Extreme black holes may have "hair," find scientists

Researchers discover black holes that violate the uniqueness theorem and have "gravitational hair."

Extreme black holes may have "hair," find scientists

Black hole illustration.

Credit: Adobe Stock
  • Scientists discover that some extreme black holes may violate the "no hair" theorem.
  • These black holes feature properties outside of the three classical black hole traits of mass, spin, and charge.
  • The researchers ran sophisticated simulations to discover these space oddities.

Black holes are wonderfully weird, sparking the imagination with the many mysteries surrounding their formation and functions in our universe. Now scientists found a new kind of extreme black hole, one that breaks the so-called "ho hair" theorem. In other words, this black hole has "hair."

The idea of the "no hair" or "black hole uniqueness" theorem was encapsulated by the American theoretical physicist John Wheeler who claimed: "Black holes have no hair." What he meant is that black hole solutions to Einstein's field equations of general relativity can be completely characterized by only three physical quantities: mass, spin, and charge. There aren't supposed to be any other "hairy" traits that can make one black hole different from another. Black holes with the same mass, spin, and charge should be identical, explains the press release from Theiss Research, which was behind the new discovery.

The team involved Dr. Lior Burko of Theiss Research, Professor Gaurav Khanna of the University of Massachusetts Dartmouth and the University of Rhode Island, as well as his former student Dr. Subir Sabharwal.

They found there's an extremal black hole that may violate the "no hair" theorem. This type of black hole is "saturated" with the maximum charge or spin it can potentially carry. The researchers discovered that there exists a conserved quantity or property that can be constructed from the spacetime curvature at such a black hole's horizon. It may be measurable from Earth by gravitational wave observatories like LIGO and LISA. Since this property is dependent on how the black hole was formed, it breaks the black hole uniqueness theorem and is considered "gravitational hair."

"This new result is surprising because the black hole uniqueness theorems are well established, and in particular their extension to extreme black holes," shared Dr. Burko. "There has to be an assumption of the theorems that is not satisfied, to explain how the theorems do not apply in this case."

The mind-blowing science of black holes | Michio Kaku, Bill Nye, Michelle Thaller & more 

For their findings, the researchers employed elaborate numerical simulations running on dozens of the top Nvidia graphics-processing-units (GPUs) that had over 5,000 cores each, working in parallel. "Each of these GPUs can perform as many as 7 trillion calculations per second; however, even with such computational capacity the simulations look [sic] many weeks to complete," shared Khanna.

Another type of black hole "hair" was proposed by Stephen Hawking who predicted that quantum particles would leak out of black holes, in a phenomenon dubbed "Hawking radiation." This claim was possibly proven correct by a 2020 study that found evidence of "quantum fuzz" and gravitational wave "echoes" beyond black hole event horizons.

Check out the new study published in Physical Review D.

CT scans of shark intestines find Nikola Tesla’s one-way valve

Evolution proves to be just about as ingenious as Nikola Tesla

Credit: Gerald Schömbs / Unsplash
Surprising Science
  • For the first time, scientists developed 3D scans of shark intestines to learn how they digest what they eat.
  • The scans reveal an intestinal structure that looks awfully familiar — it looks like a Tesla valve.
  • The structure may allow sharks to better survive long breaks between feasts.
Keep reading Show less

“Acoustic tweezers” use sound waves to levitate bits of matter

The non-contact technique could someday be used to lift much heavier objects — maybe even humans.

Levitation by hemispherical transducer arrays.

Kondo and Okubo, Jpn. J. Appl. Phys., 2021.
Surprising Science
  • Since the 1980s, researchers have been using sound waves to move matter through a technique called acoustic trapping.
  • Acoustic trapping devices move bits of matter by emitting strategically designed sound waves, which interact in such a way that the matter becomes "trapped" in areas of particular velocity and pressure.
  • Acoustic and optical trapping devices are already used in various fields, including medicine, nanotechnology, and biological research.
Keep reading Show less

Cockatoos teach each other the secrets of dumpster diving

Australian parrots have worked out how to open trash bins, and the trick is spreading across Sydney.

Surprising Science
  • If sharing learned knowledge is a form of culture, Australian cockatoos are one cultured bunch of birds.
  • A cockatoo trick for opening trash bins to get at food has been spreading rapidly through Sydney's neighborhoods.
  • But not all cockatoos open the bins; some just stay close to those that do.
  • Keep reading Show less
    Culture & Religion

    Godzilla and mushroom clouds: How the first postwar nuclear tests made it to the silver screen

    The few seconds of nuclear explosion opening shots in Godzilla alone required more than 6.5 times the entire budget of the monster movie they ended up in.

    Quantcast