Rewrite

by Gregory Benford

  The only failure is to live a life without risks.

  It is up to him to shape all of this, to make it finally matter.

  He will have a life that means something.

  He gets out of the Dodge Dart, pats its warm hood, takes a deep, luxurious breath, and walks decisively across the street into a life remade.

  * * *

  AFTERWORD

  * * *

  The plot of this novel is intentionally a puzzle that the reader needs to solve, proceeding through it. But here are some hints. When Charlie dies first, he does not come from our time line. Our own historical time line arises later in the book, in part thanks to Charlie’s own actions. But Charlie’s narrative does not remain in our own time line. Rather, he proceeds to create yet another time line. That is why many of the specifics of the different time lines vary.

  At the conclusion, Charlie has produced a time line he believes will lead to a better world than he or we knew. Because he has eliminated the assassins responsible for the attempt on Martin Luther King’s life, and they intended to carry out the Robert Kennedy attack too, neither assassination occurs. Kennedy then beats Nixon in 1968 and the Vietnam war ends in 1969—a consequence that is not in the novel.

  Spring 1968 was perhaps the most consequential season in American politics since WWII, in my view. I wanted to underline this by writing both a meditation on the implications of quantum mechanics (an ongoing issue, still) and on the fragility of our republic’s history.

  * * *

  This novel is a conceptual sequel to my earlier work Timescape. That novel I wrote within the confines of how physicists thought about time in the late 1970s. Much has changed. Indeed, all the events of that novel now lie in our past.

  Timescape was based on a paper I published in Physical Review D2 in July 1970 (p. 263) under the title “The Tachyonic Antitelephone”—see, even in dry old Phys Rev you can have fun with titles, if you try. Written with David Book and Bill Newcomb, it remains the only scientific paper of the over two hundred I have written that doesn’t have a single equation in it; the argument is logical, not really technical. In the late 1970s we used several ideas then current to frame an answer to the famous grandfather paradox that backward-in-time travel or communication provokes. By traveling faster than light, tachyons (if they existed) could send backward signals. It’s all there in Einstein’s theory of special relativity.

  Timescape concludes with a solution to the paradox, based on an interpretation of quantum mechanics that has now gathered a considerable following: Hugh Everett’s Many-Worlds Interpretation. He said that all the possible outcomes predicted by the probability analysis of quantum mechanics are separately real. Envision separable worlds peeling off from every microscopic event. Every event generates great handfuls of other worlds—a cosmic plentitude of astronomical extravagance.

  I trimmed Everett’s idea: only a paradox-causing event generates a split-off universe. That seemed intellectually thrifty and, further, made for a bittersweet finish: You can change that past, but it’s not going to occur in your world. You’ve improved the lot of others, but not your own. It seemed a good idea at the time. . . .

  The novel appeared, won awards, and has sold over a million copies in many languages. I moved on to other physics, other novels.

  Imagine my surprise when, while I was visiting Cambridge in November of 1992, Martin Rees pointed out a paper in Physical Review D, the same journal where our old tachyon paper had appeared. Martin thought it important. Titled somewhat forbiddingly “Quantum Mechanics Near Closed Timelike Lines,” it constructs a theory for effects in highly curved space-time that contains causal loops—“closed timelike lines,” in the jargon. It was written by David Deutsch, who has been studying these matters for a decade at Oxford (not Cambridge, the site of the experiments in Timescape). “Contrary to what has usually been assumed,” Deutsch says, “there is no reason in what we know of fundamental physics why closed timelike lines should not exist.” In twenty pages of quantum logic calculations, he shows that no obstacle to free will or even grandfather murder really exists.

  It’s all done with the Everett interpretation. In quantum cosmology there is no single history of space-time. Instead, all possible histories happen simultaneously. For the vast preponderance of cases, this doesn’t matter—the bloat of an uncountable infinitude of worlds has no observable consequences. It’s just a way of talking about quantum mechanics.

  Not so for time machines. Then a quantum description requires a set of “classical” (ordinary) space-times that are similar to one another—except in the important history of the paradox loop. The causal loop links all the multiple histories. Think of unending sheets stacked on end and next to each other, like pages. Time lines flow up, piercing them. A causal loop snakes through these sheets, so the parallel universes become one. If the grandson goes back in time, he crosses to another time-sheet. There he shoots granddad and lives thereafter in that universe. His granddad lived as before and had grandchildren, one of whom disappears, period.

  Quantum mechanics always furnishes as many linked universes as there would be conflicting outcomes; it’s quite economical. In this view, as Deutsch says: “It is only ever an approximation to speak of things happening ‘in a universe.’ In reality the ‘universes’ form a part of a larger object . . . which, according to quantum theory, is the real arena in which things happen.” No one in either universe thinks the world is paradoxical. Cosmic stuff indeed.

  If you know this, then such a past-altering act is the ultimate altruism: you cannot then benefit in any way from usefully adjusting the past (or suffer, either). Someone exactly like you does benefit (yes, a twin; and I wonder how much my being an identical twin has led to my interest in these ideas)—but you will never see him and cannot know this except in theory. Most of all, I was struck in writing the closing pages of Timescape with that glimpse of vistas unknown, whole universes beyond our grasp, times untouched. To me, that is the essential science-fictional impulse.

  Since that 1992 paper, quantum entanglement, which Einstein termed “spooky action at a distance,” has entered the logic of quantum causal loops. This I sketch out in the present novel. It is a field of restless energy. Can entanglements leak between the multiverses? What would make that happen? Our own minds have the highest information density we know, so perhaps entangled minds can skate among the quantum layers of space-times we do not know.

  I’ll leave the logic that led me to my work on the present novel now, for ultimately, whether ideas work in fiction is up to the reader. I do want to reassure readers that the ideas that come up in the second half of the novel emerge from current speculative thinking.

  This novel has characters based on real people I knew, now deceased. This brings in the many associations with the above ideas, as I have mined them for fictive uses. I intend no insult to them, and indeed mostly these are sketches of people I miss very much. My memories of them became part of the mix. Writers are magpies. (I also use this blending in my alternative history novel of the Manhattan Project, The Berlin Project, too. If there is a writers’ adage even more important than Show, don’t tell it’s Write what you know.)

  Then, too, there is the issue of the greats I did not know. William Shakespeare, whose imagination seemed limitless, who traveled freely to magical isles and enchanted forests, did not—could not—imagine different times. The past and present are all the same to Shakespeare: mechanical clocks strike the hour in Caesar’s Rome, and Cleopatra plays billiards. So even our finest, most expansive writer from centuries past did not reflect, as we moderns do, on time as fluid.

  As the Queen said to Alice, “It’s a poor sort of memory that only works backwards.”

  “So in the future, the sister of the past,” thinks young Stephen Dedalus in Ulysses, “I may see myself as I sit here now but by reflection from that which then I shall be.”

  So, too, with Casanova, a protomodern. It is widely agreed by those who have made a study of
him that Giacomo was far kinder to his lovers than was the manipulative Don Giovanni, for whom a woman was no more than a notch on his belt. (The real Casanova is reported to have attended the Prague premiere of Don Giovanni in 1787 and, according to Michael Sturminger, had “a close friendship” with Da Ponte.) I tried to convey him as speaking in a plummy, variable accent that suggests someone who, though born on the Continent, attended English boarding schools. He also exudes that vague state of impassioned indolence, emerging into an impressionistic portrait of a libertine from the age of Enlightenment. Sex is the flip side of the coin, death the other.

  Then, again, Heinlein, whom I did know for decades. I’ve tried to echo his voice, its cadences and ideas. He was fond of repeating George Bernard Shaw’s saying “The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.” I’ve tried to convey him, as I did Phil Dick. Phil actually said many of the lines of dialogue I’ve reproduced here. He was one of the oddest people I’ve ever known, in a life rich in odd people trying to get even.

  And Einstein, yes. A visitor to Einstein’s office in Prague noted that the window overlooked the grounds of an insane asylum. Einstein explained that these were the madmen who did not think about quantum mechanics. He was fond of a German saying of life: Der Appetit kommt beim Essen. “The appetite develops as one eats.” Quantum mechanics can be like this; look at the many variations it has inspired, like Deutsch’s.

  We moderns have all learned to visualize history as a time line, with the past stretching to the left, say, and the future to the right, perhaps because we have been conditioned Sapir-Whorf-style by a left-to-right written language. Our own life spans occupy a short space in the middle. Now—the infinitesimal slide of the present—is just the point where our puny consciousnesses happens to be.

  This troubled Einstein. A lot. He recognized that the present is special; it is, after all, where we live. (In Ted Chiang’s fine tale Story of Your Life, Louise says to her infant daughter: “NOW is the only moment you’ll perceive; you’ll live in the present tense. In many ways, it’s an enviable state.” The film of that story, Arrival, gets at this admirably well.) But Einstein felt that this was fundamentally a psychological matter; that the question of now need not, or could not, be addressed within physics. The specialness of the present moment doesn’t show up in the equations; mathematically, all the moments look alike. Now seems to arise in our minds. It’s a product of consciousness, inextricably bound up with sensation and memory. And it’s a fleeting image, tumbling continually into the past.

  Still, if the sense of the present is an illusion, it’s awfully powerful for us humans. I don’t know if it’s possible to live as if the physicists’ time-symmetric mathematical model is real, as if we never make choices, as if the very idea of purpose is imaginary. I haven’t tried. We may be able to visualize the time before our birth and the time after our death as mathematically equivalent, though it’s a stretch. Yet we can’t help but fret more about what effects we might have on the future in which we will not exist, than about what might have happened in the past when we did not exist. Nor does it seem possible to tell a story or enjoy a narrative that is devoid of intention. Choice and purpose—that’s where the suspense comes from. What is your purpose on Earth? There’s your story.

  As Einstein said, “Space and time are modes by which we think, not conditions under which we live.” I feel that these are not properties of the world we live in, but concepts we have invented to help us organize classical events. There are others, too. Yet to be discovered . . .

  Physics is the belief that a simple and consistent description of nature is possible. Occam’s razor slices sure.

  We human beings, even those who have been studying quantum mechanics for a long time, still think in terms of classical concepts. We evolved to do that. It helps us live.

  The real world simply is quantum mechanical from the start; it’s not a quantization of some classical system. The universe is described by an element of Hilbert space, a mathematical region in which vectors and calculus can function in useful ways. Quantum mathematical concepts are easily done in such abstract spaces, which can have any number of dimensions. All of our usual classical notions should be derived from that conceptual regime, not the other way around—even space itself. We think of the real space through which we move as one of the most basic and irreducible constituents of the real world, the essential underpinning. It might better be thought of as a good approximation for primates who evolved on flat plains and threw spears in a simple gravitational field, so a parabola was a beautiful, useful curve. This works at large distances (meters) and low energies (ours)—where we smart primates live and die. But reality may be a far broader thing. Indeed, it must be.

  Hard science fiction is about the beauty of a small “reasoning reed,” in Pascal’s phrase, that can see past its own mortality and wonder at the vistas beyond. Its essential drama lies in that huge leap of scale.

  Michael Rose helped me start the novel, though of course I finished it. I thank for readings, suggestions, and corrections many people, especially Blanca Cervantes; Gregg Rickman; John Silbersack; Joe Monti; Elisabeth Brown; David Truesdale; Sheila Finch; David Brin; Kathryn Cramer and her husband, the late, much missed David Hartwell; Martin Rees; David Deutsch; Gary Wolfe. Especially, thanks to my identical twin brother, James Benford, who agreed to stand in for me at UCI to show that the second Charlie time line is not ours, and for getting me interested in Einstein’s twin paradox when we were ten years old.

  Gregory Benford

  February 2018

  * * *

  ABOUT THE AUTHOR

  * * *

  photo courtesy of the author

  Gregory Benford is a professor of physics at the University of California, Irvine, where he has been a faculty member since 1971. He is the author of over twenty novels, including In the Ocean of Night, Heart of the Comet (with David Brin), Foundations Fear, Bowl of Heaven (with Larry Niven), Timescape, and The Berlin Project. A two-time winner of the Nebula Award, Benford has also won the John W. Campbell Award, the British Science Fiction Association (BSFA) Award, the Australian Ditrnar Award, and the 1990 United Nations Medal in Literature.

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  This book is a work of fiction. Any references to historical events, real people, or real places are used fictitiously. Other names, characters, places, and events are products of the author’s imagination, and any resemblance to actual events or places or persons, living or dead, is entirely coincidental. | Text copyright © 2018 by Gregory Benford & Michael Rose | Jacket photographs copyright © 2018 by Thinkstock | All rights reserved, including the right to reproduce this book or portions thereof in any form whatsoever. For information address Saga Press Subsidiary Rights Department, 1230 Avenue of the Americas, New York, NY 10020. | SAGA PRESS and colophon are trademarks of Simon & Schuster, Inc. | For information about special discounts for bulk purchases, please contact Simon & Schuster Special Sales at 1-866-506-1949 or business@simonandschuster.com. | The Simon & Schuster Speakers Bureau can bring authors to your live event. For more information or to book an even
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