I sat at my desk, pondering the result. On one level, it was just a scaling-up of the quantum eraser experiments of the ’90s, but the image of a tiny computer program running through its paces, appearing “to itself” to be unique and alone, while in fact a second, equally oblivious version had been executing beside it all along, carried a lot more resonance than an interference experiment with photons. I’d become used to the idea of quantum computers performing several calculations at once, but that conjuring trick had always seemed abstract and ethereal, precisely because the parts continued to act as a complicated whole right to the end. What struck home
here
was the stark demonstration of the way each calculation could come to appear as a distinct classical history, as solid and mundane as the shuffling of beads on an abacus.
When Francine arrived home I was cooking dinner, but I grabbed my notepad and showed her the paper.
“Yeah, I’ve seen it,” she said.
“What do you think?”
She raised her hands and recoiled in mock alarm.
“I’m serious.”
“What do you want me to say? Does this prove the Many Worlds interpretation? No. Does it make it easier to understand, to have a toy model like this? Yes.”
“But does it sway you at all?” I persisted. “Do you believe the results would still hold, if they could be scaled up indefinitely?” From a toy universe, a handful of qubits, to the real one.
She shrugged. “I don’t really need to be swayed. I always thought the MWI was the most plausible interpretation anyway.”
I left it at that, and went back to the kitchen while she pulled out a stack of assignments.
That night, as we lay in bed together, I couldn’t get the Delft experiment out of my mind.
“Do you believe there are other versions of us?” I asked Francine.
“I suppose there must be.” She conceded the point as if it was something abstract and metaphysical, and I was being pedantic even to raise it. People who professed belief in the MWI never seemed to want to take it seriously, let alone personally.
“And that doesn’t bother you?”
“No,” she said blithely. “Since I’m powerless to change the situation, what’s the use in being upset about it?”
“That’s very pragmatic,” I said. Francine reached over and thumped me on the shoulder. “That was a compliment!” I protested. “I envy you for having come to terms with it so easily.”
“I haven’t, really,” she admitted. “I’ve just resolved not to let it worry me, which isn’t quite the same thing.”
I turned to face her, though in the near-darkness we could barely see each other. I said, “What gives you the most satisfaction in life?”
“I take it you’re not in the mood to be fobbed off with a soppy romantic answer?” She sighed. “I don’t know. Solving problems. Getting things right.”
“What if for every problem you solve, there’s someone just like you who fails, instead?”
“I cope with my failures,” she said. “Let them cope with theirs.”
“You know it doesn’t work like that. Some of them simply
don’t
cope. Whatever you find the strength to do, there’ll be someone else who won’t.”
Francine had no reply.
I said, “A couple of weeks ago, I asked Sadiq about the time he was doing mine clearance. He said it was more satisfying than mopping up DU; one little explosion, right before your eyes, and you know you’ve done something worthwhile. We all get moments in our lives like that, with that pure, unambiguous sense of achievement: whatever else we might screw up, at least there’s one thing that we’ve done right.” I laughed uneasily. “I think I’d go mad, if I couldn’t rely on that.”
Francine said, “You can. Nothing you’ve done will ever disappear from under your feet. No one’s going to march up and take it away from you.”
“I know.” My skin crawled, at the image of some less favored alter ego turning up on our doorstep, demanding his dues. “That seems so fucking selfish, though. I don’t want everything that makes me happy to be at the expense of someone else. I don’t want every choice to be like … fighting other versions of myself for the prize in some zero-sum game.”
“No.” Francine hesitated. “But if the reality is like that, what can you do about it?”
Her words hung in the darkness. What could I do about it? Nothing. So did I really want to dwell on it, corroding the foundations of my own happiness, when there was absolutely nothing to be gained, for anyone?
“You’re right. This is crazy.” I leaned over and kissed her. “I’d better let you get to sleep.”
“It’s not crazy,” she said. “But I don’t have any answers.”
#
The next morning, after Francine had left for work, I picked up my notepad and saw that she’d mailed me an e-book: an anthology of cheesy “alternate (sic) history” stories from the ’90s, entitled
My God, It’s Full of Tsars!
“What if Gandhi had been a ruthless soldier of fortune? What if Theodore Roosevelt had faced a Martian invasion? What if the Nazis had had Janet Jackson’s choreographer?”
I skimmed through the introduction, alternately cackling and groaning, then filed the book away and got down to work. I had a dozen minor administrative tasks to complete for UNESCO, before I could start searching in earnest for my next position.
By mid-afternoon, I was almost done, but the growing sense of achievement I felt at having buckled down and cleared away these tedious obligations brought with it the corollary: someone infinitesimally different from me – someone who had shared my entire history up until that morning – had procrastinated instead. The triviality of this observation only made it more unsettling; the Delft experiment was seeping into my daily life on the most mundane level.
I dug out the book Francine had sent and tried reading a few of the stories, but the authors’ relentlessly camp take on the premise hardly amounted to a
reductio ad absurdum
, or even a comical existential balm. I didn’t really care how hilarious it would have been if Marilyn Monroe had been involved in a bedroom farce with Richard Feynman and Richard Nixon. I just wanted to lose the suffocating conviction that everything I had become was a mirage; that my life had been nothing but a blinkered view of a kind of torture chamber, where every glorious reprieve I’d ever celebrated had in fact been an unwitting betrayal.
If fiction had no comfort to offer, what about fact? Even if the Many Worlds cosmology was correct, no one knew for certain what the consequences were. It was a fallacy that literally everything that was physically possible had to occur; most cosmologists I’d read believed that the universe as a whole possessed a single, definite quantum state, and while that state would appear from within as a multitude of distinct classical histories, there was no reason to assume that these histories amounted to some kind of exhaustive catalog. The same thing held true on a smaller scale: every time two people sat down to a game of chess, there was no reason to believe that they played every possible game.
And if I’d stood in an alley, nine years before, struggling with my conscience?
My subjective sense of indecision proved nothing, but even if I’d suffered no qualms and acted without hesitation, to find a human being in a quantum state of pure, unshakeable resolve would have been freakishly unlikely at best, and in fact was probably physically impossible.
“Fuck this.” I didn’t know when I’d set myself up for this bout of paranoia, but I wasn’t going to indulge it for another second. I banged my head against the desk a few times, then picked up my notepad and went straight to an employment site.
The thoughts didn’t vanish entirely; it was too much like trying not to think of a pink elephant. Each time they recurred, though, I found I could shout them down with threats of taking myself straight to a psychiatrist. The prospect of having to explain such a bizarre mental problem was enough to give me access to hitherto untapped reserves of self-discipline.
By the time I started cooking dinner, I was feeling merely foolish. If Francine mentioned the subject again, I’d make a joke of it. I didn’t need a psychiatrist. I was a little insecure about my good fortune, and still somewhat rattled by the news of impending fatherhood, but it would hardly have been healthier to take everything for granted.
My notepad chimed. Francine had blocked the video again, as if bandwidth, even here, was as precious as water.
“Hello.”
“Ben? I’ve had some bleeding. I’m in a taxi. Can you meet me at St Vincent’s?”
Her voice was steady, but my own mouth went dry. “Sure. I’ll be there in fifteen minutes.” I couldn’t add anything:
I love you, it will be all right, hold on.
She didn’t need that, it would have jinxed everything.
Half an hour later, I was still caught in traffic, white-knuckled with rage and helplessness. I stared down at the dashboard, at the real-time map with every other gridlocked vehicle marked, and finally stopped deluding myself that at any moment I would turn into a magically deserted side-street and weave my way across the city in just a few more minutes.
In the ward, behind the curtains drawn around her bed, Francine lay curled and rigid, her back turned, refusing to look at me. All I could do was stand beside her. The gynecologist was yet to explain everything properly, but the miscarriage had been accompanied by complications, and she’d had to perform surgery.
Before I’d applied for the UNESCO fellowship, we’d discussed the risks. For two prudent, well-informed, short-term visitors, the danger had seemed microscopic. Francine had never traveled out into the desert with me, and even for the locals in Basra the rates of birth defects and miscarriages had fallen a long way from their peaks. We were both taking contraceptives; condoms had seemed like overkill.
Had I brought it back to her, from the desert? A speck of dust, trapped beneath my foreskin? Had I poisoned her while we were making love?
Francine turned toward me. The skin around her eyes was gray and swollen, and I could see how much effort it took for her to meet my gaze. She drew her hands out from under the bedclothes, and let me hold them; they were freezing.
After a while, she started sobbing, but she wouldn’t release my hands. I stroked the back of her thumb with my own thumb, a tiny, gentle movement.
2020
“How do you feel now?” Olivia Maslin didn’t quite make eye contact as she addressed me; the image of my brain activity painted on her retinas was clearly holding her attention.
“Fine,” I said. “Exactly the same as I did before you started the infusion.”
I was reclining on something like a dentist’s couch, halfway between sitting and lying, wearing a tight-fitting cap studded with magnetic sensors and inducers. It was impossible to ignore the slight coolness of the liquid flowing into the vein in my forearm, but that sensation was no different than it had been on the previous occasion, a fortnight before.
“Could you count to ten for me, please.”
I obliged.
“Now close your eyes and picture the same familiar face as the last time.”
She’d told me I could choose anyone; I’d picked Francine. I brought back the image, then suddenly recalled that, the first time, after contemplating the detailed picture in my head for a few seconds – as if I was preparing to give a description to the police – I’d started thinking about Francine herself. On cue, the same transition occurred again: the frozen, forensic likeness became flesh and blood.
I was led through the whole sequence of activities once more: reading the same short story (“Two Old-Timers” by F. Scott Fitzgerald), listening to the same piece of music (from Rossini’s
The Thieving Magpie
), recounting the same childhood memory (my first day at school). At some point, I lost any trace of anxiety about repeating my earlier mental states with sufficient fidelity; after all, the experiment had been designed to cope with the inevitable variation between the two sessions. I was just one volunteer out of dozens, and half the subjects would be receiving nothing but saline on both occasions. For all I knew, I was one of them: a control, merely setting the baseline against which any real effect would be judged.
If I was receiving the coherence disruptors, though, then as far as I could tell they’d had no effect on me. My inner life hadn’t evaporated as the molecules bound to the microtubules in my neurons, guaranteeing that any kind of quantum coherence those structures might otherwise have maintained would be lost to the environment in a fraction of a picosecond.
Personally, I’d never subscribed to Penrose’s theory that quantum effects might play a role in consciousness; calculations dating back to a seminal paper by Max Tegmark, twenty years before, had already made sustained coherence in any neural structure extremely unlikely. Nevertheless, it had taken considerable ingenuity on the part of Olivia and her team to rule out the idea definitively, in a series of clear-cut experiments. Over the past two years, they’d chased the ghost away from each of the various structures that different factions of Penrose’s disciples had anointed as the essential quantum components of the brain. The earliest proposal – the microtubules, huge polymeric molecules that formed a kind of skeleton inside every cell – had turned out to be the hardest to target for disruption. But now it was entirely possible that the cytoskeletons of my very own neurons were dotted with molecules that coupled them strongly to a noisy microwave field in which my skull was, definitely, bathed. In which case, my microtubules had about as much chance of exploiting quantum effects as I had of playing a game of squash with a version of myself from a parallel universe.
When the experiment was over, Olivia thanked me, then became even more distant as she reviewed the data. Raj, one of her graduate students, slid out the needle and stuck a plaster over the tiny puncture wound, then helped me out of the cap.
“I know you don’t know yet if I was a control or not,” I said, “but have you noticed significant differences, with anyone?” I was almost the last subject in the microtubule trials; any effect should have shown up by now.