• Oct 18 2011

    WITS Node Seminar: Prof. Julian Barbour (University of Oxford)

    The National Institute for Theoretical Physics, and the Centre for Theoretical Physics, School of Physics, would like to invite to its coming talk in the theory seminar series, entitled:

    "Gravity as Machian Shape Dynamics"

    to be presented by Prof. Julian Barbour (University of Oxford)

    Abstract: Shape Dynamics, described in arXiv: 1105.0183, is an alternative theory of gravity inspired by Mach's penetrating critique of Newton's concepts of absolute space and time. Mach's ideas were the primary stimulus to Einstein's creation of general relativity, but he attempted to implement them indirectly. Shape Dynamics is a direct implementation and requires that time, position, and size should all be relative. Relativity of size, realized through three-dimensional conformal invariance, is a symmetry requirement that Einstein did not invoke, but leads rather remarkably to a classical theory that agrees with Einstein's general relativity in the so-called constant-mean(extrinsic)-curvature (CMC) foliation and provides a first-principles dynamical derivation of York's invaluable method for solving the initial-value problem of general relativity. There are indications that, through its different symmetry principle and introduction of a distinguished notion of simultaneity, Shape Dynamics may be better suited to quantization than general relativity. I shall concentrate on the conceptual aspects, which relate to the centuries-old debate about the nature of time, space and motion, and keep the technical details to the essential minimum.

    Date: Tuesday, 18th October 2011
    Venue: Frank Nabarro Lecture Theatre P216
    Time: 13.20 - 14.10

    For more information please contact:

    Alan S. Cornell

    School of Physics
    University of the Witwatersrand
    Private Bag 3
    Wits 2050
    South Africa