According to Descartes, the physical is that which has extension in space. That's a common definition of existence.

Roger Clough, rclo...@verizon.net 10/24/2012 "Forever is a long time, especially near the end." -Woody Allen ----- Receiving the following content ----- From: Stephen P. King Receiver: everything-list Time: 2012-10-23, 18:35:10 Subject: Re: Interactions between mind and brain On 10/23/2012 1:29 PM, meekerdb wrote: > On 10/23/2012 3:40 AM, Stephen P. King wrote: >> On 10/23/2012 2:03 AM, meekerdb wrote: >>> On 10/22/2012 11:35 AM, Stephen P. King wrote: >>>> On 10/22/2012 6:05 AM, Quentin Anciaux wrote: >>>>> I don't understand why you're focusing on NP-hard problems... >>>>> NP-hard problems are >>>>> solvable algorithmically... but not efficiently. When I read you >>>>> (I'm surely >>>>> misinterpreting), it seems like you're saying you can't solve >>>>> NP-hard problems... it's >>>>> not the case,... but as your input grows, the time to solve the >>>>> problem may be bigger >>>>> than the time ellapsed since the bigbang. You could say that the >>>>> NP-hard problems for >>>>> most input are not technically/practically sovable but they are in >>>>> theories (you have >>>>> the algorithm) unlike undecidable problems like the halting problem. >>>>> >>>>> Quentin >>>> Hi Quentin, >>>> >>>> Yes, they are solved algorithmically. I am trying to get some >>>> focus on the >>>> requirement of resources for computations to be said to be >>>> solvable. This is my >>>> criticism of the Platonic treatment of computer theory, it >>>> completely ignores these >>>> considerations. The Big Bang theory (considered in classical terms) >>>> has a related >>>> problem in its stipulation of initial conditions, just as the >>>> Pre-Established Harmony of >>>> Leibniz' Monadology. Both require the prior existence of a solution >>>> to a NP-Hard >>>> problem. We cannot consider the solution to be "accessible" prior >>>> to its actual >>>> computation! >>> >>> Why not? NP-hard problems have solutions ex hypothesi; it's part of >>> their defintion. >> >> "Having a solution" in the abstract sense, is different from >> actual access to the solution. You cannot do any work with the >> abstract fact that a NP-Hard problem has a solution, you must >> actually compute a solution! The truth that there exists a minimum >> path for a traveling salesman to follow given N cities does not guide >> her anywhere. This should not be so unobvious! > > But you wrote, "Both require the prior existence of a solution to a > NP-Hard problem." An existence that is guaranteed by the definition. Hi Brent, OH! Well, I thank you for helping me clean up my language! Let me try again. ;--) First I need to address the word "existence". I have tried to argue that "to exists" is to be "necessarily possible" but that attempt has fallen on deaf ears, well, it has until now for you are using it exactly how I am arguing that it should be used, as in "An existence that is guaranteed by the definition." DO you see that existence does nothing for the issue of properties? The existence of a pink unicorn and the existence of the 1234345465475766th prime number are the same kind of existence, once we drop the pretense that existence is dependent or contingent on physicality. Is it possible to define Physicality can be considered solely in terms of bundles of particular properties, kinda like Bruno's bundles of computations that define any given 1p. My thinking is that what is physical is exactly what some quantity of separable 1p have as mutually consistent (or representable as a Boolean Algebra) but this consideration seems to run independent of anything physical. What could reasonably constrain the computations so that there is some thing "real" to a physical universe? There has to be something that cannot be changed merely by changing one's point of view. > When you refer to the universe computing itself as an NP-hard problem, > you are assuming that "computing the universe" is member of a class of > problems. Yes. It can be shown that computing a universe that contains something consistent with Einstein's GR is NP-Hard, as the problem of deciding whether or not there exists a smooth diffeomorphism between a pair of 3,1 manifolds has been proven (by Markov) to be so. This tells me that if we are going to consider the evolution of the universe to be something that can be a simulation running on some powerful computer (or an abstract computation in Platonia) then that simulation has to at least the equivalent to solving an NP-Hard problem. The prior existence, per se, of a solution is no different than the non-constructable proof that Diffeo_3,1 /subset NP-Hard that Markov found. > It actually doesn't make any sense to refer to a single problem as > NP-hard, since the "hard" refers to how the difficulty scales with > different problems of increasing size. These terms, "Scale" and "Size", do they refer to some thing abstract or something physical or, perhaps, both in some sense? > I'm not clear on what this class is. It is an equivalence class of computationally soluble problems. http://cs.joensuu.fi/pages/whamalai/daa/npsession.pdf There are many of them. > Are you thinking of something like computing Feynman path integrals > for the universe? Not exactly, but that is one example of a computational problem. > >> >>> What would a "prior" computation mean? >> >> Where did you get that cluster of words? > From you, below, in the next to last paragraph (just because I quit > writing doesn't mean I quit reading at the same point). Ah, I wrote "...if the prior computation idea is true. " I was trying to contrast two different ideas: one where all of the computations are somehow performed "ahead of time" (literally!) and the other is where the computations occur as they need to subject to restrictions such as only those computations that have resources available can occur. > >> >>> Are you supposing that there is a computation and *then* there is an >>> implementation (in matter) that somehow realizes the computation >>> that was formerly abstract. That would seem muddled. >> >> Right! It would be, at least, muddled. That is my point! > > But no one but you has ever suggested the universe is computed and > then implemented to a two-step process. So it seems to be a muddle of > your invention. No, I am trying to explain something that is taken for granted; it is more obvious for the Pre-established harmony of Leibniz, but I am arguing that this is also the case in Big Bang theory: the initial condition problem (also known as the foliation problem) is a problem of computing the universe ahead of time. > > Brent > >> >>> If the universe is to be explained as a computation then it must >>> be realized by the computation - not by some later (in what time >>> measure?) events. >> >> Exactly. The computation cannot occur before the universe! >> >>> >>> Brent >>> >>>> The calculation of the minimum action configuration of the >>>> universe such that there >>>> is a universe that we observe now is in the state that it is and >>>> such is consistent with >>>> our existence in it must be explained either as being the result of >>>> some fortuitous >>>> accident or, as some claim, some "intelligent design" or some >>>> process working in some >>>> super-universe where our universe was somehow selected, if the >>>> prior computation idea is >>>> true. >>>> I am trying to find an alternative that does not require >>>> computations to occur prior >>>> to the universe's existence! Several people, such as Lee Smolin, >>>> Stuart Kaufmann and >>>> David Deutsch have advanced the idea that the universe is, >>>> literally, computing its next >>>> state in an ongoing fashion, so my conjecture is not new. The >>>> universe is computing >>>> solutions to NP-Hard problems, but not in any Platonic sense. >>>> >>> >> >> > -- Onward! Stephen -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.