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Physicist Claims Black Holes Mathematically Don't Exist

Posted by Soulskill on from the plot-twist dept.

Koreantoast writes: Black holes, the stellar phenomena that continue to capture the imagination of scientists and science fiction authors, may not actually exist. According to a paper published by physics professor Laura Mersini-Houghton at the University of North Carolina and Mathematics Professor Harald Pfeiffer of the University of Toronto, as a collapsing star emits Hawking radiation, it also sheds mass at a rate that suggests it no longer has the density necessary to become a black hole — the singularity and event horizon never form. While the arXiv paper with the exact solution has not yet been peer reviewed, the preceding paper by Mersini-Houghton with the approximate solutions was published in Physics Letters B.

"I'm still not over the shock," said Mersini-Houghton. "We've been studying this problem for a more than 50 years and this solution gives us a lot to think about... Physicists have been trying to merge these two theories – Einstein's theory of gravity and quantum mechanics – for decades, but this scenario brings these two theories together, into harmony."

7 of 356 comments (clear)

  1. Black holes are real, we observe them all the time by Anonymous Coward · · Score: 4, Interesting

    IAAASBH (I am an astrophysicist studying black holes): Yeah, um, no.

  2. Hmmm ... by gstoddart · · Score: 5, Interesting

    So, what are those big honking things seeing?

    Is this a case where something has been mathematically proven to not exist after it's been observationally confirmed?

    --
    Lost at C:>. Found at C.
    1. Re:Hmmm ... by i+kan+reed · · Score: 5, Interesting

      And there's also a reallllllllllllly telling quote in the actual paper I'm still reading to make sure I understood the context right, but,

      Consider a spherically symmetric, uniform density, perfect-fluid star, undergoing gravitational collapse. The stress energy tensor of the fluid is ...

      Looks like a hell of assumption to make about stellar density. We know the cores are way more dense than the rest of the star, that's the magic that makes the fusion happen.

      Now if this assumption is qualified and addressed later in the paper, I'll be guilty of not being careful enough, but I haven't found that clue yet.

    2. Re:Hmmm ... by medv4380 · · Score: 5, Interesting

      Since Hawking Radiation hasn't been observed in any repeatable experiment, and the universe is too warm to tell it apart from the background radiation if black holes do emit it I'd say that the assumptions could be wrong. Since the claim is that the event horizon never forms it's claiming that those black things in the center of galaxies don't exist, or should be just above the minimum to be a black hole. I'd say this is actually a hit against Hawking Radiation, or one of the other assumption, and not a hit against Black Holes.

  3. That's not what she's saying by Lucas123 · · Score: 5, Interesting

    She's not saying the things are not "very very dense" rather just that they never collapse further than the state that gravity can overcome the speed of light. I believe she's saying a black hole's mass would be "evenly" (or not) spread out over the volume encompassed by the event horizon, rather than in a singularity.

  4. Re:"into harmony" by RobinH · · Score: 4, Interesting

    We have two theories: quantum mechanics and relativity, and they disagree about what happens when really massive stars collapse (or relativity predicts a singularity and quantum mechanics doesn't have much to say about what happens at those energies). The relativity answer seems impossible because when you get infinity out of an answer in physics, your math is probably wrong. Quantum mechanics only covers the 3 other forces, not gravity. So really we know that we probably don't know what's going on with this phenomenon. The term "black hole" is a little bit like "dark matter". It's a placeholder for what we don't know. We have observed evidence that there are extremely heavy and dense objects affecting nearby stars, but we can't observe them directly. So, what we've observed is not necessarily exactly what relativity predicts is there. This paper is offering a different theory (which may or may not be more correct).

    --
    "I have never let my schooling interfere with my education." - Mark Twain
  5. Black holes can exist without a singularity by NEDHead · · Score: 4, Interesting

    It is generally posited that a singularity is the result of a gravitational collapse resulting in a black hole. However an event horizon will form whenever sufficient mass density occurs, thus a 'black hole'. If the contention is that the Hawking radiation dissipates the mass before the singularity forms, so be it. Does not mean no black hole, just no singularity.

    I have not read the article, so I don't know if this is reflective of her contention, however:

    Imagine 2 observers, 1 falling into the black hole, one with great patience a safe distance away. Over time the distant observer will see the black hole eventually become isolated and cease to accumulate new mass (trillions of years perhaps). Thereafter, Hawking radiation begins to dominate and the black hole goes on a diet, eventually going out of existence with a hot bang.

    Meanwhile the more adventurous observer is falling toward the postulated center of the black hole, but is experiencing greater and greater time dilation relative to the low density external universe. Thus at some point, before reaching the singularity state, the observer 'sees' the entire future of the external universe, including an ever increasing flood of Hawking radiation that results in the black hole evaporation. So incoming matter never gets to infinite density, no singularity occurs because the evaporation happens on a different time scale than the collapse. Black hole? Yes, Singularity? No

    If this is not the equivalent of the cited paper, I am free to go to Oslo at any time.