Or maybe I’ve ended up squeezed out of part of the flow. The theoretical conditions for that have always struck me as far too bizarre to be fulfilled in real life . . . but what if it
has
happened? A gap in my presence, downstream from me, would have left a set of worlds with no bomb planted at all — which then flowed along and caught up with me, once I moved away from the building and my shift rate dropped.
I ‘return’ to the stairwell. There’s no unexploded bomb, no sign that any version of me has been here. I plant the backup device, and run. This time, I find no shelter on the street, and I simply hit the ground.
Again, nothing.
I struggle to calm myself, to visualise the possibilities. If the gap without bombs hadn’t fully passed the gap without me, when the first bombs went off, then I’d still have been missing from a part of the surviving flow — allowing exactly the same thing to happen all over again.
I stare at the intact building, disbelieving.
I
am the ones who succeed. That’s all that defines me.
But who, exactly, failed? If I was absent from part of the flow, there were no versions of me in those worlds
to
fail. Who takes the blame? Who do I disown? Those who successfully planted the bomb, but ‘should have’ done it in other worlds?
Am I amongst them?
I have no way of knowing.
So, what now? How big is the gap? How close am I to it? How many times can it defeat me?
I have to keep killing the dreamer, until I succeed.
I return to the stairwell. The floors are about three metres apart. To ascend, I use a small grappling hook on a short rope; the hook fires an explosive-driven spike into the concrete floor. Once the rope is uncoiled, its chances of ending up in separate pieces in different worlds is magnified; it’s essential to move quickly.
I search the first storey systematically, following procedure to the letter, as if I’d never heard of Room 522. A blur of alternative dividing walls, ghostly spartan furniture, transient heaps of sad possessions. When I’ve finished, I pause until the clock in my skull reaches the next multiple of ten minutes. It’s an imperfect strategy — some stragglers will fall more than ten minutes behind — but that would be true however long I waited.
The second storey is deserted, too. But a little more stable; there’s no doubt that I’m drawing closer to the heart of the whirlpool.
The third storey’s architecture is almost solid. The fourth, if not for the abandoned ephemera flickering in the corners of rooms, could pass for normal.
The fifth—
I kick the doors open, one by one, moving steadily down the corridor.
502. 504
.
506.
I thought I might be tempted to break ranks when I came this close, but instead I find it easier than ever to go through the motions, knowing that I’ll have no opportunity to regroup.
516. 518. 520.
At the far end of Room 522, there’s a young woman stretched out on a bed. Her hair is a diaphanous halo of possibilities, her clothing a translucent haze, but her body looks solid and permanent, the almost-fixed point about which all the night’s chaos has spun.
I step into the room, take aim at her skull, and fire. The bullet shifts worlds before it can reach her, but it will kill another version, downstream. I fire again and again, waiting for a bullet from a brother assassin to strike home before my eyes — or for the flow to stop, for the living dreamers to become too few, too sparse, to maintain it.
Neither happens.
‘You took your time.’
I swing around. The blue-haired woman stands outside the doorway. I reload the gun; she makes no move to stop me. My hands are shaking. I turn back to the dreamer and kill her, another two dozen times. The version before me remains untouched, the flow undiminished.
I reload again, and wave the gun at the blue-haired woman. ‘What the fuck have you done to me?
Am I
alone?
Have you slaughtered all the others?’ But that’s absurd — and if it were true, how could she see me? I’d be a momentary, imperceptible flicker to each separate version of her, nothing more; she wouldn’t even know I was there.
She shakes her head, and says mildly, ‘We’ve slaughtered no one. We’ve mapped you into Cantor dust, that’s all. Every one of you is still alive — but none of you can stop the whirlpool.’
Cantor dust. A fractal set, uncountably infinite, but with measure zero. There’s not
one
gap in my presence; there’s an infinite number, an endless series of ever-smaller holes, everywhere. But—
‘How?
You set me up, you kept me talking, but how could you coordinate the delays? And calculate the effects? It would take . . .’
‘Infinite computational power? An infinite number of people?’ She smiles faintly. ‘I
am
an infinite number of people. All sleepwalking on S. All dreaming each other. We can act together, in synch, as one — or we can act independently. Or something in between, as now: the versions of me who can see and hear you at any moment are sharing their sense data with the rest of me.’
I turn back to the dreamer. ‘Why defend her? She’ll never get what she wants. She’s tearing the city apart, and she’ll never even reach her destination.’
‘Not here, perhaps.’
‘Not here?
She’s crossing all the worlds she lives in! Where else is there?’
The woman shakes her head. ‘What creates those worlds? Alternative possibilities for ordinary physical processes. But it doesn’t stop there; the possibility of motion
between
worlds has exactly the same effect. Superspace
itself
branches out into different versions, versions containing all possible cross-world flows. And there can be higher-level flows, between those versions of superspace, so the whole structure branches again. And so on.’
I close my eyes, drowning in vertigo. If this endless ascent into greater infinities is true—
‘Somewhere, the dreamer always triumphs? Whatever I do?’
‘Yes.’
‘And somewhere, I always win? Somewhere, you’ve failed to defeat me?’
‘Yes.’
Who am I?
I’m the ones who succeed. Then who am
I
? I’m nothing at all. A set of measure zero.
I drop the gun and take three steps towards the dreamer. My clothes, already tattered, part worlds and fall away.
I take another step, and then halt, shocked by a sudden warmth. My hair, and outer layers of skin, have vanished; I’m covered with a fine sweat of blood. I notice, for the first time, the frozen smile on the dreamer’s face.
And I wonder: in how many infinite sets of worlds will I take one more step? And how many countless versions of me will turn around instead, and walk out of this room?
Who exactly am I saving from
shame, when I’ll live and die in every possible way?
Myself.
* * * *
THE HUNDRED-LIGHT-YEAR DIARY
Martin Place was packed with the usual frantic lunchtime crowds. I scanned the faces nervously; the moment had almost arrived, and I still hadn’t even caught sight of Alison.
One twenty-seven and
fourteen seconds.
Would I be mistaken about something so important? With the knowledge of the mistake still fresh in my mind? But that knowledge could make no difference. Of course it would affect my state of mind, of course it would influence my actions — but I already knew exactly what the net result of that, and every other, influence would be: I’d write what I’d read.
I needn’t have worried. I looked down at my watch, and as
1:27:13
became
1:27:14,
someone tapped me on the shoulder. I turned; it was Alison, of course. I’d never seen her before, in the flesh, but I’d soon devote a month’s bandwidth allocation to sending back a Barnsley-compressed snapshot. I hesitated, then spoke my lines, awful as they were:
‘Fancy meeting you here.’
She smiled, and suddenly I was overwhelmed, giddy with happiness — exactly as I’d read in my diary a thousand times, since I’d first come across the day’s entry at the age of nine; exactly as I would, necessarily, describe it at the terminal that night. But — foreknowledge aside — how could I have felt anything but euphoria? I’d finally met the woman I’d spend my life with. We had fifty-eight years together ahead of us, and we’d love each other to the end.
‘So, where are we going for lunch?’
I frowned slightly, wondering if she was joking — and wondering why I’d left myself in any doubt. I said, hesitantly, ‘Fulvio’s. Didn’t you . . . ?’ But of course she had no idea of the petty details of the meal; on 14 December, 2074, I’d write admiringly:
A. concentrates on the things that matter; she never lets
herself be distracted by trivia.
I said, ‘Well, the food won’t be ready on time; they’ll have screwed up their schedule, but—’
She put a finger to her lips, then leant forward and kissed me. For a moment, I was too shocked to do anything but stand there like a statue, but after a second or two, I started kissing back.
When we parted, I said stupidly, ‘I didn’t know ... I thought we just ... I—’
‘James, you’re blushing.’
She was right. I laughed, embarrassed. It was absurd: in a week’s time, we’d make love, and I already knew every detail — yet that single unexpected kiss left me flustered and confused.
She said, ‘Come on. Maybe the food won’t be ready, but we have a lot to talk about while we’re waiting. I just hope you haven’t read it all in advance, or you’re going to have a very boring time.’
She took my hand and started leading the way. I followed, still shaken. Halfway to the restaurant, I finally managed to say, ‘Back then — did you know that would happen?’
She laughed. ‘No. But I don’t tell myself everything. I like to be surprised now and then. Don’t you?’
Her casual attitude stung me.
Never lets herself be distracted by trivia.
I struggled for words; this whole conversation was unknown to me, and I never was much good at improvising anything but small talk.
I said, ‘Today is important to me. I always thought I’d write the most careful — the most
complete —
account of it possible. I mean, I’m going to record the time we met, to the second. I can’t imagine sitting down tonight and
not even mentioning
the first time we kissed.’
She squeezed my hand, then moved close to me and whispered, mock-conspiratorially: ‘But you will. You know you will. And so will I. You know exactly what you’re going to write, and exactly what you’re going to leave out — and the fact is, that kiss is going to remain our little secret.’
* * * *
Francis Chen wasn’t the first astronomer to hunt for time-reversed galaxies, but he was the first to do so from space. He swept the sky with a small instrument in a junk-scattered near-Earth orbit, long after all serious work had shifted to the (relatively) unpolluted vacuum on the far side of the moon. For decades, certain — highly speculative — cosmological theories had suggested that it might be possible to catch glimpses of the universe’s future phase of re-contraction, during which — perhaps — all the arrows of time would be reversed.
Chen charged up a light detector to saturation, and searched for a region of the sky which would
unexpose it —
discharging the pixels in the form of a recognisable image. The photons from ordinary galaxies, collected by ordinary telescopes, left their mark as patterns of charge on arrays of electro-optical polymer; a time-reversed galaxy would require instead that the detector
lose
charge, emitting photons which would leave the telescope on a long journey into the future universe, to be absorbed by stars tens of billions of years hence, contributing an infinitesimal nudge to drive their nuclear processes from extinction back towards birth.
Chen’s announcement of success was met with virtually unanimous scepticism — and rightly so, since he refused to divulge the coordinates of his discovery. I’ve seen the recording of his one and only press conference.
‘What would happen if you pointed an
uncharged
detector at this thing?’ asked one puzzled journalist.
‘You can’t.’
‘What do you mean, you
can’t?’
‘Suppose you point a detector at an ordinary light source. Unless the detector’s not working, it
will
end up charged. It’s no use declaring:
I
am going to expose this detector to light, and it will end up
uncharged.
That’s ludicrous; it simply won’t happen.’
‘Yes, but—’
‘Now time-reverse the whole situation. If you’re going to point a detector at a time-reversed light source, it
will
be charged beforehand.’
‘But if you discharge the whole thing thoroughly, before exposing it, and then . . .’
‘I’m sorry. You won’t.
You can’t.’
Shortly afterwards, Chen retired into self-imposed obscurity — but his work had been government funded, and he’d complied with the rigorous auditing requirements, so copies of all his notes existed in various archives. It was almost five years before anyone bothered to exhume them — new theoretical work having made his claims more fashionable — but once the coordinates were finally made public, it took only days for a dozen groups to confirm the original results.
Most of the astronomers involved dropped the matter there and then — but three people pressed on, to the logical conclusion:
Suppose an asteroid, a few hundred billion kilometres away, happened to block the line of sight between Earth and Chen’s galaxy. In the galaxy’s time frame, there’d be a delay of half an hour or so before this occultation could be seen in near-Earth orbit — before the last photons to make it past the asteroid arrived. Our time frame runs the other way, though; for us, the ‘delay’ would be
negative.
We might think of the detector, not the galaxy, as the source of the photons — but it would still have to stop emitting them half an hour
before
the asteroid crossed the line of sight, in order to emit them only when they’d have a clear path all the way to their destination. Cause and effect; the detector has to have a reason to lose charge and emit photons — even if that reason lies in the future.