James Higgo I have been devouring your recent papers with great interest. I know you're not a many-worlder (in this universe, anyway), but have you considered the implications of substituting your analysis of the synaptic calcium ion for the machine gun apparatus in the 'quantum suicide' experiment as described by Max Tegmark? If I'm right, it means that we're all immortal, or at least it will seem so to us.

Henry Stapp Could you remind me about Tegmark's experiment? As for many-worlds, I find it the next most atractive possibility, But I do believe that it has technical difficulties in "Specifying the Questions" As you know, in quantum theory one must PRE-SPECIFY a question (Or a set of "orthogonal" questions, each) with a Yes-or-No answer before quantum theory can assign a set of consistent probabilities to the two answers. Normally in a scientific experiment the human observer/experimenter sets up the experiment in such a way as to define a set of empirically (experientially) distinguishable outcomes. But in a normal evolving system there are an infinite number of ways of dividing a state into orthogonal components. If one counts them all, then the probabilities will add to infinity. not unity. And in the state all branches appear conjunctively, not disjunctively. So one must have must have a principle that specifies how the whole state is going to be decomposed into components in some particular way, and a principle that converts a conjunction of these components into a disjunction. The only sensible conception of this conversion from a conjunction to a disjunction of alternative "possibilities" with a sum of probabilities that sum to unity seems to bring in an infinite number of minds or monads or something-or-others that divide in the right perportions among the "branches" (which we do not know how to define except in simple cases) or make some "events" occur with appropriate "probabilities". The whole situation is very murky and cloudy. It would seem that one ought to make the rules so that the separation into branches is coordinated into a separation into (possible) different conscious experiences.

Is it really better to introduce an infinite number of minds, than the pragmatically confirmed principle that the empirical experiences are represented by a reduction of the state to one compatible with the new knowledge. I feel uncomfortable getting so far away from what is pragmatically comfirmed, as to introduce an infinite number of parallel minds, each with a rule for which path it will follow, or a single "me" that will (if we say that the wave functions is all there is) that becomes two "me's", both presents, but one with a, say, ten times greater "probability" than the other. But what does that probability mean if the one "me" divides into two "me's", both present? If the psychological mind is to be brought in, is it not more sensible to have it DO SOMETHING, rather than just be ripped apart into to full copies, both presents, but one more "probable"?

James Higgo On your first issue, which I paraphrase as: 'how do we know which branch of the infinitely many we'll end up in?', I would cite the anthropic principle. I have no problem with infinite numbers of monads, and I give no special status to one 'surfer' over another. They are all equally real, as per Deutsch in 'Fabric of Reality' and, I am told by Vic Stenger, Everett in the original thesis, which I have not read. To say that that is wasteful is to be very anthropocentric; the other surfers could say the same.

I know it's a matter of taste but I think an infinite number of branches is less of an artificial construct than a collapse.

I think this problem with the mind being 'ripped apart' will vanish once we have a better understanding of what mind is. This is the reason I think your work is very valuable.

I am glad that MWI is your second favourite - despite the fact that it invalidates the Bohmian idea of a link between consciousness and the 'real world', which seems to be the basis of your metaphysics. John Gribbin and Vic Stenger have also said it's their second favourite, although their favourite is very different from yours.

James Higgo: In section 9 of Atomic Metaphysics , you say: "with the simple inclusion of time reversibility... without the need for superluminal connections". I can't help thinking that time-reversibility gives you faster-than-light with knobs on. Velocity is distance/time, v=d/t. Superluminal means v>c. Obviously, you can achieve this by increasing d or reducing t. Fiddling with the flow of t means you are effectively getting superluminal by another name.

Vic Stenger That's what the figure on my home page in fact shows. The point is that it is indeterministic, so no signals can be transferred at v > c.

James Higgo Does t suddenly switch sign? What is the mechanism for this?

Vic Stenger Not proper time, just coordinate time. Just as coordinate x or coordinate y can switch, though the particle remains at proper position x = y = z = 0. Look at the detector as a source. The mechanism is the time reversed process. If a photon is absorbed by exciting an electron from level 1 to level 2, the reverse is a photon emitted by the transition 2 -> 1.

James Higgo Some people would read your paragraph and think that the inclusion of time reversibility was a lot less simple than warp speed, Mr Sulu.

Vic Stenger It sure is.

James Higgo Incidentally, I have now established that MWI is the second-favourite interpretation of you, Henry Stapp and John Gribbin. It is the favourite of almost everyone else I've spoken with. You are doing a very good job of stemming the tide.

Vic Stenger I don't think Stapp or Gribbon listen to me.

James Higgo I guess the problem is I can understand MWI intuitively, but I just can't understand time-reversibility yet. Must try harder! I'll keep bashing my head with your book until something gives. I glanced through the Tao of Physics this morning, because I remembered it had Feynman diagrams in it. Ironically Capra uses the ontological underpinnings of time-reversibility to buttress his mystical world-view:

"Many of the eastern teachers emphasize that thought must take place in time, but that vision can transcend it. 'Vision', says Govinda, 'is bound up with a space of a higher dimension and is therefore timeless'... It has therefore been said that Eastern mysticism is a liberation from time. In a way, the same may be said of relativistic physics."

James Higgo In response to my last post - In which I said that fiddling with the flow of time gave you superluminality by another name - you said that it was merely coordinate time that was changing sign. Does this mean that there is a preferred frame of reference - a 'real' time which is different to co-ordinate time? If so, you have discarded the general theory of relativity, which does not admit a preferred frame of reference.

Vic Stenger In a way. As I said in a message last night the proper time is real enough. But there is not one global proper time. I am sure there will be more on this.

JamesHiggo On another point, Gribbin argues (Schroedinger's Kittens) that the Aspect experiment's violation of the Bell inequality proved "that *any* interpretation of quantum reality must involve non- locality" p.158.

Vic Stenger Depends on how you define nonlocality. I have been generally defining it as the opposite of locality, which has to do with superluminal signaling. Others use nonlocality to mean nonseparability, which is definitely a feature of QM. Most analysts of the EPR business have concluded that you can still achieve Bell's inequality with means other than nonlocality. Gribbon expresses a consensus view of physicists that is based on a proof by Stapp. But when I asked Stapp about this recently, he admitted that he had second thoughts. In particular, he assumes time-directed causality. If you look at my zigzag plot, you will see inseparability which only becomes nonlocality when the motion is deterministic. This is discussed full in _The Unconscious Quantum_. One thing is clear: it has been proved that any superluminal signaling violates the axioms of relativistic quantum field theory, so any nonlocality as I define it would require a theory that goes beyond conventional theory. Bohm's theory, for example does that.

James Higgo MWI does involve non-locality of a sort, as does the Bohm- stuff, and as far as I can see, having still not understood it, your time-reversibility also involves non-locality, as argued above. Only Copenhagen, which is effectively no interpretation, does not involve non-locality.

Vic Stenger In TR, the particles never move faster than light and all forces are local. I consider it local.

James Higgo Let me put my finger on the reason why I, as an economist, have not fallen for the allure of time-reversibility and remain faithful to MWI. With MWI, I can see that the particle goes through all the slits, and interferes with its other-worldly selves. With time reversibility, could you explain WHY it goes through one, then reverses in time back through the other? It seems to be acting as if it wants to fool us into believing something else. Or does the particle exist in an endless loop going backwards and forwards in every possible direction?

Vic Stenger It does not reverse through the other slit, although I think I said that in The Unconscious Quantum. It goes back along the same path in sort of a four-dimensional elastic collision in which all four components of momentum, including energy, are reversed. I am not sure the best way to view this. The particle is simultaneously going both ways along the same path, but simultaneity is a meaningless concept so this is probably not the way to say it. In the particle's reference frame it is always at the origin and its clock keeps running the same way, so nothing funny there. The reverse-time is really an artifact of our way of looking at things, seen only in other reference frames. Things often look funny when viewed at certain angles, so this does not worry me too much. All I am really doing is following the prescription that all possible paths must be summed over and we have no basis for excluding the backward time paths. Indeed, because of the way this so easily explains the quantum paradoxes, we have every reason for including them.

James Higgo If you can explain that to we laymen, you'll have won the argument to our satisfaction and we can go on with our lives confident that we can still believe all those Newtonian determinist things that we always did.

Vic Stenger Not determinist. In fact, one of my points is that event this picture becomes non-local when the paths are determined, because then you can have superluminal signaling. To maintain locality, you need the paths to be indeterminate. That it, the locations of the zigs and zags are random.

Edmund Weinmann James wrote: "It seems to be acting as if it wants to fool us into believing something else."

No, there can be no intention of fooling us on its part... this would be a kind of "demon mechanics" such as once was suggested on the old Omega Point mailing list I ran a few years back. Einstein once put this as "subtle is the Lord, but not malicious" (substitute "nature" for "the Lord", if you prefer).

James also wrote: "Or does the particle exist in an endless loop going backwards and forwards in every possible direction?"

It seems to me that this is clearly the ontological implication... it brings us to the "Eleatic" position of Zeno and Parmenides... this is what the "Eleatic stranger" suggests in the _Sophist_, challenging Platonic dualism... and what Vic Stenger again suggests, today, again suggesting a solution to the Platonic problem, other than Platonic dualism, in line with modern physical theory.

Ricardo Mur I still don't have a clear image of how the double slit experiment is explained ... The EPR experiment is beautifully solved by time symmetry (you have to take into account both past and future. In Scott's terms, if I understand him correctly, both of them would be "causes".). This is what you and Huw Price do. However, Huw Price didn't have a go for the double slit experiment in his book using time symmetry. Your own attempt involves time reversibility. But how is this supposed to give the observed probability distribution? (sorry I go back to this again ...).

Let's imagine that interference is just adding both photon internal arrows (or clocks, or whatever) and that the result (the module) is the magnitude measured by the detectors. So, if both arrows point in opposite directions, 0 would be measured. If both of them point in the same direction, 2*i would be measured, etc. Now, *this* could be easily explained by a photon going through one slit, going back and then forward again through the other slit and then "interfering" with itself. After all, it's very similar to classical waves interference. But this is not what we want to explain. The result of adding the two arrows is not what is measured, but the probability of detecting the photon there. How does this probability distribution arise?. Here there is an imaginary mechanism to show what I mean: a "ghost" undetectable particle is sent in all directions starting from the lamp, going through both slits, reaching all detectors (all possible outcomes), interfering with itself, obtaining probabilities and coming back to the lamp with that information. At this point, the actual photon would know what's the probability of reaching any possible outcome and then, an outcome would be chosen according to that probability, and the photon would just follow one of the paths followed "previously" by the ghost particle (BTW, the actual photon would only need to go through just one of the slits, because it already knows where to go). A similar effect might be obtained by the detectors sending ghost particles towards the past and reaching the lamp. To be sure, I'm not proposing this as an explanation (although I don't think it is much different than Bohm's pilot wave or Cramer's Transactional Interpretation) but as an example of what an explanation could look like. How does the lamp know what the possible outcomes and associated probabilities are (even those with probability 0)?. It is fine to have that information coming from the future, but how does it work?.

Vic Stenger On the first part of Ricardo’s post: Let's talk paradigm rather than metaphysics, and see about the metaphysics later. The Feynman path integral method sums the amplitudes over all paths. Including the time-reversed paths does not change the interference result. I actually have the equations in the "Atomic Metaphysics" paper linked at the top of the same page where the book chapters are linked.

On the second part: Yes, this is in the same spirit as Cramer, and Cramer's idea works. But its a paradigm and not a metaphysics. We still have waves that have to be either etheric or platonic (see Chapter 11) in the metaphysics. How about this idea: Think of each path as a vibrating string fixed at each end. I think we can do this in four dimensions, so they are vibrating worldlines. Those paths that have standing waves will result in the largest amplitudes and set the detector jiggling the most. So the interference is there in the paradigm and adding the time-reversed paths does not change that. What time reversal does for you is enable you to understand how a particle can have definite paths and still interfere with itself.

Ricardo Yes, I have no problems with [your comment on part 1]

[on part 2] Yes. The problem is that the result of the interference is not what is actually measured but a probability of finding the photon there. Time-reversibility could explain how an actual particle can interfere with itself just as an actual wave can interfere with itself. If when a photon interferes with itself gives a result of 0.23 and 0.23 is measured by the detector, I'd have no objection. But 0.23 is not what is measured: a whole photon is detected instead by one of the detectors, and no photon is detected by the rest of them. 0.23 is just a probability, or a expectation of the number of different photons that will be detected there. Just another example. In the paradigm, you can have a photon going forward, then backward, then forward again, interfere with itself and ... give an arrow with modulus 0. This means that we'll never find the photon there. So, although this path appears in the paradigm, it could never appear in reality!. But, how could the photon know that the probability of getting there is 0 without actually going there and interfering with itself?. But if it goes there it will be detected, won't it?.

Scott Dalton Ricardo, myself and others get the sense that there is still something unexplained in your metaphysics: "The main issue" seems to boil down to *the measurement problem*. I think we all agree with the paradigm: [Vic Stenger wrote] "Let's talk paradigm rather than metaphysics, and see about the metaphysics later. The Feynman path integral method sums the amplitudes over all paths. Including the time-reversed paths does not change the interference result. I actually have the equations in the Atomic Metaphysics paper linked at the top of the same page where the book chapters are linked." But your "new" attempt here at explaining why *one* detector goes off and not the others does not work or is incomplete: [Vic Strenger Wrote] "How about this idea: Think of each path as a vibrating string fixed at each end. I think we can do this in four dimensions, so they are vibrating worldlines. Those paths that have standing waves will result in the largest amplitudes and set the detector jiggling the most." There is still going to be a continuum of amplitudes and by implication a continuum of jiggling detectors. No single set of paths will have the *largest* amplitude--in fact, many sets of paths will have the same amplitude when the probability distribution is uniform or periodic, for example. I think what is needed in QM is something no one has yet provided to many people's satisfaction--a *mechanism* for "apparent collapse" or *detection*.

Your new metaphysics may provide a means which I will suggest (nowhere near completely) after considering the related issue of zero amplitude values of the wavefunction in your AM vs. Deutsch's MWI. Ricardo describes the zero amplitude problem as follows: "Just another example. In the paradigm, you can have a photon going forward, then backward, then forward again, interfere with itself and ... give an arrow with modulus 0. This means that we'll never find the photon there. So, although this path appears in the paradigm, it could never appear in reality!. But, how could the photon know that the probability of getting there is 0 without actually going there and interfering with itself?. But if it goes there it will be detected, won't it?. First consider Duetsch's "solution" to the problem, since it also afflicts his "particle" MWI presented in "Fabric of Reality" (FoR). The first question I asked him after joining the FoR list--I unsubscribed shortly after joining AVOID--was how could the paths in a Feynman diagram be *real* in cases when the resulting amplitude is zero? In MWI, this means there are zero universes which have that outcome. Since in Deutsch's MWI, particles from many universes are supposed to interfere to produce the wavefunction, this seems to be contradictory: a bunch of particles produce a (zero amplitude) wavefunction which implies that they don't exist! Deutsch's response was a dodge: he said that particles jump off those paths which might eventually cancel and jump on to other paths which don't. But the fact is that those paths from which the particles veered still remain in the QM paradigm. Deutsch's dodge is one way for his MWI to remain consistent but it constitutes an *exception* (which, as Vic has taught us, is unparsimonious) to the reification of the Feyman path integral method: paths exist in the QM paradigm which do not exist in "particle" MWI reality. (Correct me if I'm wrong...I think a "wave" MWI reality can allow zero amplitudes, since only the wavefunction--and not Feynman's mathematical algorithm for calculating it--is assumed to exist.)

And now my incomplete suggestion for completing Vic's AM detection/measurement mechanics... Atomic Metaphysics does allow the *possibility* of reifying *all* paths in the QM paradigm, including travel along those paths which cancel and result in zero amplitude at the detector. I would try to build on Vic's previous ideas of treating particles and detectors as harmonic oscillators, each with their own magnitudes and phases. The detection/measurement mechanism might then include the following features:

1) The particle wavefunction would be as usually given, so that its "magnitude-squared" gives the probability density function for detection at the detector.

2) The detector wavefunction would have the same magnitude for all detectors (so that each is equally probable to go off) but random phase.

3) A normalized threshold of 50% actually *exists* such that when the combined particle/detector wavefunction magnitude is over this amount, the detector trips.

4) A random *sequence* of particle arrivals at the detectors are undertaken, with resulting particle/detector magnitudes between 0 and 1, depending on both the particle's usual complex amplitude and the random phase of the detector it "tries". The math is *somehow* based on Vic's analogy of detectors and particles pushing each other like swings, where *phase* is a critical variable (the "hidden variable"?) affecting amplitude.

5) Once a the 50% threshold is exceeded for a given detector, that detector goes off and the sequencing process *stops*, as both the particle and detector wavefunctions change radically due to the subsequent cascade of events in, say, the photomultiplier tube.

Virtues of the above: a) Zero (and less than 50% for that matter) magnitude particle/detector wavefunctions can exist, but the detector won't go off and the attempt fails. Time-reversibility allows subsequent attempts at the same or other detectors. For example, if the same detector's phase changes on a subsequent attempt (if there is one at that detector) so that the particle/detector magnitude exceeds 50%, that detector would go off. b) Because the trials are sequential and because the sequencing stops at the first detection, not all detectors will fire at which the usual *particle* wavefunction magnitude is regarded as exceeding 50%.

Problems (and I'm sure there are many more) with the above: A) A single "attempt" by the particle at triggering a particular detector would seem to require that all paths to that detector happen for the attempt in order to get the correct particle wavefunction amplitude. So we have an arbitrary dividing line in which individual paths are not sequenced but rather entire sets of paths. This seems to violate a primary metaphysical virtue of AM, in which a particle zigs and zags to and from detectors in any order and the amplitudes for being at any of the detectors "eventually" reach those predicted by QM. In my proposal, any partial set of paths triggering a given detector would skew the observed distribution, which must agree with QM. B) The random phase contribution of the detector (to the overall particle/detector amplitude) would need to be *additive*--as in swing pushing--in order to have any effect on the *magnitude*, since phase does not affect magnitude when two complex numbers are multiplied. But when working out the probabilities for detectors firing, the Feynman rules say *multiply* the amplitudes of events which must happen concurrently. So, a particle arriving at a detector *and* that detector firing would dictate multiplying the amplitudes of those two events to get the probability. (By the way, it *must* be the case that this gives the same wavefunction as the particle considered by itself, since the latter is all we need to get the correct probabilities). C) Since sequencing of *sets* of paths is now required, there is now no good metaphysical picture (yet) for how this happens. Ideally, I would rather have a mechanism for detection which involves the particle interacting (either hit or miss) *each* time it hits a detector, not just when the whole group of paths hits. It's as if the detector has to "wait" for all the paths to come in before deciding whether to fire. Well, Vic, a while back you asked for suggestions to make your harmonic oscillator idea work and I gave it a go. I don't know if something can be cobbled together from this "handwaving" response I have given. I do know that I would want any attempt to be backed up by mathematics—even if very simplified--so that we aren't implicitly violating QM in spite of what we *say*.

Vic Stenger Ricardo describes the zero amplitude problem as follows: "Just another example. In the paradigm, you can have a photon going forward, then backward, then forward again, interfere with itself and ... give an arrow with modulus 0. This means that we'll never find the photon there. So, although this path appears in the paradigm, it could never appear in reality!. But, how could the photon know that the probability of getting there is 0 without actually going there and interfering with itself?. But if it goes there it will be detected, won't it?.". I can never understand why this sort of argument is given. Why do photons need to "know" anything? Strikes me as antropomorphing them. And, I do not think amplitude modulus zero is a problem either. A non vibrating spring has zero modulus, but is still a spring. I am not denying Ricardo has astutely pointed out problems, but this is not one. The main problem is how to transform oscillator amplitudes into probability amplitudes.

Scott Dalton says "First consider Deutsch's "solution" to the problem, since it also afflicts his "particle" MWI presented in "Fabric of Reality" (FoR). The first question I asked him after joining the FoR list--I unsubscribed shortly after joining AVOID--was how could the paths in a Feynman diagram be *real* in cases when the resulting amplitude is zero? In MWI, this means there are zero universes which have that outcome. Since in Deutsch's MWI, particles from many universes are supposed to interfere to produce the wavefunction, this seems to be contradictory: a bunch of particles produce a (zero amplitude) wavefunction which implies that they don't exist!" See my spring retort above. But, I agree that MWI has a problem in providing a mechanism by which ghost paths interfere. At least my paths are all in the same universe.

James Higgo Vic, you know at least as well as I do that it's just a matter of terminology. We could say multiverse, snapshot or whatever you like. In any new branch of science throughout the ages there has been confusing misuse of new terms before everyone settles on an agreed vocabulary. You have mastered the one-liner put-down of MWI but I would really be very interested to hear your review of any real problems with it. Finding reasons to disbelieve MWI is just as important as finding reasons to believe your ontology in my attempt to make the conversion.

Vic Stenger I do not think MWI as originally promulgated is an ontology. That's why its called an interpretation. The put down is meant for those who in fact take the many universes as a reality.

Scott Dalton So MWI was originally meant to clean up the math or something—allow using the wave equation all the time and not add "collapse" ad hoc? What is the purpose of an interpretation if not to provide or assert an ontology?

John H. Metzier In my debates and conversations with a small group of local cognitive

science enthusiasts, I keep smacking up against a wall of intuitions that motivate a belief in various sorts of dualism. There exists an utter bafflement over the proposition that mind can consist in body-brain processes. Sentience is taken as somehow something other than mere molecules in motion, no matter how complex that motion may be. I find this to mark a failure of imagination more than a substantive objection. Mentalistic vitalism is absurd to me, and the

onus of proof is on those proposing it. More generally, I disdain dualisms. Yet, I find another kind of dualism inescapable. Perhaps it is merely a product of language that I haven’t quite seen through. This is the dualism of form and substance. I find echoes of this dualism in the writings of realists, naïve or sophisticated. And I see Scott’s attempt to demote the ontological status of math as an attempt to surpass such dualism. Another echo lies in Vic’s referral to "accidents" of history which shape the evolution of material form, once we establish the fundamental elements and processes via AM. Where do these accidents come from? Where does the math come from? The situation reminds me of my puzzlement as a child while reading the Old Testament account of the first humans: after Eve, where did all the women who wedded the patriarchs come from? On first take, math seems to be an extension and elaboration of the capacity of organisms to track significant parts of their environment. Visualize a child learning to mark off a cluster of blocks on the floor before her. Optical and tactile representations in the body-brain of the child (mental images of blocks/environment) are linked to other symbolic processes which sum over much of the perceptual field and "point to" an aspect of the items before her in an economical fashion. She can increase her purchase on the world with this short hand tool of description and prediction. Still, this activity seems to subsume a free floating, pre-extant order, thus simply postpones the questions. Is math the act of describing pre-extant regularities, or is it the

regularities themselves? Sorry if this is a bit incoherent. I’m working on it.

interference, or EPR experiments, we can just as well use electrons as photons.

must happen. And so the electron must cover all paths before it is detected.

---------

David Zachmann Vic Stenger says "Huw Price has a good discussion of this in his book. I have no problem time symmetry on the cosmic scale, or even the human scale. I view this as a Boltzmann statistical effect. As for time asymmetry being counterintuitive, remember that proper time does not change direction. Only coordinate time. Once you accept the fact the relativity demands some kind of equivalence between space and time, then it became very easy to view coordinate time changing direction as nothing more special than spatial coordinates changing direction. But, then, this seems to be completely consistent by what is said below."

"Great set of quotations. So where is the problem? Clearly I disagree with Penrose, Prigogine, and others. But I am certainly not out on a limb all by myself. In fact, I regard them out on a limb and myself as making the minimal assumptions consistent with all the data and conventional theory."

My Reaction: I may have this all wrong, but I think that Vic Stenger's consistency problems lies in his failure to understand the radical implications of what is known as the tenseless theory of time -- and apply said consistent understanding to his book "Atomic Reality."

Simply stated, the problems, as *I* see them, are these:

(i) Vic *appears* to affirm the reality of time and change for macroscopic systems,

(ii) Vic *appears* to affirm the indeterminacy (or openness) of what we call the future for macroscopic systems,

Yet,

(iii) Vic explicitly invokes and affirms Huw Price's tenseless theory of time which denies that time and change (as common-sensically understood and experienced) are objective features of our world. The only "problem" with this view is that it makes ALL time and change and flowing illusory, while giving all moments of time fully determinate ontological status (i.e., fully real status). Stated differently, what the tenseless theory of time amounts to is nothing less than the assertion that there is nothing at all in reality which corresponds to one state of affairs ceasing and giving way to another. Moreover, according to this view, each moment of time involving the awareness of, say, a human being, will contain an incredible and ineradicable ERROR which I illustrate as follows: Imagine watching your son running in a marathon race which, to all appearances, he is about to win and, indeed, eventually does win. Now according to the tenseless theory of time, all those "changing" states of your son’s body MOVING from one position to the next are complete illusions. In reality, the whole race, from start to finish, is immutably and timelessly incorporated within the so-called Block Universe.

If this seems a bit too recondite, imagine that you have filmed the race with a VCR camera and have taken the film home and stored it in a vault. Now past, present, and future events in the Block Universe have precisely the same status as each moment & movement of your son's body does in that race immutably captured on VCR film and stored in a vault. This may be too steep a price to pay for those who wish to solve the problem of Time's Arrow via the tenseless theory of time -- possibly.

(iv) Then there is the old problem of the classical and QM boundary. Vic attempts to solve this problem by setting up an adamantine duality between the macroscopic realm and the microscopic QM realm. He seems to be telling us that causal precedence (real time and real change) may be actually existing *emergent properties* of many-body systems -- he even seems to endorse Ludwig Boltzmann's proposal that the arrow of time of common experience is a purely statistical phenomenon, meaningful only for large numbers of particles. Yet, on the other hand, he tells us that there is no distinction between cause and effect (i.e., no time at all) in the microscopic QM realm. This is fine by me hypothetically speaking. However, does not this set up Vic up for a vicious infinite regress of sorts: for we can we not always ask the question (ad infinitum) as to precisely what happens at the classical and QM boundary? And how can that which is timeless (the QM realm) give rise to real change and time asymmetry? A dualism of this kind cannot answer such questions I believe.

Therefore the solution to this conundrum is to collapse the duality in favor of either (a) the tensed theory of time or (b) the tenseless theory of time. That is to say, if one opts for the ontological reality of time, change, and flowing then at least some of the interpretations of the formalisms of QM, STR, GTR must change. In fact, GTR gives us good reasons to believe that spacetime is something real, and is a kind of thing which can, in consonance with the laws of nature, exist independently of material things (energy and matter and whatever else), and which can be properly characterized as having its own properties above and beyond the properties of any material things (including energy) which may occupy it. Speaking the language of, for example, "gravitational waves" gives credence to such talk, moreover.

On the other hand, if one opts for the unreality of time and change, then one must apply this theory at ALL levels -- QM, mesoscopic, and macroscopic – as does Hwu Price I believe (but I am not sure though). I think Price realizes that he cannot have temporal symmetry at the QM level and also have temporal asymmetry at the mesoscopic and macroscopic levels. Indeed, he says: "...how would things seem if time did not flow? If we suppose for the moment that there is an objective flow of time, we [still] seem to be able to imagine a world which would be just like ours, except that it would be a four- dimensional block universe rather than a three-dimensional dynamic one. It is easy to see how to map events-at-times in the dynamic universe onto events-at- temporal-locations in the block universe. Among other things, our individual mental states get mapped over, moment by moment. But then surely our copies [of ourselves] in the block universe would have the same experiences that we do -- in which case they are not distinctive of a dynamic universe after all. Things would seem this way, even if we ourselves were elements of a block [i.e., *static*] universe." Further study of these matters is called for on my part ASAP. I hope the essence of what I am trying to communicate is getting through to someone, even though I lack the powers of articulation and knowledge to express them properly.

A Fellow Student Having Difficulty in Learning Difficult Things,