Schild’s Ladder

References

Quantum Graph Theory is fictitious, but the spin networks on which Sarumpaet’s work is based are part of a real theory, known as loop quantum gravity, discovered by Lee Smolin and Carlo Rovelli. There is a considerable literature on this subject; two comprehensive review papers are:

'An Introduction to Spin Foam Models of Quantum Gravity and BF Theory” by John C. Baez, in Geometry and Quantum Physics, edited by Helmut Gausterer and Harald Grosse, Springer, Berlin, 2000.

www.arXiv.org/abs/gr-qc/9905087

and

'The Future of Spin Networks” by Lee Smolin, in The Geometric Universe, edited by S. A. Huggett et al., Oxford University Press, Oxford, 1998.

www.arXiv.org/abc/gr-qc/9702030

I’m indebted to John Baez, who very kindly explained several points to me directly, as well as posting numerous articles on the news group sci.physics.research making these ideas more accessible to nonspecialists. Of course, any errors I’ve committed in describing the real theory, and any absurdities in the way I’ve imagined its future, are my fault entirely.

Decoherence is a real phenomenon, and it is widely accepted as playing a major role in the absence of detectable quantum effects in macroscopic objects. Its role in relation to the superselection rules that forbid superpositions of certain kinds of quantum states is more controversial. These ideas are discussed in:

Decoherence and the Appearance of a Classical World in Quantum Theory by D. Giulini, E. Joos, C. Kiefer, J. Kupsch, I.-O. Stamatescu, and H. D. Zeh, Springer, Berlin, 1996.

I learned about the construction known as Schild’s ladder from:

Gravitation by C. W. Misner, K. S. Thorne and J. A. Wheeler, W. H. Freemann, New York, 1970.

who cite an unpublished lecture by Alfred Schild on January 19, 1970, at Princeton University.

Supplementary material for this novel can be found at www.netspace.net.au/?gregegan.

About the Author

Greg Egan is the author of several acclaimed SF novels and short stories. A winner of the Hugo Award and the John W. Campbell Memorial Award, he was voted the “Most Popular Science Fiction Author of the Decade” (1990s) by Interzone magazine. Mr. Egan lives in Australia.

www.netspace.net.au/~gregegan

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Credits

Cover design by Ervin Serrano

Cover illustration by John Lewis

This is a work of fiction. Names, characters, places, and incidents are products of the author’s imagination or are used fictitiously and are not to be construed as real. Any resemblance to actual events, locales, organizations, or persons, living or dead, is entirely coincidental.

SCHILD’S LADDER.

Copyright © 2002 by Greg Egan. All rights reserved under International and Pan-American Copyright Conventions. By payment of the required fees, you have been granted the non-exclusive, non-transferable right to access and read the text of this e-book on-screen. No part of this text may be reproduced, transmitted, down- loaded, decompiled, reverse engineered, or stored in or introduced into any information storage and retrieval system, in any form or by any means, whether electronic or mechanical, now known or hereinafter invented, without the express written permission of PerfectBound™.