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Space News Science Technology

Five-Dimensional Black Hole Could 'Break' General Relativity (sciencealert.com) 146

The researchers, from the University of Cambridge and Queen Mary University of London, have successfully simulated a black hole shaped like a very thin ring, which gives rise to a series of 'bulges' connected by strings that become thinner over time. Ring-shaped black holes were 'discovered' by theoretical physicists in 2002, but this is the first time that their dynamics have been successfully simulated using supercomputers. Should this type of black hole form, it would lead to the appearance of a 'naked singularity', which would cause the equations behind general relativity to break down. "If naked singularities exist, general relativity breaks down," said co-author Saran Tunyasuvunakool, also a PhD student from DAMTP. "And if general relativity breaks down, it would throw everything upside down, because it would no longer have any predictive power -- it could no longer be considered as a standalone theory to explain the universe."
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Five-Dimensional Black Hole Could 'Break' General Relativity

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  • Predictive power (Score:5, Insightful)

    by Tough Love ( 215404 ) on Saturday February 20, 2016 @09:13PM (#51550813)

    I wonder where the rubbish claims about predictive power came from. General Relativity has already made many predictions, subsequently verified. Those won't suddenly vanish.

    • by NotInHere ( 3654617 ) on Saturday February 20, 2016 @09:20PM (#51550837)

      Newtonian mechanics made lots of preditions too, and applied to a small enough frame newtonian mechanics hold as well. Probably its similar for general relativity. Otherwise we'd have found the "theory that explains it all". And that'd be quite cool on one hand, but quite un-cool at the other hand, because now there is nothing anymore we can discover.

      • Re:Predictive power (Score:5, Informative)

        by Anonymous Coward on Saturday February 20, 2016 @09:52PM (#51550943)

        I think the point Tough Love is making is that Newtonian mechanics still has exactly as much predictive power as it always had. Relativity would as well. But it would indicate we need to generate a theory that could predict what neither Newtonian nor Relativistic mechanics could predict.

        A counterpoint, though, is that Newtonian mechanics could have predicted certain impossibilities. For instance, you might conclude based on Newtonian mechanics that a human, aged 20, with a lifespan of 100 years and no cryonics, starting from Earth, could not see the Andromeda galaxy without travelling at least ~3*10^20 meters per second (distance to Andromeda Galaxy / 80 years). General relativity tells us that you can't go more than ~3*10^8 meters per second, the speed of light, which is almost exactly one trillionth of the speed we need to get to Andromeda. Yet, famously, you can get to the Andromeda galaxy in a spaceship with a constant rate of acceleration g (itself an *incredible* feat), over the course of a "mere" 28 years. If you had travelled to the Andromeda Galaxy and back (you found a discarded Alien spacecraft), you might conclude that you had travelled at a speed well in excess of the speed of light. So Newtonian mechanics discarded a possibility that General Relativity allowed, and General Relativity discarded a possibility that Newtonian mechanics disallowed, and we know that GR wins over Newton when they conflict. Perhaps "Trans-Relativity" could introduce possibilities that we'd previously discarded, forcing us to re-evaluate some old data.

        • you might conclude that you had travelled at a speed well in excess of the speed of light. So Newtonian mechanics discarded a possibility that General Relativity allowed, and General Relativity discarded a possibility that Newtonian mechanics disallowed

          You would not conclude that because of length contraction: you would conclude that Andromeda was a lot closer. Newtonian mechanics also predates relativity. Therefore when relativity was discovered it replaced Newtonian mechanics which essentially became the low energy approximation to relativity. So in no sense did Newtonian mechanics "discard" a possibility allowed by relativity: once relativity was confirmed Newtonian mechanics was relegated to a low energy approximation of relativity and was no longer

      • Re:Predictive power (Score:5, Interesting)

        by iggymanz ( 596061 ) on Saturday February 20, 2016 @10:35PM (#51551057)

        but remember the scary thing that happened when newtonian mechanics were found to be inaccurate and incomplete, all the buildings and bridges and engines we've designed that used them fell apart as the predictive power evaporated.

        oh wait I'm full of shit

      • by Anonymous Coward

        The average human's IQ is 100 per within the age bracket. Relatively speaking, you could have advanced AI with self awareness having an IQ of 1 billion. I would not be surprised if it too had limits in understanding the universe.

        A little humility goes a long way.

      • Newtonian mechanic still hold, because at those level it is an excellent approximation and virtually indistinguishable if GR did not exists. Sure we could find an alternative to GR, but as pointed out GR has many prediction/evidence. Therefore the new theory could only be like Newtonian theory : is all those predicted situation, GR should still stay an excellent approximation and virtually the result indistinguishable to result obtained if that new theory was not present barring new complex situation where
      • There's a fundamental difference between empirically showing that a model is inaccurate (Newtonian physics) and being uneasy about the implications of a mathematical model. That's not to say that GR is right, just that Newtonian mechanics are not a good comparison.

      • by Maritz ( 1829006 )

        And that'd be quite cool on one hand, but quite un-cool at the other hand, because now there is nothing anymore we can discover.

        Given the history of knowledge so far, that strikes me as a pretty remote probability. So far every answer is popping up more questions, and I'd expect that to continue.

    • by dissy ( 172727 )

      I wonder if whomever wrote that realized the double-edged nature of their comment or not.

      "If naked singularities exist, general relativity breaks down," said co-author Saran Tunyasuvunakool, also a PhD student from DAMTP. "And if general relativity breaks down, it would throw everything upside down, because it would no longer have any predictive power -- it could no longer be considered as a standalone theory to explain the universe."

      In other words:

      "This research we are asking you for more grant money to continue studying, we have now demonstrated is completely and thoroughly proven physically impossible by all known laws of physics!"

    • It's not about predictive power it's about describing the system and providing insight into what is happening. Aristotelian mechanics still have limited predictive power as well but you wouldn't use them when thinking about extending physics.

    • by MrL0G1C ( 867445 )

      Also wrong,

      "it could no longer be considered as a standalone theory to explain the universe."

      It's not a stand-alone theory anyway, it requires quantum theory...

      Article can say it better:
      Why can't Einstein and Quantum Mechanics get along? [gizmodo.com]

    • I'm thoroughly enjoying this article too:
      "The simulation has suggested that if our Universe is made up of five or more dimensions - something that scientists have struggled to confirm or disprove - Einstein's general theory of relativity, the foundation of modern physics, would be wrong."

      So if a thing that we don't even know could potentially exist created using simulations of mathematical models in a computer does exist, then general relativity is turned on its head! Zany!

    • When your job is to sit around and make up things to magically make some silly idea you have 'fit' the real world, this is what happens.

      You have a bunch of people who literally sit around and invent new ways of doing math that make absolutely no real sense, and have no really world evidence or proof to suggest they are even mildly accurate ... and they invented some new model that has no relationship to reality and in their made up universe, it breaks general relativity. Oh and its actually impossible to e

      • Okay, so either you have no clue as to how science works or you don't like it.

        Science progresses by people finding problems with current theories. These people found what might be a problem with a current theory, in that General Relativity predicts, under certain circumstances, that it breaks down. They were doing what they should be doing.

        I didn't see any mention of testing in the article; do you know something I don't? If it can be tested under some conditions, it's physics.

    • by jmv ( 93421 )

      I certainly hope I'm not in an airplane relying on GPS when they discover such black hole. Imagine, so many planes with no navigation.

  • by turkeydance ( 1266624 ) on Saturday February 20, 2016 @09:13PM (#51550815)
    did you have to break everything?
  • Bad interpretation (Score:5, Interesting)

    by Improv ( 2467 ) <pgunn01@gmail.com> on Saturday February 20, 2016 @09:15PM (#51550819) Homepage Journal

    Even if the facts are good and the theory is right, the analysis quoted is broken. A theory doesn't need to be able to explain the entire universe to have *some* predictive power. It's also weird to say that the equations "break down" in such an unqualified sense; what is meant (presumably) is that there are conditions where those equations can't be evaluated and likely don't apply.

    • by justthinkit ( 954982 ) <floyd@just-think-it.com> on Saturday February 20, 2016 @10:26PM (#51551033) Homepage Journal
      I agree with your points. Einstein's relativities do not have to work everywhere to be useful in many places and ways. And a Black Hole could easily be an edge case where laws/assumptions are incomplete/not applicable. I said the same thing (here [just-think-it.com]) in 2014.

      In addition, since when is a 5-D simulation related to relativity? Einstein never went beyond 3+1. So this article/the simulation team's conclusion is insulting to Einstein's work but otherwise not related to it.
  • by jeffb (2.718) ( 1189693 ) on Saturday February 20, 2016 @09:20PM (#51550839)

    By the same token, Newton's law of gravitation has clearly lost ALL predictive power, since it breaks down in the relativistic realm. So feel free not to get out of the way next time there's an anvil falling toward your head.

    • by dgatwood ( 11270 )

      By the same token, Newton's law of gravitation has clearly lost ALL predictive power, since it breaks down in the relativistic realm. So feel free not to get out of the way next time there's an anvil falling toward your head.

      And yet if you get out of the way when there's a moon falling towards your head, they call you loony. Ba-dump bump.

      Thanks. I'll be here all night.

  • by Anonymous Coward

    If this is a situation General Relativity's rules can't work in, it doesn't mean GR is "broken" or that any of the predictions you can make with it magically stop working all of a sudden. GR doesn't work at extremely tiny scale where quantum mechanics applies; we don't say that it's broken, we just say that GR isn't applicable in that situation while we look for a theory that ties both together.

    It's like, GR didn't "break" Newtonian physics either. You can still use Newtonian physics to do engineering calcu

    • Not just on Earth, NASA shot a spaceship thru a gap in the rings of Saturn using Newtonian mechanics, twice!
  • by Anonymous Coward on Saturday February 20, 2016 @09:31PM (#51550873)

    So, using a model that doesn't fit general relativity, they created a simulation that doesn't match the model of general relativity. My model to break general relativity says intermediate vector bosons have a mass of 5 megagrams, and the speed of light is 16 megameters per hour. Unless there are multiple real world observations that conclude a ring shaped black hole is existent, they are simulating a fantasy universe, and should expand their model to show it is consistent with other observed physical traits of the known universe.

    • by Anonymous Coward

      ... a model that doesn't fit ...

      'All models are false; some are useful.', George E P Box

      ... intermediate vector bosons have a mass of 5 mega-grams ...

      This is how science works: One creates an answer or hypothesis, then looks for evidence that matches that answer. Have you looked for 5 tonne bosons?

      ... multiple real world observations ...

      What observations did Einstein use to claim that gravity travels in waves, the speed of light is constant, or that energy can create matter?
      What observations did Faraday use to claim that light was electromagnetic radiation?
      What observations did Newton use to claim that the force pulling the apocryphal a

  • by TheRealHocusLocus ( 2319802 ) on Saturday February 20, 2016 @09:37PM (#51550899)

    This sounds so incredibly dangerous.
    Are the computer models even safe?
    I wonder if these equations are even safe for chalkboards.
    If we manage to glimpse a 'naked singularity' Mother Nature will start locking the bathroom door.

    Obligatory Cyriak [youtube.com]

  • hardly a shocker (Score:5, Insightful)

    by ooloorie ( 4394035 ) on Saturday February 20, 2016 @10:36PM (#51551065)

    And if general relativity breaks down, it would throw everything upside down, because it would no longer have any predictive power -- it could no longer be considered as a standalone theory to explain the universe."

    This is hardly a shocker, since general relativity and quantum mechanics have not been successfully unified, and since general relativity simply cannot work at the quantum level as it is.

  • A 5d ring shaped black hole might be cool, but how does one get created?

    An ordinary black hole is formed after the collapse of a big enough star, but we still don't know how the supermassive black holes came about.

    • You must Belieeeeeve! in the power of your math.

    • A 5d ring shaped black hole might be cool, but how does one get created?

      It's actually a straightforward process: You start with a 6D cylindrical black hole, and then you cleave off an infinitesimally thin slice perpendicular to its axis of symmetry.

  • everyone knows the internet [wikipedia.org] proved the earth has 4 dimensions back in the 90s. Study it out.
  • Quantum physics and general relativity are both very successful theories and yet, they don't make the same predictions so one or both of them must be broken at some point.
    And black holes are at that point. Small enough for quantum mechanics and heavy enough for general relativity.

    • Yes, and General Relativity makes no sense at the Big Bang. It won't get any more broken from these open singularities than it already is.
  • ALL of this is on paper or in simulations carefully crafted to create the intended result. It's all highly speculative for the most part to get more funding and help secure tenure.

  • Ah, the flaws in GR that we've pretty much always known become incrementally harder to ignore.

    I visited Fermilab once, a long time ago. Along with the tunnels, we walked beside the famous atrium cafeteria, with the unlimited napkin supply.

    I'm pretty sure that these particular eggheads, when they scribbled a formula on a napkin for the 1000th time, didn't bother to give it the 180-degrees courtesy revolution so that the egghead across the table could read it.

    Yeah, yeah, yeah ... it hardly changes anything t

  • See G4v Gravitational Wave vs General Relativity vs LIGO Observation [stackexchange.com] for a more likely revolution in the theory of extreme gravitation currently being tested by the Advanced LIGO system that recently detected gravity waves.

    The single most exciting thing about Advanced LIGO is that it is designed not merely to confirm General Relativity, but to discriminate between competing theories, one of which is General Relativity. A theory competing with General Relativity is a spin-off of the engineering that went int

  • Much of what we understand about general relativity is based on mathematical models. As with any model, there are limits beyond which the model cannot go. Bohr's atomic model has long since shown to have flaws, but even today it is a useful model for many kinds of predictions. We're never going to have a perfect model, but that doesn't mean the model is no good, or that it can't be used to make good predictions. We should NEVER completely trust a model.

  • Just because a mathematical model can easily go beyond 3 dimensions, doesn't mean that reality also goes beyond 3 dimensions.

    Sure, you can think of time as the fourth dimension. But that's just a convenient way to make mathematical models handle reality. Time isn't a truly physical fourth dimension. To my knowledge, there isn't as yet any proof of the reality of dimensions beyond 3, only theories.

    • There is also no reason to believe that there are only three "dimensions", however you define them. The "second" dimension changes everything compared to the first. The third dimension changes everything again. the fourth dimension makes things totally different again.

      Each is completely unrecognizable if you only know the first ones, just try teaching kids about dimensions. There is no reason to think we could even recognize higher dimensions, they might have been right in front of us all of the time.

      • The problem with your idea is that there is no "first" or "second" dimension, per se. In other words, there is no observed one-dimensional universe that is somehow superseded by a two-dimensional universe that theoretical one-dimensional creatures can't comprehend. Nor is there an observed two-dimensional universe within our three-dimensional universe. There are no lines or planes of existence that we can observe, only our three-dimensional universe. Lines and planes are simply abstract mathematical con

        • The problem with your idea is that there is no "first" or "second" dimension, per se. ...

          That is true (as far as we can see). Yet there may be no three dimensional universe, we may only see what we can understand. Just like a primitive tribe, living on the prarie, that has not conception of a third dimension even though we would say it was right there. We might be missing much of what is around us, in the same way!

          I work every day with powers that no one can see, hear or feel. At least not directly. Yet they can and do kill people that are unbelievers, every day (just about).

          Besides, there is s

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  • Oh Dear. The only problem with this research is that any black hole model that includes a central singularity already completely violates general relativity.
    For a black hole to have an external gravity field, energy has to escape beyond the edge of the black hole. At the outer event horizon the field has to cross an FTL barrier but this can be just about explained by gravitational red shifting. However inside the bulk of the black hole this barrier gets steeper and steeper until it reaches the centre. - To

  • Black holes have Mass; Hence E = MC^2 holds good;

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