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Space Math Science

Math Shows Some Black Holes Erase Your Past and Give You Unlimited Futures (vice.com) 190

dmoberhaus writes: An international team of mathematicians has found that there are theoretical black holes that would allow an observer to survive passage through the event horizon. This would result in the breakdown of determinism, a fundamental feature of the universe that allows physics to have predictive power, and result in the destruction of the observer's past and present them with an infinite number of futures. The findings were detailed in a report published last week in Physical Review Letters.
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Math Shows Some Black Holes Erase Your Past and Give You Unlimited Futures

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  • by ITRambo ( 1467509 ) on Tuesday February 27, 2018 @03:25AM (#56192701)
    This seems risky, even if it were possible to approach a black hole. In this case, I'll choose to not believe what my teacher tells me.
    • Given that the nearest candidate for a black hole is approximately 3,300 light-years away, isn't this all kind of speculative?

      • It's all speculative until someone proves it in meat space, but seeing as the people involved are mathematicians they have little interesting in so doing.

        Actually it says at the bottom of the article that this probably will never happen, in fact the particular style of black-hole that makes TFS claims true may not even exist. Further, there are a lot of questions I have about the term "observer" and "making your past not exist".

        Because one way I interpret this is that you won't be destroyed, you will be un

      • No no no no - they have PROOF that no fewer than 42 angels can dance on the head of a pin. The exact number is still under debate - some people say it's up to 700 angels. They have big math equations and everything. This is SCIENCE were talking about here, buddy!

    • by gl4ss ( 559668 )

      well how would you know you sent someone in if their past got erased?

      the theory seems like a math foobar to me really, intuitively it cannot be true. of course the "erasing the past" in this sense I guess means something different, like they cannot access past information about themselves or something like that(meaning they're atom pulp) and have infinite futures (their atom pulp could become anything).

      how is that even a theory though?

    • Re: (Score:2, Insightful)

      by Anonymous Coward

      Theory and practice are the same in theory, but not in practice.

      • Theory and practice are the same in theory, but not in practice.

        Theory and practice are different in practice, but not in theory

  • by TheNarrator ( 200498 ) on Tuesday February 27, 2018 @03:28AM (#56192709)

    "Math isn't going to bring you back from the dead"

    https://www.youtube.com/watch?... [youtube.com]

  • by RightwingNutjob ( 1302813 ) on Tuesday February 27, 2018 @03:39AM (#56192733)
    Summary implies conflation of mathematical artefacts with physical reality. Real paper is probably quite dry and abstract.
    • by Anonymous Coward

      Or maybe just the hypothesis being espoused is. It seems like an indeterministic universe where effect no longer follows cause would be completely antithetical to life. Our existence utterly relies on cause and effect, without it, the first problem would be creating matter at all, let alone organizing into elements, then minerals, amino acids, cells, cell groups, and so on.

      So... you don't have infinite futures if you were to cross the event horizon. You still have none.

  • by Joao Cordeiro ( 3780295 ) on Tuesday February 27, 2018 @03:47AM (#56192749)
    This looks like a division by zero.. but instead of understanding the logical error that put them in that impossible situation and fixing it, they just keep on doing more math over it....
    When mass hits the speed of light, it does not travel back in time... It just louses all mass properties and turns into light.
    1/(x*x) will never be negative with a real input!!!
    • by Anonymous Coward

      # Given equal nonzero values a and b:
      a = b
      # multiply by a
      a^2 = ab
      # subtract b^2
      a^2 - b^2 = ab - b^2
      # factor
      (a - b) * (a + b) = b * (a - b)
      # divide out (a - b)
      a + b = b
      # observe that a = b
      b + b = b
      # combine like terms
      2b = b
      # divide out b
      2 = 1

    • For all we know, nature is following rules of logic and mathematics, she cannot perform IF/THEN, SWITCH or GOTO statements.
  • Physicists should not be mathematicians, they should be primarily physicists. Not everything is real what math allows. If that were the case, the SU(5)
      model (https://en.wikipedia.org/wiki/Georgi%E2%80%93Glashow_model) would have worked.

    Mathematics can describe reality, but reality is not mathematics.

    • by Anonymous Coward

      Mathematics can describe reality, but reality is not mathematics.

      A claim often made, but no-one have succeeded.

      What we do know is that mathematics can describe models of reality that have been specifically made to work with mathematics.
      There are also other models that have been made with religion but those are mostly just wrong. (But interesting to mention as an example of non-mathematical models.)

      So far no models have been perfect and we do not really know if reality follow the same laws as mathematics yet.

    • by dohzer ( 867770 )

      Applied vs Pure, etc.
      Keep hodling.

    • Re:Seriously? (Score:5, Informative)

      by gotan ( 60103 ) on Tuesday February 27, 2018 @07:48AM (#56193211) Homepage

      In quantum physics the approach of following the mathematical theory to its logical conclusion, how weird that may sound, has been quite successful. In any case such speculations make sense to test a theory and see where it leads to. Maybe it'll even lead to possible experimental tests of the theory (although I don't think humanity will have access to a black hole (specifically one that is big enough) to play around with.

      The Einstein-Podolsky-Rosen-Paradoxon is a good example of following a theory (here quantum mechanics) to it's logical conclusion. Effectively the "paradoxon" exposes the nonlocality of quantum mechanics i.e. it implies "spooky actions at a distance", a picture that clashes with our classical world view. Based on this an experiment was thought up, a test of the "bell inequality". Basically any classical theory that preserves locality should always fulfil the bell inequality. OTOH quantum mechanics predicts a violation of the bell inequality in experiments specifically designed for that purpose. Such experiments then showed a violation of the inequality. This means, that a classical theory (which would include locality) can not explain those experimental results (which are predicted by quantum mechanics).

      So the speculations of Einstein, Podolsky and Rosen about the strange consequences of quantum mechanic theory led to a fundamental insight about the nature of reality, namely that there are aspects of it that can not be explained by a "classical" theory that includes locality.

      So if one wants to test a mathematical description of reality one has to follow the mathematics to its logical conclusions and if possible test if these apply to the real world. Even if such a test is not possible it is often helpful to see what the implications of a mathematical model are. Maybe it leads to a better understanding, uncovers contradictions or shows that a theory is incomplete, but in some cases it can also lead to a deeper understanding of reality.

  • Only problem (Score:5, Insightful)

    by gweihir ( 88907 ) on Tuesday February 27, 2018 @03:52AM (#56192761)

    Math does not apply to reality. It always only applies to an abstraction of reality and that loses accuracy, sometimes catastrophically as almost certainly happened in this case.

    • by gl4ss ( 559668 )

      well, it most certainly can't erase it's own past effects on the universe by entering the black hole.

      • Re:Only problem (Score:4, Interesting)

        by uvajed_ekil ( 914487 ) on Tuesday February 27, 2018 @06:03AM (#56192991)

        well, it most certainly can't erase it's own past effects on the universe by entering the black hole.

        How can you be so sure? if it did, you wouldn't know.

      • by gweihir ( 88907 )

        Well, at least if it can, then that would be dramatically unexpected ;-)

  • by Anonymous Coward

    A human surviving forever in one piece? Or a single particle stuck in time? Or?

  • by Guillermito ( 187510 ) on Tuesday February 27, 2018 @04:14AM (#56192803) Homepage
    People tend to believe that physics is applied math. It's not. The universe doesn't care about your math. General Relativity is a set of mathematical equations that were picked because they could model the observed experimental data. Yes, it proved to be a very accurate theory by predicting future experimental results decades after it was published. That doesn't mean that every single prediction will be true. So until an experiment can confirm these results, nothing has been "shown", as the headline implies. This doesn't mean these findings aren't relevant. On the contrary, finding these edge cases is what allows theories to be tested and be eventually replaced by a better model.
    • by Anonymous Coward on Tuesday February 27, 2018 @05:18AM (#56192907)

      People tend to believe that physics is applied math. It's not. The universe doesn't care about your math. General Relativity is a set of mathematical equations that were picked because they could model the observed experimental data.

      The problem here isn't the mathematics or whether it applies to physics - or to reality, for that matter. The real problem is people's lack of insight - including many physicists. Take for example the idea of determinism - naively, this means that everything is pre-determined from some set of equations, which are assumed to have unique, well-defined solutions; but we already know of many cases where seemingly simple sets of equations behave chaotically. Now, I know well enough that mathematically, 'chaos' only means that a dynamic system is extremely sensitive to initial conditions, but since our understanding of quantum mechanics seems to indicate that we can't fix initial conditions of any system with arbitrary precision, there must be a limit to how deterministic any set of deterministic equations are in practise.

      The point I'm making here isn't really about whether either GR or QM are 'true' or model reality correctly - we already know they don't - but the fact that we know far too little to make sweeping statements about anything as profound as determinism and causality. Apart from that, I can't see that this new calculation concerning certain types of black holes says anything of the sort; time and causality are strictly local - time experienced being the path integral of something or other in the 4-dimensional space-time manifold - and whether you travel in a closed loop or otherwise pass through events (~ 4-dim points in space-time) that you have passed before, the time you experience is still only your own, individual, highly local time, which does not necessarily have much to do with the rest of the universe.

      A final point: mathematics is true - it is the only science that can claim to be absolutely tru, but the price we pay is that it is only true within its set of axioms. What this means is that as long as the axioms of any theory in the empirical sciences, match the reality we're trying to model, the conclusions of the theory MUST be correct - that is in fact the fundamental assumption behind the scientific method: it means we can falsify our assumptions by conducting experiments.

      • Re: (Score:3, Interesting)

        by Anonymous Coward

        The point you are making is entirely moot.
        Our current understanding of quantum mechanics already dictates that we live in an nondeterministic universe.
        Quantum interactions are already expressed as probabilities and uncertainties.
        Just look at nuclear decay. There is no way to mathematical model that can calculate when an atom will decay.
        Hell, they can't even predict what will happen when you collide two particles.
        You get several outcomes with different probabilities of happening.

        • Re: (Score:2, Interesting)

          by Anonymous Coward

          Our current understanding of quantum mechanics already dictates that we live in an nondeterministic universe.

          Our current understanding on quantum mechanics isn't necessarily correct.

          It could be worth to consider that all measurements we have ever done on quantum level are with methods and equipment design with the assumption of determinism being true.
          So quantum mechanics appearing to be nondeterministic causes a bit of a paradox.
          If determinism is proven to be false then we can not rely on the the measurements that led us to believe that determinism is false.
          Quantum mechanics being deterministic but extremely compl

        • by Goldsmith ( 561202 ) on Tuesday February 27, 2018 @01:17PM (#56194803)

          I am a physicist. This is not how quantum mechanics works. Probability and randomness are the result of measurement and not knowing the starting conditions. Should you completely know the quantum state (singular) of all the interacting particles in your system, you could exactly predict the outcome. Our change of "quantum state" to "quantum states" is useful to describe what we observe in the real world, but requires an assumption that the two "states" we're looking at are at some point separated by an infinite distance. This is a fine approximation, but not fundamental to physics.

          • I am a physicist. This is not how quantum mechanics works. Probability and randomness are the result of measurement and not knowing the starting conditions. Should you completely know the quantum state (singular) of all the interacting particles in your system, you could exactly predict the outcome.

            I am not a physicist, but doesn't this assertion rely on the hidden variables interpretation of the uncertainty principle, which has fallen out of favor? If there are no hidden variables, then the uncertainty pri

    • by gotan ( 60103 )

      In some cases testing such "edge cases" may also prove that certain aspects of a theory, how unintuitive they may sound, are necessary for an accurate model of reality. E.g. tests of the bell inequality show, that any theory that describes quantum phenomena must be a nonlocal one.

    • I agree that math can't tell you "what is" (cf French existentialism, SK, etc) ... but perhaps the way we have modeled it indicates something that applies physically as well?
  • Black hole mysticism (Score:2, Informative)

    by Anonymous Coward

    Only difference between black holes and neutron stars is black holes overcome pauli and everything collapses into a shared state. Big whoop. Assertions of "infinite density" are nonsense. There is no evidence single massive shared states have exactly zero extent or that length is not quantized and energy sure as heck is not infinite so jumping to "infinite density" conclusions is premature at best. Neither is there anything special about escape velocities approaching C. Of course there are effectively

  • by phonewebcam ( 446772 ) on Tuesday February 27, 2018 @04:45AM (#56192855) Homepage

    Those experiencing it claim the past really did change and it's not their faulty memory. It's name comes from them remembering Nelson Mandela dying in prison in the 80's. [alternatememories.com]

  • All those parking tickets: gone!

  • by Errol backfiring ( 1280012 ) on Tuesday February 27, 2018 @05:17AM (#56192901) Journal

    ... determinism, a fundamental feature of the universe ...

    While we may wish for determinism, it has been shown long before that it does not exist.Since it was shown that we can not accurately know both the position of a particle and its speed, it has been proven that predicting the future is impossible because it is impossible to know the present, let alone calculate the future by using the present as a starting condition. So determinism is absolutely not a feature of the universe.

    • by Anonymous Coward on Tuesday February 27, 2018 @05:40AM (#56192939)

      Not quite, e.g.: https://en.wikipedia.org/wiki/Superdeterminism

    • by zifn4b ( 1040588 )

      While we may wish for determinism, it has been shown long before that it does not exist.Since it was shown that we can not accurately know both the position of a particle and its speed

      This is just pure common sense sprinkled with a slight bit of meta physics. We know this is true for now because all methods of taking these measurements you describe involves "bumping" the particles in question thus changing their state. In order to truly know the state at some fixed time, we would need to plug into the back-end of the system from outside of it and to our knowledge this is impossible. From a software developer's perspective, this is akin to being able to write something directly from th

    • On a fundemental level, eliminating large class of hidden variable, you have an unpredictible system. But while unpredictible it still follow a distributioon of probability, which when you go to the macro level end up eliminating it partially enough that our own macro world looks deterministic enough to be qualified as such. Think about it as newton physic versus GR, for a moving car newton is enough, for shooting a ball or cascading domino determinism is good enough. I would argue that as such the universe
    • Just to nitpick: thr fact that we can not measure the present does not mean that the future is not deterministic.
      The particle you measure will go where it goes, unless you measure it. Then it is going where your measurement is deflecting it to.

      • by slew ( 2918 )

        Just to nitpick: thr fact that we can not measure the present does not mean that the future is not deterministic.
        The particle you measure will go where it goes, unless you measure it. Then it is going where your measurement is deflecting it to.

        That is one way of thinking about how the universe *might* work.

        Another way to think about it is a particle exists in a superposition state of many positions (each with their own probability), and it will effectively go everywhere, until you measure it and then all the things that it has interacted with in the past and transferred momentum to (even if they are now far away) are adjusted to be consistent with your current measurement.

        Although you might think the second way of thinking of how the universe mig

  • The future is ours!
  • by Anonymous Coward

    To cover this ( if valid they no doubt will) already have a collection of blackhole episodes
    https://m.youtube.com/results?q=space%20time%20black%20hole%20&sm=1

  • So in other words, they supposedly discovered: The History Eraser Button. The JOLLY CANDY LIKE BUTTON [youtube.com]. Sometimes when I read this drivel I wish someone did actually find the history eraser button to erase human stupidity.
  • by burtosis ( 1124179 ) on Tuesday February 27, 2018 @08:04AM (#56193239)
    I hereby demonstrate my complete lack of understanding slashdot readers by linking to the full article on arxiv [arxiv.org] It's kind of an interesting mathematical exercise in the physics of charged black holes under various conditions but obviously does not reflect reality. For example, you would need a large positive cosmological constant, and an extreme ratio of charge to mass for this to be relevant. Further the clickbait headline implies some kind of retroactive erasure of the onserver when in reality it just means you can't reconstruct the past from future observations due to a breakdown in how the math works. This may not even be true at all because we know that general relativity does not fully describe spacetime at the extremes found at the surface horizons of black holes anyway.
  • With my past destroyed, the one where I *didn't* enter a future-granting black hole and lived a mundane human life didn't happen.

    Infinite futures means that in one of my futures, benevolent aliens gave me two cloned Jessica Alba sexbots.

    WOO!

    Do I get to tell people I had a threesome with Jessica Alba now?

  • and result in the destruction of the observer's past and present them with an infinite number of futures.

    Nooooo!!!

    That's just what they want you to think!

    Don't get on the carousel [wikipedia.org]!!!

  • against spreading of pseudo-scientific highly abstract disconnected from reality unverifiable utter bullshit, like the laws against spreading of porn.
  • Berenstein Bears and the black hole!

  • Just to put a damper on discussions...
    1) "theoretical black holes", meaning they may not exist naturally. If they do, they could be rare. At any rate travelling to any of them in the near future is impossible.

    2) If one were to say artificially construct one of these things, in order for it to be big enough to fit a human though, it would have to be at least a certain size. A casual search indicates that a 5m event horizon black hole will have the approximate mass of Jupiter. So if it is constructed anywhere

  • Or for the more sophisticated among us, Command-Z.

  • oops, sorry about that.

  • Go, travel to a black hole, go through the event horizon and have the eternal life you always wanted and deserve.

    Wish you all the happiness you deserve!

    DT arrives at the pearly gate to enter heaven. Trumpets sound, the gates open and he is guided by two huge angles on his side to the throne with the almighty god.
    God addressed DT and asks: "Do you have anything to say to me?".
    DT: Ah, you are the guy sitting in my seat, get out!
  • Sounds to me like they are describing movement to a different bubble universe, where you did not exist before. The math is incomplete, though, so it is not includng the bounds of the previous universe. Your history probably still would exist there.

    I wonder if their math encountered the square root of minus one? That usually indicates that there are other dimensions/degrees of freedom that were not taken into account.

  • That getting to the event horizon takes an infinite amount of time. So it will never occur. Hawking radiation will make the event horizon recede before you can get there anyway, and probably kill you in the process.

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