Electronic Newsletter -- #2 Spring, 1997

Items for this newsletter should be emailed to the editor: asgrg *AT* hotmail *DOT* com

  • Subscriptions due;
  • Logo competition winners: Michael Ashley and Geoffrey Ericksson (ANU);
  • ACGRG2, Sydney, 6-11 July, 1998, First Announcement;
  • 6th Monash GR workshop, 11-12 April 1997, Melbourne - report
  • GR15, 16-21 Dec 1997, Pune, India (3rd and final circular)
  • GR15, Gravitational wave detection session
  • ACGRG1 proceedings book announcement & order form
  • "Cosmology - Physics of the Universe" book announcement
  • Recent Australasian preprints on gr-qc
  • News snippets (large scale cosmological anisotropy?);


    The logo competition has been won by Michael Ashley and Geoffrey Ericksson of the A.N.U. for their entry depicting the Penrose diagram of the Schwarzschild spacetime superimposed on a map of Australia. A symbolic beam splitter has been added at t=0 to represent the activities of ACIGA. The resulting logo is thus similar to the cover of the ACGRG1 Proceedings, except that New Zealand and Papua New Guinea do not figure in the logo. This is not meant as a slight to members in those countries, but is simply a reflection of the fact that a logo must be simple, and with all the countries of the region included it becomes too cluttered.

    The result may be viewed on the ASGRG home page at


    The Sixth Monash Relativity Workshop was held on April 11-12, 1997 at the Department of Mathematics in Monash University (Clayton), to mark the occasion of Colin McIntosh's early retirement. The workshop, organised by Tony Lun was an intensive action packed two days, with 18 talks, including many aspects of relativity related to Colin's interests in relativity. There were 26 participants from Monash U., La Trobe U., Deakin U., James Cook U., A.N.U., and the Universities of Adelaide, Canberra, Sydney and Waterloo (Canada).

    Talks covered such wide-ranging ground as invariants of the Riemann tensor, perfect fluid and shear-free cosmologies and ultra-relativistic fluid dynamics, isotropic singularities, numerical relativity and gravitational radiation, Regge calculus, symmetry techniques applied to differential equations in relativity, black hole perturbations and thermodynamics, the thorny topic of signature change, an axiomatic approach to spacetime structure and computer tools for visualising geometry in relativity. The workshop finished with a joint talk by Colin and his student Khai Vu on "Desolv: a MAPLE package for solving differential equations".

    Highlights were the talks by Colin's former students Graeme Sneddon, Leo Brewin and Tony Lun, which gave a glimpse of the enormous work that Colin has done for Australian relativity in building up the group at Monash and in encouraging networking among the various groups in Australia. A number of anecdotes these speakers told vividly reflected the vitality of the group that Colin has built up. We wish Colin all the best in his early retirement to undertake fulltime church activities, and hope that he will still find occasions to drop in on our conferences and maintain some contact with the scene that he has contributed so much to.


                               Proceedings of
              12-17 February, 1996, Institute for Theoretical Physics,
                   University of Adelaide, South Australia.
                            Editor D.L. Wiltshire
    Published by Institute for Theoretical Physics, University of Adelaide, 1996.
    ISBN: 0-86396-430-3. 242 + vi pp. Paperback.
    Price A$ 20 (approx US $16), credit card payments accepted.
    To order click here.
    Contains 22 articles on classical relativity, numerical relativity, quantum
    gravity and gravitational wave detection.
    * A cosmological background of gravitational waves produced by supernovae in
      the early universe ... D.G. Blair and L. Ju
    * The development of technology for high performance laser interferometer
      gravitational wave detectors at the UWA ... C.N. Zhao et al.
    * Post-Newtonian smooth particle hydrodynamics
       ... M.C. Thompson and J.J. Monaghan
    * Einstein equations in the null quasi-spherical gauge: Progress report
      ... Robert Bartnik
    * Spectral collocation methods for solution of Einstein's equations in null
      quasi-spherical coordinates ... Andrew H. Norton
    * Computational methods in the physical interpretation of Robinson-Trautman
      spacetimes ... Daniel A. Prager and Anthony W.C. Lun
    * Using Riemann normal coordinates in numerical relativity
      ... Leo Brewin
    * An application of Regge calculus to axisymmetric initial data
      ... A.P. Gentle and L.C. Brewin
    * The cosmological singularity
      ... Peter Szekeres
    * The gravitational effects of cusps on cosmic strings
      ... Malcolm R. Anderson
    * Square of general relativity
      ... D.V. Gal'tsov
    * Remarks on the Yilmaz and Alley papers
      ... Edward D. Fackerell
    * On the key functions of axisymmetric gravitation
      ... P.C. Waylen
    * Debye potentials for the massless Dirac equation in algebraically special
      spacetimes ... Philip Charlton
    * Gauge invariant perturbations of black holes using the modified
      Newman-Penrose formalism ... Joe F.Q. Fernandes and Anthony W.C. Lun
    * How wrinkled is the surface of a black hole?
      ... Rafael D. Sorkin
    * Quantum cosmology, supersymmetry, and the problem of time
      ... Hugh Luckock
    * Solving the fine-tuning problem of inflation 
      ... Andrew Matacz
    * Quantum gravity: A brief review
      ... Tze-Chuen Toh
    * Holonomies in quantum gravity
      ... E.E. Wood
    * Pregeometric modelling of the spacetime phenomenon
      ... Reginald T. Cahill and Christopher M. Klinger
    * Polarisation of instantons in the SO(4) gauge theory results in gravity
      ... M.Yu. Kuchiev


            (Order from World Scientific or your local distributor)
                   Proceedings of the 8th Physics Summer School,
           Australian National University, 16 January - 3 February, 1995
                 Editors B. Robson, N. Visvanathan and W.S. Woolcock
    Published by World Scientific, Singapore, 1996.
    ISBN: 981-02-2513-X. 531 + x pages. Price: US$ 82.50. Hardcover.
    * Introduction to General Relativity ... M.R. Anderson
    * Classical Cosmology ... G. Boerner
    * Particle Physics Applied to Cosmology ... J. Ellis
    * Dark Matter in Galaxies ... K.C. Freeman
    * High Red-Shift Galaxies ... R.W. Hunstead
    * The Very Early Universe ... V.N. Lukash
    * The Hubble Constant and the Age of the Universe ... J. Mould
    * Topological Defects ... S.J. Poletti
    * Cosmological Implications of Nuclear Physics ... D.N. Schramm, C. Copi and
       X. Shi
    * The Epoch of Galaxy Formation ... J. Silk
    * Statistical Aspects of Large Scale Structure ... A.S. Szalay
    * Gravitational Lensing ... R. Webster and D. Mortlock
    * An Introduction to Quantum Cosmology ... D.L. Wiltshire

    Australasian postings to gr-qc or cross-listings in gr-qc since last newsletter (past 18 months):

    N.B. The Australasian mirror for the Los Alamos archive is now operational at

    Paper: gr-qc/9605018
    From: (<>)
    Date: Thu, 09 May 96 15:58:46 +0930
    Title: Pregeometric modelling of the spacetime phenomenology
    Authors: Reginald T. Cahill, Christopher M. Klinger (Dept. of Physics, Flinders
    Comments: 13 page LateX, no figures
    Journal-ref: Phys.Lett. A223 (1996) 313-319
      At present we have only the very successful but phenomenological Einstein
    geometrical modelling of the spacetime phenomenon. This geometrical model
    provides a `container' for other theories, in particular the quantum field
    theories. Here we report progress in developing a {\em Heraclitean Quantum
    System}. This is a particular pregeometric theory for space and time in which
    no classical or geometric structures are assumed, but rather the emergence of
    such phenomena is sought.
    Paper: gr-qc/9605029
    From: Neil Cornish <>
    Date: Thu, 16 May 1996 21:15:51 +1000
    Title: The mixmaster universe is chaotic
    Authors: Neil J. Cornish (Uni. Melbourne) and Janna J. Levin (UC, Berkeley)
    Comments: 4 pages, RevTeX, 3 figures included
    Report-no: UM-P-96/33, CfPA-96-TH-10
      For the past decade there has been a considerable debate about the existence
    of chaos in the mixmaster cosmological model. The debate has been hampered by
    the coordinate, or observer dependence of standard chaotic indicators such as
    Lyapanov exponents. Here we use coordinate independent, fractal methods to show
    the mixmaster universe is indeed chaotic.
    Paper: gr-qc/9606021
    From: Neil Cornish <>
    Date: Tue, 11 Jun 1996 22:10:58 +1000   (148kb)
    Date (revised): Wed, 29 Jan 1997 00:42:15 +1100
    Title: The Princess and the Pea
    Authors: Neil Cornish (DAMTP, Cambridge), Norm Frankel (Univ. Melbourne)
    Comments: 5 pages, RevTeX, 6 figures, revised and expanded version
    Report-no: UM-P-96/45
      Like a fairy-tale princess, trajectories around black holes can be sensitive
    to small disturbances. We describe how a small disturbance can lead to erratic
    orbits and an increased production of gravitational waves.
    Paper: gr-qc/9609016
    From: Neil Cornish <cornish@physics.unimelb.EDU.AU>
    Date: Sat, 7 Sep 1996 03:05:39 +1000
    Title: The black hole that went away
    Authors: Neil J. Cornish (Uni. of Melbourne)
    Comments: 1 page, RevTeX, no figures
    Report-no: UM-P-96/74
      A purported black hole solution in (2+1)-dimensions is shown to be nothing
    more than flat space viewed from an accelerated frame.
    Paper: hep-th/9610033
    From: Steven Brumby <spb@physics.unimelb.EDU.AU>
    Date: Mon, 7 Oct 1996 20:48:19 +1000
    Title: Global effects in quaternionic quantum field theory
    Authors: S.P. Brumby and G.C. Joshi (Melbourne Uni.)
    Comments: 11 pages, no figures, revtex
    Report-no: UM-P-96/88; RCHEP 96/11
      We present some striking global consequences of a model quaternionic quantum
    field theory which is locally complex. We show how making the quaternionic
    structure a dynamical quantity naturally leads to the prediction of cosmic
    strings and non-baryonic hot dark matter candidates.
    Paper: gr-qc/9610037
    From: Jonathan Kress <>
    Date: Wed, 16 Oct 1996 20:13:27 MDT
    Title: Debye Potentials for Maxwell and Dirac Fields from a Generalisation of
      the Killing-Yano Equation
    Authors: I. M. Benn, Philip Charlton and Jonathan Kress
    Comments: 35 pages, plain TeX
      By using conformal Killing-Yano tensors, and their generalisations, we obtain
    scalar potentials for both the source-free Maxwell and massless Dirac
    equations. For each of these equations we construct, from conformal
    Killing-Yano tensors, symmetry operators that map any solution to another.
    Paper: hep-th/9610194
    From: Hilary Booth <>
    Date: Fri, 25 Oct 1996 09:26:24 +1000 (EST)
    Title: The Dirac-Maxwell Equations with Cylindrical Symmetry
    Authors: Hilary Booth, Chris Radford (University of New England, Australia)
    Comments: 17 pages, Latex, 5 figures, psfig, to be published in J. Maths Phys
    Report-no: 96-125
      A reduction of the Dirac-Maxwell equations in the case of static cylindrical
    symmetry is performed. The behaviour of the resulting system of o.d.e.'s is
    examined analytically and numerical solutions presented. There are two classes
    of solutions.
     The first type of solution is a Dirac field surrounding a charged "wire". The
    Dirac field is highly localised, concentrated in cylindrical shells about the
    wire. A comparison with the usual linearized theory demonstrates that this
    localization is entirely due to the non-linearities in the equations which
    result from the inclusion of the "self-field".
     The second class of solutions have the electrostatic potential finite along
    the axis of symmetry but unbounded at large distances from the axis.
    Paper: hep-th/9610210
    From: Steven Brumby <spb@physics.unimelb.EDU.AU>
    Date: Mon, 28 Oct 1996 17:25:00 +1000
    Title: Implications of quaternionic dark matter
    Authors: S.P. Brumby, B.E. Hanlon and G.C. Joshi (Melbourne Uni.)
    Comments: 14 pages, RevTeX, no figures
    Report-no: UM-P-96/90; RCHEP 96/12
      Taking the complex nature of quantum mechanics which we observe today as a
    low energy effect of a broken quaternionic theory we explore the possibility
    that dark matter arises as a consequence of this underlying quaternionic
    structure to our universe. We introduce a low energy, effective, Lagrangian
    which incorporates the remnants of a local quaternionic algebra, investigate
    the stellar production of the resultant exotic bosons and explore the possible
    low energy consequences of our remnant extended Hilbert space.
    Paper: gr-qc/9611045
    From: Robert Bartnik <>
    Date: Fri, 15 Nov 96 15:15:17 GMT   
    Date (revised): Thu, 29 May 1997 17:10:14 MDT
    Title: Einstein equations in the null quasi-spherical gauge
    Authors: Robert Bartnik (University of Canberra)
    Comments: 12 pages, LaTeX (revtex, amssymb), revision 18 pages, contains
             expanded  discussion and explanations, updated references
    Journal-ref: Class.Quant.Grav. 14 (1997) 2185-2194
      The structure of the full Einstein equations in a coordinate gauge based on
    expanding null hypersurfaces foliated by metric 2-spheres is explored. The
    simple form of the resulting equations has many applications -- in the present
    paper we describe the structure of timelike boundary conditions; the matching
    problem across null hypersurfaces; and the propagation of gravitational shocks.
    Paper: gr-qc/9611063
    Date: Wed, 27 Nov 96 10:29:14 +1100
    Date (revised): Wed, 04 Dec 96 15:38:07 +1100
    Title: Inflation and the Fine-Tuning Problem
    Author: Andrew Matacz (University of Sydney, Australia)
    Comments: 5 pages in Latex (uses Revtex), no figures. Minor changes to the text
      I describe a recently derived stochastic approach to inflaton dynamics which
    can address some serious problems associated with conventional inflationary
    theory. Using this theory I derive an exact solution to the stochastic dynamics
    for the case of a $\lambda\phi^4$ potential and use it to study the generated
    primordial density fluctuations. It is found that on both sub and super-horizon
    scales the theory predicts gaussian fluctuations to a very high accuracy along
    with a near scale-invariant spectrum. Of most interest is that the amplitude
    constraint is found to be satisfied for $\lambda\sim 10^{-5}$ rather than
    $\lambda\sim 10^{-14}$ of the conventional theory. This represents a dramatic
    easing of the fine-tuning constraints, a feature likely to generalize to a wide
    range of potentials.
    Paper: gr-qc/9612011
    From: Philip Charlton <>
    Date: Tue, 3 Dec 1996 22:00:23 MST
    Title: Dirac symmetry operators from conformal Killing-Yano tensors
    Authors: I. M. Benn and Philip Charlton
    Comments: 8 pages, TeX
    Report-no: 96/28
      We show how, for all dimensions and signatures, a symmetry operator for the
    massless Dirac equation can be constructed from a conformal Killing-Yano tensor
    of arbitrary degree.
    Paper: quant-ph/9612016
    From: Don Koks <>
    Date: Tue, 3 Dec 1996 14:11:51 +1030 (CST)
    Title: Entropy and Uncertainty of Squeezed Quantum Open Systems
    Authors: D. Koks, A. Matacz and B.L. Hu
    Comments: 36 pages, epsfig, 2 in-text figures included
    Report-no: ADP-96-42/M50, umdpp 97-63, School of Mathematics and Statistics
      We define the entropy S and uncertainty function of a squeezed system
    interacting with a thermal bath, and study how they change in time by following
    the evolution of the reduced density matrix in the influence functional
    formalism. As examples, we calculate the entropy of two exactly solvable
    squeezed systems: an inverted harmonic oscillator and a scalar field mode
    evolving in an inflationary universe. For the inverted oscillator with weak
    coupling to the bath, at both high and low temperatures, $S\to r $, where r is
    the squeeze parameter. In the de Sitter case, at high temperatures, $S\to
    (1-c)r$ where $c = \gamma_0/H$, $\gamma_0$ being the coupling to the bath and H
    the Hubble constant. These three cases confirm previous results based on more
    ad hoc prescriptions for calculating entropy. But at low temperatures, the de
    Sitter entropy $S\to (1/2-c)r$ is noticeably different. This result, obtained
    from a more rigorous approach, shows that factors usually ignored by the
    conventional approaches, i.e., the nature of the environment and the coupling
    strength betwen the system and the environment, are important.
    Paper: gr-qc/9701046
    From: David Hartley <>
    Date: Tue, 21 Jan 1997 14:12:02 +1030
    Title: Tensor distributions on signature-changing space-times
    Authors: David Hartley, Robin W. Tucker, Philip A. Tuckey, Tevian Dray
    Comments: 9 pages, LaTeX 2.09
    Report-no: ADP 96-41/M49
      Irregularities in the metric tensor of a signature-changing space-time
    suggest that field equations on such space-times might be regarded as
    distributional. We review the formalism of tensor distributions on
    differentiable manifolds, and examine to what extent rigorous meaning can be
    given to field equations in the presence of signature-change, in particular
    those involving covariant derivatives. We find that, for both continuous and
    discontinuous signature-change, covariant differentiation can be defined on a
    class of tensor distributions wide enough to be physically interesting.
    \\ ( ,  11kb)
    Paper: gr-qc/9701057
    From: Leo Brewin <>
    Date: Tue, 28 Jan 1997 01:00:24 MST   (195kb)
    Title: Riemann Normal Coordinates, Smooth Lattices and Numerical Relativity
    Authors: Leo Brewin
    Comments: 49 pages, 18 epsf figures, plain tex
      A new lattice based scheme for numerical relativity will be presented. The
    scheme uses the same data as would be used in the Regge calculus (eg. a set of
    leg lengths on a simplicial lattice) but it differs significantly in the way
    that the field equations are computed. In the new method the standard Einstein
    field equations are applied directly to the lattice. This is done by using
    locally defined Riemann normal coordinates to interpolate a smooth metric over
    local groups of cells of the lattice. Results for the time symmetric initial
    data for the Schwarzschild spacetime will be presented. It will be shown that
    the scheme yields second order accurate estimates (in the lattice spacing) for
    the metric and the curvature. It will also be shown that the Bianchi identities
    play an essential role in the construction of the Schwarzschild initial data.
    \\ ( ,  195kb)
    Paper: hep-th/9702070
    From: Simon Davis <>
    Date: Sun, 9 Feb 1997 13:29:22 +1100 (EST)   (31kb)
    Title: Scalar Field Theory in Curved Space and the Definition of Momentum
    Author: Simon Davis
    Comments: 41 pages, TeX, 3 figures
    Report-no: DAMTP-R/96/8
      Some general remarks are made about the quantum theory of scalar fields and
    the definition of momentum in curved space. Special emphasis is given to field
    theory in anti-de Sitter space, as it represents a maximally symmetric
    space-time of constant curvature which could arise in the local description of
    matter interactions in the small regions of space-time. Transform space rules
    for evaluating Feynman diagrams in Euclidean anti-de Sitter space are initially
    defined using eigenfunctions based on generalized plane waves. It is shown
    that, for a general curved space, the rules associated with the vertex are
    dependent on the type of interaction being considered. A condition for
    eliminating this dependence is given. It is demonstrated that the vacuum and
    propagator in conformally flat coordinates in anti-de Sitter space are
    equivalent to those analytically continued from $H^4$ and that transform space
    rules based on these coordinates can be used more readily. A proof of the
    analogue of Goldstone's theorem in anti-de Sitter space is given using a
    generalized plane wave representation of the commutator of the current and the
    scalar field. It is shown that the introduction of curvature in the space-time
    shifts the momentum by an amount which is determined by the Riemann tensor to
    first order, and it follows that there is a shift in both the momentum and mass
    scale in anti-de Sitter space.
    \\ ( ,  31kb)
    Paper: gr-qc/9704074
    From: Don Koks <>
    Date: Sun, 27 Apr 1997 13:18:00 +0930 (CST)
    Title: Thermal Particle Creation in Cosmological Spacetimes: A Stochastic Approach
    Authors: Don Koks, B. L. Hu, Andrew Matacz, Alpan Raval
    Comments: 17 pages, revtex (aps, eqsecnum), submitted to PRD, April 1997
    Report-no: UMDPP 96-116
    Journal-ref: Phys.Rev. D56 (1997) 4905-4915
      The stochastic method based on the influence functional formalism introduced
    in an earlier paper to treat particle creation in near-uniformly accelerated
    detectors and collapsing masses is applied here to treat thermal and
    near-thermal radiance in certain types of cosmological expansions. It is
    indicated how the appearance of thermal radiance in different cosmological
    spacetimes and in the two apparently distinct classes of black hole and
    cosmological spacetimes can be understood under a unifying conceptual and
    methodological framework.
    \\ ( ,  31kb)
    Paper: gr-qc/9705079
    From: Robert Bartnik <>
    Date: Wed, 28 May 1997 17:40:18 MDT   (20kb)
    Title: Shear-free Null Quasi-Spherical Spacetimes
    Authors: Robert Bartnik
    Comments: 20 pages, revtex
    Report-no: UNE-MSCS-96-128
      The residual gauge freedom within the null quasi-spherical coordinate
    condition is studied, for spacetimes admitting an {\em expanding, shear-free}
    null foliation. The freedom consists of a boost and rotation at each coordinate
    sphere, corresponding to a specification of inertial frame at each sphere.
    Explicit formulae involving arbitrary functions of two variables are obtained
    for the accelerated Minkowski, Schwarzschild, and Robinson-Trautman spacetimes.
    These examples will be useful as test metrics in numerical relativity.
    \\ ( ,  20kb)
    Paper: hep-ph/9707324
    From: (Ruth A W Gregory)
    Date: Fri, 11 Jul 1997 14:40:19 +0100   (55kb)
    Title: Effective action and motion of a cosmic string
    Authors: Malcolm Anderson, Filipe Bonjour, Ruth Gregory and John Stewart
    Comments: 24 pages revtex, 12 figures
    Report-no: DTP/97/5, DAMTP/R-97/27
      We examine the leading order corrections to the Nambu effective action for
    the motion of a cosmic string, which appear at fourth order in the ratio of the
    width to radius of curvature of the string. We determine the numerical
    coefficients of these extrinsic curvature corrections, and derive the equations
    of motion of the worldsheet. Using these equations, we calculate the
    corrections to the motion of a collapsing loop, a travelling wave, and a
    helical breather. From the numerical coefficients we have calculated, we
    discuss whether the string motion can be labelled as `rigid' or `antirigid,'
    and hence whether cusp or kink formation might be suppressed or enhanced.
    \\ ( ,  55kb)
    Paper: gr-qc/9708013
    From: "" <>
    Date: Thu, 07 Aug 97 10:45:47 +0930 
    Title: Bootstrap Universe from Self-Referential Noise
    Authors: Reginald T. Cahill, Christopher M. Klinger (Flinders University)
    Comments: 10 pages, Latex
      We further deconstruct Heraclitean Quantum Systems giving a model for a
    universe using pregeometric notions in which the end-game problem is overcome
    by means of self-referential noise. The model displays self-organisation with
    the emergence of 3-space and time. The time phenomenon is richer than the
    present geometric modelling.
    \\ ( ,  10kb)
    Paper: gr-qc/9708039
    From: Leo Brewin <>
    Date: Tue, 19 Aug 1997 02:58:16 MDT   
    Title: An ADM 3+1 formulation for Smooth Lattice General Relativity
    Authors: Leo Brewin
    Comments: 18 pages, plain TeX, 5 epsf figues, gzipped ps file also available
              at this http URL
    A new hybrid scheme for numerical relativity will be presented. The scheme will
    employ a 3-dimensional spacelike lattice to record the 3-metric while using the
    standard 3+1 ADM equations to evolve the lattice. Each time step will involve
    three basic steps. First, the coordinate quantities such as the Riemann and
    extrinsic curvatures are extracted from the lattice. Second, the 3+1 ADM
    equations are used to evolve the coordinate data, and finally, the coordinate
    data is used to update the scalar data on the lattice (such as the leg
    lengths). The scheme will be presented only for the case of vacuum spacetime
    though there is no reason why it could not be extended to non-vacuum
    spacetimes. The scheme allows any choice for the lapse function and shift
    vectors. An example for the Kasner $T^3$ cosmology will be presented and it
    will be shown that the method has, for this simple example, zero discretisation
    \\ ( ,  38kb)


    Reprinted from:

    [Follow up papers ]
                      ALL SPACE IS NOT EQUAL:
    Physicists at the University of Rochester and the University of Kansas have
    found evidence that flies in the face of the long-held belief that space is the
    same in all directions (isotropic). In fact, measurements indicate something
    seldom considered by physicists: that the universe has an orientation. The
    unexpected finding, determined by measuring the polarization of light as it
    travels to Earth from the far reaches of the universe, is the subject of a
    paper in the April 21 issue of Physical Review Letters [Phys Rev Lett 78 (1997)
    The work, which may be one of the most fundamental findings about the universe
    in recent years, could affect physicists' views about the birth of the universe
    and suggests that scientists will need to explore how Einstein's theory of
    relativity and the theory of electromagnetism might explain the finding. That's
    quite an impact from an effect so tiny that it's betrayed only by light
    traveling across most of the observable universe, from 15 billion years ago.
    Physicists have dubbed the effect the "corkscrew effect" for the way it twists
    light crossing the heavens.
    "The big news is that perhaps not all space is equal, for as far back as we can
    peer in time," says Borge Nodland of the University of Rochester.
    Adds co-investigator John Ralston of the University of Kansas: "The shocking
    thing about our result is that there seems to be an absolute axis, a kind of
    cosmological north star that orients the universe. We don't really know yet
    what this axis represents."
    This axis of orientation is not a physical entity but rather defines a
    direction of space that somehow determines how light travels through the
    universe. In effect, Ralston and Nodland have discovered a direction in space
    that is out of the ordinary or different from all other directions. The idea
    that any direction of space is in any way "special" has long been taboo among
    "This work defies the notion that there is no 'up' or 'down' in space," says
    Nodland, research fellow at Rochester's Theory Center for Optical Science and
    From Earth, the axis of this orientation runs toward the constellation Sextans,
    roughly in the direction of Leo and Gemini and high in the southern evening sky
    this time of year. The other end of the axis points toward the constellations
    Aquila and Equuleus. (Stargazers, of course, will see nothing special when they
    look in that direction.) Nodland and Ralston, a professor of physics and
    astronomy at Kansas, say the axis might have several interpretations: It could
    be an intrinsic property of the universe, or it might indicate that an
    undiscovered particle, such as the long- theorized axion, is at work.
    The team made the finding by studying the polarization (orientation of electric
    fields) of radio waves from 160 distant galaxies as measured in previous
    experiments by astronomers around the world. Nodland and Ralston found that the
    plane of polarization of the light rotates like a corkscrew as the light
    travels through space, and that the orientation of the universal axis that
    they've discovered is key to the amount of rotation. The rotation of
    polarization depends on the angle at which the light moves relative to the axis
    and on the distance the light travels before being measured. The effect is
    crudely analogous to that of a crystal that twists light depending on the
    direction light is traveling through the crystal.
    Astronomers have long known about a somewhat similar effect called the Faraday
    effect, which is caused by magnetic fields between galaxies and causes the
    plane of polarization of light to rotate as the light travels through space.
    The newly discovered effect is in addition to the Faraday effect.
    Though the cause of the corkscrew effect remains unknown, in their paper the
    team constructs a mathematical theory that explains the observations. The data
    indicate that light actually travels through space at two slightly different
    speeds. Such a mismatch in speeds would cause the polarization plane to rotate
    in a well known manner, in a way that physics students see when they pass light
    through corn syrup and look at the light with polarizing filters. This
    corkscrew effect is far more subtle, though: Light traveling across the heavens
    undergoes one full rotation of its plane of polarization about once in a
    billion years.
    Whatever the cause, the work could have widespread implications. Scientists
    have long theorized that the Big Bang was completely symmetric. Says Nodland:
    "Perhaps it was not a perfect Big Bang, but a Big Bang with a twist to space
    and time." Such a twist would be seen today as a ripple of non-uniformity,
    perhaps as the axis (an "axis of anisotropy") represents.
    Much more speculatively, the work may provide some of the first experimental
    evidence for physicists who have theorized the existence of other universes. If
    our universe was asymmetric at creation, and symmetry in the cosmos is
    maintained as many physicists believe, it raises the possibility of the
    simultaneous creation of another universe with an opposite twist.
    The work also seems to run counter to the notions that all space is uniform and
    that the speed of light in a vacuum is always precisely the same, key
    assumptions of the theory of special relativity.
    Though the researchers say there's only a few chances in a thousand that the
    result comes from statistical fluctuations, they stress the need for other
    scientists to confirm their results.
    Questions about the universe and our role in it have fascinated Nodland ever
    since he can remember, filling his mind as he took long hikes while growing up
    in his native Norway.
    "I've always had a passionate interest in the universe and its origins," he
    says. "We're on a little planet going around some burning mass that we call a
    sun, in a certain region of space. What is this space, and why are we here? The
    universe is amazing, and I want to know the most I can about it."
    The team's work is funded by the U.S. Department of Energy, the National
    Science Foundation, the New York State Energy Research and Development
    Authority, and the Kansas Science and Technology Advanced Research (KSTAR)