The Arrows of Time: Orthogonal Book Three (52 page)
Read The Arrows of Time: Orthogonal Book Three Online
Authors: Greg Egan
The names of colours are translated so that the progression from ‘red’ to ‘violet’ implies shorter wavelengths. In the
Orthogonal
universe this
progression is accompanied by a decrease in the light’s frequency in time. In our own universe the opposite holds: shorter wavelengths correspond to higher frequencies.
The smallest possible wavelength of light, λ
min
, is about 231 piccolo-scants; this is for light with an infinite velocity, at the ‘ultraviolet
limit’. The highest possible time frequency of light, ν
max
, is about 49 generoso-cycles per pause; this is for stationary light, at the ‘infrared limit’.
Gravitation and cosmology in the
Orthogonal
universe are governed by essentially the same equation that governs the geometry of our own universe: the relationship
between the curvature of space-time and the density and flow of matter and energy that was proposed by Einstein in 1916. The solutions of Einstein’s equation that describe our universe have
three dimensions of space and one of time, but the equation itself can easily accommodate four space-like dimensions.
As in our own universe, Newtonian gravity with its inverse-square law of attraction serves as a good approximation to the effects of mass on curvature. The only departures on the scale of
planetary systems are in the very same subtle effects that were ultimately understood through general relativity in our own history – but here they are reversed. The precession of close
orbits goes backwards in the
Orthogonal
universe, compared with the precession of Mercury’s orbit that Einstein’s theory explained. And where Einstein predicted twice as much
deflection of starlight by the sun than would be expected under Newtonian gravity, the degree to which light is bent is
less
in Lila’s relativistic theory than in the classical
version attributed here to Vittorio.
In cosmology, the solutions with and without a time dimension have much more radical differences. For example, there is no equivalent in our own universe of the kind of high-entropy state where
the world lines of star clusters are equally likely to be pointing along any direction in all four dimensions, and the arguments in the novel over the inevitability or otherwise of the entropy
gradient are very different from arguments over possible explanations for the low entropy of our own universe at the Big Bang.
But it’s the necessity for the
Orthogonal
universe to be finite in all directions that has the most striking consequences, requiring the entire history of the universe to return
eventually to its initial state – wherever one starts from, and whichever direction in four-space is treated as ‘time’.
Supplementary material for this novel can be found at
www.gregegan.net
.
Also by Greg Egan from Gollancz:
AXIOMATIC
DISTRESS
LUMINOUS
PERMUTATION CITY
QUARANTINE
TERANESIA
DIASPORA
SCHILD’S LADDER
INCANDESCENCE
OCEANIC
ZENDEGI
THE CLOCKWORK ROCKET
THE ETERNAL FLAME
A Gollancz eBook
Copyright © Greg Egan 2013
All rights reserved.
The right of Greg Egan to be identified as the author of this work has been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.
First published in Great Britain in 2013 by
Gollancz
The Orion Publishing Group Ltd
Orion House
5 Upper Saint Martin’s Lane
London, WC2H 9EA
An Hachette UK Company
This eBook first published in 2013 by Gollancz.
A CIP catalogue record for this book is available from the British Library.
ISBN 978 0 575 10579 9
All characters and events in this publication are fictitious and any resemblance to real persons, living or dead, is purely coincidental.
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