On Wed, Feb 16, 2011 at 11:41 AM, 1Z <peterdjo...@yahoo.com> wrote: > > > On Feb 16, 3:40 pm, Jason Resch <jasonre...@gmail.com> wrote: > > On Wed, Feb 16, 2011 at 9:04 AM, 1Z <peterdjo...@yahoo.com> wrote: > > > > > On Feb 16, 8:27 am, Jason Resch <jasonre...@gmail.com> wrote: > > > > On Tue, Feb 15, 2011 at 4:19 PM, 1Z <peterdjo...@yahoo.com> wrote: > > > > > > > On Feb 15, 10:12 pm, Brent Meeker <meeke...@dslextreme.com> wrote: > > > > > > On 2/15/2011 1:48 PM, 1Z wrote: > > > > > > > > I agree. Although it's interesting that some people with > synasthesia > > > > > > apparently perceive numbers as having various perceptual > properties. > > > > > > > Some people "perceive" pink elephants too. However, other people > don't > > > > > "perceive" them , leading cynics to suppose that they are not > > > > > really being perceived at all. > > > > > > The guy who reported seeing the digits of pi like a vast landscape > also > > > > receited over 20,000 digits from memory. That should lend a little > more > > > > credence to his claims. > > > > > Which are what? I don't think *he* is claiming numbers objectively > > > exist. And isn't the fact that all synaesthetes visualise them > > > differently > > > somehat contrary to *that* claim. > > > > > > Sure. Horses are real and unicorns aren't. Didn't you know that? > > > > > > Unless you've visited every time period in every corner of reality > how > > > can > > > > you assert unicrons don't exist? > > > > > The same way I assert everything: the evidence I have is good enough. > > > > > >The fossile record might suggest they have > > > > never lived on this planet but that hardly rules out their existence > > > > everywhere. > > > > > > "Does XYZ exist?" > > > > "Let me look around... I can't see it right now, it must not exist!" > > > > > > Instead we should take a more humble approach: > > > > > > "I've looked around and cannot see it here, it probably doesn't exist > > > here, > > > > however I have no idea whether or not it exists in places I cannot > see or > > > > have not looked." > > > > > > I think Bayesian inference: > > >http://en.wikipedia.org/wiki/Bayesian_inference#Evidence_and_changing. > .. > > > > Is particularly useful in answering questions relating to existence. > The > > > > question is, what prior probability would you set to a proposition > such > > > as > > > > "Other universes not visible to us exist". 1Z and Brent would seem > to > > > > assign a rather low probability, but that just means a higher > threshold > > > of > > > > evidence will be required to convince them. Lacking any evidence at > all, > > > > the least biased prior probability to begin with is 0.5. If some > > > evidence, > > > > for fine tuning for example, accumulates then you should adjust your > > > assumed > > > > probability that the proposition "Other universes not visible to us > > > exist" > > > > is true. > > > > > > Are you aware of a better or more fair way of addressing such a > question? > > > > > I am a fallibilist. You are preaching to the converted. > > > > Okay it seems we have a common foundation we agree on. Can you explain > why > > you have confidence in the unreality of other possible universes rather > than > > uncertainty? What evidence have you seen for or against that > proposition? > > > Peter,

Thank you for your very detailed and thoughtful response. > The mathematical multiverse suffers from a double wammy: it is > predicts > too much (white rabbits) and explains too little (time and > consciousness are > not explained). Physical multiverses are a bit more of a nuanced > issue. Many worlds > is not my favourite interpretation of QM, but at the end of the day > there could be > empirical evidence one way or the other. > If universes are mathematical objects, they follows well-defined equations. A few, more rare, universe may have an additional law, at time X, in location Y, a white rabbit will pop into existence, but the description for such a universe is much longer. In self-similar mathematical structures, such as the programs generated by the UDA, the simpler structures recur much more frequently, and so the measure for a particular instantiation of an observer would have a higher measure in universes with shorter descriptions/definitions. Further, life cannot evolve in a universe with unpredictable laws or with laws which constantly change. If evolution is the most common path to observers, then again the measure will be higher for observers located in orderly predictable universes. Where randomness and unpredictability come from results from observers lacking sufficient knowledge to locate in which universe they exist, or in which universe their next consciousness moment may be. Consider this simple experiment: You will be anesthetized on Friday and awoken on Monday morning. Once you awake you will be asked what day it is. Your answer is clear in this case: It will be Monday. But then consider this twist: After giving your answer you will be given a memory formation blocking drug, and anesthetized again until Tuesday morning. Where upon you will be asked what day it is. When you are informed of this second part of the experiment on Friday, can you still be sure when you are woken, that it is in fact Monday? This experiment duplicates your conscious state in two different times, and when you are awoken you cannot tell if it is for the first time or the second. >From the bird's eye view there is no indeterminism. > > Mathematical monism is both too broad and too narrow. > > Too broad: If I am just a mathematical structure, I should have a much > wider range of experience than I do. There is a mathemtical structure > corresponding to myself with all my experiences up to time T. There is > a vast array of mathematical structures corresponding to other > versions of me with having a huge range of experiences -- ordinary > ones, like continuing to type, extraordinary ones like seeing my > computer sudenly turn into bowl of petunias. Imagine you were to watch 1000 movies in a row, and your memory would be erased between each viewing. In 999 of the cases, the movie is exactly the same, but in one of the viewings an alternate surprise ending is shown instead. During any particular viewing, you should expect a low probability of seeing the surprise ending, because most of your experiences are of the ordinary normal ending of the movie. Now substitute movie for Peter's various lives throughout the multiverse, and assuming simpler universes occur more often you should expect white rabbit experiences to be rare. > All these versions of me > share the memories of the "me" who is writing this, so they all > identify themselves as me. Remember, that for mathematical monism it > is only necessary that a possible experience has a mathematical > description. This is known as the White Rabbit problem. If we think in > terms of multiverse theories, we would say that there is one "me" in > this universe and other "me's" in other universes,a nd they are kept > out of contact with each other. The question is whether a purely > mathematical scheme has enough resources to impose isolation or > otherwise remove the White Rabbit problem. > In any case, while the WR problem is deserving of a solution, I don't think it has disproved mathematical realism. It is like the Borne rule and QM. It is just something in need of a resolution. > > Too narrow: there are a number of prima-facie phenomena which a purely > mathematical approach struggles to deal with. > > * space > * time > * consciousness > * causality > * necessity/contingency > > Why space ? It is tempting to think that if a number of, or some other > mathematical entity, occurs in a set with other numbers, that is, as > it were, a "space" which is disconnected from other sets, so that a > set forms a natural model of an *isolated* universe withing a > multiverse, a universe which does not suffer from the White Rabbit > problem. However, maths per se does not work that way. The number "2" > that appears in the set of even numbers is exactly the same number "2" > that appears in the list of numbers less than 10. It does not acquire > any further characteristics from its context. > > It is difficult to envision life existing without there being dimensions. Separate locations are needed for different organisms and their information to exist without being on top of each other, yet allowing degrees of freedom for life forms to interact and share information. > The time issue should be obvious. Mathematics is tradionally held to > deal with timeless, eternal truths. This is reflected in the metpahor > of mathematical truth being discovered not found (which, in line with > my criticism of Platonism, should not be taken to seriously). It could > be objected that physics can model time mathematically; it can be > objected right back that it does so by spatialising time, by turning > it into just another dimension, in which nothing really changes, and > nothing passes. Some even go so far as to insist that this model is > what time "really" is, which is surely a case of mistaking the map for > the territory. > Relativity rather conclusively shows that there is no objective progression of time, the content of the present moment is different for every reference frame. Therefore the present time is only a mutual opinion of contemporaries and the flow of time is a subjective illusion. That our universe is conceivable as a static four dimensional block is supportive of the theory that it is a mathematical object. > > There are a number of reasons why it is unlikely that there are purely > mathematical reasonse why one mathematical structre exists, and > another does not. For one, it is well-known that existence is not a > first-order property. It is therefore possible that a Plenitude or > Platonia of all combinations of first-order properties would not > explain and second order properties. There is also the mismatch > between the tradtional contingency of existence, and the equally > traditional necessity of mathematics. > I don't understand what you mean about existence being first order or not. Can you provide a reference? > > Consciousness is a problem for all forms of materialism and > physicalism to some extent, but it is possible to discern where the > problem is particularly acute. There is no great problem with the idea > that matter considered as a bare substrate can be the bearer of mental > properities. Any inability to bear mental properties would itself be a > property and therefore be inconsistent with the bareness of a bare > substrate. The "subjectivity" of conscious states, often treated as > "inherent" boils down to a problem of communicating one's qualia -- > how one feels, how things seem. Thus it is not truly inherent but > depends on the means of communication being used. Feelings and > seemings can be more readily communicated in artistic, poetic > language, and least readily in scientific, technical language. Since > the harder, more technical a science is, the more mathematical it is, > the communication problem is at its most acute in a purely > mathematical langauge. Thus the problem with physicalism is not its > posit of matter (as a bare substrate) but its other posit, that all > properties are physical. Since physics is mathematical, that amounts > to the claim that all properties are mathematical (or at least > mathematically describable). In making the transition from a > physicalist world-view to a mathematical one, the concept of a > material substrate is abandoned (although it was never a problem for > consciousness) and mathematical properties become the only possible > basis for qualia. Qualia have to be reducible to, or identifiable > with, mathematical properties, if they exist at all. This means that > the problem for consciousness becomes extreme, since there is no > longer the possibility of qualia existing in their own right, as > properties of a material substrate, without supervening on > mathematically describable properties. > Consciousness is made of information, information is encodable as relations between objects. What these objects may be is of no importance, be they sticks, ping pong balls, electrons in silicon, nerve impulses in a brain, or perhaps even relations between numbers, so long as the informational content is the same. I think Chalmers said something like consciousness is information as seen from the inside, and physics is information seen from the outside. Tegmark would add that physics is mathematics seen from the inside. > > The interesting thing is that these two problems can be used to solve > each other to some extent. if we allow extra-mathemtical properties > into our universe, we can use them to solve the White Rabbit problem. > There are two ways of doing this: We can claim either:- > > * White Rabbit universes don't exist at all > * White Rabbit universes are causally separated from us (or remote > in space) > > The first is basically a reversion to a single-universe theory (1). > Mathematical monists sometimes complain that they can't see what role > matter plays. One way of seeing its role is as a solution to the WR > problem. For the non-Platonist, most mathematical entitites have a > "merely abstract" existence. Only a subset truly, conceretely, exist. > Children younger than 1 often do not understand that an object continues to exist even when it cannot be seen. See ( http://en.wikipedia.org/wiki/Object_permanence ). There appears to be a natural bias innate in humans which disbelieves in the concrete existence of things not seen. Most people probably conceive of the past and future as immaterial, or not fully real, and this is understandable because people don't see the past moments again after experiencing them, and don't have access to knowledge of future events, but Relativity suggests the past and future are just as real as the present. Intuition is a poor guide to what exists and what does not. > There is an extra factor that the priveleged few have. What is it ? > Materiality. For the physicalist, matter is the token of existence. > Maerial things, exist, immaterial ones don't. > An artificial intelligence in a virtual environment would have its own conception of what material things are. To it, the idea of a universe like ours would have no accessible material existence. Does that fact undermine the concreteness of the world we experience? Is the AI's material world any less real than ours? You may say that it is not, because it is contained by our universe, but what if our universe is a world like that in the Matrix? The higher-level physics of the universe containing the computer running our universe simulation could be completely alien. > > The second moves on from a Mathematical Multiverse to a physical one > (3). The interesting thing about the second variety of non-just- > mathematical monism is that as well as addressing the White Rabbit > problem, it removes some further contingency. If the matter, physical > laws, and so on, are logically possible, then the general approach of > arguing for a universe/multiverse on the grounds of removing > contingency must embrace them -- otherwise it would be a contingent > fact that the universe/multiverse consists of nothing but > mathematics. > > > If more evidence accumulated for Fine-Tuning, would that be sufficient > for > > you to believe it is probably true that universes ruled by other laws > exist > > also? > > Fine tuning seems to be a dubious idea > We agreed that all ideas are dubious (doubtable), to various extents. Nevertheless, my question is still valid. More evidence may accumulate for it in the future. This should adjust the Bayesian estimate for the probability that other universes with different laws exist. > > Do you think the prior probability that "other physical universes exist" > > should be greater than the prior probability that "mathematical objects > > exist"? If so, why and to what degree? > > That's apples and oranges. There are good armchair arguments against > Platonism, but physical multiverses are much more an empirical issue > > > Finally, do you see any difference between "all possible > (self-consistent) > > universes exist" vs. "all logically possible objects in math exist"? > > There's no contradiction in the existence of an object > that is inhernetly unmathematical. That would be a level V > multiverse--all > kinds of everything. Jason -- 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.