Quantum erat demonstrandum

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Surfing the treacherous data wave.

Credit: JACEY

The shrill ring of a phone pierces the slam and rattle of the Thursday afternoon table-football game. Last ball. I'm losing 5–4. The head of compliance is standing ready to pounce, her lines of men angled threateningly. I reach for the phone to delay the inevitable, and for a brief moment the office recaptures its mechanical silence.

“Simon Erat speaking,” I answer.

“Mr Erat, this is Frank Hauptmann. It's good to speak to you again. Can you talk?”

“Of course. All our lines are secure.”

“I need something brought from Tokyo to Zurich.”

“You do remember that I'm based in London? It'd be cheaper for you to contact the Tokyo office direct.”

“Commendably honest Mr Erat, but we want you to carry the data.”

Four hours later I'm on the first BA flight to Narita. As there are no films I haven't seen, I while away the time before the first meal by playing chess against my entertainment screen. It doesn't stand a chance against a quantum mind.

Tokyo. A black Lexus whisks me from the airport to the skyscraper that is my collection point. On most trips, I'd get the Skyliner or the Narita Express, but I wasn't going to object to the red-carpet treatment. I'm only carrying a small bag, but Tokyo is not somewhere you want to be encumbered by luggage. After three intense hours in the basement plugged into a sleek, offline computer, half-sensing ethereal streams of glowing data points pouring in, the same car takes me back to the airport. Same car, but I never see the driver.

Dutifully packed onto the next plane, I loosen my tie, sink back into the seat and taste the Châteauneuf-du-Pape that the friendly German air stewardess hands me. Perhaps Swiss. I'm not good at accents, particularly with my head heavy with data. Air France this time. You can usually rely on them for a decent wine in business class. I've barely finished the drink before I pass out with exhaustion and I'm gently awoken to Zurich by the same stewardess.

New York wants to suck you in, London wants to spit you out and Paris wants to seduce you, but I like clean, efficient Zurich. The people are friendly, and the place doesn't seem to care whether I'm there, which suits me. I shake the sleep from my head, grab my small bag and I'm down the steps to the next car.

Retrieval is as painful as always. The microchip-sized gyroscopic box in my frontal lobe takes the energy it needs from my neural pathways as it does its trillions of calculations a second. Data exit is a cruel, wrenching twist of the beautiful stream that entered. Once it's done and the information is deleted, I flick the mental switch to off, unplug the jack from my temple and drop it back in its sterilizing solution. The past day or two have become a haze — it's almost painful to try to pierce the cloud shrouding the half-remembered facts. It hurts to think. It hurts to sense.

I step out into the dusky promise of an evening. No car this time, as I'm staying the night to recover. Dog-tired, but light-headed now the information's been lifted, I wander until I find myself by the dark waters of the Schanzengraben canal. Heading north, past the former botanic gardens, I glimpse an eerily lit bar above a pool. Crammed full, the bar's laughter travels to me on the breeze. Déjà vu. Did I come here the last time I was in Zurich? Rimini? Is that what it was called? Maybe. Threading my way between pot plants and people, I tread the faux-oriental mats and get a Bloody Mary and a raw kebab.

A girl bumps into me, laughing. She sees my predicament, grabs my arm and leads me towards one of the many grills. Was she here last time? For safety's sake, I should probably be in a hotel room by now — transfer leaves me like a lost puppy. And yet, I stay.

In no time, I'm absorbed into her group of friends and I attempt broken German and shattered French before they take pity and apologize for their expert English. The night drifts into an unlikely-to-be-remembered blur of noise, light and excitement. I can rarely lay down new memories immediately after data exit.

I awake in a hotel room. Mine? My bag is on a chair, unopened. I'm undressed and there's a note scrawled on the hotel paper on my pillow.

Ich hatte eine wundervolle Zeit.

Vielen Dank für alles. x

The phone is ringing.

“Yea ... Ja?” I enquire, stealing a glance at the time. 7:21.

“Good morning Mr Erat,” Hauptmann purrs. “I'd just like to thank you for a thoroughly professional and faultless service. Quod erat demonstrandum eh? Or rather Quod erat faciendum?” He laughs. “The balance will be transferred by midday.”

“Always nice to hear,” I smile back, the relief obvious to me, even if not to him.

Further words catch in my throat as I see the Air France hat on the bedside table.

“Until next time,” I close off.

Anger and fear struggle for superiority. Thanks for everything? I flick to quantum. Of course there are no data — nothing to steal. Then they'd hired her to watch me. But why leave the hat?

“Thoroughly professional,” I repeat under my breath with a hollow laugh. How had Hauptmann known where I'd go? Suddenly the idea of someone plugging a cord into my brain felt like violation.

Now Zurich had noticed me, it didn't feel quite the same.

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Simms, C. Quantum erat demonstrandum . Nature 456, 280 (2008) doi:10.1038/456280a

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