Post 11: Sat Oct 29, 2011 4:49 pm


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In science a theory is a framework for answering all questions in its domain by making quantitative falsifiable predictions that are borne out by experiment. Quantum is that and spectactularly successful at it. There are those  the Positivists including Bohr  who claim that is all anyone can ever do. But this is the Philosophy forum. 'Why' is always a legitimate question here. 

Post 12: Sat Oct 29, 2011 6:03 pm


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I am concerned about the wellbeing of Schrödinger's Cat and pleased that the "Many Worlds" interpretation of quantum mechanics provides a safe haven for it in a nearby parallel world, separated from us only by an infinitesimal distance in the direction of a 4th spatial dimension. I know there is no experimental verification of this interpretation, but neither is there any verification of any other explanation for quantum wierdness. The popular claim that when an observer makes an observation, the "wave function" of the entire universe travels faster than light and instantly collapses to agree with his observation is a little too grandiose for my taste. It makes much more sense to me that all possibilities "really" exist simultaneously, that the observer's mind or awareness is constantly cycling or scanning through a number of nearby universes, and the result of an observation randomly locks or synchronizes his awareness to one particular world in which a particular result exists, together with any and all even very distant "entanglements" of that quantum result. The randomness is in the observer's mind, not in the external universe. After an observation, the observer's mind or awareness would have landed in another parallel universe, probably very similar to his previous one, with only a few differences at the quantum level, but very improbably in a much more distant and very different parallel universe. The observer would not be aware of this change, since his mind would now reside in the version of him existing in that new universe, and all his memories and perceptions would now come from that new 3D brain. This idea would explain at least some of the quantum wierdness. Of course, it also raises many more questions. What we see as a human being is really only a section or threedimensional "slice" of a much larger fourdimensional entity. What does a fourdimensional cat look like? John 

Post 13: Sun Oct 30, 2011 5:57 am


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Or that cat might be definitively saved or killed as the case may be by a spontaneous decoherence effect that may be natural to large systems without a conscious observer. I am a big fan of the multiverse on philosophical grounds but my version requires fairly strong isolation.


Post 14: Sun Oct 30, 2011 3:11 pm


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ThatGirlAgain wrote:
I prefer to believe that the cat is neither alive nor dead, but that all possible versions of it continue to "really" exist, some of them alive and some dead, distributed in accordance with the probabilities derived from quantum theory, each in its own separate 3D universe but all still part of a larger fourdimensional reality. From what little I understand about the modern idea of "decoherence," it seems to be a pathetic attempt to save the idea of a collapsing wave function while avoiding the need for a conscious observer. I am a little suspicious of theories that use words like "spontaneous" and "may be." When Everett's "Many Worlds" interpretation of quantum physics came out in 1957, I was fascinated. It seemed to offer the possibility of actually explaining something. I first became interested in physics and cosmology back in ancient times when I was in high school and read some of the books of Eddington, Jeans, and Gamow. Things were much clearer back then. Now we have been floundering around in String Theory for more than 30 years, producing a lot of "elegant" mathematics but absolutely no coherent theory and certainly no testable predictions. I have been reading the book, "The Trouble with Physics" by Lee Smolin. He is careful to avoid insulting any fellow theoretical physicists, but has some unkind things to say about String Theory. John 

Post 15: Sun Oct 30, 2011 7:52 pm


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Just because you say something has semantic content does not mean it does. I am holding that the proposition "A causes (B or C)" is meaningless like "God could create a stone so heavy He could not lift it" or "A square circle would be like this" are meaningless. It requires some enumeration of the meaning that builds into the concepts touched upon, but an understanding of those underlying concepts yields the fact that the only possible conclusion is one of negation. 

Post 16: Mon Oct 31, 2011 5:12 am


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The 'spontaneous' aspect is simply to distinguish it from observer dependent. Interactions with other entities that cause irreversible changes is what is the alleged cause of the decoherence. Personally that sounds more reasonable than requiring a conscious and presumably human observer to establish whether the cat is dead or alive. Doesn't the cat know? And the retroactive aspect of large scale wave function collapse is puzzling as well. The cat does not die on the spot but is already dead and partly decomposed. Or the cat has been alive and drunk all the milk. A different world branch is selected retroactively depending on the kind of observation made? In any case there is the issue that the status of the cat cannot be completely isolated from the outside world. The movement or lack thereof of the cat, even to the extent of breathing, will have immediate (subject to c) gravitational consequences for the entire universe. I know of Smolin's distaste for an extremely abstract branch of physics, a branch with a thousand different leaves on it, that so far is totally divorced from any observation. 

Post 17: Mon Oct 31, 2011 2:29 pm


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ThatGirlAgain wrote:
Too many questions have accumulated. It is time for another Einstein to appear. Not only the discovery of a few "hidden variables" is needed, but also a completely new way of thinking of reality. I liked the intuitive simplicity of Einstein's early model of the universe as a fourdimensional hypersphere, the center as the timeorigin and the 3D "surface" as our perceived universe. Now the String Theory idea of "branes" flapping around in 10dimensional spaces repels me and provides no intuitive picture of reality. Meanwhile, to get back to the subject of this thread: Randomness. Back when I was young and foolish, I was interested in gambling systems. To provide a sample of random events to test my ideas, I flipped a coin over a period of months for a total of 30,000 flips (I was a little compulsive). When I tabulated the results, I was surprised to find that the average length of "runs" in my sample was slightly longer than mathematically expected. Not much, but very statistically significant for a sample of that size. In other words, there seemed to be a slight tendency for a head to be followed by another head, a tail by another tail, etc. Later, when I started working as a computer programmer (only large very expensive mainframes existed then), I gave up on gambling systems after testing my ideas on much larger simulated samples and found they all eventually failed. However, the statistical deviation in my original sample of coin flips continued to trouble me. I had used many different coins, and could think of no explanation for it. More recently, I decided to try the experiment again, but this time carefully turned the coin over each time before flipping it again. After only 3000 flips, I found that the average length of runs was now slightly shorter than statistically expected!!! Have you ever heard of such a result? John 

Post 18: Sun Nov 06, 2011 4:25 pm


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Thus we could redefine randomness as: When something occurs for no reason that we can determine. Now, if we decide to assume there is a fourth dimension, then it would imply a universe that's totality is based not only on the laws of time and space. In the same way that the 3rd dimension can be thought of as a transcendent sum of infinite 2nd dimensional existences pieced together, so could be the same for the 3rd dimension in relation to the 4th. When we add the factor of depth to the two previous concepts of length and width, we get an increased amount of possible universes that equals infinity. Could a second dimensional being become aware of these new possibilities in the universe simply by being aware that there is something called depth, that transcends what it understood before about how it's decisions are made? Could we at some point become aware of infinite parallel universes by realizing another factor in our existence that transcends time and space? Assuming there are these parallel universes that take our existence in different directions, is it also possible that we are, at any given moment, unknowingly choosing out of infinite possibilities ahead of us in time, and entering into new universes with their own infinite sets of probabilities. If we can't know how these decisions are being made, due to our ignorance of this new factor in the fourth dimension, then can our actions be seen as random? I think it is relevant to take into consideration the idea that at any given moment, there are infinite factors determining how following events will be played out. Currently, we do not have a method for quantitatively measuring infinity. If this is true, then everything is to some degree random because we could never account for all the factors leading into how future events will occur. 

Post 19: Sun Nov 06, 2011 5:17 pm


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Your idea of parallel 3dimensional universes forming a larger 4dimensional reality is similar to my understanding of the "Many Worlds" interpretation of Quantum Mechanics proposed by Everett in 1957. (This is not the same as the current Multiverse of String Theory). In this view, reality consists of an infinity of 3D universes arranged like the pages of a book, in which each page represents a complete 3D universe, and the "thickness" of the book is a fourth spatial dimension. (not the same as the 4th dimension traditionally reserved for time) Slightly different versions of 3D reality simutaneously exist in these sidebyside universes. When an observer makes an observation of a quantum event, it is not the "wave function" of his universe that instantly collapses faster than light to agree with his observation. Instead, it is his own conscious awareness that randomly synchronizes or locks on to a particular nearby universe which contains a particular result of his observation, one of the many possible results predicted by the probabilities of Quantum theory. All other possible results continue to "really" exist as "real" in their own universes. In accordance with the probabilities calculated by Quantum theory, it is probable that his awareness will land in a nearby universe which is very similar to his old universe, except for a few microscopic quantum differences, but it is also possible but very improbable that his awareness could land in a distant universe which is very different. He could suddenly find himself to be a Klingon. He would not be aware of the change, since all his memories, perceptions, etc, would now come from his new Klingon 3D brain, and he would have no access to his old memories. In this idea, the observer is like the 2 dimensional flatlander described in the book, "Flatland" who is surprised to see the varying circular cross sections or 2D "slices" of a 3D sphere as it passes through his flat universe. Most of this is my own speculation, and certainly not contained in Everett's theory. A little more farout speculation would see us humans as merely 3D cross sections or slices of larger 4D entities existing in a larger 4D universe. John 

Post 20: Mon Feb 20, 2012 3:37 pm


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Science does not deal with an individual elementary event but with general patterns that can be found across large numbers of events  and physical experiments involve huge numbers of similar events, making possible to verify probability laws. So indeed it would not make scientific sense to question whether an individual elementary event with a couple of possible results, is random or not random, if this event was the only event that happened in the universe. But, in the case we are facing, that is a very large number of observations to be compared with the values of their respective probabilities calculated from a welldefined theory, then the claim that those events obey those probability laws, has all qualities of a scientifically falsifiable claim. Randomness can directly be falsified by expressing a rule that generates the given data. More generally and precisely, the claim of obedience of measured events to a given probability law, is the claim that "The optimal compression format of the file of observed data, is the format defined by this probability law". Ifever it is false, its falsity can readily be shown by finding a set of observed data and another compression format (expressing another probability law) that makes this file significantly shorter (say, more than 100 bytes shorter, which should not be hard for a gigabytes long file if there really were hidden causes) than with the format of the first probability law. Until now, the quantum probability law resisted quite well, at least in nonbiological systems, and possibly observed deviations from this law (in parapsychology) are very small. This is telling: randomness heavily exists in physics. On the other hand, there is a mathematical theorem essentially stating that as long as no explicit rule could be found, the belief that some large random piece of data would in fact be following some unknown hidden law, is unfalsifiable. This theorem was discovered by G. Chaitin. I summed it up (with the proof) in my metaphysics page (just seach "Chaitin" there).
So what ? Of two things one: Either the hidden causes produce a pattern of deviations of possibly observable results (= results of specially designed experiments able to display such deviations) away from the quantum probability law, in which case this pattern can be observed and tentatively expressed as new modified probability law (that may not be the ultimate one either, but already a proof that the first law was not a complete account of reality). Or it doesn't produce any such pattern in any possible observation, in which case any speculation about it remains futile and sterile for any purpose.
What these experiments exactly say cannot be summed up in so few words. Just telling that "classical" variables are impossible while "nonclassical" variables are possible, does not mean anything as it begs the question what is meant by "classical". To try to be more precise, it is a matter of whether this variable is local or nonlocal. What it says (or at least what it would say if it was verified with concious observers many thousands of kilometers apart, each able to immediately observe his local subsystem of a correlated system faster than light speed communication between them) is that the measurement result of a physical system at a given place cannot be locally determined by a hidden property (a hidden variable) of the measured system (or even of the local [system+observer]) that is a local property, which means a property that has no ability to be affected by a distant event (the measurement of another system) faster than the speed of light. Nor can it even be an independent (local) random effect with fixed probabilities determined by such hidden local properties. (Well I admit that the logical deduction of this result from possible observational verifications of quantum theory, is not completely rigorous as it assumes the possibility of a sudden free choice of what aspect of his system each observer will decide to measure, but... looking for a way around the conclusion here based on an assumed physical determinism of what observers would choose to measure, would be rather farfetched).
Decoherence is NOT an interpretation, but it is an effective physical property that can be deduced from quantum theory disregarding the choice of interpretation. Its precise definition is : A system S is said to have decohered with respect to a possible measurement M, if there will be no more difference on the probabilities of any future possible measurement of S, whether or not the wavefunction of S is assumed to be now already collapsed with respect to M. In other words, a decoherence is NOT a spontaneous collapse, but it is the description of the circumstances where the question whether a collapse happened or not, becomes unverifiable, so that the "already collapsed" hypothesis becomes compatible with the predictions of quantum theory on future measurement results (while a collapse before decoherence would violate the predictions of quantum theory on future measurements). However, this property of decoherence is an emergent property that only makes sense as a limit property of large systems instead of elementary ones, because it depends on which future measurements can remain possible or not in practice, and this is a fuzzy condition. It is not exactly an internal change, but an external irreversible loss of future opportunities to make measurements capable of deducing the past characters of the system expressed by components of the wavefunction that an hypothetical present collapse would destroy. In practice, decoherence happens as soon as (but not only if) a measurement has been "physically processed", in the sense that we have a macroscopic delivery of the measured result, that is, when the information of the result is "out of the box" with many copies of this information escaping in the environment, so that it cannot be anymore securely hidden by any further operation. Examples of physical circumstances that produce decoherence are already given here (even if we would not assume that cats have souls):
Quantum theory describes physical systems as locally (in every place of finite size at every given time) only having a finite (though large) "number of possible states" (with a concept of "number of possible states" that is a specifically quantum theoretical concept, but...). Thus any idea of a presence of an infinity of factors, must refer to nonphysical factors, if by "physical" we mean the kind of states of physical systems that quantum theory describes. Of course you may imagine that there are more physical aspects of systems than those described by quantum theory, but well, such other physical causes remained undetected yet.
Indeed and just as JonhPaul already mentioned, this is an effective, nonmetaphysical conception of randomness that is very important to the events of daily life, for example when you stumble on some preacher of a sect who tries to convince you that God has plans for your life and that your stumbling on him could not be a mere accident.
Imagine an experiment producing a linearly polarized photon, and its polarization is measured by some detector in another direction forming an arbitrary chosen angle with the direction of the arriving photon. In other words, it is an experiment with exactly 2 possible results with the "same quality" (one bit of stored information in the detector) but theoretical probabilities have an arbitrary value other than 1/2 each. Now can you make sense of the claim:
I think such a claim is logically inconsistent. In other words, the idea of "real existence" of all possible results, is logically incompatible with the conformity of the effective (observed) probabilities to those predicted by quantum theory. Thus, that the experimental verification of this conformity, refutes the idea of the "real existence" of all possibilities. Unless of course you find a way to make sense of the claim that a given precise scenario has x times more reality than an other if x is an irrational number, but I fail to figure out one now. Let's further push the examination of the thought experiment: Note that anyway, any possible "difference of quality" of the final state of the detector between both possible results, remains independent of the angle between the directions of arrived and measured polarization; and even if you consider the whole system "emitter + detector", I fail to see how to consider any "difference of quality" between its 2 possible final states (making the one "more frequent" than the other), in such a way that this "difference of quality" depends on the configuration of whatever optical device that could have been on the way of the photon and that could have modified the direction of polarization, without itself keeping any trace of its interaction with the photon. If a possibility is said to "more probably exist" than another as defined by the ratio of the numbers of possible "final states", then it all depends on the time at which you choose to stop the experiment and make the count of the number of possible "final states". You may as well decide to cheat by waiting longer (make more experiments...) in one case than in the other before doing the counting, so as to change the ratio of these numbers. Finally, I think such a metaphysical definition of "probability" turns out to be empty and incompatible with the effective (experimentally verifiable) meaning of "probability".
I think these two sentences contradict each other, expressing two very different and incompatible interpretations of quantum theory. The first sentence precisely expresses my own view, that is the "conciousness causes collapse" interpretation, where conciousness is beyond physics. The second sentence, claiming for an independent reality of all alternative possible results, gets conciousness out of the picture, or in other words, provides all possible results their own respective concious observers so as to make their respective "realities" worthy of that name. But if conciousness is divided (or multiplied) across all possibilities, then how can there still be anything "random", what is a probability, and how can it make any sense to claim that calculated probabilities are "correct" and can be or have been experimentally verified ? My own view, the "conciousness causes collapse" interpretation which I expressed in my metaphysics page, is that physical objects are not essential beings, but the only real things are:
 concious events (including concious perceptions of the physical world) 



