The Light of Other Days

by Arthur C. Clarke

  He said evenly, “I haven’t made up my mind yet.”

  She actually smiled at that. “At least that’s a fair answer. Anyway, how did you know about my software?”

  “You’re a WormCam user,” he said. “One of the conditions of use of the Wormworks is that any innovation you make to the equipment is the intellectual property of OurWorld. It’s in the agreement I had to sign on behalf of your mother — and you.”

  “Typical Hiram Patterson.”

  “You mean, good business? It seems reasonable to me. We all know this technology has a long way to go.”

  “You’re telling me. The whole user interface sucks, David.”

  “- and who better to come up with ways of putting that right than the users themselves, the people who need to make it better now?”

  “So you have spies? People watching the pastwatchers?”

  “We have a layer of metasoftware which monitors user customization, assessing its functionality and quality. If we see a good idea we may pick up on it and develop it; best of all, of course, is to find something which is a bright idea and well developed.”

  She showed a flicker of interest, even pride. “Like mine?”

  “It has potential. You’re a smart person, Mary, with a bright future ahead of you. But — how would you put it? — you know diddly-squat about developing quality software.”

  “It works, doesn’t it?”

  “Most of the time. But I doubt that anybody but you could make an enhancement without rebuilding the whole thing from the ground up.” He sighed. “This isn’t the 1990s, Mary. Software development is a craft now.”

  “I know, I know. We get all this at school… You think my idea works, though.”

  “Why don’t you show me?”

  She reached for the SoftScreen; he could see she was about to clear the settings, set up a fresh WormCam run.

  Deliberately he put his hand over hers. “No. Show me what you were looking at when I sat down.”

  She glared at him. “So that’s it. My mother did send you, didn’t she? And you’re not interested in my tracking software at all.”

  “I believe in the truth, Mary.”

  “Then start telling it.”

  He picked off the points on his fingers. “Your mother’s concerned about you. It was my idea to come to you, not hers. I do think you ought to show me what you’re watching. Yes, it serves as a pretext to talk to you, but I am interested in your software innovation in its own right. Is there anything else?”

  “If I refuse to go along with this, will you throw me out of the Wormworks?”

  “I wouldn’t do that.”

  “Compared to the equipment here, the stuff you can access via the net sucks.”

  “I told you, I’m not threatening you with that.”

  The moment stretched.

  Subtly, she subsided in her seat, and he knew he had won the round.

  With a few keystrokes she restored the scene.

  It was a small garden — a yard, really, strips of sun-baked grass separated by patches of gravel, a few poorly tended flower beds. The image was bright, the sky blue, the shadows long. There were toys everywhere, splashes of colour, some of them autonomously toiling back and forth on their programmed tasks and routines.

  Here came two children: a boy and a girl, aged maybe six and eight respectively. They were laughing, kicking a ball between them, and they were being chased by a man, also laughing. He grabbed the girl and whirled her high in the air, so that she flew through shadows and light. Mary froze the scene.

  “A cliché,” she said. “Right? A childhood memory, a summer’s afternoon, long and perfect.”

  “This is your father and your brother — and yourself.”

  Her face twisted into a sour smile. “The scene is barely eight years old, but two of the protagonists are dead already. What do you think of that?”

  “Mary.”

  “You wanted to see my software.”

  He nodded. “Show me.”

  She tapped at the ’Screen; the viewpoint panned from side to side, and stepped forward and back in time, through a few seconds. The girl was raised and lowered and raised again, her hair tumbling this way and that, as if this was a film being wound back and forth.

  “Right now I’m using the standard workstation interface. The viewpoint is like a little camera floating in the air. I can control its location in space and move it through time, adjusting the position of the wormhole mouth. Which is fine for some applications. But if I want to scan more extended periods, it’s a drag — as you know.”

  She let the scene run on. The father put down child-Mary. Mary focused the viewpoint on her father’s face and, with taps of the SoftScreen, tracked it, jerkily, as the father ran after his daughter across that vanished lawn. “I can follow the subject,” she said clinically, “but it’s difficult and tedious. So I’ve been seeking a way to automate the tracking.” She tapped more virtual buttons. “I used pattern-recognition routines to latch on to faces. Like his.”

  The WormCam viewpoint swung down, as if guided by some invisible cameraman, and focused on her father’s face. The face stayed there, central to the image, as he moved his head this way and that, talking, laughing, shouting; the background swung around him disconcertingly.

  “All automated,” David said. “Yes. I have subroutines to monitor my preferences, and make the whole thing a little more professional…” More keystrokes, and now the viewpoint pulled back a little. The camera angles were more conventional, stabilized, no longer slaved to that face. The father was still the central protagonist, but his context became more clear.

  David nodded. “This is valuable, Mary. This, tied to interpretative software, might even allow us to automate the compilation of historic-figure biographies, at first draft anyhow. You’re to be commended.”

  She sighed. “Thanks. But you still think I’m a wacko because I’m watching my father rather than John Lennon. Don’t you?”

  He shrugged. He said carefully, “Everybody else is watching John Lennon. His life. for better or worse, is common property. Your life — this golden afternoon — is your own.”

  “But I’m an obsessive. Like those nuts you find watching their own parents making love, watching their own conception.”

  “I’m no psychoanalyst,” he said gently. “Your life has been hard. Nobody denies that. You lost your brother, your father. But…”

  “But what?”

  “But you’re surrounded by people who don’t want you to be unhappy. You have to believe that.”

  She sighed heavily. “You know, when we were little — Tommy and I — my mother had a habit of using other adults against us. If I was bad, she’d point to something in the adult world — a car sounding its horn a kilometre away, even a jet airplane screaming overhead — and she’d say, ‘That man heard what you said to your mother, and he’s showing you what he thinks about it.’ It was terrifying. I grew up with the impression that I was alone in a huge forest of adults, all of whom watched over me, judging me the whole time.”

  He smiled. “Full-time surveillance. Then you won’t find it hard to get used to life with the WormCam.”

  “You mean, the damage has been done to me already? I’m not sure that’s a consolation.” And then she eyed him. “So, David — what do you watch when you have the WormCam to yourself?”

  •

  He went back to his apartment. He slaved his own workstation to Mary’s back at the Wormworks, and ran through the recordings OurWorld routinely made of every user’s utilization of its WormCams.

  He’d done enough, he felt, not to feel guilty over what he had to do next to fulfill his obligation to Heather. Which was to spy on Mary.

  It didn’t take him long to get to the heart of it. She did, after all, view the same incident, over and over.

  It had been another bright afternoon of sun and play and family, not long after the one he’d watched with her. Here she was at age eight with her father an
d family, hiking — easily, at a six-year-old’s pace — through the Rainier National Park. Sunlight, rock, trees.

  And then he came to it: the crux of Mary’s life. It lasted only seconds.

  It wasn’t as if they’d taken any risks; they hadn’t strayed from the marked path, or attempted anything ambitious. It had just been an accident

  Tommy had been riding his father’s neck, clinging to handfuls of thick black hair, with his legs draped over his shoulders, firmly grasped by his father’s broad hands. Mary had gone running past, eager to chase what looked like the shadow of a deer. Tommy reached for her, unbalancing a little, and the father’s grasp slipped — just a little, but enough.

  The impact itself was unspectacular: a soft crack as that big skull hit a sharp volcanic rock, the strange limp crumpling of the body. Just unfortunate, even in the way he hit the ground so lethally. Nobody’s fault.

  That was all. Over in a heartbeat. Unfortunate, commonplace, nobody’s fault — save, he thought with unwelcome anger, the Cosmic Designer who chose to lodge something as precious as the soul of a six-year-old in a container so fragile.

  The first time Mary (and now David, like an unwelcome ghost) had watched this incident, she’d used a remarkable WormCam viewpoint: looking out through child-Mary’s own eyes. It was as if the viewpoint was lodged right at the centre of her soul, that mysterious place in her head where “she” resided, surrounded by the soft machinery of her body.

  Mary saw the boy falling. She reacted, reached out her arms, took a pace toward him. He seemed to fall slowly, as if in a dream. But she was too far away to reach him, could do nothing to change what unfolded.

  …And now, tracking Mary’s usage, David was forced to watch the same incident from the father’s point of view. It was like looking down from a watchtower, with child-Mary a blur below him, the boy a thing of dark shadows around his head. But the same events unfolded with grisly inevitability: the unbalancing, the slip, the boy falling, his legs impeding him so that he fell upside down and descended headfirst toward the stony ground.

  But what Mary watched over and over, obsessively, was not the death itself, but the moments before. Little Tommy, falling, was only a meter from Mary, but that was too far, and no more than centimetres from his father’s grasp, a fraction of a second’s reaction time. It might have been a kilometre, hours of delay; it would have made no difference.

  And this, David suspected, was the real reason her father had committed his suicide. Not the publicity that suddenly surrounded him and his family — though that couldn’t have helped. If he was anything like Mary, he must have seen immediately the implications of the WormCam for himself — just like millions of others, now exploring the capabilities of the WormCam, and the darkness in their own hearts.

  How could that bereaved father not watch this? How could he not relive those terrible moments over and over? How could he turn away from this child, trapped within the machine, as vivid as life and yet unable to grow a second older or to do anything the slightest bit different, ever again?

  And how could that father bear to live in a world in which the terrible clarity of the incident was available for him to replay any time he wished, from any angle he chose — and yet knowing he would never be able to change a single detail?

  How indulgent he had been — David himself — to sit and watch gruesome episodes from the history of the Church, incidents centuries removed from his own reality. After all, Columbus’ crimes hurt nobody now — save perhaps the man himself, David thought grimly. How much greater had been the courage of Mary, a lonely, flawed child, as, alone, she faced the moment that had shaped her life, for good or ill.

  For this, he realized, is the core of the WormCam experience: not timid spying or voyeurism, not the viewing of some impossibly remote period of history, but the chance to review the glowing incidents that make up my life.

  But my eyes have not evolved to see such sights. My heart has not evolved to cope with such repeated revelations. Once, time was called the great healer; now the healing balm of distance has been torn away.

  We have been granted the eyes of God, he thought, eyes which can see the immutable, bloodstained past as if it were today. But we are not God, and the burning light of that history may destroy us.

  Anger coalesced. Immutability. Why should he accept such unfairness? Maybe there was something he could do about that.

  But first he would have to figure out what to say to Heather.

  •

  The next time he called, when more weeks had gone by, Bobby was shocked by David’s deterioration.

  David was wearing a baggy jumpsuit that looked as if it hadn’t been changed for days. His hair was mussed, and he had shaved only carelessly. The apartment was even more of a mess now, the furniture littered with SoftScreens, opened-out books and journals, yellow pads, abandoned pens. On the floor, stacked around an overflowing garbage pail, there were soiled paper plates and pizza boxes and microwave junk-food cartons.

  But David seemed defensive, perhaps apologetic. “It’s not what you’re thinking. WormCam addiction, yes? I may be an obsessive, Bobby, but I think I pulled myself back from that.”

  “Then what.”

  “I have been working.”

  A whiteboard had been set up against one wall; it was covered with scarlet scrawl, equations, scraps of phrases in English and French, connected by swirling arrows and loops.

  Bobby said carefully, “Heather told me you dropped out of the 12,000 Days project. The Christ TrueBio.”

  “Yes, I dropped out. Surely you understand why.”

  “Then what have you been doing here, David?”

  David sighed. “I tried to touch the past, Bobby. I tried, and I failed.”

  “…Whoa,” said Bobby. “Did I understand that right? You tried to use a wormhole to affect the past? Is that what you’re saying? But your theory says that’s impossible. Doesn’t it?”

  “Yes. I tried anyway. I ran some tests in the Wormworks. I tried to send a signal back in time, through a small wormhole, to myself. Just across a few milliseconds, but enough to prove the principle.”

  “And?”

  David smiled wryly. “Signals can travel forward in time through a wormhole. That’s how we view the past. But when I tried to send a signal back in time, there was feedback. Imagine a photon leaving my wormhole mouth a few seconds in the past. It can fly to the future mouth, travel back in time, and emerge from the past mouth at the precise moment it started its trip. It overlies its earlier self.”

  “- and doubles the energy.”

  “Actually more than that, because of Doppler effects. It’s a positive feedback loop. The bit of radiation can travel through the wormhole over and over, piling up energy extracted from the wormhole itself. Eventually it becomes so strong it destroys the wormhole — a fraction of a second before it operates as a full time machine.”

  “And so your test wormhole went bang.”

  David said dryly, “With more vigor than I’d anticipated. It looks as if dear old Hawking was right about chronology protection. The laws of physics do not allow backwards-operating time machines. The past is a relativistic block universe, the future is quantum uncertainty, and the two are joined at the present — which, I suppose, is a quantum gravity interface… I am sorry. The technicalities do not matter. The past, you see, is like an advancing ice sheet, encroaching on the fluid future; each event is frozen into its place in the crystal structure, fixed forever.

  “What is important is that I know, better than anyone on the planet, that the past is immutable, unchangeable — open to us to observe, through the wormholes, but fixed. Do you understand how this feels?”

  Bobby walked through the apartment, stepping over mounds of paper and books. “Fine. You’re suffering. You use abstruse physics as therapy. What about your family? Do you ever spare a thought for us?”

  David closed his eyes. “Tell me. Please.”

  Bobby took a breath. “Well, Hiram�
�s gone into deeper hiding. But he’s planning to make even more money from weather forecasting — vastly better predictions, based on precise data centuries deep, thanks to the WormCam. He thinks it may even be possible to develop climate control systems, given the new understanding we have of long-term climate shifts.”

  “Hiram is -” David sought the right word. “ — a phenomenon. Is there no limit to his capitalistic imagination? And the news of Kate?”

  “The jury’s out.”

  “I thought the evidence was circumstantial.”

  “It is. But to actually see her at her terminal at the time the crime was committed, to see that she had the opportunity — I think that swayed a lot of the jurors.”

  “What will you do if she’s convicted?”

  “I haven’t decided.” That was true. The end of the trial was a black hole, waiting to consume Bobby’s future, as unavoidable and as unwelcome as death. So he did his best not to think about it.

  “I saw Heather,” he said. “She’s well, in spite of everything. She’s published her Lincoln TrueBio.”

  “Good piece of work. And her pieces on the Aral Sea war were remarkable.” David eyed Bobby. “You must be proud of her — of your mother.”

  Bobby thought that over. “I suppose I should be. But I’m not sure how I’m supposed to feel about her. You know, I watched her with Mary. For all their friction, there’s a bond there. It’s like a steel rope that connects them. I don’t feel anything like that. It’s probably my fault.”

  “You said you watched them? Past tense?”

  Bobby faced him. “I guess you haven’t heard, Mary left home.”

  “…Ah. How disappointing.”

  “They had one final fight about the way Mary was using the WormCam. Heather is frantic with worry.”

  “Why doesn’t she trace Mary?”

  “She’s tried.”

  David snorted. “Ridiculous. How can any of us hide from the WormCam?”

  “Evidently there are ways. Look, David, isn’t it time you rejoined the human race?”