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Gravity and BECs

  1. Apr 10, 2005 #1

    wolram

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    http://arxiv.org/PS_cache/gr-qc/pdf/0503/0503067.pdf

    arXiv:gr-qc/0503067 v1 16 Mar 2005
    Can Spacetime be a Condensate?
    B. L. Hu
    Department of Physics, University of Maryland,
    College Park, Maryland 20742-4111, USA
    (Dated: March 14, 2005)
    We explore further the proposal [1] that general relativity is the hydrodynamic limit of some fundamental
    theories of the microscopic structure of spacetime and matter, i.e., spacetime described by a differentiable manifold is an emergent entity and the metric or connection forms are collective variables valid only at the low energy, long wavelength limit of such micro-theories. In this view it is more relevant to find ways to deduce the microscopic ingredients of spacetime and matter from their macroscopic attributes than to find ways to quantize general relativity because it would only give us the equivalent of phonon physics, not the equivalents of atoms or quantum electrodyanmics. It may turn out that spacetime is merely a representation of collective state of matter in some limiting regime of interactions, which is the view expressed by Sakharov [2]. In this talk, working within the conceptual framework of geometro-hydrodynamics, we suggest a new way to look at the nature
    of spacetime inspired by Bose-Einstein Condensate (BEC) physics. We ask the question whether spacetime could be a condensate, even without the knowledge of what the ‘atom of spacetime’ is.
    We begin with a summary of the main themes for this new interpretation of cosmology and spacetime physics, and the ‘bottom-up’ approach to quantum gravity. We then describe the ‘Bosenova’ experiment of controlled collapse of a BEC and our cosmology-inspired interpretation of its results.
    We discuss the meaning of a condensate in different context. We explore how far this idea can sustain, its advantages and pitfalls, and its implications on the basic tenets of physics and existing programs of quantum gravity.
    - Invited Talk presented at the Peyresq Meetings of Gravitation and Cosmology, 2004. To appear in Int. J. Theor. Phys.
    Electronic address: hub@physics.umd.edu
     
  2. jcsd
  3. Apr 10, 2005 #2

    wolram

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    Can Spacetime be a Condensate?

    I am not sure, is spacetime noisy? maybe in quantum gravity.
     
  4. Apr 11, 2005 #3

    Mk

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    Space time is most definitely nosiy. The quantum fluctuations in spacetime were deriven by John Wheeler in 1955. It is called quantum foam, spacetime foam, and Wheeler foam, in his honor.
    http://www.pbs.org/wgbh/nova/elegant/media2/nav-chicon-3013_01.jpg
    The quantum fluctuations in spacetime are on the order of the Planck length, spacetime itself ceases to be smooth, and starts resembling instead, a rapidly changing foam, because of Heisenberg's Uncertainty Principle.

    The importance of quantum foam is that it is thought to give rise to virtual particles. They pop in and out of existance out of nowhere quicker than Planck time, so they do not succeed in violation of the 1st Law of Thermodynamics.

    Reginald Cahill developed process physics theory, it says space is a quantum foam system where gravity is an inhomogeneous flow of quantum foam into matter. According to this theory, the spiral galaxy rotation-velocity anomaly can be explained without the need of dark matter.

    A few weeks ago a galaxy was found that was and still is thought to be made almost completely out of dark matter.
     
    Last edited: Apr 11, 2005
  5. Apr 11, 2005 #4

    wolram

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    Gold Member

    By MK
    Space time is most definitely nosiy. The quantum fluctuations in spacetime were deriven by John Wheeler in 1955. It is called quantum foam, spacetime foam, and Wheeler foam, in his honor.
    http://www.pbs.org/wgbh/nova/elegan...con-3013_01.jpg
    The quantum fluctuations in spacetime are on the order of the Planck length, spacetime itself ceases to be smooth, and starts resembling instead, a rapidly changing foam, because of Heisenberg's Uncertainty Principle.

    The importance of quantum foam is that it is thought to give rise to virtual particles. They pop in and out of existence out of nowhere quicker than Planck time, so they do not succeed in violation of the 1st Law of Thermodynamics.

    Reginald Cahill developed process physics theory, it says space is a quantum foam system where gravity is an inhomogeneous flow of quantum foam into matter. According to this theory, the spiral galaxy rotation-velocity anomaly can be explained without the need of dark matter.

    A few weeks ago a galaxy was found that was and still is thought to be made almost completely out of dark matter.

    Thank you MK, I have some understanding of quantum fluctuations, when
    i asked is spacetime noisy i meant is it," detectably noisy in theory", The
    BEC approach seems to have possibilities.
     
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