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In New Paradox, Black Holes Appear to Evade Heat Death
- zmgsabst 3y agoThere’s a fairly obvious connection: Braiding is equivalent to circuits, as shown by Microsoft’s idea for a topological quantum computer. If you start a system braiding, it will build complexity because braiding appears to be non-local — and so the tangle becomes an increasingly complex circuit. The cusp of a black hole is a regime we’d expect such topological effects to accumulate. AdS/CFT suggests that maybe there’s something deeper to the relationship between braiding in spacetime and quantum systems. Indeed, braiding is one of the few ways we know to generate quantized properties within a continuous geometric setting.
- EddieEngineers 3y agoThis feels like what GPT-4 would say on the Rogan podcast after mushrooms
- aaroninsf 3y agoIf I could give HN comments reddit awards, I'd start with this one.
- jiggawatts 3y agoI asked GPT-4 to pretend it's on shrooms and talking about these topics: https://chat.openai.com/share/b76b8139-4224-4de7-87ce-0e2a3aaa17b6 https://chat.openai.com/share/b76b8139-4224-4de7-87ce-0e2a3a...
- EddieEngineers 3y ago> Let's talk about braid theory. In the quantum world, particles can be thought of as strands, and their interactions as braids. The braids weave and loop around each other, creating intricate patterns, a dance of existence. Each unique pattern, or braid, represents a different state of the particle. The magic is that the braids can't get tangled. That is not too far off hahahaha
- zmgsabst 3y agoChatGPT is wrong in that they do get tangled: https://en.wikipedia.org/wiki/Anyon https://en.wikipedia.org/wiki/Anyon
- didgeoridoo 3y agoObviously!
- uoaei 3y ago> If you start a system braiding, it will build complexity because braiding appears to be non-local — and so the tangle becomes an increasingly complex circuit. The cusp of a black hole is a regime we’d expect such topological effects to accumulate. Would you please expand on the connections between the first and second sentence here? What does braiding 'look' like in topological spacetime?
- zmgsabst 3y agoBraiding is easier in a restricted topology. That’s why research on anyons uses restricted topologies which cross world lines rather than trying to construct 2-knots in a 3+1D spacetime. As you approach a singularity, “around” becomes much shorter than “across”, effectively restricting the space you’re in. Around being shorter than across is why black holes form Einstein rings: the light is taking the shortest path! So if paths cross while going around the singularity, they can’t untangle by moving across the singularity. Hence you have an easier time building topological modes, akin to the restricted topologies for anyons. (Or so my conjecture goes.)
- ChatGTP 3y agoBlackholes and Microsoft...
- sdfghswe 3y agoMeaningless word salad.
- SanderNL 3y agoYour comment raises important points. The non-local nature of braiding in topological quantum computing contrasts with the inherent locality of the AdS/CFT correspondence, prompting us to wonder how these paradigms might coexist. Could braiding and entanglement entropy, both non-local quantum properties, hint at new understandings in the AdS/CFT framework? Additionally, might these braided structures help illuminate the microstate structure of black holes as theorized by string theory? Finally, your insight into quantized properties emerging from continuous geometry recalls how quantum field theory has been linked to knot theory. Can we use these ideas to further probe the quantization of spacetime? Your reflections beautifully intertwine quantum computing, holography, and quantum gravity, encouraging us to weave together these disparate strands in the tapestry of theoretical physics.
- zmgsabst 3y agoMy understanding is that the non-locality is a feature of AdS/CFT: The map from the interior to exterior sends information that may be “local” on the interior across the surface (eg, crossing of a knot). That information isn’t lost… but it can get smeared across the surface. You can even imagine a situation where the surface as a whole contains the crossing information, but the projected shadow is locally a pseudoknot which doesn’t contain that locally for any “interaction”. Hence a local theory on the surface would need to not only be quantized (eg, a theory of crossing numbers), but statistically so (eg, a distribution of pseudoknot resolutions).
- SanderNL 3y agoYou've captured a fascinating aspect of AdS/CFT: how information in the interior, while local, can manifest non-locally on the surface, akin to a tug on a knot rippling through its structure. The pseudoknot example underscores the need for a statistical approach in our understanding of quantum gravity. It brings to mind the question: could there be dynamics in quantum gravity analogous to decoherence in quantum mechanics that can account for this statistical nature?
- CaptainNegative 3y agoI don't understand how this is obvious -- non-locality does not inherently imply that iteration increases complexity. For a concrete not-entirely-trivial counterexample, von Neumann's middle-square method also appears "non-local" (in that every output bit is a function of a majority of the input bits including well-separated ones) but famously tends to converge to short orbits if not a single constant value.
- dustingetz 3y ago“system braiding” - what is the wikipedia or googleable term for this?
- zmgsabst 3y agoI’m not sure there’s a good reference, but a few related topics: https://en.wikipedia.org/wiki/Anyon https://en.wikipedia.org/wiki/Anyon https://en.wikipedia.org/wiki/Topological_quantum_computer https://en.wikipedia.org/wiki/Topological_quantum_computer https://en.wikipedia.org/wiki/Tangle_(mathematics) https://en.wikipedia.org/wiki/Tangle_(mathematics)
- cyberax 3y agoSo they're integrating across a singularity to compute volume? That's always a bad idea.
- jareklupinski 3y agoMaybe black holes were torn in spacetime by advanced civilizations in previous iterations of the Universe in an effort to escape their own Universe's heat death
- BudaDude 3y agoThis sounds like a great premise for a sci-fi novel
- pelagicAustral 3y agoIndeed, I just ask ChatGPT to write me a story using this premise and it was gold.
- haneefmubarak 3y agoPlease share with the class, what did our dear AI come up with?
- jareklupinski 3y ago"To Hitch a Ride on a Dying Star" will be the title :)
- Timon3 3y ago"The Hitchhiker's Guide to the End of the Galaxy"
- pezezin 3y agoThere are some hypothesis that the universe might be the inside of black hole from a parent universe: https://en.wikipedia.org/wiki/White_hole#Big_Bang/Supermassive_White_Hole https://en.wikipedia.org/wiki/White_hole#Big_Bang/Supermassi... https://en.wikipedia.org/wiki/Black_hole_cosmology https://en.wikipedia.org/wiki/Black_hole_cosmology https://en.wikipedia.org/wiki/Cosmological_natural_selection https://en.wikipedia.org/wiki/Cosmological_natural_selection
- SomeCallMeTim 3y agoReading about how, over time, the volume of a black hole seems to grow infinitely makes me immediately jump to an obvious connection: The universe as a whole is ALSO a system that appears to grow infinitely. I mean, there have been many conjectures that a black hole could contain a new universe, and that the creation of a black hole also creates a new universe. This would seem to hint at another potential connection. That said...I'm really not a physicist, so maybe that connection is at best a hook for a science fiction story. But it surprises me that the article didn't even mention the parallel.
- pdonis 3y ago> over time, the volume of a black hole seems to grow infinitely Unfortunately, the article fails to note that this is a speculative hypothesis with which not all physicists agree. It's not an established fact. It's not even an established theoretical prediction.
- Freestyler_3 3y agoI like that idea, a bubble has small bubbles inside. All of them growing, but one inside it is growing more, and it "eats" the others until it consumes the bubble it is in, and then it pops and all matter starts moving from center outwards. Now we need to find some way to prove this is real.
- hinkley 3y agoI'd be willing to put $100 on longbets to say our universe is inside a singularity, but I doubt anyone who remembers I existed will still be alive when we figure it out.
- ben_w 3y agoYou can't be inside a singularity because that's a point, but we are inside (surrounded on all sides by) an event horizon.
- boringuser2 3y agoWhat proof exists for this hypothesis?
- denton-scratch 3y ago> Once they cross the event horizon, they are moving at the speed of light toward certain doom. Can that be correct? I thought the falling man experienced no change on crossing the event horizon (other than the effects of spaghettification, which begins long before arriving at the horizon). I thought that you'd continue accellerating toward the singularity, asymptotically approaching both the speed of light and infinite inertial mass. Am I wrong?
- pdonis 3y ago> Can that be correct? The "towards certain doom" part is correct. The "at the speed of light" is not. Unfortunately this kind of thing is typical for pop science articles. > I thought the falling man experienced no change on crossing the event horizon That's correct. The infalling person has no way of knowing, locally, that they have crossed the horizon and are now doomed to hit the singularity. But that doesn't change their doom. > (other than the effects of spaghettification, which begins long before arriving at the horizon).* Not for the typical black holes we observe in the universe. Tidal gravity at their horizons is too small for spaghettification; that doesn't happen until the infaller is well inside and approaching the singularity. > I thought that you'd continue accellerating toward the singularity, asymptotically approaching both the speed of light and infinite inertial mass. Am I wrong?* Yes. None of these things are true. Your acceleration is zero--you're in free fall. There is no well-defined notion of "speed" at all, but your worldline remains timelike. Your inertial mass is unchanged. And, finally, the singularity is not a place. It's a moment of time. You can't "accelerate towards" it any more than you can accelerate towards next week.
- denton-scratch 3y ago> Your acceleration is zero--you're in free fall. So if I jump out of an aeroplane, I don't accelerate towards the ground? Apparently my understanding of the natural world needs some enhancements.
- ninkendo 3y agoNope, you're in an inertial reference frame when in free-fall. Ignoring air resistance, if you were to take an apple out of your pocket and place it next to you in mid-air, it would be motionless relative to yourself. Put a box around you with no windows and you'll have no idea whether you're floating through space in the absence of gravity, or if you're free-falling inside a gravity well. This is the main difference between general relativity and the newtonian notion of gravity: GR says gravity is just spacetime curvature, and by following an inertial (geodesic) path through spacetime, it appears to be acceleration to certain observers, but is in fact inertial. Newtonian mechanics says instead that gravity is a force and you're indeed accelerating, but it's a view that breaks down at high mass/speed, and GR makes correct predictions where Newtonian mechanics does not, so we generally prefer the GR interpretation.
- RecycledEle 3y agoMay someone who does not understand any of this ask a question? Years ago scientists made small black holes here in Earth, and, while I was screaming in protest, they assured me they would not fall to the center of the Earth and slowly eat us all. They assured us those black holes would evaporate. Has anything changed? Should I be worried?
- beecafe 3y agoNo black holes have ever been produced on Earth
- devoutsalsa 3y agoScientists have not made black holes here on earth. The energy required to do this is insanely higher than anything we are currently capable of. Even at the LHC we aren’t even hitting the energy levels of cosmic rays hitting out own atmosphere. These aren’t the most reputable sources, but you’ll get the basic idea… https://www.scientificamerican.com/article/has-anyone-created-a-black-hole-on-earth/ https://www.scientificamerican.com/article/has-anyone-create... https://www.forbes.com/sites/startswithabang/2019/08/23/cosmic-rays-are-more-energetic-than-lhc-particles-and-this-faster-than-light-trick-reveals-them/?sh=5d1523cc2f15 https://www.forbes.com/sites/startswithabang/2019/08/23/cosm...
- drdeca 3y agoIn addition to what the other reply points out (that the LHC and such are not sufficient to produce a black hole), another calculation I've seen shows that, even if it had produced a black hole with mass given by the energy of these collisions, and even if these black holes had started at rest with respect to the earth, and like, fallen into the earth (and started oscillating around the center), and if they did not evaporate (say, if Hawking radiation wasn't actually a thing), then the amount of time needed for them to swallow any appreciable amount of matter at all, would be very very long, and so would not actually cause any problem for the forseeable future. (not that any were created. The detectors would have noticed. But even if they had been created, it wouldn't have been a problem, even if we are wrong in thinking that they would immediately evaporate.) The thing is, if the black hole is made from something of a given mass, then, well, it only has the amount of gravitational attraction associated with that quantity of mass. And, that is a very small amount unless the-thing-to-be-attracted is very very very very close to it, and, a point particle falling through the earth wouldn't be likely to get that close to many atoms. Ok, found the link I read this on : https://4gravitons.com/2023/01/27/lhc-black-holes-for-the-terminally-un-reassured/ https://4gravitons.com/2023/01/27/lhc-black-holes-for-the-te... He says that it would take 10^67 years for the black hole to double in mass. So.... Not really a problem.
- passion__desire 3y agoSo Roger Penrose was right all along. CCC. This[0] is a nice overview lecture by Scott. Lenny and Scott were exploring these ideas long time ago. [0] Scott Aaronson: Black Holes, Firewalls, and the Complexity of States and Unitaries https://www.youtube.com/watch?v=zJdTtL3ajaI https://www.youtube.com/watch?v=zJdTtL3ajaI
- proce55ing 3y agoMy first thoughts were CCC when I read the article but could it not be an example of Poincaré recurrence?
- denton-scratch 3y agoWhat's CCC?
- floxy 3y agoConformal Cyclic Cosmology https://en.wikipedia.org/wiki/Conformal_cyclic_cosmology https://en.wikipedia.org/wiki/Conformal_cyclic_cosmology
- cyberax 3y agoSo just to add another note, the infinite volume of black holes is likely an artifact of the classical (not quantum) representation. Just like the ultraviolet catastrophe. Think about volume like this: it's measured by the amount of "liquid" that fills the given shape. This liquid consists of infinitely small idealized "atoms". Volume in curved space is similar, except that the "liquid" has different "densities" at different points in space. This breaks down in case of black holes, as the central singularity can "compress" this "liquid" infinitely.
- mjan22640 3y agoFor a notion of density to have a meaning, the atoms need to be finitely small.
- cyberax 3y agoWhy? Density can be defined for a classic fluid, without any need to make it atomic.
- HyperSane 3y ago> The inside looks very different, however. The spherical volume formula that you learned in grade school doesn’t apply. The problem is that spatial volume is defined at one moment in time. To calculate it, you have to slice up the space-time continuum into “space” and “time,” and inside a black hole there is no unique way to do that. Susskind argued that the most natural choice is a slicing process that maximizes the spatial volume at every moment; by the logic of relativity, it amounts to the shortest distance across the hole. “It’s a natural volume analogue of the shortest-line rule,” said Adam Brown, a physicist at Stanford. And because the interior space-time is so warped, the volume by this measure grows with time forever. “The slice on which I measure this volume gets deformed more and more,” said Luca Iliesiu, a physicist also at Stanford."
- cyberax 3y agoYes, that's what I'm talking about. You need to take curvature into account, and it blows up into infinity near the black hole singularity. But I believe that this is purely an artifact of using classic mechanics for that. The similar thing happened in classic electrodynamics with the "ultraviolet catastrophe". Basically, you measure how much radiation would be inside a box at a temperature T, and you get an infinite amount. So any closed box should become a source of unlimited power. And for very similar reasons, there's no low limit on the wavelength, so there is an infinite number of wavelengths that can fit inside a box. And more importantly, each wavelength should still carry some power, so the total sum diverges if you try to integrate all of their contributions. The fix was to assume that light can only exist in discrete wavelengths, thus setting the lower limit for the wavelength. The resulting total sum then converges, removing the paradox.
- ithkuil 3y ago> there is life after heat death Sure, this was known since Boltzmann and doesn't require a quantum mechanics twist. Given infinite time any unlikely thing will happen unlikely