the Bose-Einstein condensate fluid flowed at supersonic speeds, with the other at subsonic — the boundary between the two effectively acts as the analogue’s event horizon.
  • When the scientists sent sound waves through the fluid, they found that some pairs of waves would appear near the event horizon, with one falling in and the other escaping, much like what’s expected to happen with Hawking radiation at a black hole.
  • The researchers were also able to measure the temperature of the radiation in the experiment for the first time, which matches what Hawking predicted.

But, but, but: This new study isn’t conclusive proof that Hawking radiation is happening on a large scale in the universe, but it could help refine these analogue experiments more in the future.

The bottom line: “One could also argue that it is already sufficiently exciting to discover that something as exotic as Hawking radiation predicted for astrophysical black holes can also be found in other completely unrelated systems,” Daniele Faccio, a black hole scientist at the University of Glasgow, told Axios via email.

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