A world of possibilities.
Ever since the quantum universes reunited, I haven't been able to find my favourite pen.
It seems like such a small thing, but there it is, or rather, there it isn't: a black fountain pen with gold in the nib. I had black ink in it at the time, the only black ink I've ever found that was really dark enough. The grip was smoothed to my hand. I'm old-fashioned, I guess, but little things like that matter to me.
I remember losing it at the Midwest Medieval History Conference, just as I remember putting it neatly away in the drawer when I got home. This quantum re-entanglement: it's harder than it sounds.
I firmly remember my wife always being alive, except that I also firmly remember that she had a rare kidney infection that killed her two years ago. You would think this would be a bigger deal than the pen, and it is, but there's nothing I can do about it. I keep thinking the pen must be somewhere, and I know where Sara is; she's right here. Right where she's always been. Except for the two years I spent grieving for her every day and night.
Sara has memories of dying, too, which is as hard as you might think on her. Maybe. She says it could be worse. She says she is less afraid.
I am more afraid.
I am afraid of what other worlds are going to come in on us in a tangle.
I am afraid of my job going wrong, although it hasn't; they say that these worlds were able to re-entangle because the large-scale events stayed so similar. But I'm afraid next time we won't be so lucky.
I am afraid of losing my wife again.
As a historian, I study the ins and outs of what makes each path, what contributes to each decision, and I want them to make sense. I want them to be inevitable. I want them to follow patterns that I can find, so that I can say: “If the French had done this, then the Burgundians would have done that — but they didn't. If the Spanish had responded thusly — but no.”
But this, this re-entanglement, it says yes. It says they did. It says that the patterns are all followed. Not here. But somewhere. And we could get back there.
Perhaps if we got back there, I could find my pen.
Perhaps if we got back there, I would lose my wife.
The rest of the world — the rest of these united worlds — I don't know how to say it, even. The people around me seem to be navigating by touch, by not thinking of what they have gained, or what they have lost, in this reunification.
Last month I flew to Germany. I asked people on the street whether it was like their other reunification. Most of the people I asked were my own age, too young to really remember what it was like. I identified myself as a historian, and they sent me trundling off to an old folks' care home, where people would care about history. I should be used to this, in any world, in any reality, but the truth is that my field is obscure enough that even the elderly are presumed not to mind about it.
The elderly were more like me — more disturbed, more upset. I felt fussy among them, rebellious against my own interest, but I had to ask again, about reunification.
“The Communists did not take my favourite slippers,” said one woman in impeccable English, although I had asked her in German, “and they did not undo the dishes I had already done. For my part, I prefer the Communists.”
“Former Communists,” muttered her roommate.
The first woman ignored her. “We are Germans. We understand quantum mechanics. We understand that we do not understand quantum mechanics, and that is understanding quantum mechanics. Now they tell us that there is re-entanglement and that is why the trains are here and gone and cats we remember burying are still waking us to ask for food. Very well.”
“Very well?” I demanded. “Very well?”
“It is not a cat for you.”
“My wife,” I wanted to say, but instead, I said: “You haven't seen a black fountain pen? I think I've lost it.”
“Young man, they never should have told us. They should have let us think we were confused. We would have each made up stories and smoothed it over for ourselves. Now we can't go back.”
“I have to go back,” I said, but I didn't see how, except literally, and the literal had never satisfied me.
I took a taxi back from the airport. I couldn't tell whether I was jet-lagged or something worse. Quantum mechanics would be the death of me, I felt sure. I was second-guessing every billboard: had they changed it while I was gone, or had it always been like that? Had the neighbour pruned her roses, or were they supposed to be hydrangeas? My house was my house. Surely it would be my house.
There was a red fountain pen in the middle of the kitchen desk. I had never seen it before. I remembered buying it on a trip I took alone, after my wife Sara was hit by a car and died. I uncapped it and wrote on the notepad we kept there for groceries. The ink was black, blacker than any ink I'd seen.
“Sara?” I called into the bedroom. “Sara?”
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Lingen, M. Entanglement. Nature 471, 402 (2011). https://doi.org/10.1038/471402a