David Gelernter - Mirror Worlds : Or the Day Software Puts the Universe in a Shoebox ... How It Will Happen and What It Will Mean

Mirror Worlds

Mirror Worlds

or the Day Software Puts the Universe in a Shoebox
How It Will Happen and What It Will Mean

DAVID GELERNTER

Department of Computer Science
Yale University

New York Oxford Oxford University Press

Oxford University Press

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Copyright 1992 by Oxford University Press, Inc.

First published in 1991 by Oxford University Press, Inc.,
200 Madison Avenue, New York, New York 10016

First issued as an Oxford University Press paperback, 1992

Oxford is a registered trademark of Oxford University Press

All rights reserved. No part of this publication may be reproduced,
stored in a retrieval system, or transmitted, in any form or by any means,
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without the prior permission of Oxford University Press, Inc.

Library of Congress Cataloging-in-Publication Data
Gelernter, David Hillel.
Mirror worlds or the day software puts the universe in a shoebox :
how it will happen and what it will mean / David Gelernter.
p. cm. Includes bibliographical references (p. ) and index.
ISBN 0-19-506812-2
ISBN 0-19-507906-X (PBK.)
1. Computer software. 2. Software engineering. I. Title.
QA76.754.G45 1991 005dc20 91-19178

10 9 8 7 6 5 4 3 2 1

Printed in the United States of America

These DBTs are for
my grandmother Dorothy Rothchild Lewis,
my mother,
and my Jane

Contents

A computational landscape

The landscape created by the Pascal program

Gathering plots into modules

An inward-spiralling computational landscape

A Linda program

Life cycle of an infomachine

Piranha Parallelism

The Trellis

Espalier

The intensive care unit monitor: Excerpt

The intensive care unit monitor

The Trellis dashboard

A Turingware Trellis

The transcript

The Agent Space

By way of comparison

An Agent

Recursive free-form dollhouse: partial floorplan

Piffelbourg Mirror World

The structure of a City Finances viewpoint

Thanks are due first of all to my graduate students, who made much of this work possible: particularly to Robert Bjornson, Michael Factor, Scott Fertig, Jerry Leichter and Venkatesh Krishnaswamy; to Mauricio Arango and Donald Berndt, for their important contributions to our software; and to Suresh Jagannathan, for countless indispensable hard-core technical discussions.

It takes money to do research: many thanks, accordingly, to Richard Lau of the Office of Naval Research, to Charles Holland of the Air Force Office of Scientific Research, and to the National Science Foundations Computer Science Program, more or less in toto. These three agencies, models of seriousness and of scientific integrity, have championed progressive computing throughout the research community.

Thanks to George McCorkle for valuable suggestions about the manuscript, and for general wisdom and encouragement. However good or bad the final product, its a lot better than it would have been without his help.

Thanks to Chris Hatchell for providing the administrative glue that holds the whole research effort together, and to Morrow Long of the Yale Computer Science Department and Glenn Fleishman of the Yale Printing Service for their help in producing the manuscript.

This book draws on the fruits of several particularly valuable ongoing collaborations: with Perry Miller and the Medical Informatics Group at the Yale Medical School; with Craig Kolb and Ken Musgrave, of Benoit Mandelbrots group in the Yale Mathematics Department; with Joe Harris and his colleagues at Sandia National Laboratory in Livermore. Finally, in a category of its ownour ongoing, ever more productive, important and valued collaboration with Scientific Computing Associates in New Haven.

Thanks to OUP in general and (especially) to my editor Jeff Robbins in particular

And thanks, finally, to several people who have provided both technical and meta-technical advice and guidance: Steven Nowick, Martin Schultz, Nicholas Carriero, my brother Joel and my father. They have all contributed to this book, and made other contributions besidesuvamakom sheeiyn anashim, hishtadeil lihyot ish. (In a place where there are no men you strive to be a man) (Pirkei Avos, 2:6.) Instead of man, read mensck, as a matter of fact, this is what Hillel meant.

by Michael Factor, Craig Kolb and the author. The others are by the author.

No changing of place

at a hundred miles an hour,

You cant imagine how strange it seemed

to be journeying on thus, without

any visible cause of progress

other than the magical machine,

nor making of stuffs a thousand

yards a minute,

with its flying white breath and

rhythmical, unvarying pace,

between these rocky walls, which are

already clothed with moss and

ferns and grass;

will make us

one whit stronger, happier

or wiser.

and when I reflected that

There was always more

in the world

than men could see,

walked they ever so slowly;

these great masses of stone had been cut

asunder to allow our passage thus far

below the surface of the earth, I felt that

they will see it no better

for going fast.

JOHN RUSKIN (1856)

no fairy tale

was every half so wonderful

as what I saw.

FANNY KEMBLE (1830)

This book describes an event that will happen someday soon: You will look into a computer screen and see reality. Some part of your worldthe town you live in, the company you work for, your school system, the city hospitalwill hang there in a sharp color image, abstract but recognizable, moving subtly in a thousand places. This Mirror World you are looking at is fed by a steady rush of new data pouring in through cables. It is infiltrated by your own software creatures, doing your business.

People are drawn to these software gadgets: When you switch one on, you turn the world (like an old sweater) inside out. You stuff the huge multi-institutional ratwork that encompasses you into a genie bottle on your desk. You can see over, under and through it. You can see deeply into it. A bottled institution cannot intimidate, confound or ignore its members; they dominate it. And your computers screen is transformed, into a clear surface with brilliant multi-colored life unfolding just beyond. People will stop looking at their computer screens and start gazing into them.

Mirror worlds will transform the meaning of computer. Our dominant metaphor since 1950 or thereabouts, the electronic brain, will go by the boards. Instead people will talk about crystal balls, telescopes, stained glass windowswine, poetry or whateverthings that make you see vividly.

Dont like computers? Unamused by technology? For most people, technology is the ocean on a bright cool Spring day. Sparkling in the far distance; breathtakingly cold; exhilarating once youve plunged in. At any rate, not to be over-delicate: This cold and beautiful Ocean is coming to meet you. Mirror Worlds mean another overwhelming rise in sea level. If you dont choose to jump in, what exactly do you choose?

Why not give it a try? Hold your breath. Lets plunge.

What are they?

They are software models of some chunk of reality, some piece of the real world going on outside your window. Oceans of information pour endlessly into the model (through a vast maze of software pipes and hoses): so much information that