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Published online 30 April 2008 | 453, 22-25 (2008) | doi:10.1038/453022a
News Feature
Physics: Quantum all the way
How does our classical world emerge from the counterintuitive principles of quantum theory? Can we even be sure that the world doesn't 'go quantum' when no one is watching? Philip Ball talks to the theorists and experimentalists trying to find out.
Keith Schwab builds bridges. By most people's standards, they are very small bridges indeed: around 8 thousandths of a millimetre long and 200 millionths of a millimetre wide, visible only under a microscope.
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This is something quite extraordinary – a decoherence theory that attempts to link the illusive quantum realm to the realistic classical realm. Quantum theory bends on AND/OR, a thing can be both AND as well as OR simultaneously, whereas classical theory suggests otherwise. Quantum phenomena continue to split physicists into camps. The 'Tao' of Physics would continue to exert its presence. In the final analysis, the thing that can be described is not Tao, the thing that can be named cannot be Tao too. Perhaps the mystic Lao-Tzu has been right all this time. (Tan Boon Tee)
Decoherence by itself cannot explain the quantum-classical transition; it must be supplemented by the many-worlds interpretation. This is because while decoherence destroys interference amongst alternatives, it preserves superpositions, since it works within the framework of linear quantum mechanics. An alternate explanation for emergent classicality, not ruled out by experiments, is that quantum mechanics is modified, say to a non-linear theory, on mesoscopic scales. As a result of the non-linearity, the life-time of a quantum superposition becomes dependent on the number of degrees of freedom of the system, and goes to zero for large systems. Experiments should be attempted, to test for the presence/absence of non-linearity in quantum mechanics on the mesoscopic scale. T. P. Singh, Tata Institute of Fundamental Research, Mumbai
Very good review of Philip Ball of the 'hottest potato' in quantum physics. That's clear that decoherence is the main obstacle on the way to macroscopic entanglement. So, does it mean that this phenomena is possible only at ultra low temperature at conditions of macroscopic Bose condensation, like superfluidity or superconductivity? I have developed the physical model, describing possible mechanism, turning the mesoscopic Bose condensation (coherent molecular clusters) to macroscopic one, via intermediate stage of IR photons exchange between these remote in water coherent clusters. The nonuniform macroscopic Bose condensation (BC) can be a result of remote EM interaction and entanglement between cluster in state of mesoscopic Bose condensate (i.e. coherent water clusters inside the microtubules of neurons). This system of nonuniform macroscopic BC is coherently 'flickering' with frequency 10^6 - 10^7 per second of simulateneous disassembly - assembly of huge number of water clusters inside the same microtubule and remote microtubules also. This mechanism is described in chapter "Cycle of Mind" of my recent book: “The Hierarchic Theory of Liquids and Solids. Computerized Applications for Ice, Water, and Biosystems†(2008), just published by Nova Science Publ. (NY, USA). This book is also available online: http://arxiv.org/abs/physics/0102086 . This theory proves new basic idea of coherent water clusters, as mesoscopic Bose condensate, since they are located in the volume of 3D de Broglie standing waves, related to molecular librations. Using Hierarchic theory based computer program, I can calculate over 300 physical parameters of water, including number of molecules in clusters and their life-time in wide T-range. The results of evaluation of dimensions of water clusters in ice and water are presented in my book: http://arxiv.org/ftp/physics/papers/0102/0102086.pdf in section 6.3.4, see Figs. 6 and 7. I hope that this new approach to condensed matter problems will be also useful in understanding of macroscopic entanglement and nonlocality phenomena, which looks to be much more general phenomena, than it is accepted. Alex Kaivarainen alex@h-systems.be http://web.petrsu.ru/~alexk
According to some theories the thermo-quantum dynamics of an open system obeys a nonlinear Schrodinger equation (arXiv:0711.1442). The linear Schrodinger equation is applicable only to closed systems but they are not present in the Nature due to the infinite range of the fundamental interactions (the only exception is probably the whole Universe). Therefore, the linear Schrodinger equation is an approximation and this questions the accuracy of many effects due to the superposition principle following from to its linearity. Thus, the Fourier transform and Wigner function are no more applicable, while the Bohmian mechanics seems more plausible (arXiv:0803.4409). Another example is the traditional theory of decoherence, which is based on a linear master equation and hence the decoherence takes place continuously in time. According to the new theory, the entropy (information) exchange between the system and its environment results in a nonlinear Schrodinger equation. Therefore, from the very beginning decoherence takes place, thus solving the contradiction between quantum and classical reality immediately. For instance, in the Schrodinger cat paradox the entropy of mixing causes non-linear terms in the Schrodinger equation and hence the outcome is either alive or dead cat but never a linear superposition of these excluding events.
The Anthropic principle tells us that the observer cannot be separated from what is observed. Observation alwys plays a role. obervation implies consciousness and consiousness is always consciousness of something. Consciousness is an act of making a distiction between what something is and what it is not. Thus the act of becoming conscious is equivalent to making a distinction. This distiction creates a boundary that defines what someting is and what it is not. Consciousness is an act of symmetry breaking and the creation of a duality of complementary opposites. What something is not is both the negation of what something is and it is also the inverse of what something is. as the domain of waht something is gets larger the domain of what something is not decreased by an equivalent amount. Now we can ask what is the nature of this boundary? First it has two sides and an space that is excluded from either domain. It is in this exclued middle that things are neither one thing or the other, but rather are both and neither. This is the incompleteness that Godel speaks of, the sum of both domains is incoplete becasue they do not include this exclued middle. or we could view this as in included middle where the two domains over lap, where something is both what it is and what it is not. the ratio of this middle space to the sum of the two opposiing domains is afunction of whether we see two things as similar or as differnt. In truth any tow things are both similar in some ways and differnt in other ways so that where we draw the boundary is rather arbitrary.this middle is also Heisenbergs space of uncertianty. Now in this transitional space, the interaction between one domain (something) and the other Domain (what it is not) is fractal. Thus as one moves upscale the exluded middle gets smaller and smaller but it never completely goes away, as we go down scale it gets larger and larger Thus the smallest scale has the widest transition space, the highest degree of uncertainty while the largest scale has the smallest transition space and the least degree of uncertainty. WHy is this so? it is because observation requires that one use energy to probe and measure the world. aas we probe deeper the energy requires increases to such a degree that it produces a great change in the world. Observation also requires that we take up a position and motion,a spatial-temporal location, relative to what we are observing.It it this spatial temporal relationship that established the values of rules and clocks and thus determines the nature of our measurments there are no absolute rulers or clocks they are all relative. And since there are many positions and many motions from which we can observe there are also many differnt worlds to be seen but any single observer can only see one of these worlds, Two twins moving apart at the speed of light will each observe the other as aging slower but in truth they are both aging at the same rate . When they turn around and approach each other each will observe the other as aging very quickly, but in fact botha re aging at the same rate so that when they come back together they will be the same age. In Shrodinger's Cat, if there is only one radioactive atom the time it will decay is not definable and as we open a row of boxes each with a cat and one atom whill will find that the distribution of live and dead cates is totaly random,But in each box a cat will be either alive or dead, But we do not know which is true untill we open the box, the uncertianty is due to a lack of information and not due to the fac that the cat exists in limbo (he exists in limbo only in regards to us. Now if we put a 10oo cats in a box with a 1000 radioactive atoms then we can acke at what time will hlf the cats be dead and hlf alive and we can predict this time with a high degree of certainty This certianty arises becasue we ignore th uncertianty of which atoms decay. all we are interested is when 50% of the atoms decay not which 50% becsue the atoms are identical they are indistinguishable, and it is this indistiguishability that creates order out of disorder. But this indistiguishability is not simply as quatity of the atoms themselves but rather the quality of our observations Obervations are a function ofour spatial-temporal location which determines the scale of our observations and the nature of the distictions that are possible,it is the act of observation which detemines what we see, Just as it is the nature of our beliefs which detemine the meaning of data and create facts. Just as facts are implicit in the theroy , the theory is implicit in the facts Whether we see symmetry or asymmetry is a function of our perspective, A we can dig holes in a flat field and pile up the dirt. since the dirt piles are equal in volume to the holes whethee we see symmetry or symmetry depends upon our perspective in the one case the symmetry is explacity and the asymmetry is implicit and in the other case the symmetry is implicit and the asymmmetry is explict in a fractal structure of superimposed waves, arrythmia (no way or rhythm, pure noise) is the same as an infinite numner of superimposed waves which produce aperiodicity. A peroidicity is equivalent to aperoidicty with only a change in scale. thus zero and infinity constitute a duality where each is the negative inverse of the other. But Hiesenberg tells us that there can be no singularity and thus we get close enough that the system undergoes a negative inversion, reflection and rotation (a twist), many worlds interpretation if we line up people in a circle around the north pole the needles of their compasses will each point toward the ssme spot but while point in differnt directions. If we sum all the vectors whe would get no vector at all. Now if you stod exactly at the north pole the compass whould spin wildly it would serve for a direction but there is no direction, Thes constiture a view from the outside and a view form the inside, both all directions ans no directions are the same. It is only when we separate ourselves from the north pole that we get a direction but there are as many directions as there are obervers. a particular Direction is an illusion that occurs because we we take up a particular position. point in all directions an if you are above the north pole the needle will point down. but if you stand exactly at the center the needle would oscillate trying to pint in all directions. Ie the many worlds superimposed as opposed to the singular world of a single individual. the oscillation or wave function has collapsed