Re: Entropy and curved spacetime
Jesse Mazer laserma...@gmail.com wrote: For 2 things to be in the same macrostate small changes to the microstate must make no difference the way the things behave at the largest scale First you say Macrostates are defined only in terms of a set of *present* microstates and then you give a quote (which as usual you have absolutely no understanding of but could nevertheless still find by searching with Google with a few simple keywords) that said Standard references define macrostates either as sets of microstates, i.e. subsets of phase space, with given values of a small number of macroscopic observables. Well, all game of life patterns that contain 36 live cells is a subset, and 36 is a small number, and one element in that set will grow to infinity and the others will not, and the process of growing to infinity is certainly macroscopic and observable. So I repeat my question, do you really want to say that only the number of live cells is important not their position, so all 36 cell Game of Life patterns have the same macrostate? the definition of a macrostate says nothing whatsoever about *future* behavior. If so then the entire concept of macrostate would be a pretty damn useless idea. it would remain true that if X is proportional to the logarithm of the number of microstates in a system then according to the laws of logarithms X MUST also be proportional to the logarithm of the number of ways the system could have been produced. Not if it's non-reversible, no. YES! In non-reversible physics like the Game of Life 2,3, 4 or k different patterns could have produced the pattern you're looking at now. So however you wish to define microstate if X is proportional to the logarithm of the number of microstates in that pattern then it is also proportional to k times the logarithm of the number of microstates in that pattern because k is a constant. So if X is proportional to the logarithm of the number of microstates in a system then according to the laws of logarithms X MUST also be proportional to the logarithm of the number of ways the system could have been produced. The finite game of life example, with macrostates defined in terms of the ratio of dead to live cells, Nobody knows if our universe is a cellular automation or not but it's pretty clear it's not a finite cellular automation. And even if it were why is that definition more useful that others? Why is the number of cells more important that the position of those cells? Remember, one 36 cell pattern produced infinity, the others do not. But macrostate does not mean the same at the largest scale even though small changes have been made, that's a definition you just made up that has little to do with how physicists define it. BULLSHIT! If you don't believe me that the basic definition of what constitutes a valid macrostate in statistical mechanics can be any choice of macroscopic observable regardless of considerations like whether knowledge of the observable allows you to predict future behavior, see for example http://arxiv.org/pdf/cond-mat/0303625v1.pdf which says: I'll tell you exactly what it says, it says: The set of macrostates forms the unique maximal partition of phasespace which 1) is consistent with our observations (a subjective fact about our ability to observe the system) and 2) obeys a Markov process And a system obeys a Markov process if it is non-reversible and you can make PREDICTIONS about the FUTURE state of the system based only on the present state of the system. It also says Macrostates arrived at in this way are provably optimal statistical predictors of the future values of our observables. So wave goodbye to your previous ideas about macrostates. And that my dear Jesse is the problem in giving lengthy quotes found by Googling keywords that you have no understanding of. the definition of Boltzmann entropy in terms of the log of the number of microstates associated with a macrostate does not say that the parameter that determine the macrostate must be a useful Oh for christ sake! A scientist has an idea, he writes a paper about this idea, but if he doesn't specifically say I think this idea is worth a damn therefore we must conclude he doesn't think his idea is worth a damn. you agree it's possible to have an observer that moves inertially from top to bottom of the accelerating elevator in deep space, with no external forces from the elevator or anything else acting on him as he travels? Yes. we've been over this before, there is no contradiction everybody agrees. You would say that a triangle formed by your lasers contained exactly 180 degrees and your friend in the accelerating elevator looking at your triangle would agree with you, it has 180 degrees. But in the coordinate system of the accelerated observer moving with the elevator the paths of the lasers wouldn't even be straight lines Yes, and elevator man's triangle wouldn't
Re: Entropy and curved spacetime
On Sat, Mar 22, 2014 at 6:41 PM, Jesse Mazer laserma...@gmail.com wrote: So, you admit you were wrong to object to my statement even with reversible laws there is more than one way to get into a given MACROstate? No, sometimes that would be true but because of chaos it wouldn't always be. For 2 things to be in the same macrostate small changes to the microstate must make no difference the way the things behave at the largest scale, but some systems are inherently chaotic and any change at all in them can cause a huge macro change in behavior. Some things like a box full of gas have almost no chaos and that's why the equations of thermodynamics work. Some systems like planetary motion have only a modest amount of chaos, and some systems like global weather patterns have lots and lots of chaos. A microstate can be used to refer to the exact physical state of any system, so even if the most exact possible description of a black hole told you nothing but its mass, charge and angular momentum, you could still call that a microstate. Or you could call it a macrostate. If physics is not unitary (and it almost certainly is unitary) and a Black Hole really can be completely described by just 3 numbers (2 really because the charge is almost always zero) then the entire macrostate\microstate distinction starts to break down. It is true that if physics is non-unitary then black hole entropy could not be defined in terms of its microstates, but that's what I already said, that in this case there would be two different types of entropy, one for black holes and one for everything else. But it would remain true that if X is proportional to the logarithm of the number of microstates in a system then according to the laws of logarithms X MUST also be proportional to the logarithm of the number of ways the system could have been produced. The physical laws in the Game of Life are not unitary, so a large block of dead cells would be equivalent to a Black Hole in our universe if the laws of physics were not unitary. In both cases it would be gibberish to talk about the microstates of a block of dead cells or of a Black Hole because they would have none, they would only have a macrostate. Why would it be gibberish? The microstate would have the same meaning for a block of dead cells as it would for a block with a mix of live and dead cells, Now that I think about it in a block that has a mixture of live and dead cells in the Game of Life I know what a microstate would mean but I'm not quite sure what a macrostate would mean. It's supposed to mean behaving the same at the largest scale even though small changes have been made, but very small changes can dramatically effect a pattern's macro behavior, some patterns die completely and will fade away to nothing, some will start to oscillate and never die, and some finite patterns will generate a infinite (not just very large but infinite) number of additional live cells. if macrostates are defined in terms of the ratio of live to dead cells [...] I think that would be such a crude measure as to be useless. The smallest known Game of Life pattern that is capable of infinite growth has only 36 live cells, but kill just one of those 36 cells or move just one of the cells one space to the right (or left or up or down) and the pattern no longer has that capability to produce infinity. The difference between finite and infinite is about as macro as you can get, so do you really want to say any 36 cell pattern has the same macrostate? Of course I agree the physics in our universe is almost certainly unitary, but this whole debate about entropy got started when you suggested the second law of thermodynamics was possible to deduce from logic alone, Yes, even if we knew none of the fundamental laws of physics from logic alone we could deduce that there are more disordered states than ordered ones, if in addition we assume that in the distant past the universe was in a much more ordered state (please note this doesn't necessarily mean more complex) than it is now you could then deduce that something very much like the second law of thermodynamics must exist. This is unlike the first law of thermodynamics, we believe in that not because the contrary to it is illogical but simply because we've never observed it being violated and using induction we infer that we never will. you've got it backwards. If the fundamental laws of physics were non-reversible then it would be easy to see how time could have a preferred direction and easy to understand why the second law of thermodynamics is true. It would be easy to see why time would have a preferred direction but this wouldn't necessarily be the direction of increasing entropy, Huh? I don't know what you can say about time's dimension except that entropy increases and the universe expands when you move along it in one direction and entropy decreases and the universe contracts when
Re: Entropy and curved spacetime
On 21 Mar 2014, at 22:30, Jesse Mazer wrote: On Fri, Mar 21, 2014 at 5:15 PM, Bruno Marchal marc...@ulb.ac.be wrote: On 21 Mar 2014, at 20:17, Jesse Mazer wrote: On Fri, Mar 21, 2014 at 3:00 PM, John Clark johnkcl...@gmail.com wrote: On 18 Mar 2014, at 22:33, LizR wrote: Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? Absolutely not because in Quantum mechanics 2 very different states can evolve into the exact same state. Not if you're just talking about the evolution of the quantum state vector according to the Schroedinger equation, which is totally deterministic. Deterministic is compatible with the fact that 2 very different states can evolve into the exact same state, making it non reversible. But the solution of the SWE are more than deterministic, they are reversible. In QM (without collapse) 2 different states evolves into two different states. True. I spoke too quickly, I guess my mind jumped to determinism rather than reversibility (which is a type of reverse determinism) because I figured John was thinking of quantum randomness, which only enters in QM if you adopt the postulate of a random collapse on measurement. But John was correct in thinking that determinism does not entail reversibility. He gave the example of the game of life. But most arithmetical operations are like that too. 2+3 gives 5, but from 5 you can't necessarily retrieve 2+3, it might be 1+ 4 or 101 - 96. I agree with what you say, but I was actually the one who brought up the Game of Life in the discussion with John, because I was using it to make the point that the second law of thermodynamics is more than a tautology, that it actually depends on some specific properties of the laws of physics such as satisfying Liouville's theorem. With the appropriate choice of macrostates (namely, defining a macrostate by the ratio of live to dead cells), in the Game of Life the odds can favor a higher-entropy state evolving to a lower-entropy one (since if you start with a random 50:50 mix of live and dead cells, after enough time you are likely to end up in a state where most or all the cells are dead). OK. We agree. Thanks for the clarifications. Bruno Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
One thing about the Game of Life - in the real world it *is* in fact reversible, assuming physics is. Only the ideal, abstract, Platonic GOL isn't. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On Thu, Mar 20, 2014 at 6:00 PM, Jesse Mazer laserma...@gmail.com wrote: Chaos theory tells us that even in classical physics a change in a micro state can soon lead to a change in the macro state. And if it's a reversible theory then there are NOT 2 different states of the universe that could have produced things as they are now. Are you claiming that if the underlying micro-physics is reversible, then it's impossible for there to be two different past states that would lead to the present MACROstate? Then 2 different states of the universe could still lead to the PRESENT macrostate, but depending on if the system is chaos sensitive or not (not everything is, a cylinder of gas isn't) it might not lead to the macrostate after next. The fact remains that if Entropy is proportional to the logarithm of the number of microstates something can be in and still have the same macrostate then it's also proportional to the logarithm of the number of ways the thing could have been produced and still have the same macrostate. Only if physics is unitary, which is an open question in black hole physics. Then Entropy is NOT proportional to the logarithm of the number of microstates something can be in and still have the same macrostate because a Black Hole would have no microstates. Bekenstein DERIVED that the entropy of a Black Hole was proportional to it's 2D surface area, to just define it that way without any arguments showing how it was consistent with physics previous use of the word entropy would have been imbecilic, and Jacob Bekenstein is not an imbecile. As I already explained, what he showed was that IF you define black hole entropy by the specific equation he gave, and IF black holes also have a specific temperature defined by another equation, then the known laws of classical thermodynamics will be preserved in the presence of black holes. And that is just another way of saying Bekenstein DERIVED that the entropy of a Black Hole was proportional to it's 2D surface area. But this is not the same as deriving either of these things, Why the hell not? I suspect you're insisting on this not because you have a strong opinion on the matter but simply because you've developed a reflex to contradict anything I say. If I say white you must say black. https://www.youtube.com/watch?v=kQFKtI6gn9Y Regardless of what English word you call it if X is proportional to the logarithm of the number of microstates something can be in and still have the same macrostate then X is also proportional to the logarithm of the number of ways the thing could have been produced and still have the same macrostate. Only if physics is unitary No such qualification is necessary because if physics is not unitary then X is NOT proportional to the logarithm of the number of microstates something can be in because if that something is a Black Hole then it has no microstates. And today almost all physicists think physics is unitary, even Stephen Hawking now thinks so and he was among the last holdouts. Do you deny that the number of microstates something can presently be in could be different from the number of past microstates that could have led to the present macrostate I never denied that. if the very concept of microstates is still meaningful (that is to say if physics is unitary) then I can't say it better than what I said on March 18: I'm saying that in classical physics a state can produce only one future state, but any given state can have been produced in more than one way, therefore the number of microstates in a Black Hole must equal to k times the number of states that made it where k is some constant integer. Therefore if X is proportional to the logarithm of the number of microstates in a system then according to the laws of logarithms X MUST also be proportional to the logarithm of the number of ways the system could have been produced. in the Game of Life on a finite grid Then it's not the Game of Life. Let's not needlessly complicate things and stick to the original. if you define macrostates in terms of the ratio of black (live) to white (dead) cells, then the macrostate with ratio 0:100 has only one PRESENT microstate it could be in (since every single cell must be white to have that ratio), but lots of past microstates that could have led to it. The physical laws in the Game of Life are not unitary, so a large block of dead cells would be equivalent to a Black Hole in our universe if the laws of physics were not unitary. In both cases it would be gibberish to talk about the microstates of a block of dead cells or of a Black Hole because they would have none, they would only have a macrostate. So if you want to talk about Entropy you can only talk about the ways something could get made; however you should keep in mind that unlike the Game of Live the physics in our universe is almost certainly unitary. Remember, this whole debate
Re: Entropy and curved spacetime
On 3/22/2014 10:52 AM, John Clark wrote: I'm saying that in classical physics a state can produce only one future state, but any given state can have been produced in more than one way, This is only true if you equivocate on state. If state means microstate of a closed system (in either classical or quantum physics without collapse) then a state can produce only one future state. So the first clause would be true. And since the evolution equations are reversible it can come from only one prior state. For the second clause above to be true, state must be interpreted as a macrostate. But for a macrostate, the first clause is false since a macrostate can evolve into different future states, even different macrostates (c.f. Poincare return). Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 18 Mar 2014, at 22:33, LizR wrote: Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? Absolutely not because in Quantum mechanics 2 very different states can evolve into the exact same state. John K Clark -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On Fri, Mar 21, 2014 at 3:00 PM, John Clark johnkcl...@gmail.com wrote: On 18 Mar 2014, at 22:33, LizR wrote: Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? Absolutely not because in Quantum mechanics 2 very different states can evolve into the exact same state. Not if you're just talking about the evolution of the quantum state vector according to the Schroedinger equation, which is totally deterministic. As I said to Liz, non-reversibility only appears if you assume the collapse of the wavefunction to a new quantum state on measurement is a real physical phenomenon distinct from normal wavefunction evolution, rather than an approximate description of something that happens due to decoherence (as would be true in the many-worlds interpretation where the universal state vector is all there is, and also in Bohm's hidden variables interpretation which is deterministic at all stages). Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 21 Mar 2014, at 20:17, Jesse Mazer wrote: On Fri, Mar 21, 2014 at 3:00 PM, John Clark johnkcl...@gmail.com wrote: On 18 Mar 2014, at 22:33, LizR wrote: Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? Absolutely not because in Quantum mechanics 2 very different states can evolve into the exact same state. Not if you're just talking about the evolution of the quantum state vector according to the Schroedinger equation, which is totally deterministic. Deterministic is compatible with the fact that 2 very different states can evolve into the exact same state, making it non reversible. But the solution of the SWE are more than deterministic, they are reversible. In QM (without collapse) 2 different states evolves into two different states. But John was correct in thinking that determinism does not entail reversibility. He gave the example of the game of life. But most arithmetical operations are like that too. 2+3 gives 5, but from 5 you can't necessarily retrieve 2+3, it might be 1+ 4 or 101 - 96. With the combinators, the reduction (Kxy -- x) is deterministic, but not reversible, as KKS and KK(K K) will both gives K, and eliminates S and (K K) respectively. You can still build universal combinator base (set of combinators) which will make computation reversible. We can simulate elimination of information with process which don't eliminate information (the basic idea consist to put the information in some trash, and never empty the trash. I am rather confident that the comp+theaetetus core physical laws will be deterministic and reversible (fro formal reasons related to the material views). Bruno As I said to Liz, non-reversibility only appears if you assume the collapse of the wavefunction to a new quantum state on measurement is a real physical phenomenon distinct from normal wavefunction evolution, rather than an approximate description of something that happens due to decoherence (as would be true in the many-worlds interpretation where the universal state vector is all there is, and also in Bohm's hidden variables interpretation which is deterministic at all stages). Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On Fri, Mar 21, 2014 at 5:15 PM, Bruno Marchal marc...@ulb.ac.be wrote: On 21 Mar 2014, at 20:17, Jesse Mazer wrote: On Fri, Mar 21, 2014 at 3:00 PM, John Clark johnkcl...@gmail.com wrote: On 18 Mar 2014, at 22:33, LizR wrote: Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? Absolutely not because in Quantum mechanics 2 very different states can evolve into the exact same state. Not if you're just talking about the evolution of the quantum state vector according to the Schroedinger equation, which is totally deterministic. Deterministic is compatible with the fact that 2 very different states can evolve into the exact same state, making it non reversible. But the solution of the SWE are more than deterministic, they are reversible. In QM (without collapse) 2 different states evolves into two different states. True. I spoke too quickly, I guess my mind jumped to determinism rather than reversibility (which is a type of reverse determinism) because I figured John was thinking of quantum randomness, which only enters in QM if you adopt the postulate of a random collapse on measurement. But John was correct in thinking that determinism does not entail reversibility. He gave the example of the game of life. But most arithmetical operations are like that too. 2+3 gives 5, but from 5 you can't necessarily retrieve 2+3, it might be 1+ 4 or 101 - 96. I agree with what you say, but I was actually the one who brought up the Game of Life in the discussion with John, because I was using it to make the point that the second law of thermodynamics is more than a tautology, that it actually depends on some specific properties of the laws of physics such as satisfying Liouville's theorem. With the appropriate choice of macrostates (namely, defining a macrostate by the ratio of live to dead cells), in the Game of Life the odds can favor a higher-entropy state evolving to a lower-entropy one (since if you start with a random 50:50 mix of live and dead cells, after enough time you are likely to end up in a state where most or all the cells are dead). Jesse -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 21 Mar 2014, at 20:00, John Clark wrote: On 18 Mar 2014, at 22:33, LizR wrote: Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? Absolutely not because in Quantum mechanics 2 very different states can evolve into the exact same state. You still confuse the 1-view and the 3-view, but in the QM context. The wave equation is deterministic *and* reversible. So what you say is false in the 3p picture. But it is correct in the 1p picture, where each subject is unaware of its counterpart realities, and believe some collapse occurred. But they are just ignorant, at least in the Everett view. Bruno John K Clark -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
Jesse Mazer laserma...@gmail.com Wrote: you made a sweeping statement that If there are 2 different states of the universe that could have produced things as they are now then the laws of physics are not reversible. Yes I said that and is one of the most non-controversial things I ever said. This would be true if [...] There is no if about it! What I said was a tautology and like all tautologies it has the virtue of always being true. things as they are now referred exclusively to the MICROstate, but if it referred to the MACROstate it would be wrong, since classical statistical mechanics is definitely a reversible theory, Chaos theory tells us that even in classical physics a change in a micro state can soon lead to a change in the macro state. And if it's a reversible theory then there are NOT 2 different states of the universe that could have produced things as they are now. I am saying that Kip Thorn, one of the world's best physicists, wrote on page 446 of his book A Black Hole's entropy is the logarithm of the number of ways that the hole could have been made. He didn't say that was a new DEFINITION of entropy though Who gives a damn if it's a definition or a popsicle? And what's with the all capital letters? It's almost as if you think the word is especially relevant to the question at hand. The fact remains that if Entropy is proportional to the logarithm of the number of microstates something can be in and still have the same macrostate then it's also proportional to the logarithm of the number of ways the thing could have been produced and still have the same macrostate. I already linked in my last post to another book by Kip Thorne where he [...] In one of your typical posts you provide about 6.02 * 10^23 links, but you never give any indication that you understand one word in them. As a example see below: the entropy of a black hole, which had already been DEFINED to be the surface area times a specific constant factor based on arguments from black hole thermodynamics MEGA-BULLSHIT!!! Bekenstein DERIVED that the entropy of a Black Hole was proportional to it's 2D surface area, to just define it that way without any arguments showing how it was consistent with physics previous use of the word entropy would have been imbecilic, and Jacob Bekenstein is not an imbecile. If physicists were actually proposing a change in the basic statistical mechanics definition of entropy as a result of the theoretical study of black holes then one would expect modern statistical mechanics textbooks would reflect this re-definition, WHY?? How would it change anything about how we imagine the world works? Regardless of what English word you call it if X is proportional to the logarithm of the number of microstates something can be in and still have the same macrostate then X is also proportional to the logarithm of the number of ways the thing could have been produced and still have the same macrostate. AND if X is proportional to the logarithm of the number of ways the thing could have been produced and still have the same macrostate then X is also proportional to the logarithm of the number of microstates something can be in and still have the same macrostate. And I'm saying that in classical physics a state can produce only one future state, but any given state can have been produced in more than one way Many models in classical physics are reversible, Some deterministic laws are reversible and some, like the deterministic laws of the Game of Life, are not reversible. But even if the laws of physics were 100% reversible that wouldn't necessarily mean that a given system was symmetrical with regard to time; even the second law of thermodynamics by itself is not enough to explain the arrow of time. It's true that there are vastly more high entropy states than low ones so it's overwhelmingly likely that tomorrow entropy will be higher than it was today, but by using the very same reversible logic and reversible physical laws we could also conclude that entropy was almost certainly higher yesterday than it was today, but that is clearly not the case. So if time's preferred direction doesn't come from physical law it must come from the initial conditions, and we need to add a past hypothesis, namely that in the distant past for some reason entropy was much lower than it is today. We call that distant past event The Big Bang. why in hell do you say Entropy is proportional to the logarithm of the number of microstates something can be in and still have the same macrostate, but it is not proportional to the logarithm of the number of ways the thing could have been produced? Because it's logically possible to have laws where, unlike in unitary QM, it's NOT true that two notions are equivalent--this would be true if information is genuinely lost when a black hole swallows up matter and later evaporates. If Physics is not
Re: Entropy and curved spacetime
On 3/20/2014 9:10 AM, John Clark wrote: The fact remains that if Entropy is proportional to the logarithm of the number of microstates something can be in and still have the same macrostate then it's also proportional to the logarithm of the number of ways the thing could have been produced and still have the same macrostate. That doesn't follow. It's true only if it's a closed system so that there can't be two different ways to reach the same microstate. But in general, systems, such as a black hole, can be put in the same microstate in more than one way because they are not closed and the unitary (reversible) evolution applies only to the system plus environment. Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 3/20/2014 9:10 AM, John Clark wrote: WHY?? How would it change anything about how we imagine the world works? Regardless of what English word you call it if X is proportional to the logarithm of the number of microstates something can be in and still have the same macrostate then X is also proportional to the logarithm of the number of ways the thing could have been produced and still have the same macrostate. AND if X is proportional to the logarithm of the number of ways the thing could have been produced and still have the same macrostate then X is also proportional to the logarithm of the number of microstates something can be in and still have the same macrostate. ... why in hell do you say Entropy is proportional to the logarithm of the number of microstates something can be in and still have the same macrostate, but it is not proportional to the logarithm of the number of ways the thing could have been produced? Because it's logically possible to have laws where, unlike in unitary QM, it's NOT true that two notions are equivalent--this would be true if information is genuinely lost when a black hole swallows up matter and later evaporates. If Physics is not unitary then the old definition of Entropy becomes meaningless with regard to Black Holes because it would contain no microstates you could take a logarithm of, but it would still be true that the Entropy of a Black Hole is proportional to the logarithm of the ways it could have been formed. Among the ways a black hole could be formed are the different order in which things fall in. As an object falls in it will in theory cause a temporary disturbance of the black hole which is damped out by gravitational radiation (plus EM if it's charged) so the BH returns to the macrostate defined by mass, charge, and angular momentum. But the BH doesn't retain the information about when this happened. That information is in the radiation. So although the overall physics is reversible it doesn't follow that the BH contains all the information necessary for the reversal. Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 21 March 2014 05:10, John Clark johnkcl...@gmail.com wrote: Jesse Mazer laserma...@gmail.com Wrote: you made a sweeping statement that If there are 2 different states of the universe that could have produced things as they are now then the laws of physics are not reversible. Yes I said that and is one of the most non-controversial things I ever said. This would be true if [...] There is no if about it! What I said was a tautology and like all tautologies it has the virtue of always being true. Sorry, but I disagree about it being both true and a tautology. The statement is only true if the laws of physics working in reverse can't produce *both* the states that could have produced the current state. In the MWI that isn't so, however - the universe branches into all states that can result from the current state, and does so in both time directions, as far as I know (looked at in the normal time direction, a universe branching into the past is equivalent to different branches merging once they become indistinguishable at the quantum level). Quantum alogorithms like Shor's wouldn't work unless this was so, at least that's my understanding of it? -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 18 Mar 2014, at 16:14, John Clark wrote: And I'm the one who is supposed to be confused??? There is not one drop of Quantum Mechanics or probability in the Game of Life, it is 100% classical mechanics, and yet there CAN be 2 or more ways to get to a given macrostate. It's 100% deterministic so if I show you a Game of Life pattern you can calculate what it's future evolution will be (there doesn't seem to be anything analogous to chaos in the Game) but you can't figure out it's history was, or at least not a unique history. Unless the game of life is emulated by a reversible universal machine, in which case by reversing that reversible machine, you will find back the game of life pattern you started with. And the physical evidences are that the core physical laws are reversible (with both empirical and comp evidences). Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 18 Mar 2014, at 22:33, LizR wrote: Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? In God's eye only. Not from inside the universe, especially that from inside, you will find your self belonging to some special term of the universal wave. Theoretically, you might be able to bactrack, from inside, but only through strong 1p quantum amnesia. Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 19 Mar 2014, at 01:57, meekerdb wrote:
On 3/18/2014 5:07 PM, LizR wrote:
On 19 March 2014 12:47, meekerdb meeke...@verizon.net wrote:
But in general that would mean knowing the state of everything the
system had interacted with in the past, since it is now entangled
with them. So even if you suppose there is no collapse of the
wavefunction, decoherence has the same effect.
I was only asking about the theoretical possibility, given
unrealistically perfect information about the state of the system.
The universe (assuming unitary QM) is reversible. In fact from the
standpoint of QM there is no arrow of time - it's deterministic,
just like Laplace's universe. So, as always, when the word
possibility is used there has to be some context. To *calculate*
a history of the universe from it's present state would require
knowing its *complete* present state, including your mental state.
Is that theoretically possible? I think it involves a paradox of
self-reference.
You are almost right. We might be able to know the complete present
state, but not the complete history leading that present. You can
build a completely self-referential machine capable to describe its
entire present state, but not its entire trace. You can go very near
that goal, and write a program capable of giving, not its complete
trace, but capable of giving a program, which when run, will give the
entire trace of the first problem.
It is like in arithmetic, we can't define V = arithmetical truth (the
set of Gödel numbers of all true sentences), but arithmetical can
defined the singleton {V}.
With comp, God has no name, but the singleton {God} might have a name.
It is counter-intuitive, and I have still some problem to figure out
how this is proved, but a proof is available in the Boolos and Jeffrey
book.
To put it another way, in the Game of Life, even with perfect
information, you can't trace the state of the system backwards
because it loses information. So even the laws of physics couldn't
work backwards in a universe based on the GOL. QM, I'm informed,
doesn't lose information, so (very much in theory) you could work
backwards - or (less in theory) the laws of physics could.
Yes the universe doesn't lose information like the GoL. But
relative to any point it loses information across spacetime
horizons. So there's no way to gather that information up into a
calculation unless you have some God's eye view from outside the
universe, in which case you could see the past anyway.
OK.
There's a couple of nice papers about this by Yasunori Nomura: arXiv:
1205.267v2 is a popular exposition and arXiv:1205.5550v2 is a more
technical paper.
Nomura is very interesting, and is going into the direction that QM
belongs to the core physical laws of comp, and that this leads to
different geographical cosmologies possible. If comp is true, the
multiverse = the many-worlds = the many comp dreams. It would entail
that we are very big numbers, which are very deep. The vast majority
of our computations below our subst level, would be gievn by our
electronic configurations. Our substitution level might be that low.
Bruno
Brent
I wasn't asking whether I could build a chronoscope and watch the
past happening on TV.
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Re: Entropy and curved spacetime
Brent. Correct to a point and those networks of entanglement form the basis of my theory of how space arises piecewise from quantum events that no one here is interested in exploring even though it resolves all quantum paradox and shows how to unify QT and GR. Ah, well, there is always the Sex Pistols to occupy your intellects! :-) Edgar On Tuesday, March 18, 2014 7:47:45 PM UTC-4, Brent wrote: But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. Brent On 3/18/2014 2:52 PM, Jesse Mazer wrote: Yes, if you have the exact present quantum state and you're assuming the normal quantum rules for continuous wavefunction evolution, you can determine the past quantum state. The answer might change if you assume that there's an objective physical reality to the collapse of wavefunction with measurement, distinct from the normal wavefunction evolution rules. Jesse On Tue, Mar 18, 2014 at 5:33 PM, LizR liz...@gmail.com javascript:wrote: Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com javascript:. To post to this group, send email to everyth...@googlegroups.comjavascript: . Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com javascript:. To post to this group, send email to everyth...@googlegroups.comjavascript: . Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
Brent, If information is not being lost then the amount of information in the universe is increasing at a tremendous rate as new events occur, and has been since the beginning. So where is all that new information being stored? How can ever increasing amounts of information be being stored in the SAME amount of matter states? Presumably you do agree that information can't just float around somehow without actually being encoded in actual matter states? I think I know the answer but would like to hear your take on it first Edgar On Tuesday, March 18, 2014 8:57:57 PM UTC-4, Brent wrote: On 3/18/2014 5:07 PM, LizR wrote: On 19 March 2014 12:47, meekerdb meek...@verizon.net javascript:wrote: But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. I was only asking about the theoretical possibility, given unrealistically perfect information about the state of the system. The universe (assuming unitary QM) is reversible. In fact from the standpoint of QM there is no arrow of time - it's deterministic, just like Laplace's universe. So, as always, when the word possibility is used there has to be some context. To *calculate* a history of the universe from it's present state would require knowing its *complete* present state, including your mental state. Is that theoretically possible? I think it involves a paradox of self-reference. To put it another way, in the Game of Life, even with perfect information, you can't trace the state of the system backwards because it loses information. So even the laws of physics couldn't work backwards in a universe based on the GOL. QM, I'm informed, doesn't lose information, so (very much in theory) you could work backwards - or (less in theory) the laws of physics could. Yes the universe doesn't lose information like the GoL. But relative to any point it loses information across spacetime horizons. So there's no way to gather that information up into a calculation unless you have some God's eye view from outside the universe, in which case you could see the past anyway. There's a couple of nice papers about this by Yasunori Nomura: arXiv:1205.267v2 is a popular exposition and arXiv:1205.5550v2 is a more technical paper. Brent I wasn't asking whether I could build a chronoscope and watch the past happening on TV. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com javascript:. To post to this group, send email to everyth...@googlegroups.comjavascript: . Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On Wed, Mar 19, 2014 at 12:54 PM, Edgar L. Owen edgaro...@att.net wrote: Brent, If information is not being lost then the amount of information in the universe is increasing at a tremendous rate as new events occur, and has been since the beginning. So where is all that new information being stored? How can ever increasing amounts of information be being stored in the SAME amount of matter states? By an increase in Shannon entropy, up to a point. This is why you can compress computer files, for example. Telmo. Presumably you do agree that information can't just float around somehow without actually being encoded in actual matter states? I think I know the answer but would like to hear your take on it first Edgar On Tuesday, March 18, 2014 8:57:57 PM UTC-4, Brent wrote: On 3/18/2014 5:07 PM, LizR wrote: On 19 March 2014 12:47, meekerdb meek...@verizon.net wrote: But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. I was only asking about the theoretical possibility, given unrealistically perfect information about the state of the system. The universe (assuming unitary QM) is reversible. In fact from the standpoint of QM there is no arrow of time - it's deterministic, just like Laplace's universe. So, as always, when the word possibility is used there has to be some context. To *calculate* a history of the universe from it's present state would require knowing its *complete* present state, including your mental state. Is that theoretically possible? I think it involves a paradox of self-reference. To put it another way, in the Game of Life, even with perfect information, you can't trace the state of the system backwards because it loses information. So even the laws of physics couldn't work backwards in a universe based on the GOL. QM, I'm informed, doesn't lose information, so (very much in theory) you could work backwards - or (less in theory) the laws of physics could. Yes the universe doesn't lose information like the GoL. But relative to any point it loses information across spacetime horizons. So there's no way to gather that information up into a calculation unless you have some God's eye view from outside the universe, in which case you could see the past anyway. There's a couple of nice papers about this by Yasunori Nomura: arXiv:1205.267v2 is a popular exposition and arXiv:1205.5550v2 is a more technical paper. Brent I wasn't asking whether I could build a chronoscope and watch the past happening on TV. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
Telmo, No, compression is totally unable to explain the storage of total information in a universe which continually doubles its amount of information from one Planck time to the next and continually adds that amount to the cumulative total. Edgar On Wednesday, March 19, 2014 8:17:28 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 12:54 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Brent, If information is not being lost then the amount of information in the universe is increasing at a tremendous rate as new events occur, and has been since the beginning. So where is all that new information being stored? How can ever increasing amounts of information be being stored in the SAME amount of matter states? By an increase in Shannon entropy, up to a point. This is why you can compress computer files, for example. Telmo. Presumably you do agree that information can't just float around somehow without actually being encoded in actual matter states? I think I know the answer but would like to hear your take on it first Edgar On Tuesday, March 18, 2014 8:57:57 PM UTC-4, Brent wrote: On 3/18/2014 5:07 PM, LizR wrote: On 19 March 2014 12:47, meekerdb meek...@verizon.net wrote: But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. I was only asking about the theoretical possibility, given unrealistically perfect information about the state of the system. The universe (assuming unitary QM) is reversible. In fact from the standpoint of QM there is no arrow of time - it's deterministic, just like Laplace's universe. So, as always, when the word possibility is used there has to be some context. To *calculate* a history of the universe from it's present state would require knowing its *complete* present state, including your mental state. Is that theoretically possible? I think it involves a paradox of self-reference. To put it another way, in the Game of Life, even with perfect information, you can't trace the state of the system backwards because it loses information. So even the laws of physics couldn't work backwards in a universe based on the GOL. QM, I'm informed, doesn't lose information, so (very much in theory) you could work backwards - or (less in theory) the laws of physics could. Yes the universe doesn't lose information like the GoL. But relative to any point it loses information across spacetime horizons. So there's no way to gather that information up into a calculation unless you have some God's eye view from outside the universe, in which case you could see the past anyway. There's a couple of nice papers about this by Yasunori Nomura: arXiv:1205.267v2 is a popular exposition and arXiv:1205.5550v2 is a more technical paper. Brent I wasn't asking whether I could build a chronoscope and watch the past happening on TV. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com javascript:. To post to this group, send email to everyth...@googlegroups.comjavascript: . Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 19 Mar 2014, at 12:54, Edgar L. Owen wrote: Presumably you do agree that information can't just float around somehow without actually being encoded in actual matter states? This contradicts your statement that the physical arises from the computational. But you have not yet define what you mean by computational. Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On Wed, Mar 19, 2014 at 1:25 PM, Edgar L. Owen edgaro...@att.net wrote: Telmo, No, compression is totally unable to explain the storage of total information in a universe which continually doubles its amount of information from one Planck time to the next and continually adds that amount to the cumulative total. So you're essentially claiming that the universe is increasing exponentially in complexity? Edgar On Wednesday, March 19, 2014 8:17:28 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 12:54 PM, Edgar L. Owen edga...@att.net wrote: Brent, If information is not being lost then the amount of information in the universe is increasing at a tremendous rate as new events occur, and has been since the beginning. So where is all that new information being stored? How can ever increasing amounts of information be being stored in the SAME amount of matter states? By an increase in Shannon entropy, up to a point. This is why you can compress computer files, for example. Telmo. Presumably you do agree that information can't just float around somehow without actually being encoded in actual matter states? I think I know the answer but would like to hear your take on it first Edgar On Tuesday, March 18, 2014 8:57:57 PM UTC-4, Brent wrote: On 3/18/2014 5:07 PM, LizR wrote: On 19 March 2014 12:47, meekerdb meek...@verizon.net wrote: But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. I was only asking about the theoretical possibility, given unrealistically perfect information about the state of the system. The universe (assuming unitary QM) is reversible. In fact from the standpoint of QM there is no arrow of time - it's deterministic, just like Laplace's universe. So, as always, when the word possibility is used there has to be some context. To *calculate* a history of the universe from it's present state would require knowing its *complete* present state, including your mental state. Is that theoretically possible? I think it involves a paradox of self-reference. To put it another way, in the Game of Life, even with perfect information, you can't trace the state of the system backwards because it loses information. So even the laws of physics couldn't work backwards in a universe based on the GOL. QM, I'm informed, doesn't lose information, so (very much in theory) you could work backwards - or (less in theory) the laws of physics could. Yes the universe doesn't lose information like the GoL. But relative to any point it loses information across spacetime horizons. So there's no way to gather that information up into a calculation unless you have some God's eye view from outside the universe, in which case you could see the past anyway. There's a couple of nice papers about this by Yasunori Nomura: arXiv:1205.267v2 is a popular exposition and arXiv:1205.5550v2 is a more technical paper. Brent I wasn't asking whether I could build a chronoscope and watch the past happening on TV. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On Wed, Mar 19, 2014 at 4:45 PM, Quentin Anciaux allco...@gmail.com wrote: In the present state and the physical transition rules from one state to another ? if the transition is reversible then from only the current state you can infer the past state, without it being encoded in the present state... the current state + transition rule is enough. Exactly, which is why we can store thousands, maybe millions of seconds of video per second on youtube without having to replace the known universe with web servers. Telmo. Quentin 2014-03-19 16:33 GMT+01:00 Edgar L. Owen edgaro...@att.net: Telmo, No, that was Brent's claim. I'm asking him to tell us how it works. Where is all that additional information about past states stored if he thinks none of it is lost? Edgar On Wednesday, March 19, 2014 10:32:48 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 1:25 PM, Edgar L. Owen edga...@att.net wrote: Telmo, No, compression is totally unable to explain the storage of total information in a universe which continually doubles its amount of information from one Planck time to the next and continually adds that amount to the cumulative total. So you're essentially claiming that the universe is increasing exponentially in complexity? Edgar On Wednesday, March 19, 2014 8:17:28 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 12:54 PM, Edgar L. Owen edga...@att.netwrote: Brent, If information is not being lost then the amount of information in the universe is increasing at a tremendous rate as new events occur, and has been since the beginning. So where is all that new information being stored? How can ever increasing amounts of information be being stored in the SAME amount of matter states? By an increase in Shannon entropy, up to a point. This is why you can compress computer files, for example. Telmo. Presumably you do agree that information can't just float around somehow without actually being encoded in actual matter states? I think I know the answer but would like to hear your take on it first Edgar On Tuesday, March 18, 2014 8:57:57 PM UTC-4, Brent wrote: On 3/18/2014 5:07 PM, LizR wrote: On 19 March 2014 12:47, meekerdb meek...@verizon.net wrote: But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. I was only asking about the theoretical possibility, given unrealistically perfect information about the state of the system. The universe (assuming unitary QM) is reversible. In fact from the standpoint of QM there is no arrow of time - it's deterministic, just like Laplace's universe. So, as always, when the word possibility is used there has to be some context. To *calculate* a history of the universe from it's present state would require knowing its *complete* present state, including your mental state. Is that theoretically possible? I think it involves a paradox of self-reference. To put it another way, in the Game of Life, even with perfect information, you can't trace the state of the system backwards because it loses information. So even the laws of physics couldn't work backwards in a universe based on the GOL. QM, I'm informed, doesn't lose information, so (very much in theory) you could work backwards - or (less in theory) the laws of physics could. Yes the universe doesn't lose information like the GoL. But relative to any point it loses information across spacetime horizons. So there's no way to gather that information up into a calculation unless you have some God's eye view from outside the universe, in which case you could see the past anyway. There's a couple of nice papers about this by Yasunori Nomura: arXiv:1205.267v2 is a popular exposition and arXiv:1205.5550v2 is a more technical paper. Brent I wasn't asking whether I could build a chronoscope and watch the past happening on TV. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this
Re: Entropy and curved spacetime
On Wed, Mar 19, 2014 at 4:33 PM, Edgar L. Owen edgaro...@att.net wrote: Telmo, No, that was Brent's claim. I'm asking him to tell us how it works. Where is all that additional information about past states stored if he thinks none of it is lost? Edgar, One thing is to claim that no information is lost, another thing is to claim that the information content of the universe in increasing exponentially. Computer science shows us that there is no direct correspondence between the number of states in a system and the amount of information the system contains. Telmo. Edgar On Wednesday, March 19, 2014 10:32:48 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 1:25 PM, Edgar L. Owen edga...@att.net wrote: Telmo, No, compression is totally unable to explain the storage of total information in a universe which continually doubles its amount of information from one Planck time to the next and continually adds that amount to the cumulative total. So you're essentially claiming that the universe is increasing exponentially in complexity? Edgar On Wednesday, March 19, 2014 8:17:28 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 12:54 PM, Edgar L. Owen edga...@att.netwrote: Brent, If information is not being lost then the amount of information in the universe is increasing at a tremendous rate as new events occur, and has been since the beginning. So where is all that new information being stored? How can ever increasing amounts of information be being stored in the SAME amount of matter states? By an increase in Shannon entropy, up to a point. This is why you can compress computer files, for example. Telmo. Presumably you do agree that information can't just float around somehow without actually being encoded in actual matter states? I think I know the answer but would like to hear your take on it first Edgar On Tuesday, March 18, 2014 8:57:57 PM UTC-4, Brent wrote: On 3/18/2014 5:07 PM, LizR wrote: On 19 March 2014 12:47, meekerdb meek...@verizon.net wrote: But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. I was only asking about the theoretical possibility, given unrealistically perfect information about the state of the system. The universe (assuming unitary QM) is reversible. In fact from the standpoint of QM there is no arrow of time - it's deterministic, just like Laplace's universe. So, as always, when the word possibility is used there has to be some context. To *calculate* a history of the universe from it's present state would require knowing its *complete* present state, including your mental state. Is that theoretically possible? I think it involves a paradox of self-reference. To put it another way, in the Game of Life, even with perfect information, you can't trace the state of the system backwards because it loses information. So even the laws of physics couldn't work backwards in a universe based on the GOL. QM, I'm informed, doesn't lose information, so (very much in theory) you could work backwards - or (less in theory) the laws of physics could. Yes the universe doesn't lose information like the GoL. But relative to any point it loses information across spacetime horizons. So there's no way to gather that information up into a calculation unless you have some God's eye view from outside the universe, in which case you could see the past anyway. There's a couple of nice papers about this by Yasunori Nomura: arXiv:1205.267v2 is a popular exposition and arXiv:1205.5550v2 is a more technical paper. Brent I wasn't asking whether I could build a chronoscope and watch the past happening on TV. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to
Re: Entropy and curved spacetime
Telmo, No, that was Brent's claim. I'm asking him to tell us how it works. Where is all that additional information about past states stored if he thinks none of it is lost? Edgar On Wednesday, March 19, 2014 10:32:48 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 1:25 PM, Edgar L. Owen edga...@att.netjavascript: wrote: Telmo, No, compression is totally unable to explain the storage of total information in a universe which continually doubles its amount of information from one Planck time to the next and continually adds that amount to the cumulative total. So you're essentially claiming that the universe is increasing exponentially in complexity? Edgar On Wednesday, March 19, 2014 8:17:28 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 12:54 PM, Edgar L. Owen edga...@att.net wrote: Brent, If information is not being lost then the amount of information in the universe is increasing at a tremendous rate as new events occur, and has been since the beginning. So where is all that new information being stored? How can ever increasing amounts of information be being stored in the SAME amount of matter states? By an increase in Shannon entropy, up to a point. This is why you can compress computer files, for example. Telmo. Presumably you do agree that information can't just float around somehow without actually being encoded in actual matter states? I think I know the answer but would like to hear your take on it first Edgar On Tuesday, March 18, 2014 8:57:57 PM UTC-4, Brent wrote: On 3/18/2014 5:07 PM, LizR wrote: On 19 March 2014 12:47, meekerdb meek...@verizon.net wrote: But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. I was only asking about the theoretical possibility, given unrealistically perfect information about the state of the system. The universe (assuming unitary QM) is reversible. In fact from the standpoint of QM there is no arrow of time - it's deterministic, just like Laplace's universe. So, as always, when the word possibility is used there has to be some context. To *calculate* a history of the universe from it's present state would require knowing its *complete* present state, including your mental state. Is that theoretically possible? I think it involves a paradox of self-reference. To put it another way, in the Game of Life, even with perfect information, you can't trace the state of the system backwards because it loses information. So even the laws of physics couldn't work backwards in a universe based on the GOL. QM, I'm informed, doesn't lose information, so (very much in theory) you could work backwards - or (less in theory) the laws of physics could. Yes the universe doesn't lose information like the GoL. But relative to any point it loses information across spacetime horizons. So there's no way to gather that information up into a calculation unless you have some God's eye view from outside the universe, in which case you could see the past anyway. There's a couple of nice papers about this by Yasunori Nomura: arXiv:1205.267v2 is a popular exposition and arXiv:1205.5550v2 is a more technical paper. Brent I wasn't asking whether I could build a chronoscope and watch the past happening on TV. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com javascript:. To post to this group, send email to everyth...@googlegroups.comjavascript: . Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe
Re: Entropy and curved spacetime
Bruno, Well I'm using loose language to make it easier to understand. Actually it is the information itself that represents what are then interpreted by humans and science as matter states My point being that the information forms that manifest as matter states in human internal mental models of reality don't continually reproduce themselves to produce more of what is interpreted as matter states, so how does Brent think all the additional information of all actual prior matter states are stored, if not in the information of current matter states? That's more precise but not sure if it's clearer... Edgar On Wednesday, March 19, 2014 10:24:44 AM UTC-4, Bruno Marchal wrote: On 19 Mar 2014, at 12:54, Edgar L. Owen wrote: Presumably you do agree that information can't just float around somehow without actually being encoded in actual matter states? This contradicts your statement that the physical arises from the computational. But you have not yet define what you mean by computational. Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
In the present state and the physical transition rules from one state to another ? if the transition is reversible then from only the current state you can infer the past state, without it being encoded in the present state... the current state + transition rule is enough. Quentin 2014-03-19 16:33 GMT+01:00 Edgar L. Owen edgaro...@att.net: Telmo, No, that was Brent's claim. I'm asking him to tell us how it works. Where is all that additional information about past states stored if he thinks none of it is lost? Edgar On Wednesday, March 19, 2014 10:32:48 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 1:25 PM, Edgar L. Owen edga...@att.net wrote: Telmo, No, compression is totally unable to explain the storage of total information in a universe which continually doubles its amount of information from one Planck time to the next and continually adds that amount to the cumulative total. So you're essentially claiming that the universe is increasing exponentially in complexity? Edgar On Wednesday, March 19, 2014 8:17:28 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 12:54 PM, Edgar L. Owen edga...@att.netwrote: Brent, If information is not being lost then the amount of information in the universe is increasing at a tremendous rate as new events occur, and has been since the beginning. So where is all that new information being stored? How can ever increasing amounts of information be being stored in the SAME amount of matter states? By an increase in Shannon entropy, up to a point. This is why you can compress computer files, for example. Telmo. Presumably you do agree that information can't just float around somehow without actually being encoded in actual matter states? I think I know the answer but would like to hear your take on it first Edgar On Tuesday, March 18, 2014 8:57:57 PM UTC-4, Brent wrote: On 3/18/2014 5:07 PM, LizR wrote: On 19 March 2014 12:47, meekerdb meek...@verizon.net wrote: But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. I was only asking about the theoretical possibility, given unrealistically perfect information about the state of the system. The universe (assuming unitary QM) is reversible. In fact from the standpoint of QM there is no arrow of time - it's deterministic, just like Laplace's universe. So, as always, when the word possibility is used there has to be some context. To *calculate* a history of the universe from it's present state would require knowing its *complete* present state, including your mental state. Is that theoretically possible? I think it involves a paradox of self-reference. To put it another way, in the Game of Life, even with perfect information, you can't trace the state of the system backwards because it loses information. So even the laws of physics couldn't work backwards in a universe based on the GOL. QM, I'm informed, doesn't lose information, so (very much in theory) you could work backwards - or (less in theory) the laws of physics could. Yes the universe doesn't lose information like the GoL. But relative to any point it loses information across spacetime horizons. So there's no way to gather that information up into a calculation unless you have some God's eye view from outside the universe, in which case you could see the past anyway. There's a couple of nice papers about this by Yasunori Nomura: arXiv:1205.267v2 is a popular exposition and arXiv:1205.5550v2 is a more technical paper. Brent I wasn't asking whether I could build a chronoscope and watch the past happening on TV. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com.
Re: Entropy and curved spacetime
On 19 Mar 2014, at 16:32, Edgar L. Owen wrote: Bruno, Well I'm using loose language to make it easier to understand. Actually it is the information itself that represents what are then interpreted by humans and science as matter states OK, but then that information flows around, unless you extract it from indexicals, like in the FPI, on the iterated WM-duplication, or in arithmetic. In the step 3, the guy reconstituted in W get one bit of (Shannon) information, like the guy in M, and this without any 3p creation of information. My point being that the information forms that manifest as matter states in human internal mental models of reality don't continually reproduce themselves to produce more of what is interpreted as matter states, so how does Brent think all the additional information of all actual prior matter states are stored, if not in the information of current matter states? That's more precise but not sure if it's clearer... Not sure it is more precise either. Sorry. Bruno Edgar On Wednesday, March 19, 2014 10:24:44 AM UTC-4, Bruno Marchal wrote: On 19 Mar 2014, at 12:54, Edgar L. Owen wrote: Presumably you do agree that information can't just float around somehow without actually being encoded in actual matter states? This contradicts your statement that the physical arises from the computational. But you have not yet define what you mean by computational. Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 19 March 2014 22:41, Bruno Marchal marc...@ulb.ac.be wrote: On 18 Mar 2014, at 22:33, LizR wrote: Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? In God's eye only. Not from inside the universe, especially that from inside, you will find your self belonging to some special term of the universal wave. Theoretically, you might be able to bactrack, from inside, but only through strong 1p quantum amnesia. Yes, I was mainly interested in the god's eye (i.e. the laws of physics' eye) view. Given that we can't forward track in QM, not being able to back track either isn't very surprising! -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 20 March 2014 00:54, Edgar L. Owen edgaro...@att.net wrote: Brent, If information is not being lost then the amount of information in the universe is increasing at a tremendous rate as new events occur, and has been since the beginning. So where is all that new information being stored? How can ever increasing amounts of information be being stored in the SAME amount of matter states? As far as I know, unitary evolution in QM implies that the information contant of the universe remains constant. This is why entropy is emergent, for example, even though it appears on the macroscale to change the amount of order and disorder. Since the laws of physics are time agnostic at the fundamental level (bar the usual caveat involving CPT violation) this is to be expected. You couldn't play physical scenarios backwards even in theory if information was being created, and the evolution of the wave function wouldn't be unitary if it was being lost. Hence it stays constant.. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 19 March 2014 13:57, meekerdb meeke...@verizon.net wrote: There's a couple of nice papers about this by Yasunori Nomura: arXiv:1205.267v2 is a popular exposition and arXiv:1205.5550v2 is a more technical paper. Thanks again! The for dummies one is fascinating, I like the relativisation over history - Galilean relativity is Newtonian relativity with a particular constant (Gravitational?) set to zero, and Newtonian relativity is Einsteinian relativity with c set to infinity, and then we get another form of space-time relativity by turning on something else... I would like to get my head around the whole thing - not mathematically, unfortunately, I think that would be too much - but conceptually. The fact that the choice of reference frames affects what exists (or is visible to QM, at least) is interesting. It seems to unite a whole load of stuff, Bekenstein's Elephant (simultaneously (?) both falling into a black hole and not falling in) and the holographic bound... all of which seem rather mysterious on their own, so a grand unification is rather exciting. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 3/19/2014 8:45 AM, Quentin Anciaux wrote: In the present state and the physical transition rules from one state to another ? if the transition is reversible then from only the current state you can infer the past state, without it being encoded in the present state... the current state + transition rule is enough. Quentin 2014-03-19 16:33 GMT+01:00 Edgar L. Owen edgaro...@att.net mailto:edgaro...@att.net: Telmo, No, that was Brent's claim. I'm asking him to tell us how it works. Where is all that additional information about past states stored if he thinks none of it is lost? Edgar On Wednesday, March 19, 2014 10:32:48 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 1:25 PM, Edgar L. Owen edga...@att.net wrote: Telmo, No, compression is totally unable to explain the storage of total information in a universe which continually doubles its amount of information from one Planck time to the next and continually adds that amount to the cumulative total. So you're essentially claiming that the universe is increasing exponentially in complexity? Edgar On Wednesday, March 19, 2014 8:17:28 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 12:54 PM, Edgar L. Owen edga...@att.net wrote: Brent, If information is not being lost then the amount of information in the universe is increasing at a tremendous rate as new events occur, and has been since the beginning. That's a false premise. The universe apparently started in a state of very low entropy relative to macroscopic variables we measure. If the evolution is unitary, as we think, then there is no change in the information. The tremendous increase you refer to is relative to macroscopic constraints. It is often not appreciated that entropy is relative to assumed knowledge; see Jaynes 1996 paper The Gibbs Paradox for an exposition. Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
To whom are you answering ? It seems it is to Edgar... you should not cite a message when you want to answer to another one... Regards, Quentin 2014-03-19 22:46 GMT+01:00 meekerdb meeke...@verizon.net: On 3/19/2014 8:45 AM, Quentin Anciaux wrote: In the present state and the physical transition rules from one state to another ? if the transition is reversible then from only the current state you can infer the past state, without it being encoded in the present state... the current state + transition rule is enough. Quentin 2014-03-19 16:33 GMT+01:00 Edgar L. Owen edgaro...@att.net: Telmo, No, that was Brent's claim. I'm asking him to tell us how it works. Where is all that additional information about past states stored if he thinks none of it is lost? Edgar On Wednesday, March 19, 2014 10:32:48 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 1:25 PM, Edgar L. Owen edga...@att.net wrote: Telmo, No, compression is totally unable to explain the storage of total information in a universe which continually doubles its amount of information from one Planck time to the next and continually adds that amount to the cumulative total. So you're essentially claiming that the universe is increasing exponentially in complexity? Edgar On Wednesday, March 19, 2014 8:17:28 AM UTC-4, telmo_menezes wrote: On Wed, Mar 19, 2014 at 12:54 PM, Edgar L. Owen edga...@att.netwrote: Brent, If information is not being lost then the amount of information in the universe is increasing at a tremendous rate as new events occur, and has been since the beginning. That's a false premise. The universe apparently started in a state of very low entropy relative to macroscopic variables we measure. If the evolution is unitary, as we think, then there is no change in the information. The tremendous increase you refer to is relative to macroscopic constraints. It is often not appreciated that entropy is relative to assumed knowledge; see Jaynes 1996 paper The Gibbs Paradox for an exposition. Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- All those moments will be lost in time, like tears in rain. (Roy Batty/Rutger Hauer) -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 20 March 2014 12:23, Quentin Anciaux allco...@gmail.com wrote: To whom are you answering ? It seems it is to Edgar... you should not cite a message when you want to answer to another one... He is replying to Edgar, as you can see from the line at the *bottom *of the quoted section. But I agree, I've also suffered from this sort of apparent misattribution, as have others (not specifically from anyone - I'm sure we all get careless). So as a point of etiquette, I'd say to everyone - please try to make sure you cut the quoted post off at the right point, so the person you're replying to is the one you actually see being quoted. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On Tuesday, March 18, 2014 3:14:48 PM UTC, John Clark wrote: Jesse, somehow our conversation has bifurcated into 2 quite different topics, environmental concerns and fundamental physics, today I'll just talk about the physics. On Sun, Mar 16, 2014 at 8:05 PM, Jesse Mazer laser...@gmail.comjavascript: wrote: I already addressed your confusion about the implications of black hole entropy in detail in my post at https://groups.google.com/d/msg/everything-list/hJ9bNWqoAzI/QTrL0CopHJ8Jwhich you never replied to. And I never responded to it because it was incoherent, I give the following exchange as a example: John: If there are 2 different states of the universe that could have produced things as they are now then there is no way to decide between them and history is unknowable (just as it is in the Game of Life) and the laws of physics are not reversible. Jesse: You think in classical statistical mechanics there can't be 2 different ways to get to a given *macrostate*??? If so you are badly confused. And I'm the one who is supposed to be confused??? There is not one drop of Quantum Mechanics or probability in the Game of Life, it is 100% classical mechanics, and yet there CAN be 2 or more ways to get to a given macrostate. It's 100% deterministic so if I show you a Game of Life pattern you can calculate what it's future evolution will be (there doesn't seem to be anything analogous to chaos in the Game) but you can't figure out it's history was, or at least not a unique history. Today the deepest understanding of entropy comes from the study of Black Holes. From: http://www.phy.olemiss.edu/~luca/Topics/bh/entropy_origin.html S [entropy ] is the log of the number of quantum mechanically distinct ways that the black hole could have been made, or information lost in the creation of the black hole Are you suggesting that this new deep understanding invalidates the older understanding of entropy as the number of microstates for a given macrostate, the one you yourself quoted in your last post? I am saying that Kip Thorn, one of the world's best physicists, wrote on page 446 of his book A Black Hole's entropy is the logarithm of the number of ways that the hole could have been made. And I'm saying that in classical physics a state can produce only one future state, but any given state can have been produced in more than one way, therefore the number of microstates in a Black Hole must equal to k times the number of states that made it where k is some constant integer. Therefore if Entropy is proportional to the logarithm of the number of microstates in a system then according to the laws of logarithms Entropy MUST also be proportional to the logarithm of the number of ways the system could have been produced. Assuming the unitary nature of quantum mechanics is preserved so that information is not lost when things fall in [into a Black Hole] That is quite a assumption, today it's one of the greatest controversies in physics and nobody knows if that assumption is valid; see Leonard Susskind's book The Black Hole Wars. the number of quantum microstates that any macrostate can have NOW must be the same as the number of initial quantum microstates in the PAST which would have led to the current macrostate, so the number of distinct ways it [the current macrostate] could have been made would be exactly the same as the number of distinct quantum microstates it could be in now So why in hell do you say Entropy is proportional to the logarithm of the number of microstates something can be in and still have the same macrostate, but it is not proportional to the logarithm of the number of ways the thing could have been produced? in practice, I think almost any real-world experiment you could do in an elevator in free fall in deep space wouldn't show any divergence from the predictions of special relativity that would be measurable by modern equipment. Not true. As far back as 1963 it was noticed that clocks tick slower on the first floor of the physics building at MIT than they do on the second floor, Special Relativity had no explanation for this but General Relativity did, clocks on the first floor were closer to the center of the Earth than those on the second floor and thus were in a stronger gravitational field and thus ticked slower. And today the standard GPS receiver in your car must synchronize it's internal clock with the clocks in 3 or more navigation satellites, to do this it must take into account some pretty exotic things; for example, the satellite is moving very fast so due to Special Relativity the satellite's clock will LOSE 7210 nanoseconds a day, but the satellite's clock is in a weaker gravitational field than the clock in your car because it is further from the Earth's center, so due to GENERAL RELATIVITY the clock
Entropy and curved spacetime
Jesse, somehow our conversation has bifurcated into 2 quite different topics, environmental concerns and fundamental physics, today I'll just talk about the physics. On Sun, Mar 16, 2014 at 8:05 PM, Jesse Mazer laserma...@gmail.com wrote: I already addressed your confusion about the implications of black hole entropy in detail in my post at https://groups.google.com/d/msg/everything-list/hJ9bNWqoAzI/QTrL0CopHJ8Jwhich you never replied to. And I never responded to it because it was incoherent, I give the following exchange as a example: John: If there are 2 different states of the universe that could have produced things as they are now then there is no way to decide between them and history is unknowable (just as it is in the Game of Life) and the laws of physics are not reversible. Jesse: You think in classical statistical mechanics there can't be 2 different ways to get to a given *macrostate*??? If so you are badly confused. And I'm the one who is supposed to be confused??? There is not one drop of Quantum Mechanics or probability in the Game of Life, it is 100% classical mechanics, and yet there CAN be 2 or more ways to get to a given macrostate. It's 100% deterministic so if I show you a Game of Life pattern you can calculate what it's future evolution will be (there doesn't seem to be anything analogous to chaos in the Game) but you can't figure out it's history was, or at least not a unique history. Today the deepest understanding of entropy comes from the study of Black Holes. From: http://www.phy.olemiss.edu/~luca/Topics/bh/entropy_origin.html S [entropy ] is the log of the number of quantum mechanically distinct ways that the black hole could have been made, or information lost in the creation of the black hole Are you suggesting that this new deep understanding invalidates the older understanding of entropy as the number of microstates for a given macrostate, the one you yourself quoted in your last post? I am saying that Kip Thorn, one of the world's best physicists, wrote on page 446 of his book A Black Hole's entropy is the logarithm of the number of ways that the hole could have been made. And I'm saying that in classical physics a state can produce only one future state, but any given state can have been produced in more than one way, therefore the number of microstates in a Black Hole must equal to k times the number of states that made it where k is some constant integer. Therefore if Entropy is proportional to the logarithm of the number of microstates in a system then according to the laws of logarithms Entropy MUST also be proportional to the logarithm of the number of ways the system could have been produced. Assuming the unitary nature of quantum mechanics is preserved so that information is not lost when things fall in [into a Black Hole] That is quite a assumption, today it's one of the greatest controversies in physics and nobody knows if that assumption is valid; see Leonard Susskind's book The Black Hole Wars. the number of quantum microstates that any macrostate can have NOW must be the same as the number of initial quantum microstates in the PAST which would have led to the current macrostate, so the number of distinct ways it [the current macrostate] could have been made would be exactly the same as the number of distinct quantum microstates it could be in now So why in hell do you say Entropy is proportional to the logarithm of the number of microstates something can be in and still have the same macrostate, but it is not proportional to the logarithm of the number of ways the thing could have been produced? in practice, I think almost any real-world experiment you could do in an elevator in free fall in deep space wouldn't show any divergence from the predictions of special relativity that would be measurable by modern equipment. Not true. As far back as 1963 it was noticed that clocks tick slower on the first floor of the physics building at MIT than they do on the second floor, Special Relativity had no explanation for this but General Relativity did, clocks on the first floor were closer to the center of the Earth than those on the second floor and thus were in a stronger gravitational field and thus ticked slower. And today the standard GPS receiver in your car must synchronize it's internal clock with the clocks in 3 or more navigation satellites, to do this it must take into account some pretty exotic things; for example, the satellite is moving very fast so due to Special Relativity the satellite's clock will LOSE 7210 nanoseconds a day, but the satellite's clock is in a weaker gravitational field than the clock in your car because it is further from the Earth's center, so due to GENERAL RELATIVITY the clock will GAIN 45850 nanoseconds a day. Taking these 2 factors into account the satellite's clocks gains 45850 -7210 = 38,640 nanoseconds a day relative to the clock in your car. If your car GPS receiver
Re: Entropy and curved spacetime
On 3/18/2014 8:14 AM, John Clark wrote: Jesse, somehow our conversation has bifurcated into 2 quite different topics, environmental concerns and fundamental physics, today I'll just talk about the physics. On Sun, Mar 16, 2014 at 8:05 PM, Jesse Mazer laserma...@gmail.com mailto:laserma...@gmail.com wrote: I already addressed your confusion about the implications of black hole entropy in detail in my post at https://groups.google.com/d/msg/everything-list/hJ9bNWqoAzI/QTrL0CopHJ8J which you never replied to. And I never responded to it because it was incoherent, I give the following exchange as a example: John: If there are 2 different states of the universe that could have produced things as they are now then there is no way to decide between them and history is unknowable (just as it is in the Game of Life) and the laws of physics are not reversible. Jesse: You think in classical statistical mechanics there can't be 2 different ways to get to a given *macrostate*??? If so you are badly confused. And I'm the one who is supposed to be confused??? There is not one drop of Quantum Mechanics or probability in the Game of Life, it is 100% classical mechanics, and yet there CAN be 2 or more ways to get to a given macrostate. It's 100% deterministic so if I show you a Game of Life pattern you can calculate what it's future evolution will be (there doesn't seem to be anything analogous to chaos in the Game) but you can't figure out it's history was, or at least not a unique history. Today the deepest understanding of entropy comes from the study of Black Holes. From: http://www.phy.olemiss.edu/~luca/Topics/bh/entropy_origin.html http://www.phy.olemiss.edu/%7Eluca/Topics/bh/entropy_origin.html S [entropy ] is the log of the number of quantum mechanically distinct ways that the black hole could have been made, or information lost in the creation of the black hole Are you suggesting that this new deep understanding invalidates the older understanding of entropy as the number of microstates for a given macrostate, the one you yourself quoted in your last post? I am saying that Kip Thorn, one of the world's best physicists, wrote on page 446 of his book A Black Hole's entropy is the logarithm of the number of ways that the hole could have been made. And I'm saying that in classical physics a state can produce only one future state, but any given state can have been produced in more than one way, therefore the number of microstates in a Black Hole must equal to k times the number of states that made it where k is some constant integer. Therefore if Entropy is proportional to the logarithm of the number of microstates in a system then according to the laws of logarithms Entropy MUST also be proportional to the logarithm of the number of ways the system could have been produced. But Kip is speaking loosely. If you look at the original paper with Zurek http://journals.aps.org.proxy.library.ucsb.edu:2048/prl/pdf/10.1103/PhysRevLett.54.2171 you see that they are counting up the number of states by imagining adding quanta of energy as small as possible at each step to building up a black hole. But this is just a way to aid the counting, the result has no dependence on the imagined order. It's just a way to calculate the number of internal states consistent with the macro-states of the no-hair theorem. Assuming the unitary nature of quantum mechanics is preserved so that information is not lost when things fall in [into a Black Hole] That is quite a assumption, today it's one of the greatest controversies in physics and nobody knows if that assumption is valid; see Leonard Susskind's book The Black Hole Wars. the number of quantum microstates that any macrostate can have NOW must be the same as the number of initial quantum microstates in the PAST which would have led to the current macrostate, so the number of distinct ways it [the current macrostate] could have been made would be exactly the same as the number of distinct quantum microstates it could be in now So why in hell do you say Entropy is proportional to the logarithm of the number of microstates something can be in and still have the same macrostate, but it is not proportional to the logarithm of the number of ways the thing could have been produced? in practice, I think almost any real-world experiment you could do in an elevator in free fall in deep space wouldn't show any divergence from the predictions of special relativity that would be measurable by modern equipment. Not true. As far back as 1963 it was noticed that clocks tick slower on the first floor of the physics building at MIT than they do on the second floor, Special Relativity had no explanation for this but General Relativity did, clocks on the first floor were closer to the
Re: Entropy and curved spacetime
Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
Yes, if you have the exact present quantum state and you're assuming the normal quantum rules for continuous wavefunction evolution, you can determine the past quantum state. The answer might change if you assume that there's an objective physical reality to the collapse of wavefunction with measurement, distinct from the normal wavefunction evolution rules. Jesse On Tue, Mar 18, 2014 at 5:33 PM, LizR lizj...@gmail.com wrote: Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
OK, thanks. PS I realise that wavefunction collapse involves information loss and creates a fundamental time asymmetry, but I was under the impression that's the only place in QM that those things can occur - hence Stephen Hawking famously losing a bet (I thnk the prize was an encyclopaedia). So it's nice to have that view confirmed by someone who knows a lot more about the subject than I ever will. On 19 March 2014 10:52, Jesse Mazer laserma...@gmail.com wrote: Yes, if you have the exact present quantum state and you're assuming the normal quantum rules for continuous wavefunction evolution, you can determine the past quantum state. The answer might change if you assume that there's an objective physical reality to the collapse of wavefunction with measurement, distinct from the normal wavefunction evolution rules. Jesse On Tue, Mar 18, 2014 at 5:33 PM, LizR lizj...@gmail.com wrote: Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. Brent On 3/18/2014 2:52 PM, Jesse Mazer wrote: Yes, if you have the exact present quantum state and you're assuming the normal quantum rules for continuous wavefunction evolution, you can determine the past quantum state. The answer might change if you assume that there's an objective physical reality to the collapse of wavefunction with measurement, distinct from the normal wavefunction evolution rules. Jesse On Tue, Mar 18, 2014 at 5:33 PM, LizR lizj...@gmail.com mailto:lizj...@gmail.com wrote: Am I right in assuming that in a quantum mechanical universe you can trace the history backwards? -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com mailto:everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com mailto:everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com mailto:everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com mailto:everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 19 March 2014 12:47, meekerdb meeke...@verizon.net wrote: But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. I was only asking about the theoretical possibility, given unrealistically perfect information about the state of the system. To put it another way, in the Game of Life, even with perfect information, you can't trace the state of the system backwards because it loses information. So even the laws of physics couldn't work backwards in a universe based on the GOL. QM, I'm informed, doesn't lose information, so (very much in theory) you could work backwards - or (less in theory) the laws of physics could. I wasn't asking whether I could build a chronoscope and watch the past happening on TV. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 3/18/2014 5:07 PM, LizR wrote: On 19 March 2014 12:47, meekerdb meeke...@verizon.net mailto:meeke...@verizon.net wrote: But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. I was only asking about the theoretical possibility, given unrealistically perfect information about the state of the system. The universe (assuming unitary QM) is reversible. In fact from the standpoint of QM there is no arrow of time - it's deterministic, just like Laplace's universe. So, as always, when the word possibility is used there has to be some context. To *calculate* a history of the universe from it's present state would require knowing its *complete* present state, including your mental state. Is that theoretically possible? I think it involves a paradox of self-reference. To put it another way, in the Game of Life, even with perfect information, you can't trace the state of the system backwards because it loses information. So even the laws of physics couldn't work backwards in a universe based on the GOL. QM, I'm informed, doesn't lose information, so (very much in theory) you could work backwards - or (less in theory) the laws of physics could. Yes the universe doesn't lose information like the GoL. But relative to any point it loses information across spacetime horizons. So there's no way to gather that information up into a calculation unless you have some God's eye view from outside the universe, in which case you could see the past anyway. There's a couple of nice papers about this by Yasunori Nomura: arXiv:1205.267v2 is a popular exposition and arXiv:1205.5550v2 is a more technical paper. Brent I wasn't asking whether I could build a chronoscope and watch the past happening on TV. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com mailto:everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com mailto:everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
Thanks. I couldn't find the exact references. Is this the popular one? http://arxiv.org/abs/1205.2675 On 19 March 2014 13:57, meekerdb meeke...@verizon.net wrote: On 3/18/2014 5:07 PM, LizR wrote: On 19 March 2014 12:47, meekerdb meeke...@verizon.net wrote: But in general that would mean knowing the state of everything the system had interacted with in the past, since it is now entangled with them. So even if you suppose there is no collapse of the wavefunction, decoherence has the same effect. I was only asking about the theoretical possibility, given unrealistically perfect information about the state of the system. The universe (assuming unitary QM) is reversible. In fact from the standpoint of QM there is no arrow of time - it's deterministic, just like Laplace's universe. So, as always, when the word possibility is used there has to be some context. To *calculate* a history of the universe from it's present state would require knowing its *complete* present state, including your mental state. Is that theoretically possible? I think it involves a paradox of self-reference. To put it another way, in the Game of Life, even with perfect information, you can't trace the state of the system backwards because it loses information. So even the laws of physics couldn't work backwards in a universe based on the GOL. QM, I'm informed, doesn't lose information, so (very much in theory) you could work backwards - or (less in theory) the laws of physics could. Yes the universe doesn't lose information like the GoL. But relative to any point it loses information across spacetime horizons. So there's no way to gather that information up into a calculation unless you have some God's eye view from outside the universe, in which case you could see the past anyway. There's a couple of nice papers about this by Yasunori Nomura: arXiv:1205.267v2 is a popular exposition and arXiv:1205.5550v2 is a more technical paper. Brent I wasn't asking whether I could build a chronoscope and watch the past happening on TV. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 3/18/2014 6:13 PM, LizR wrote: Thanks. I couldn't find the exact references. Is this the popular one? http://arxiv.org/abs/1205.2675 Yep, that's it. Sorry, I left a digit off. Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entropy and curved spacetime
On 19 March 2014 14:16, meekerdb meeke...@verizon.net wrote: On 3/18/2014 6:13 PM, LizR wrote: Thanks. I couldn't find the exact references. Is this the popular one? http://arxiv.org/abs/1205.2675 Yep, that's it. Sorry, I left a digit off. Odd. According to QM that should be impossible... (Sorry :-) -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
