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Quantum Trickery - Einstein's Strangest Theory 531

Posted by ScuttleMonkey
from the fun-with-physics dept.
breckinshire writes "The New York Times is running an interesting story on Einstein's strangest theory. The theory was brought to light this past fall when 'scientists announced that they had put a half dozen beryllium atoms into a "cat state." [...] These atoms were each spinning clockwise and counterclockwise at the same time.' It is an interesting writeup for even the uninitiated and also concentrates on Einsteins role as a 'founder and critic of quantum theory.'"
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Quantum Trickery - Einstein's Strangest Theory

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  • Founder? (Score:3, Funny)

    by benna (614220) <mimenarrator@g m a i l .com> on Wednesday December 28, 2005 @06:23AM (#14350920) Journal
    I suppose that is why Planck's Constant is named after him.
    • Re:Founder? (Score:3, Informative)

      by Anonymous Coward
      Einstein was a founder of quantum theory, along with Planck, Heisenberg, Pauli, Dirac, Schrodinger and many many more. There was no single founder.
      • Re:Founder? (Score:5, Funny)

        by labyrinth (65992) on Wednesday December 28, 2005 @11:06AM (#14351785)
        Planck, Heisenberg, Pauli, Dirac, Schrodinger and Einstein are each the single founder of quantum mechanics in different superimposed universes. It is impossible for us to find out in which of these universes we live without killing all the cats,
        • ...and name it Schrodinger. Then I can break physicists' brains (ie return the favour for what they usually do to me) by wearing this tee-shirt while out surfing with my cat:
          Schrodinger
          rules the waves
          • Of the worst type, from the New York Pravda. I would rip it myself, but spacetimecurves.blogspot.com did a good job, already.

            Quantum Fluff and the Rodham-Clintoris Uncertainty Principle

            Nowhere is the "he-said-but-she-said" style of journalism more pretentious and annoying than in The New York Pravda.

            Example #1: the Science Times' piece on "Quantum Trickery: Testing Einstein's Strangest Theory", where we are told that:

            This fall scientists announced that they had put a half dozen beryllium ato

      • Re:Founder? (Score:5, Funny)

        by ultranova (717540) on Wednesday December 28, 2005 @05:54PM (#14354224)

        Einstein was a founder of quantum theory, along with Planck, Heisenberg, Pauli, Dirac, Schrodinger and many many more. There was no single founder.

        Of course there was a single founder, but his identity is uncertain. Whenever you ask a scientist, you can't be certain beforehand who he'll name; you can only say that the founder will be named as a certain person with certain propability.

    • by Anonymous Coward
      They had something to do with it.
    • Re:Founder? (Score:2, Informative)

      by krazikamikaze (888506)
      Sure, it's called Plank's constant because Plank was the first to assume energy was quantized, but it was just seen as a mathematical trick (to make the correct prediction for black body radiation) until Einstein used it to explain the photoelectric effect.
    • Re:Founder? (Score:5, Informative)

      by Beolach (518512) <(beolach) (at) (juno.com)> on Wednesday December 28, 2005 @06:35AM (#14350952) Homepage Journal
      It says "a founder", not "the founder". Einstein and Planck can both be considered joint founders of quantum theory, along with Bohr, Heisenberg, Schrödinger, and others.
      • But didnt Einstein spend most of his later life trying to prove that quantum mechanics was just new age hippie physics? From what I understand he only came up with the whole EPR thing because he wanted to make quantum physics look bad, because it conflicted with his base of "nothing can go faster than light"
        • Re:Founder? (Score:5, Informative)

          by Edward Kmett (123105) on Wednesday December 28, 2005 @08:20AM (#14351161) Homepage
          The EPR (Einstein, Podolsky and Rosen) states WERE originally proposed as an attack on quantum mechanics, but the argument swung the other way.

          Strangely enough, almost all of the power of quantum computing derives from the strange consequences of this would-be counter-example.

          Quantum teleportation and basically all of other quantum computation tricks use qubits in EPR states, but even 'teleportation' doesn't really allow sending information faster than light, since you have to send conventional bits of information about the observations in order to reconstruct the quantum state on the other end.

          So in one sense, the original Einstein concern about information traveling faster than the speed of light is valid. It just takes a different form to fit into quantum mechanics.
          • EPR does not allow communication because the states of the entangled matter in question cannot be known prior to measurement at the end points and is completely random.

            EPR does suggest (and this has been proven in tests) that states measured at one side of the entangled matter are exactly opposite of those on the other side thus enabling a method of distribution of random sets without comprimise (as measuring in transit violates the sets).

            So, if you want to call it teleportation, go ahead, just understa

        • Re:Founder? (Score:5, Informative)

          by Beolach (518512) <(beolach) (at) (juno.com)> on Wednesday December 28, 2005 @08:37AM (#14351196) Homepage Journal
          Yes and no. There were several aspects of the some of the emerging quantum theories that Einstein argued against, but that's actually a significant part of how he contributed to the development of quantum mechanics; and really all of the founders of quantum mechanics did the same thing: when Bohr, Heisenberg and Pauli first proposed the Copenhagen interpretation (as of 1997 the most widely-accepted interpretation of quantum mechanics), Einstein didn't approve of it - but neither did Planck or Schrödinger. And there were several theories that form the basis of quantum mechanics that Einstein developed. So just because he argued against aspects of quantum theory that are now generally accepted, does not mean that he wasn't a significant contributor to its development.
    • Re:Founder? (Score:5, Informative)

      by kisak (524062) on Wednesday December 28, 2005 @12:52PM (#14352449) Homepage Journal
      I guess you wanted to be funny, but the joke is on you. The Planck constant was named the Planck constant by Einstein himself, who was the first to understand that the constant Planck introduced in his equations to derive the black body radition law actually was a fundamental physical constant. (Planck himself just thought it was a clever mathematical trick). Einstein assumed that light comes in quanta (the so-called photon) to explain the photo-electric effect, and Einstein understood that the Planck constant gives the size of the quanta (together with the frequency of the light). In 1905 Einstein created the fundament of quantum mechanics and relativity with two ground breaking articles, while a third paper on Brownian motion gave the first direct evidence for the existence of atoms. Not bad for a Swiss patent clerk.

      As a side note, the history is a bit similar to the Boltzmann constant which was named by Planck after he understood that the constant Boltzmann had introduced in his equation (giving a microscopic theory of entropy) was one of the fundamental physical constants.

  • by Saven Marek (739395) on Wednesday December 28, 2005 @06:27AM (#14350925)
    Support one of the sites giving this story for free. Google news link [google.com.au]
  • Correction: (Score:2, Funny)

    by Anonymous Coward
    "To a physicist, a "cat state" is the condition of being two diametrically opposed conditions at once, like black and white, up and down, or dead and alive."

    Actually, this term was coined by Nikola Tesla and refered to his observations of the violent sub-molecular reaction created when a cat with a cheese pizza tied to its back is dropped onto expensive carpeting. What, you didn't think that his silly "death ray" is what caused the Tunguska event, did you?
  • by User 956 (568564) on Wednesday December 28, 2005 @06:30AM (#14350935) Homepage
    Einstein said there would be days like this.

    This fall scientists announced that they had put a half-dozen beryllium atoms into a "cat state."

    No, they were not sprawled along a sunny windowsill. To a physicist, a "cat state" is the condition of being in two diametrically opposed conditions at once, such as black and white, up and down, or dead and alive.

    These atoms were each spinning clockwise and counterclockwise at the same time. Moreover, like miniature Rockettes, they were all doing whatever it was they were doing together, in perfect synchrony. Should one of them realize, like the cartoon character who runs off a cliff and doesn't fall until he looks down, that it is in a metaphysically untenable situation and decide to spin only one way, the rest would instantly fall in line, whether they were across a test tube or across the galaxy.

    The idea that measuring the properties of one particle could instantaneously change the properties of another one (or a whole bunch) far away is strange to say the least -- almost as strange as the notion of particles spinning in two directions at once. The team that pulled off the beryllium feat, led by Dietrich Leibfried at the National Institute of Standards and Technology, in Boulder, Colo., hailed it as another step toward computers that would use quan- tum magic to perform calculations.

    But it also served as another demonstration of how weird the world really is according to the rules known as quantum mechanics.

    The joke is on Albert Einstein, who, back in 1935, dreamed up this trick of synchronized atoms -- "spooky action at a distance," as he called it -- as an example of the absurdity of quantum mechanics.

    "No reasonable definition of reality could be expected to permit this," he, Boris Podolsky and Nathan Rosen wrote in a paper in 1935.

    Today, that paper, written when Einstein was a relatively ancient 56 years old, is the most cited of Einstein's papers. But far from demolishing quantum theory, that paper wound up as the cornerstone for the new field of quantum information.

    Nary a week goes by that does not bring news of another feat of quantum trickery once only dreamed of in thought experiments: particles (or at least all their properties) being teleported across the room in a microscopic version of "Star Trek" beaming; electrical "cat" currents that circle a loop in opposite directions at the same time; more and more particles farther and farther apart bound together in Einstein's spooky embrace now known as "entanglement." At the University of California, Santa Barbara, researchers are planning an experiment in which a small mirror will be in two places at once.

    Niels Bohr, the Danish philosopher king of quantum theory, dismissed any attempts to lift the quantum veil as meaningless, saying that science is about the results of experiments, not ultimate reality.

    But now that quantum weirdness is not confined to thought experiments, physicists have begun arguing again about what this weirdness means, whether the theory needs changing, and whether in fact there is any problem.

    This fall, two Nobel laureates, Anthony Leggett of the University of Illinois and Norman Ramsay of Harvard University, argued in front of several hundred scientists at a conference in Berkeley about whether, in effect, physicists are justified trying to change quantum theory, the most successful theory in the history of science. Leggett said yes; Ramsay said no.

    It has been, as Max Tegmark, a cosmologist at the Massachusetts Institute of Technology, noted, "a 75-year war." It is typical in reporting on this subject to bounce from one expert to another, each one shaking his or her head about how the other one just doesn't get it.

    "It's a kind of funny situation," N. David Mermin of Cornell University, who has called Einstein's spooky action "the closest thing we have to magic," said, referring to the recent results. "These are extremely difficult experiments that
  • Ah ha (Score:5, Funny)

    by Auckerman (223266) on Wednesday December 28, 2005 @06:30AM (#14350937)
    This is just further proof that we are living in the Matrix. With each and every absurd observation, man is getting closer to the truth that we are the cat in the box.
    • Chances there are that we are the box.
  • by User 956 (568564) on Wednesday December 28, 2005 @06:32AM (#14350940) Homepage
    "The New York Times is running an interesting story on Einstein's strangest theory. The theory was brought to light this past fall when 'scientists announced that they had put a half dozen beryllium atoms into a "cat state."

    Wouldn't that be Schroedinger's strangest theory?
    • Moreover, I thought Einstein was referring to the uncertainties of the quantum theory (i.e. Schrödinger's cat) when he said, "God does not play dice", meaning that he didn't accept it. Anyone care to enlighten me?
      • by pnewhook (788591) on Wednesday December 28, 2005 @09:30AM (#14351326)
        Moreover, I thought Einstein was referring to the uncertainties of the quantum theory (i.e. Schrödinger's cat) when he said, "God does not play dice", meaning that he didn't accept it. Anyone care to enlighten me?
        To severely paraphrase, Einstein believed the unverse has a fundamental, simple order to it. To have random unknown chance (for example the probability waves) be part of the equation severely bothered him and was the fundamental part of quantum physics that he could not accept. That was also why he believed there was some model underneath quantum physics that would predict and bring determinism to the randomness.
      • by Sique (173459) on Wednesday December 28, 2005 @09:46AM (#14351395) Homepage
        Quite easy. A. Einstein took the Quantum Theory and tried to get very, very strange predictions from it. Basicly he did what Science is about: To test the theory, he used it to predict the outcome of certain experiments.

        Most of the predictions appeared completely absurd to him, and he wrote papers about those (like the Bose-Einstein-Condensate or the synchronous state as mentioned in the article). Because of the counterintuitive results he was getting from applying Quantum Theory he doubted its validity.

        But most of the described experiments weren't feasible at the time they were thought out. Some of them are right now, and the Bose-Einstein-Condensate is a reality, and this article in the NYT describes another one of the strange predictions being proved.

        So with doubting the predictions of Quantum Theory and describing experiments to falsify them A. Einstein in fact lead the way to the advancement of the same theory he had his problems with. That's a fine example of how Science is supposed to work: Always try to find contradictions to the theories and describe experiments which might falsify the theory. Advancement of Science doesn't care if you believe the theories to be correct. Every new hypothesis has its bugs and rough edges which can only be corrected if someone actually finds experiments where the bugs show up.
  • by Phariom (941580) on Wednesday December 28, 2005 @06:33AM (#14350942)
    "To a physicist, a "cat state" is the condition of being two diametrically opposed conditions at once, like black and white, up and down, or dead and alive."

    Or something happy to have its tummy rubbed only to bite you seconds later.
  • by Yirimyah (884895) on Wednesday December 28, 2005 @06:35AM (#14350953) Homepage
    Don't expect to understand. We evolved to run around on a plain and throw spears at antelopes, so we shouldn't be suprised when we don't understand complex things.
  • Should one of them realize, like the cartoon character who runs off a cliff and doesn't fall until he looks down, that it is in a metaphysically untenable situation and decide to spin only one way, the rest would instantly fall in line, whether they were across a test tube or across the galaxy.


    Do I read that right and they created entangled atoms, giving us possible faster than light communications? Or is this just the usual journalists misreporting of scientific facts?
    • by RedLaggedTeut (216304) on Wednesday December 28, 2005 @06:47AM (#14350978) Homepage Journal
      Strange that you bring up that entangled atoms allow faster than light communication.

      The known problem with this is that no information actually is transferred as far as we know; it is is only acquired at both ends at the same time (that is, you can't decide what you read).

      Entangled atoms allow safe FTL cryptography though, because uncovering and reading the state of the atom creates a bit of a key that is shared at both ends.

      • by Kjella (173770) on Wednesday December 28, 2005 @09:30AM (#14351325) Homepage
        The known problem with this is that no information actually is transferred as far as we know; it is is only acquired at both ends at the same time (that is, you can't decide what you read).

        Entangled atoms allow safe FTL cryptography though, because uncovering and reading the state of the atom creates a bit of a key that is shared at both ends.


        Not really FTL, it's more like a read-once OTP. You entangle two atoms, which is like creating two identical OTPs (even though you do not know the values). You then split the atoms (OTPs) at sub-light speed. You can then read out the same OTP at both ends. You still need to encrypt/send at sub-light speed/decrypt. The big point is that the OTP is verifiably *one time*, it can not be read twice. I suppose you can call it "security by quantum obscurity", since the entire point is that the key is kept behind a veil of quantum mechanics.
    • No, you may have not read that right. Entanglement (AKA spooky action at a distance) is all about faster than light communication (between the particles) but it can not be used for communications like a walkie-talkie. I didn't RTF(NewYork Times)A, but I read one I found with news.google and that one made that point pretty clear.
    • by judmarc (649183) on Wednesday December 28, 2005 @08:08AM (#14351141)

      If I remember some of the stuff I've read correctly, it's a bit more complicated than the article's summary made it seem, and no, it doesn't make FTL communication possible.

      What the experiments have shown is that if A and B are "entangled," then whatever state A is observed to be in, B will be in that state also, regardless of whether A and B are too far apart at the time the observation is made to have any communication with each other. This can be thought of as Einstein characterized it, as "spooky action at a distance," i.e., the observation of A somehow affects B (which is what makes the action spooky, since there is no known way for any information to be communicated between the two). However, it can also be thought of in other ways - for instance, that A and B were in the same state when they were entangled (though there's no way to determine that for sure, since the states aren't observed at that time), and the observations of A and B are just showing the states they've "always" been in. In the latter way of thinking, the spooky part is that these randomly selected particles always turn out to have the same state when observed. It's like sticking your hand into your sock drawer 100 times at random and always coming up with matched pairs.

  • by RedLaggedTeut (216304) on Wednesday December 28, 2005 @06:38AM (#14350958) Homepage Journal
    I believe the existance of a working quantum theory means that the universe can be considered as a simulation insofar as there might exist a universe without quantum physics and just particle physics.

    Now assume someone with insufficient knowledge about such a universe who tries to model a simulation to get predictions, much like having for of war in a strategy game - when a unit disappears into fog of war (since x turns ago), it would be essentially in all places that in could reach in x turns at once.

    An interesting question then might be, is then human knowledge and usage of quantum theory a desired property of the simulation, or an artifact that invalidates the simulation results?
    • As in: The granularity (bits) of the computer would be the Planck scale, and the top speed of the computer's operations would be the speed of light.

      • As in: The granularity (bits) of the computer would be the Planck scale, and the top speed of the computer's operations would be the speed of light.

        Well yes and no. That is a completely different angle. The "real" universe I was talking about might have quantums and planck squales as well.
        But I can add something to your point of view:

        • gravity might equal clustering of processors with similar tasks
        • a black hole would be a cluster that was so busy that it would be almost unable to communicate with the r
      • and the top speed of the computer's operations would be the speed of light. But it still wouldn't be able run Duke Nukem Forever...
    • by meringuoid (568297) on Wednesday December 28, 2005 @08:15AM (#14351153)
      Now assume someone with insufficient knowledge about such a universe who tries to model a simulation to get predictions, much like having for of war in a strategy game - when a unit disappears into fog of war (since x turns ago), it would be essentially in all places that in could reach in x turns at once.

      Not quite. That would be what's called a hidden variables [wolfram.com] system: the unit still does have a real location, which is tracked by the program, even if it's inaccessible to an observer within the system. However, that doesn't appear to be the way our universe works; the Bell inequalities [wolfram.com] show that hidden variables are incompatible with locality.

      • Quoting from Wolfram:

        However, at present there are no "clean" experiments unambiguously verifying the inequalities.

        In addition to that, I am not stating that the program does have hidden variables, but that the program uses quantum logic to treat unknown states. Of course these would collapse somewhere, but not necessarily at the time of the measurement from our human POV; That is, if it is not necessary for a measurement to know a hidden variable it will not be determined.

        This matches in some respec

    • I believe the existance of a working quantum theory means that the universe can be considered as a simulation insofar as there might exist a universe without quantum physics and just particle physics.

      This is extremely doubtful, as it is hard to see how there could even be particles without quantum physics. What would these particles be? Infinitesimal points? If so, how could they react?
  • by putko (753330) on Wednesday December 28, 2005 @06:39AM (#14350960) Homepage Journal
    One thing I got from the article is that physicists don't really care that the Quantum mechanics doesn't make sense at the macro level, nor that there isn't a clear boundary between big systems and quantum systems.

    That's the whole point of the cat-in-a-box: if an electron can be superposed, why not a whole cat? And what does that say about reality, if the quantum theory makes no sense? E.g. our sense of reality says the cat is either alive or dead, not both. Hence, shouldn't an electron be one or the other? Q.T. says no.

    That "why" issue is the sort of thing that troubled a philosopher-type like Einstiein --- someone who wonders "why?" compulsively is likely to keep on digging. The physicists seem happy to crunch the numbers, do an experiment and see if it agrees with the numbers.

    Which is in keeping with my observations of physicists: they are essentially applied mathematicians. Mathematicians (like Einstein) are a different sort.

    • by Vellmont (569020) on Wednesday December 28, 2005 @07:26AM (#14351060)
      As Richard Feynman pointed out, "why" is a question of philosophy, not science. The question why has no end. Why do electrons repel each other? That no one knows, they just do. I might go so far as to say it can't be known. Most people stop asking why when they get an answer they're familiar with. Science deals with questions of how. How do electrons repel each other? Well, current theory says that photons travel from one electron to another and push them apart.
    • by thesandtiger (819476) on Wednesday December 28, 2005 @09:39AM (#14351362)
      There are, broadly speaking, two types of scientist - theorists and experimentalists.

      Theorists focus on the "why" (to some extent, but really more of a "how") - "Why don't we see starlight in every portion of the sky?" leads to a question of "What are the possible scenarios in which we would see the sky as we see it?" leads to theories - "We see the night sky the way it is because [...]"

      Experimentalists then enter the picture. "Well, if [...] was the reason for the sky looking as it does, then we should find X and Y traits also." Then they do their experiments and record the observations. Sometimes, those observations match up with the theoretical predictions. Sometimes, those observations are almost, but not quite right, and sometimes they're incredibly far off, and everyone needs to go back and look for sources of difference.

      Now, you dismiss experimentalists as being just "applied mathematicians" (or, at least, that is certainly what your tone implies - they're somehow less relevant, valuable, whatever than "pure" mathematicians) - however, one cannot be terribly effective without the other.

      Some scientists are exceptional at both theory and experiment - Issac Newton would be an excellent example of that fusion. Some are pure theorists - Einstein is a poster child for those folks. And some are pure experimentalists - Hubble would be my pick as an archetypical experimentalist.
  • by theheff (894014) on Wednesday December 28, 2005 @06:45AM (#14350974)
    If you were to look at a clock backwards, the hands would be moving counter-clockwise from your perspective. It's all relative. So in theory, both could be happenning at the same time.
    • by Anonymous Coward
      what if you were to look at a clock from it's (the clock) perspective. would the hands be moving clockwise or counter-clockwise?
    • by kirinyaga (652081) on Wednesday December 28, 2005 @07:49AM (#14351102) Homepage
      In fact, the spin stay the same from any perspective. I.e. the particle is "spinning" exactly the same way whatever the angle you look at it : you watch it from the top, from the left, from behind, you always see it spinning clockwise, a bit like if it turns to face you. It's call the "spin" because its property _looks_ like it was spinning, but the particle doesn't really move or turn. Actually, a particle doesn't have a form, it isn't a sphere. Form is like temperature : temperature being the average speed of individual atoms inside a set of atoms, temperature only exist at a macro level, that is for a large set of atom. For a single atom, temperature doesn't exist. It's the same for form, thus for "spinning". Those are called _emergent_ properties (i.e. properties of a whole that cannot be predicted from properties of the parts), and they are meaningless for particles. In the case of this weird instant remote "action", the two linked particles are in fact a _single_ entity. There is no sending of information since the two are only one "thing" : the two don't have the same property, the particle pair have a property. Indeed, for the same reason particles doesn't have a form, their _identity_ is not what you may think. If two particles have exactly the same property, they, err, _it_, is the same particle. And, since it is a property of the pair, you cannot choose it, thus sending information, the particle pair just has it. Of course you can select particle pairs with the property you want before sending them apart, but then they have to travel at the speed of light, no instant communication is possible. And whatever you do by acting on one won't do anything to the other, they just share the same property. Thus, what is troubling is not this but the fact that before you "look" at a particle property, the particle has all the values this property can take at once (e.g. clockwise AND counterclockwise). When you "look" at it, when you try to measure the property, one of this value is then selected. The paradox is while the previous experiment seems to tell us this value is chosen from the beginning (particles seems to share an initial property, revealed once you look at them), the quantum mechanics proves the actual value you observe is randomly selected at the time you observe it and not before. What is tranported by the particles from the time they are emitted is not the value of the property but the very property itself. Another reason why a particle properties define this particle identity : particles doesn't have a "soul", an inner hidden self thing, they only are what they appear to be.
  • by sl4shd0rk (755837) on Wednesday December 28, 2005 @06:57AM (#14350994)
    Nevertheless, he would be pleased.
    http://www.phobe.com/s_cat/s_cat.html [phobe.com]
  • by broothal (186066) <christian@fabel.dk> on Wednesday December 28, 2005 @07:22AM (#14351051) Homepage Journal
    Bohr and Heisenberg made a popular interpretation of the duality paradox called The Copenhagen Interpretation [wikipedia.org]. Needless to say, Einstein disagreed with this interpretation.
  • by ultracool (883965) on Wednesday December 28, 2005 @07:34AM (#14351077)
    "Most physicists agreed with Bohr, and they went off to use quantum mechanics to build atomic bombs and reinvent the world."

    Why do they always have to use the atomic bomb as an example of the applications of quantum mechanics? It really gives it a bad name.
    • "Why do they always have to use the atomic bomb as an example of the applications of quantum mechanics?"

      It's the only way to get some Americans interested in science. ;)

      [obligatory karma-burning acknowledgement goes here]
  • by minkwe (222331) on Wednesday December 28, 2005 @07:36AM (#14351079) Journal
    The core of this issue is one of epistemiology. Bohr and his followers want to transfer a property of the mind (knowledge) to a property of nature (reality).

    It's like saying, something happens in reality only the very moment you know it. Turn on CNN, and all what they are reporting on, just happened at that very moment you learnt of it, and if you did not hear it or know it, then it did not happen! Crack!

    An electron has a specific velocity, whether any person knows it or not. The probability distribution of the electron's velocity (wavefunction) is not a property of nature as Heisenberg states, but a property of our minds (lack of complete information). When that value is finally measured, we have a single value rather than a wavefunction (complete information). It is our minds that have changed, not reality. Therefore it is crack to say the electron has many velocities (wavefunction) before measurement but as soon as it is measured, it collapses (wavefunction collapse) into a single value.

    The strangest part of this is that this blatant confusion has not totally incapacitated the usefulness of quantum mechanics. Imagine what will happen if more physicists could get their ducks in line and properly understand why Quantum mechanics works. Einstein was on track. Others have followed him and been able to do great things, although clearly disagreeing with the "spooky action at a distance" "copenhagen" interpretation. Such as Schrödinger, Edward Thomson Jaynes, the father of "maximum entropy".

    ET Jaynes wrote about the possibility of doing a thesis under Oppenheimer:

    After some months of correspondence I first met J. R. Oppenheimer in September 1946, when I arrived at Berkeley as a beginning graduate student, to learn quantum theory from him -- the result of Bill Hansen having recommended us strongly to each other. When in the Summer of 1947 Oppy moved to Princeton to take over the Institute for Advanced Study, I was one of four students that he took along. The plan was that we would enroll as graduate students at Princeton University, finish our theses under Oppy although he was not officially a Princeton University faculty member; and turn them in to Princeton (which had agreed to this somewhat unusual arrangement in view of the somewhat unusual circumstances). My thesis was to be on Quantum Electrodynamics. ...
    But, as this writer learned from attending a year of Oppy's lectures (1946-47) at Berkeley, and eagerly studying his printed and spoken words for several years thereafter, Oppy would never countenance any retreat from the Copenhagen position, of the kind advocated by Schrödinger and Einstein. He derived some great emotional satisfaction from just those elements of mysticism that Schrödinger and Einstein had deplored, and always wanted to make the world still more mystical, and less rational. ...
    If this meant standing in contradiction with the Copenhagen interpretation, so be it; I would be delighted to see it gone anyway, for the same reason that Einstein and Schrödinger would. But I sensed that Oppy would never tolerate a grain of this; he would crush me like an eggshell if I dared to express a word of such subversive ideas. I could do a thesis with Oppy only if it was his thesis, not mine.

    http://bayes.wustl.edu/etj/etj.html [wustl.edu]
    Oppy is Oppenheimer.

    Quantum mechanics works, there is no question about it. The question is why does it work. IMHO, the majority of physicists today are backing up the wrong tree -- the copenhagen interpretation. Further progress is, thus being hindered.

    • by Anonymous Coward
      I'm afraid you have misunderstood the EPR paradox.

      look up Bell's inequality. You will see that *no amount* of extra information 'hidden' from us but carried by the particles can explain the observed phenomena of both EPR entangled particles and the distribution of states observed at one end.

      QM in that sense is not shown to be incomplete by EPR. it is truly non-local. Or there are many universes. It is not at all the case that an electron 'has a velocity' and we don't know it. It really does only have a velo
      • Electrons don't carry information. Information is a property of the mind not reality. And that's the part you don't get.

        I just dropped a coin on my floor. Tell me what I got, Heads or Tails. Or tell me that I got 50% heads and 50% tails, and the moment I finally tell you the TRUE results, what I got automatically changes.

        You see, there is a difference between TRUTH and KNOWLEDGE(information). What you know about my coin is just that, information, not reality.

        BTW my post was not about the EPR paradox. But y
        • I don't know enough/anything about quantum mechanics to agree or disagree, but I don't really like your distinction between our minds and reality/nature. Our minds are a part of nature, and all the knowledge contained in them is a part of nature. Anything we observe is through interaction with other parts of nature. Perhaps you can rephrase your arguments to take that into account?
      • And if an electron does not have a velocity before measurement, then what are you trying to measure?
    • It's like saying, something happens in reality only the very moment you know it. Turn on CNN, and all what they are reporting on, just happened at that very moment you learnt of it, and if you did not hear it or know it, then it did not happen! Crack!

      Firstly, just because they say something on CNN doesn't mean it actually happened. But that's got nothing to do with this discussion.

      Secondly, you're inferring too far. You can't discount perspective from measurement, perspective being a point in space an

      • If a tree falls in the woods and no one's there to hear it, does it make a sound? The correct answer is: Who gives a shit?

        The tree does, as far as there are people trying to say the tree is 50% standing, and 50% fallen. Just like the cat being 50% alive and 50% dead.

        Now the more reason why you should "give a shit" also is because, your ability to reason correctly depends on how you answer the question.

        Do you also believe that an electron does not have a velocity until it is measured? Then don't even bother
    • by bad mechanic (649757) on Wednesday December 28, 2005 @09:55AM (#14351430)
      Sorry man, but you're just wrong. If this was actually just an incompleteness of information, then the classic double slit experiment wouldn't work. When the experiment is done emitting just one photon at a time, if the particle always has a specific location and speed in time then the experiment would break and you wouldn't get the interference pattern, you'd just get two bands of light on the target. However, since the position of the photon actually is indeterminist until measurement, it interferes with itself, thus creating the interference pattern, even though only one photon at a time is being emitted.

      It has withstood rigorous experimentation. Just because you do not understand Quantum Mechanics (very few people, if that, would claim to understand Quantum Mechanics) doesn't make it false.
    • "I could do a thesis with Oppy only if it was his thesis, not mine."This is very common in Academia, especially the experimental sciences, in fact, if you want to do a thesis with someone famous and reputable, as I had the experience with a world authority on a topic, you better be humble enough to bin your ideas for a good while and do his, however hard you try to be assertive and however nice he may try to be. It just won't work out otherwise. If this is not the case, you're not working with someone impor
    • "Bohr and his followers want to transfer a property of the mind (knowledge) to a property of nature (reality)."

      Hey, mind and reality are not diametrically opposed opposites, as 3000+ years of western philosophy would have you believe.

      I think in order to move forward, we are going to have to have a better idea about the relationship between mind and reality.

      Note: I am not saying that people create reality with their minds or anything like that. All I am saying is that mind and reality are not opposites.
  • by Vellmont (569020) on Wednesday December 28, 2005 @08:02AM (#14351130)
    Anytime quantum mechanics is brought up among a non-science crowd (sorry, desipte the geekyness of slashdot, the moderation and general comments I see indicate it's a non-science crowd) you wind up getting half-truth mystical garbage like this [imdb.com] and this. [imdb.com] The more hard to understand it is, the more people will come up with their own, wrong interpretations.
    • The more hard to understand it is, the more people will come up with their own, wrong interpretations.

      There is no such thing as "wrong interpretation".

      If there was "wrong interpretation" then there would be "right interpretation" also.

      But, the very meaning of the word "interpretation" is "not the original".

      Because interpretation is not the original, it is always, always misleading (or, plainly put, false).

      When we say that something is a mystery we mean we don't understand it. There is only one kind of pers

      • There is no such thing as "wrong interpretation"

        Sorry, but in science there is. If you don't like being wrong I suggest you take up a pursuit like philosophy.


        The scientific community tends to fall into "I am quite satisfied with my understanding of the universe" crowd.

        I don't know where you got this idea, but it's exactly the opposite. Science deals with things that AREN'T understood. Scientists, by definition are people who aren't satisfied with the "explanations" (science is about understanding and pre
  • by misanthrope101 (253915) on Wednesday December 28, 2005 @08:22AM (#14351165)
    This subject is why I always sneer a bit when I hear/read a 'concerned Christian' pontificating on the unscientific nature of evolutionary theory. You find dozens and dozens of pages of closely worded arguments slicing the meaning of words ever so closely, delving deep into semantics and epistemology to show that evolution isn't really science, that methodological naturalism doens't really follow the evidence wherever it may lead, and so on. But the sound and fury are only heard concerning evolution--I have yet to see any of these ur-skeptics pop up with "how can you treat a theory as fact? why are you lying to our children" when the topic is any other branch of science.

    The real kicker is that evolutionary theory makes sense on an intuitive level. Random variation + natural selection = genetic change. Genetic change + time = a lot of change. Divergent change = speciation. I'm no scientist--I'm not even that bright. But the ideas are simple and elegant if you make even a token effort to understand. Not so with quantum mechanics. It means what again? If any thse creationists or ID advocates were actually moved by their supposed skepticism about methodologial naturalism, they would be up in arms about quantum mechanics. Instead you hear what from them? Silence. The only branch of science that their profound, deeply conscientious, implacable intellectual integrity can concern itself with is the only one that has implications for a simplistic reading of Genesis. Every time I read "I'm no creationist, but I can't stand by when our children are sold half-baked theories as fact!" I want to crack up laughing. Quantum mechanics is such an easier target because maybe 50 people worldwide really understand it (okay, I'm exaggerating, but by how much?) and high school teachers probably don't make a large percentage. If the issue were just the nature of methodological naturalism, or the limits of human knowledge, or the nature of science, then evolution would never be the easiest target. But as it is, it's the only target.

    Perhaps I'm coming late to this realization. Despite my noted cynicism, the very act of debate requires a little respect for the opposing view. But if the opposition is just flat-out lying, not only about their facts, but about their very motivating premises, then what is there to talk about? I guess it had to come to this eventually--if the other side really thinks you are working for the devil, you can't help but call them kooks sooner or later. What else is there?

    No, this post o' mine didn't address quantum mechanics. It's just that the sheer inscrutability of the subject (to me) got me to wondering--where are all the gadflies who normally come out of the woodwork with dire warnings about passing off rank theory as fact? Where are the lessons in the scientific theory, the exhortations to "prove" it before we poison the minds of the next generation?

    • by meringuoid (568297) on Wednesday December 28, 2005 @10:20AM (#14351530)
      Quantum mechanics is such an easier target because maybe 50 people worldwide really understand it (okay, I'm exaggerating, but by how much?)

      I'd say by about 50.

    • by ronys (166557) on Wednesday December 28, 2005 @10:28AM (#14351581) Journal
      Simple, really:

      1. Evolution theory is, in essence, simple. You've described it pretty accurately in a couple of sentences. It's also very simple to misunderstand, e.g., get only the "random variation part". Quantum mechanics is so counter-intuitive as to be considered incomprehensible.

      2. Evolution theory poses a clear and present danger to the religious worldview, insofar as one of the strongest (perhap the strongest) cases for belief in a diety is the argument from design ("can you imagine a building without a builder?" etc.). The whole point of evolution undermines this argument: Yes, it is possible to get from something simple to something complex without a "designer". Quantum mechanics, OTOH, falls under "god works in mysterious ways" to most folks.

    • by Jerf (17166) on Wednesday December 28, 2005 @12:30PM (#14352307) Journal
      where are all the gadflies who normally come out of the woodwork with dire warnings about passing off rank theory as fact?

      All over the place. They just aren't connected to religion (or at least not major religions), so they don't get the microphone of a major religious organization.

      Hang out on one of Usenet's science groups, or look through the archive, and you'll find all sorts of kooks with all sorts of theories "proving" QM, or General Relativity (link to examples) [google.com], or Gravitation, or the accepted theories of Cosmology, wrong.

      The thought has crossed my mind [jerf.org] that more people would be more upset about physics if they realized how thorougly it contradicts their ideas about how the universe works, and really, that statement isn't just limited to the religious, either. But most people live in varying states of blissful ignorance, and ultimately, that's probably just fine.
  • That if a tree falls in a forest and no one is there to hear it
    it makes no sound?
  • Isn't it possible that the reason we find this so difficult to grasp is because of our perception of reality? We perceive these particles purely in four dimensions but if it was the case that there was only a single particle moving in a dimension that intersected with the four we are capable of perceiving we would see much the same effect. Any action on one "particle" would affect all the others, because they are actually the same particle. Similarly, one particle could exist in two mutually exclusive state
  • by digitaldc (879047) * on Wednesday December 28, 2005 @09:07AM (#14351272)
    Such an influence, or disturbance, would have to travel faster than the speed of light. "My physical instincts bristle at that suggestion," Einstein later wrote.
    Bohr responded with a six-page essay in Physical Review that contained but one simple equation, Heisenberg's uncertainty relation. In essence, he said, it all depends on what you mean by "reality."


    This reminds me of the quote by the great Neil Peart "the more we think we know about, the greater the unknown."
  • by GuyFawkes (729054) on Wednesday December 28, 2005 @09:16AM (#14351287) Homepage Journal
    it's bloody obvious that nothing can spin clockwise and anticlockwise simultaneously.

    this is an experiment in heisenbergs closed box, it's not factual, it's not real world, it's a thought experiment in the realms where we have a whole bunch of other thought experiments that attempt to explain the real world.

  • by Himring (646324) on Wednesday December 28, 2005 @09:25AM (#14351309) Homepage Journal
    This fall, two Nobel laureates, Anthony Leggett ... and Norman Ramsay ..., argued in front of several hundred scientists about whether physicists are justified trying to change quantum theory. Leggett said yes; Ramsay said no.

    And then, the two scientists began spinning clockwise and counterwise at the same time....

  • by couch_warrior (718752) on Wednesday December 28, 2005 @10:14AM (#14351512)
    This article, in it's attempt to maximize the "weirdness factor", ignored what I find to be the most palatable explanation of quantum uncertainty. That is that the universe is five-dimensional. What makes everything seem so wierd is that we are not neutral observers. Our conciousness is created by phenomena that only exist when confined to a three-dimensional snapshot of that universe. We percieve the fourth dimension as time, because it allows our three dimensional snapshot to change as we move in the fourth dimension. We perceive the fifth dimension as probability because it allows multiple possible paths into the future. When an experiment, like determining the spin of one electron out of a pair of emitted electrons shows a particular outcome, the spin of the other particle is not magically changed. Instead we are simply determining which of two possible paths into the future our three-dimensional snapshot of reality happens to have taken. When we compare our results to a distant test of the spin of the other electron, we are not experiencing super-luminal communications, we are simply limited from seeing any other spin for that electron because of our limited three-dimensional conciousmess which can encompass only one state for that particle, which has to be compatible with the state discovered for its fellow electron.

    The real surprise here is how very limited our intelligence is, and how little of the true universe we are able to percieve. It is a terrible conceit to believe that we are a neutral observer capable of impartially observering the universe. We literally create our reality by observering it because our reality is a tiny three-dimensional slice of all possible realities. The universe isn't weird, we are just hopelessly myopic.

    This interpretation has the benefit of proving Einstein right. God does not play dice with the universe. Since it is commonly accepted that God would transcend the Universe, his conciousness would be at least five-dimensional. He would be simoultaneously aware of all possible paths into the future. When we pick one, we experience a true free-will choice, but the transcendent observer knows which path we will pick - without affeting the nature of the choice iteself. As a side benefit, free will and omniscience are reconciled, and one of the major arguments against the existence of God crumbles into dust.

    We aren't programs in the Matrix, we are ants in an ant farm - trapped in a tiny little slice of reality.
  • by MECC (8478) on Wednesday December 28, 2005 @11:15AM (#14351836)
    Even subatomic particles have to put up with politicians...

  • by Medievalist (16032) on Wednesday December 28, 2005 @01:20PM (#14352656)
    From the article:
    ...quantum theory, the most successful theory in the history of science...
    I wonder how much crack one must smoke daily to be a science journalist.
    • Quantum is a theory, based on completely counter-intuitive postulates, which predicts completely ludicrous sounding experimental results, many years before we are technologically advanced enough to carry out the experiments. NO other theory has ever come close to the impact of quantum physics - to not only explain these really strange results, but to predict them many years before they could be tested. Einstein considered many of his thought experiments to be a way to show that quantum physics was an inco
  • by robert.elliott.smith (941856) on Wednesday December 28, 2005 @01:58PM (#14352889)

    Some people commenting on this thread will find the transactional theory of quantum mechanics [washington.edu] (powerpoint) of interest. (Less clear cut paper in HTML here [washington.edu]).

    In my opinion, this is the most reasonable, extant interpretation. From my perspective, it says that the paradoxes of QM are perceptual, arising from our perception of time as entirely forward moving. If waves move backwards in time (as in the transactional theory), everything makes sense, though it won't appear to make sense to us.

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