Re: Bitstrings, Ontological Status and Time
Hal wrote: I agree that in our particular universe the role of time is complex IF there is anything that is not complex... Time is definitely not a Ding an sich, definitely not a 'thing' and as agreed: we really don't know how to identify that word. The phenomena we assign as 'time related' are poorly identified. ...It's entirely possible that time may yet turn out to be a simple coordinate. ... I tried once to consider it a 'motion'-coordinate (in strictly 'physical' motion - paired with space) - later tried to alter it to a 'change-coordinate' but neither motion nor change turned out to be exactly identifiable concepts (ie how far we can refine our model views). As we learn more, we know less and less. Respectfully John Mikes - Original Message - From: Hal Finney [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Saturday, May 07, 2005 4:55 PM Subject: Re: Bitstrings, Ontological Status and Time Stephen Paul King writes: I would agree that Time is just a coordinate (system), or as Leibniz claimed an order of succession, if we are considering only events in space-time that we can specify, e.g. take as a posteriori. What I am trying to argue is that we can not do this in the a priori case for reasons that have to do with Heisenberg's Unceratanty Principle. Since it is impossible to construct a space-time hypersurface where each point has associated with it all of the physical variables that we need to compute the entire global manifold, from initial Big Bang singulary to the, possibly, infinite future, it is a mistake to think of time simply as a coordinate. OTOH, it is consistent if we are dealing with some particular situation and using Special (or General) Relativity theory to consider the behavious of clocks and rulers. ;-) I agree that in our particular universe the role of time is complex. Since we don't have a unified theory yet, we really can't say anything definitive about what time will turn out to be. It's entirely possible that time may yet turn out to be a simple coordinate. Wolfram is pushing ideas where the universe is modeled as a cellular automaton (CA) which has discrete units of space and time. Of course his theories don't quite work yet, but then, nobody else's do, either. I am trying to include the implications of QM in my thinking and hence my point about time and my polemics against the idea of block space-time. I do not care how eminent the person is that advocates the idea of Block space-time, they are simply and provably wrong. In this universe, perhaps so, although as I argued above absent a true and accurate theory of physics I don't agree that we can so assertively say that block models are disproven. But I do agree that a simple, relativity-based block model (if such exists) is incomplete as a model for our universe since it does not include QM. BTW there is also a block-universe type construction possible in QM. Let phi(t) represent the state function of the entire universe at time t. Then Schrodinger's equation H(phi) = i hbar d/dt(phi) shows how the wave function will evolve. It is determinstic and in a many worlds interpretation this is all there is to the underlying physics. So this is a block-universe interpretation of QM. However, it is non relativistic. From what I understand, a full marriage of QM and special relativity requires quantum field theory, which is beyond my knowledge so I don't know whether it can be thought of as a block universe. And then of course that still leaves gravitation and the other phenomena of general relativity, where we have no theory at all that works. Whether it will be amenable to a block universe view is still unknown as far as I understand. I don't see why you are so bound on rejecting block universes. You just don't like them? If you look around in the journals and books you will find discussion of the implications of multiple-time dimensions. For example: Sure, in fact I first learned of the idea from one of Tegmark's papers, he who is unknowingly one of the founding fathers of this list. http://space.mit.edu/home/tegmark/dimensions.html describes his ideas for why universes with 2 or more time dimensions are unlikely to have observers. The point is, you can't go quoting Leibniz about this stuff. We've left him far behind. Hal Finney
Re: Bitstrings, Ontological Status and Time
On Sat, May 07, 2005 at 01:55:39PM -0700, Hal Finney wrote: Sure, in fact I first learned of the idea from one of Tegmark's papers, he who is unknowingly one of the founding fathers of this list. Unknowingly? Tegmark was certainly involved in this list in the early days, but I suspect he doesn't bother with it much these days... -- *PS: A number of people ask me about the attachment to my email, which is of type application/pgp-signature. Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 pgpLvgEMkkGvT.pgp Description: PGP signature
Re: Bitstrings, Ontological Status and Time
Dear Jesse, I must apologize for my post last night, I had drunk a little too much beer. ;-) - Original Message - From: Jesse Mazer [EMAIL PROTECTED] To: [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Saturday, May 07, 2005 12:24 AM Subject: Re: Bitstrings, Ontological Status and Time snip The mind/body problem, the problem of what qualia are and where they come from, is not something you're likely to solve with a mathematical proof. But again, I see no reason why the problem becomes any easier to solve if we assume there is a world of physical particles separate from the world of mathematical forms. I am arguing exactly that, that assuming a duality at some ontological level makes it easier to solve the problem. For much of the basic ideas please read the paper found here: http://citeseer.ist.psu.edu/pratt95rational.html Stephen
Re: Bitstrings, Ontological Status and Time
Hi Stephen: At 04:37 PM 5/6/2005, you wrote: Dear Hal, No, I disagree. The mere a priori existence of bit strings is not enough to imply necessity that what we experience 1st person view points. At best it allows the possibility that the bit strings could be implemented. You see the problem is that it is impossible to derive Change or Becoming from Being. Which is why I have focused my efforts in this venue on finding a simple system that has a natural dynamic. The fact that my result so far is a random dynamic does not prevent long sequences where reality visits information kernels [bit strings] such that the trace can be encoded in a set of rules [including simple ones] such as those we call physics [whatever they may actually be if we do not know them now]. Hal Ruhl
Re: Bitstrings, Ontological Status and Time
Time is just a coordinate, in relativity theory. The time coordinate has an opposite sign to the space coordinates, and that subtle difference is responsible for all of the enormous apparent difference between space and time. Granted, relativity theory is not a complete and accurate specification of the world in which we live (that requires QM to be incorporated), but it is still a self-consistent model which illustrates how time can be dealt with mathematically in a uniform way with space. Time and space are not fundamentally different in relativity; they shade into one another and can even change places entirely, if you cross the event horizon of a black hole. In fact, one can construct models in which there are more than one dimension of time, just as we have more than one dimension of space. How would your renaissance philosphers deal with two dimensions of time? I think their ideas are obsolete and have no reference or value given our much deeper modern understanding of these issues. Hal Finney
Re: Bitstrings, Ontological Status and Time
Dear Hal, - Original Message - From: Hal Finney [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Saturday, May 07, 2005 2:48 PM Subject: Re: Bitstrings, Ontological Status and Time Time is just a coordinate, in relativity theory. The time coordinate has an opposite sign to the space coordinates, and that subtle difference is responsible for all of the enormous apparent difference between space and time. [SPK] I would agree that Time is just a coordinate (system), or as Leibniz claimed an order of succession, if we are considering only events in space-time that we can specify, e.g. take as a posteriori. What I am trying to argue is that we can not do this in the a priori case for reasons that have to do with Heisenberg's Unceratanty Principle. Since it is impossible to construct a space-time hypersurface where each point has associated with it all of the physical variables that we need to compute the entire global manifold, from initial Big Bang singulary to the, possibly, infinite future, it is a mistake to think of time simply as a coordinate. OTOH, it is consistent if we are dealing with some particular situation and using Special (or General) Relativity theory to consider the behavious of clocks and rulers. ;-) [HF] Granted, relativity theory is not a complete and accurate specification of the world in which we live (that requires QM to be incorporated), but it is still a self-consistent model which illustrates how time can be dealt with mathematically in a uniform way with space. Time and space are not fundamentally different in relativity; they shade into one another and can even change places entirely, if you cross the event horizon of a black hole. [SPK] I am trying to include the implications of QM in my thinking and hence my point about time and my polemics against the idea of block space-time. I do not care how eminent the person is that advocates the idea of Block space-time, they are simply and provably wrong. In fact, one can construct models in which there are more than one dimension of time, just as we have more than one dimension of space. How would your renaissance philosphers deal with two dimensions of time? I think their ideas are obsolete and have no reference or value given our much deeper modern understanding of these issues. [SPK] If you look around in the journals and books you will find discussion of the implications of multiple-time dimensions. For example: http://www.google.com/search?hl=enq=multiple+time+dimensions+physics Kindest regards, Stephen Hal Finney
Re: Bitstrings, Ontological Status and Time
Stephen Paul King wrote: Dear Hal, [HF] Granted, relativity theory is not a complete and accurate specification of the world in which we live (that requires QM to be incorporated), but it is still a self-consistent model which illustrates how time can be dealt with mathematically in a uniform way with space. Time and space are not fundamentally different in relativity; they shade into one another and can even change places entirely, if you cross the event horizon of a black hole. [SPK] I am trying to include the implications of QM in my thinking and hence my point about time and my polemics against the idea of block space-time. I do not care how eminent the person is that advocates the idea of Block space-time, they are simply and provably wrong. What would your proof be? All quantum field theories are Lorentz-invariant (so the same laws apply in different reference frames with different definitions of simultaneity), although this refers only to the equations governing the dynamics of the fields in between measurements. The measurement process itself is still somewhat mysterious, so perhaps some interpretations of QM would say that it violates Lorentz-invariance, like Bohm's interpretation (although Bohm's interpretation has never been successfully extended from nonrelativistic quantum mechanics to relativistic quantum field theory) or certain variations of the Copenhagen interpretation. But I don't think any version of the MWI would say that measurement introduces a preferred reference frame. Jesse
Re: Bitstrings, Ontological Status and Time
Stephen Paul King writes: I would agree that Time is just a coordinate (system), or as Leibniz claimed an order of succession, if we are considering only events in space-time that we can specify, e.g. take as a posteriori. What I am trying to argue is that we can not do this in the a priori case for reasons that have to do with Heisenberg's Unceratanty Principle. Since it is impossible to construct a space-time hypersurface where each point has associated with it all of the physical variables that we need to compute the entire global manifold, from initial Big Bang singulary to the, possibly, infinite future, it is a mistake to think of time simply as a coordinate. OTOH, it is consistent if we are dealing with some particular situation and using Special (or General) Relativity theory to consider the behavious of clocks and rulers. ;-) I agree that in our particular universe the role of time is complex. Since we don't have a unified theory yet, we really can't say anything definitive about what time will turn out to be. It's entirely possible that time may yet turn out to be a simple coordinate. Wolfram is pushing ideas where the universe is modeled as a cellular automaton (CA) which has discrete units of space and time. Of course his theories don't quite work yet, but then, nobody else's do, either. I am trying to include the implications of QM in my thinking and hence my point about time and my polemics against the idea of block space-time. I do not care how eminent the person is that advocates the idea of Block space-time, they are simply and provably wrong. In this universe, perhaps so, although as I argued above absent a true and accurate theory of physics I don't agree that we can so assertively say that block models are disproven. But I do agree that a simple, relativity-based block model (if such exists) is incomplete as a model for our universe since it does not include QM. BTW there is also a block-universe type construction possible in QM. Let phi(t) represent the state function of the entire universe at time t. Then Schrodinger's equation H(phi) = i hbar d/dt(phi) shows how the wave function will evolve. It is determinstic and in a many worlds interpretation this is all there is to the underlying physics. So this is a block-universe interpretation of QM. However, it is non relativistic. From what I understand, a full marriage of QM and special relativity requires quantum field theory, which is beyond my knowledge so I don't know whether it can be thought of as a block universe. And then of course that still leaves gravitation and the other phenomena of general relativity, where we have no theory at all that works. Whether it will be amenable to a block universe view is still unknown as far as I understand. I don't see why you are so bound on rejecting block universes. You just don't like them? If you look around in the journals and books you will find discussion of the implications of multiple-time dimensions. For example: Sure, in fact I first learned of the idea from one of Tegmark's papers, he who is unknowingly one of the founding fathers of this list. http://space.mit.edu/home/tegmark/dimensions.html describes his ideas for why universes with 2 or more time dimensions are unlikely to have observers. The point is, you can't go quoting Leibniz about this stuff. We've left him far behind. Hal Finney
RE: Bitstrings, Ontological Status and Time
Stephen Paul King wrote: No, I disagree. The mere a priori existence of bit strings is not enough to imply necessity that what we experience 1st person view points. At best it allows the possibility that the bit strings could be implemented. You see the problem is that it is impossible to derive Change or Becoming from Being. Think of this in terms of thermodynamics, if we assume a universe that is in perfect equilibrium there will never be any possibility of a deviation from such equilibrium unless we introduce some mechanism to disturb it. If we use the mechanism of a quantum fluctuation then we are forced to introduce some kind of potential to change into a structure that by definition has none. This has long been a problem for thinkers trying to understand the notion of Time. Unless we assume some form of change or Becoming as existing a priori to time and that out notion of Time is a local measure of change, we are forced to construct ideas where we ask questions like how fast is a second. We end up with a Time_ 1 to measure the rate of change that is somehow different from the usual time (Time_0) and this, in turn, would have to have a Time_2 and thus a Time_3, etc.- an infinite number of times, each to measure the rate of change of the one below it. Why do you need to believe that there is any change at the ultimate level at all? The idea of block time has always seemed plausible to me, where events in the future and past (or various parallel futures and pasts, from a multiverse point of view) are just as real as events at other spatial locations in a single moment (and relativity suggests that there is no unique definition of the 'present moment' anyway). This point of view is discussed in a nice article from Scientific American by physicist Paul Davies: http://www.american-buddha.com/myster.flow.physics.htm Jesse
Re: Bitstrings, Ontological Status and Time
Dear Jesse, Interleaving. - Original Message - From: Jesse Mazer [EMAIL PROTECTED] To: [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Friday, May 06, 2005 5:02 PM Subject: RE: Bitstrings, Ontological Status and Time Stephen Paul King wrote: No, I disagree. The mere a priori existence of bit strings is not enough to imply necessity that what we experience 1st person view points. At best it allows the possibility that the bit strings could be implemented. You see the problem is that it is impossible to derive Change or Becoming from Being. Think of this in terms of thermodynamics, if we assume a universe that is in perfect equilibrium there will never be any possibility of a deviation from such equilibrium unless we introduce some mechanism to disturb it. If we use the mechanism of a quantum fluctuation then we are forced to introduce some kind of potential to change into a structure that by definition has none. This has long been a problem for thinkers trying to understand the notion of Time. Unless we assume some form of change or Becoming as existing a priori to time and that out notion of Time is a local measure of change, we are forced to construct ideas where we ask questions like how fast is a second. We end up with a Time_ 1 to measure the rate of change that is somehow different from the usual time (Time_0) and this, in turn, would have to have a Time_2 and thus a Time_3, etc.- an infinite number of times, each to measure the rate of change of the one below it. Why do you need to believe that there is any change at the ultimate level at all? [SPK] Honestly I have not problem at all with the idea that at the Ultimate level of existence any notion of a measure of change, i.e., time, vanishes. It is then we consider that there is no differentiation that occurs over the continuum between that Ultimate level and the Physical level that I am trying to speak. [JM] The idea of block time has always seemed plausible to me, where events in the future and past (or various parallel futures and pasts, from a multiverse point of view) are just as real as events at other spatial locations in a single moment (and relativity suggests that there is no unique definition of the 'present moment' anyway). This point of view is discussed in a nice article from Scientific American by physicist Paul Davies: http://www.american-buddha.com/myster.flow.physics.htm Jesse [SPK] The problems that I have with the block time idea are exactly the same as the problem that I have with COMP, that a pre-specified orchestration or harmony, as Leibniz proposed in his Monadology, exists that is both necessary and sufficient to explain the inescapable flow that we experience. Any kind of pre-specification, especially of a world as complex as the one we experience, requires the solution of some problems know to exist in the computational complexity class named NP-Complete. These kinds of problem as such that even if P=NP is true the computations must be run for a polynomial number of steps. Where does the notion of running a polynomial number of steps occur in a realm that is Timeless Being? Well, let's try something... http://www.claymath.org/millennium/P_vs_NP/Official_Problem_Description.pdf The idea that solutions exists to these problems as Platonic forms in itself does nothing to address how these solutions are communicated. Do you recall that Plato himself had to invent the notion of noesis to give a name to the idea that somehow, by some mysterious means, our finite and imperfect minds somehow could connect to the Perfect and Timeless Forms. http://home.uchicago.edu/~wwtx/plato.pdf Now, if it could be shown that there is a coherent and consistent way that noesis can occur, much like Sir Roger would have us believe, I would be very happy since I like the idea very much, but I will not pretend that I have some kind of difficult to explain logic system that proves that it exists. I find this idea equivalent to some the notion of action at a distance ... I will stop ranting now. ;-) I have tried to explain the problem of block time in several posts, here on the Everything-list and on the F.o.R. list, the idea of block-time simply ignores the fact that a block space-time - the notion from which block time is derived - required that at least the initial or the final boundary of such a block have associated with it definite physical quantities, such as the positions, momenta, spin, charge, color, etc. We know from QM that this idea simple does not stand up to empirical evidence. It is, at best, a fantasy and as such we should not ever find our selves having to use it to justify reasonings when even a casual reader of a laymen's book on physics knows better. I am familiar with Davies' ideas, I have read every one of his books and found them self-aggrandizing and lacking in original content. For one thing, his statement Nothing in known
Re: Bitstrings, Ontological Status and Time
Dear Brent, - Original Message - From: Brent Meeker [EMAIL PROTECTED] To: Stephen Paul King [EMAIL PROTECTED] Sent: Friday, May 06, 2005 1:30 PM Subject: RE: Bitstrings, Ontological Status and Time Julian Barbour's idea of time is just an ordering relation between self-contained 'capsules' (i.e. 'states'). Just as the states of your brain could be ordered according to the memories stored in them. [SPK] Yes, that is also my understanding of Julian's idea. The problem that I have is that he seems to completely ignore the necessary conditions requires for the construction of the time capsules. It is like assuming that an infinite pile of photographs exists without wondering exactly how the photographs came to be structured the way they are and to encode information they way they do. Using the well-order that exists over the Real numbers to explain the ordering of events in time is cheating! Additionally, Julian seems to ignor that observables, prior to the specification of the details of measurements, are not Real valued, they are Complex valued; Complex values are not well ordered! http://mathworld.wolfram.com/ComplexNumber.html Rates of change are measured by comparing clock states within different capsules. Clock's are physical devices for providing very simple memories, i.e. how many seconds have passed. So called good clocks are just the ones that make dynamical equations simple. [SPK] Julian never seems to explain how the comparison process itself that must exists between capsules gets coded into the time capsules, that I ever understood... Stephen
Re: Bitstrings, Ontological Status and Time
Stephen Paul King wrote: Dear Jesse, Interleaving. Stephen Paul King wrote: No, I disagree. The mere a priori existence of bit strings is not enough to imply necessity that what we experience 1st person view points. At best it allows the possibility that the bit strings could be implemented. You see the problem is that it is impossible to derive Change or Becoming from Being. Think of this in terms of thermodynamics, if we assume a universe that is in perfect equilibrium there will never be any possibility of a deviation from such equilibrium unless we introduce some mechanism to disturb it. If we use the mechanism of a quantum fluctuation then we are forced to introduce some kind of potential to change into a structure that by definition has none. This has long been a problem for thinkers trying to understand the notion of Time. Unless we assume some form of change or Becoming as existing a priori to time and that out notion of Time is a local measure of change, we are forced to construct ideas where we ask questions like how fast is a second. We end up with a Time_ 1 to measure the rate of change that is somehow different from the usual time (Time_0) and this, in turn, would have to have a Time_2 and thus a Time_3, etc.- an infinite number of times, each to measure the rate of change of the one below it. Why do you need to believe that there is any change at the ultimate level at all? [SPK] Honestly I have not problem at all with the idea that at the Ultimate level of existence any notion of a measure of change, i.e., time, vanishes. It is then we consider that there is no differentiation that occurs over the continuum between that Ultimate level and the Physical level that I am trying to speak. But what does physical level even mean, if universes or observer-moments are just elements of the set of all mathematical forms, as many on this list believe? [JM] The idea of block time has always seemed plausible to me, where events in the future and past (or various parallel futures and pasts, from a multiverse point of view) are just as real as events at other spatial locations in a single moment (and relativity suggests that there is no unique definition of the 'present moment' anyway). This point of view is discussed in a nice article from Scientific American by physicist Paul Davies: http://www.american-buddha.com/myster.flow.physics.htm Jesse [SPK] The problems that I have with the block time idea are exactly the same as the problem that I have with COMP, that a pre-specified orchestration or harmony, as Leibniz proposed in his Monadology, exists that is both necessary and sufficient to explain the inescapable flow that we experience. orchestration or harmony between what and what? Like I said, we needn't believe the physical world is something separate from the Platonic realm of mathematical forms. Where does the notion of running a polynomial number of steps occur in a realm that is Timeless Being? If you take the B series view of time by McTaggart that Davies discussed in his article, you can just imagine a list of numbered operations of a Turing machine which exists timelessly, without the notion that any step is specially marked out as the one that is happening now. The number of steps would just be the length of the list. The idea that solutions exists to these problems as Platonic forms in itself does nothing to address how these solutions are communicated. Do you recall that Plato himself had to invent the notion of noesis to give a name to the idea that somehow, by some mysterious means, our finite and imperfect minds somehow could connect to the Perfect and Timeless Forms. But Plato did not consider the possibility that there is no physical realm outside of the Platonic realm--that we ourselves, and the universe we live in, are just Platonic forms. I have tried to explain the problem of block time in several posts, here on the Everything-list and on the F.o.R. list, the idea of block-time simply ignores the fact that a block space-time - the notion from which block time is derived What's the difference? I thought that block time, block spacetime, and block universe were all synonymous. - required that at least the initial or the final boundary of such a block have associated with it definite physical quantities, such as the positions, momenta, spin, charge, color, etc. What do you mean by initial boundary? Like the Big Bang singularity? Why would the boundary have to have these properties? I am familiar with Davies' ideas, I have read every one of his books and found them self-aggrandizing and lacking in original content. Well, I didn't link to that article because it contained any original ideas by Davies, but just because it contained a good review of the block time vs. flowing time issue. For one thing, his statement Nothing in known physics corresponds to the passage of time. really bothers me; who
Re: Bitstrings, Ontological Status and Time
- Original Message - From: Jesse Mazer [EMAIL PROTECTED] To: [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Friday, May 06, 2005 11:31 PM Subject: Re: Bitstrings, Ontological Status and Time But what does physical level even mean, if universes or observer-moments are just elements of the set of all mathematical forms, as many on this list believe? Jesse, With all seriousness. Reach out that element of the set of all mathematical forms that most people call a hand, ball it into a fist, and pull it toward your face as hard as you can. Feel that effect, the blinding headache, please explain it away by repeating what you wrote here. It didn't go away, did it? The point that I am trying to make is that unless we can mathematically *prove* that it is NECESSARY that the results of this demonstration must obtain given the choice of the action, how is it that we can ignore a physical level that is something different from just some combination of elements of the set of all mathematical forms? The point is that we can *prove* that we can not decide whether or not some statement is true or false within some theory (that includes the ability to count), thus we can be sure that we can not be sure which element of the set of all mathematical forms coorespond to that action, in fact we can't even specify the membership function of that set! What explanatory power does a set with no definable membership function have with nothing else associated with it? I will respond to the rest of your post tomorrow. ;-) Stephen
Re: Bitstrings, Ontological Status and Time
Stephen Paul King: Jesse, With all seriousness. Reach out that element of the set of all mathematical forms that most people call a hand, ball it into a fist, and pull it toward your face as hard as you can. Feel that effect, the blinding headache, please explain it away by repeating what you wrote here. Why would I need to explain anything away? If you assume that mathematical forms can't be conscious or feel pain, you're assuming what you're trying to prove (namely, that we are not just mathematical forms); I don't see anything contradictory in the idea, myself (it's no worse than the idea that a collection of particles can feel pain). It didn't go away, did it? The point that I am trying to make is that unless we can mathematically *prove* that it is NECESSARY that the results of this demonstration must obtain given the choice of the action, how is it that we can ignore a physical level that is something different from just some combination of elements of the set of all mathematical forms? The mind/body problem, the problem of what qualia are and where they come from, is not something you're likely to solve with a mathematical proof. But again, I see no reason why the problem becomes any easier to solve if we assume there is a world of physical particles separate from the world of mathematical forms. The point is that we can *prove* that we can not decide whether or not some statement is true or false within some theory (that includes the ability to count), thus we can be sure that we can not be sure which element of the set of all mathematical forms coorespond to that action What action are you referring to? in fact we can't even specify the membership function of that set! You mean which form the action is, or which form I am? If the latter, why should a conscious element of the set of all mathematical forms necessarily be able to identify *which* mathematical form its own self is? I also can't know the exact configuration of every atom in my brain, would you take that as an argument against physicalism? Jesse