Wigner and I

A science fiction short story set in many worlds

[Ed. note¹]

Photo B. Hayes/NIST. Modified by Jason Smith.

I. Elsewhere

“Did I ever tell you about my elsewhere interpretation of quantum mechanics?” Brian asked Geneviève.

The two postdocs were in the process of aligning lasers and cleaning mirrors. Geneviève squirted a bottle of isopropyl alcohol onto a fresh square of lens paper which caused it to cling to a mirror; with a smooth pull on the tweezers originally holding the paper in place she slid the paper off parallel to the surface. She pulled back the sleeve of her thin, pale gray hoodie with her gloved hand now free of the bottle, and rotated the mirror into place on the optical bench.

“I was a grad student — at Maryland. I had been fascinated by how close ‘elsewhere’ was on a space-time diagram. Like, given a nanosecond, ‘elsewhere’ was just a foot away,” Brian said while adjusting the axis screws on another mirror.

“No matter how long they’re in the field, you can still spot an American physicist by their reversion to archaic scales derived from an appendage of a long dead Roman,” Geneviève replied.

“Anyway, I worked it out and it seemed every one of the key quantum experiments required a path to cross through ‘elsewhere’ for the observer at some point. The accelerations even required the observer and a particle to be on opposite sides of a Rindler coordinate horizon.”

“I once read a paper that showed you could reproduce the path integral from the thermodynamics of the Rindler horizon.”

“Lee Jae Weon. Yeah, there was always something missing in those papers for me — ad hoc Born rule, Euclidean space instead of Minkowski, always something. I couldn’t figure out how to get interference fringes in my ‘elsewhere’ interpretation except putting it in by hand. Tried it with a Grassmann field, but you might as well just put complex numbers in. Would have liked to have finished it before working on this project — couldn’t get myself to just go for it. Put in the time, you know?”

“Do you really think our first result put an end to the debate? That ‘Many Worlds’ won?” Geneviève asked.

Brian laughed. “Well, we wouldn’t be doing this experiment if it had — with a Guinea pig, I mean, conscious observer instead of an AI.”

“I think we’re ready.”

The door swung open and an older man with tight curly, but thinning, hair led a group of teenagers into the lab. He was in the middle of his practiced tour speech.

“… is our lab. And this is the optical bench for the Wigner’s friend experiment. Ah, Geneviève, Brian — this is the freshman undergraduate physics seminar.” The two postdocs put on smiles and wave. “Welcome.”

“I think we’re doing the conscious observer version because Aurel likes being in the New York Times,” Brian said under his breath to Geneviève. Her conscious smile turned into an involuntary one.

Aurel switched off a few lights; the apparatus flickered in the intermittent glow of the electronic indicators. “This is where our ‘cat’ — the lambda barium borate crystal — is housed. It provides the macroscopic quantum system that down-coverts the ultraviolet laser to either red or green entangled photons depending on whether the ‘cat’ is alive or dead — whether the crystal is in its red or green down-converting state. On the outside of the test chamber, we see only the interference of the polarization states — not the color. That’s when Wigner’s AI friend — our computer here — makes a measurement of both the color and polarization. The AI only reports that it made the measurement outside the chamber. In our paper, already with more than a thousand citations, we showed that what Wigner thought was anathema to sound reason is actually how reality works. We still saw the interference fringes. The AI had become entangled with the crystal cat.”

“But an AI isn’t conscious — wasn’t that the main point?” a student in the back of the group asked.

“Yes!” Aurel pointed excitedly towards the student. “That’s why we have Brian here. Our next test is going to replace the AI with Brian — and Brian’s consciousness should become entangled with the crystal just like the AI.”

Brian thought Aurel was playing his role of carnival barker well. It sounded like the breathless accounts in MIT Technology Review or Quanta magazine; so much philosophical musing built on an interference pattern. Aurel’s insistence that they file the paperwork for a human test subject seemed to be designed to simultaneously build up the impact as well as the anticipation. It had been three months waiting for Ethics Review Board approval and the final sign off on the required modifications was due any day now. The board had seemed to be delighted to take on something out of the ordinary — one of the members had even been interviewed in that New York Times science article. It’s the kind of publicity that keeps grants sold. We do science with public funds, so it makes sense to show the public something they find interesting. The weirdness of quantum mechanics was always a good story.

II. A gray hoodie

Brian gulped the last half of his coffee and set the mug on a nearby desk in the lab. “Human test subject ready to be experimented upon, professor.” Some of the grad students in attendance laughed. He fist-pumped towards his ersatz audience. “Let’s go for it!”

Aurel was not amused — or at least didn’t show any amusement. Geneviève pushed up the sleeves of her gray hoodie and helped Brian into the test chamber, closing the door behind him. The light inside was a faint blue — out of band of both the laser and the two λ-BaB₂O₄ entangled photon frequencies. The seat was uncomfortable. There was a debate as to whether the miniscule gravitational fluctuations from different body positions that couldn’t be shielded constituted a measurement, so his movement was fairly constrained. Aurel was confident the ‘conscious observer’ experiment would show the same interference fringes rendering the point moot. The chamber was air tight and sound proof with a layer of vacuum between the inner and outer shells. The ERB had suggested adding a latch inside and spare oxygen — as well as limiting the experiment to 3 minutes — out of safety concerns. The modifications had taken a couple weeks. Aurel had played it up for the press inquiries.

Brian could hear the whirr of the liquid nitrogen pump. The blue 3-minute clock had started; it looked gray in the blue light. Two minutes, fifty seconds. The experiment didn’t take that long. Ten seconds, tops. He looked at the laser light appearing on the screen. Yellow? Nah, green. He pushed the indicator letting the crew outside know he’d made his measurement.

Outside the chamber, the accumulating photons on the screen started to appear in every bin; the interference fringes had vanished.

Aurel stood up. “Huh.”

There was silence in the room.

“Maybe consciousness does cause the wavefunction to collapse,” Geneviève said with a mix of sarcasm and wonder.

“More likely there’s a mistake,” Aurel said. “Gah. I have to cancel the press conference I scheduled for next week. Everyone, we have some work to do.”

Aurel went over to the chamber door and opened it. Brian looked up from his cramped seat. “Well?”

“We proved consciousness does cause the wavefunction to collapse,” Geneviève said from behind Aurel.

“Some sort of configuration error,” Aurel said before she finished. “You and Geneviève need to do a complete check. If it’s done by this weekend, we might still be able to finalize results before next week.”

The grad students groaned. Brian didn’t mind. He and Geneviève hadn’t really had much of a social life since taking their postdocs at CU Boulder. They basically were each other’s only friend. She had moved from Haiti to Durham, NC to Paris before coming here. He had also attended Duke as an undergrad — Geneviève was in a couple of his classes — moving only as far as Maryland for grad school. It was nowhere near the journey she’d had, but still both of them were now far enough away from family and friends in a small college town that their collegial relationship was their primary outlet. If they weren’t working in the lab, they’d be hanging out at a coffee shop reading papers.

Aurel walked out of the lab. A couple of the grad students followed. Geneviève turned to the remainder. “Enjoy the weekend. Brian and I will take care of this.”

Relief spread across their faces. When they were gone, Geneviève turned to Brian, sliding the sleeves of her gray hoodie up to her elbows. “Maybe we can run the AI version again — just to be sure.”

“Nice idea. I’m going to get some more coffee from the machine. Do you want some?”

“No, thank you.”

Brian reached out in his peripheral vision swiping for his cup, spilling coffee on himself in the process. He looked down at the now quarter full cup with a quarter splashed on his leg.

“Smooth.”

“I could have sworn I finished it,” Brian said.

“I’ll set up the AI. Don’t want you dripping coffee on the equipment.”

Brian left the lab and walked down to the restrooms at the end of hall near the elevator. He grabbed a paper towel and wetted it before wiping down his pants leaving a large dark wet spot. He walked over to a urinal and relieved himself; he washed his hands. He splashed some water on his face. The sensation of gulping his coffee was still with him. A faint strain in his throat was still there. It had only been like, what, five minutes? Brian briefly considered making himself vomit up the coffee. That wouldn’t prove anything — he’d drank the other half only ten minutes earlier. He went back to the urinal and returned to wash his hands again.

When Brian got back to the lab, he saw the chamber door closed and Geneviève sitting and staring at the interference measurement. “Oh, you got it started. Nice.”

“Yes.” She didn’t look away.

There was quiet for few seconds. “The fringes are back.”

“You fixed it?”

“I didn’t do anything.”

“I think we are converging on identifying the issue — me,” Brian said.

“Obviously you are Wolfgang Pauli, making experiments break.”

“I must have messed up the measurement. I mean, maybe I’m tired. I spilled my coffee on myself, though I felt sure in my mind that I’d drank it. That kind of lack of focus could easily result in a mistake.”

“The only thing I can think to do is run the conscious observer experiment again.”

“Maybe you should be the test subject. I might mess it up again.”

“With all the ERB paperwork, I’m sure they’d get upset if someone who didn’t sign the consent form got in the chamber. Besides, it’s not that complex. We can even have the AI system run the measurement. You’ll still visually observe the color of the down-converted laser.”

Brian looked up at Geneviève quizzically. “Do — do you think it’s possible conscious observers cause the wavefunction to collapse?”

“I didn’t until just a few moments ago.”

The two postdocs looked at each other for several seconds. “Let’s go for it.” Brian got up and sat himself in the chamber. It was more cramped with the AI system shifted into its measurement position. Geneviève closed the door. Brian could see the clock reset in the blue light. The AI took longer to conduct the measurement — a full forty seconds. He watched the counter count down. He wouldn’t be able to see the laser light until the AI shifted the final mirror into position. He heard the stepper motor. Yellow-orange? No, red.

The door opened. Geneviève looked in. “No fringes.”

“This is crazy,” said Brian as Geneviève helped him out of the test chamber. “Maybe you are Wolfgang Pauli,” she replied.

“You should be the test subject,” said Brian. “I’m serious. I really think I’m the problem.”

“You didn’t touch anything, right? You just observed the light?”

“Yes.”

“Then how could you have messed it up?”

“I don’t know. Maybe the humidity from my breath or some random microscopic flakes of skin got in the beam. I’m also having trouble focusing. I didn’t remember drinking my coffee. Maybe I didn’t remember hitting the optical bench with my knee.”

“It weighs a thousand kilograms. It wouldn’t move.”

“I’m just saying I don’t feel 100% and that could be a problem.”

“Maybe we should get something to eat,” said Geneviève. She smiled. “Can you hand me my hoodie?”

Brian looked around. “Um, where is it?”

“It’s right here.” She laughed as she picked it up.

“Weren’t you wearing your gray one?”

“No.”

Brian knew he didn’t pay that much attention to people’s sartorial choices, but he didn’t think he was that oblivious. He looked over at his coffee cup — empty. Was the stress of his postdoc getting to him? Maybe he did just need some food.

The Mexican restaurant nearest to campus was loud with weekend undergraduates. Geneviève came back from the bar with two Tequila shots. “I think we should celebrate. This could be Nobel prize material. Conscious observers impact quantum measurement. I’d laugh the rest of my life if I got to go to Stockholm because of a joke that Aurel took seriously.”

Brian grabbed the shot, clinked the glass against hers, and downed it — following it up with a bite on the lime wedge. A waiter came by with a plate of nachos. Geneviève asked for two more Tequila shots. Of course, Brian thought, every physicist’s dream is to win a Nobel prize. But it’s just not a mountain you point at and head towards. Were there any called shots in Nobel-winning work? I suppose everyone working on unification and the theory of everything are pretty sure if, and it’s a big if, they make a breakthrough it’ll probably win. But Eric Cornell and Carl Wieman weren’t cooling atoms into a Bose-Einstein condensate because of a medal.

“I think I'd be right there with you if I hadn't been experiencing weird things today,” Brian said.

“Like what?”

“I was sure you were wearing your gray hoodie.”

"Both are in the wash. I wear one almost every day. You're probably just filling in memories."

“I spilled coffee on myself because I thought I drank the whole cup.”

“Spilled coffee?”

“What?”

“You did drink the whole cup — you swigged it all down just before getting in the chamber.”

Brian was both unnerved and excited. There was the wet spot on his pants. He stood up from the stool, looking down. “I — I — I went to the restroom to clean it off — it's still wet!”

The spot on his lower thigh had largely dried; there was still a slight discoloration — the fabric almost imperceptibly darker than the rest of his pants. Geneviève leaned back on her stool and narrowed her eyes.

“Maybe I'm filling in memories.”

“You also had your hoodie on, not sitting on the chair,” said Brian.

The waiter returned with shots that went unregarded by the two postdocs.

“I'm not sure damp pants, empty coffee cups, and fluctuating hoodies would hold up in peer review. I am concerned, however. Why would we both be suffering from confabulation in the lab?”

An idea started forming in his head. Yes — it made so much sense. Brian grabbed is phone from his pocket and started tapping.

“Maybe there's a gas leak.”

“The liquid nitrogen coolant for the laser?”

“Ha! Yes, nitrogen hypoxia. Memory loss is a symptom.”

“We've been in that lab nearly 18 hours a day for weeks — and you've been getting in the chamber with the laser more than I have.”

“We should check. There's an oxygen sensor — maybe it's defective. There's usually a portable unit in one of the storage cabinets in most of the labs with N2.”

Brian suddenly felt better — this was something he could grab on to. He tried to flag down their waiter. Geneviève grabbed the full shots and handed them to two young men on the stools next to them. “Do you want these? We have to leave.” An animalistic holler erupted from them. “Free shots!” Brian looked back at Geneviève, shrugged, and grabbed his wallet; he threw down three twenties. “Nachos. Shots. Tip. You can get me back later.” They waded through the Friday night reveries, out the door, and back towards the lab.

The cold night air had the pair crossing their arms tightly to their chests; the clouds of their breath reflecting white in the LED street lights.

“An N2 leak wouldn't explain the conscious observer effect,” Geneviève said as if continuing a conversation.

“Hypoxia might have made me bump a mirror and not notice or remember.”

“But I re-did the AI observer experiment without re-aligning any of the mirrors. So you couldn't have perturbed anything physical. It was still working. I mean ...”

Brian looked up from methodically watching the ground in front of his feet. “Hey, I told you about my elsewhere interpretation — you can make any bold claims you'd like.”

Geneviève smiled. “I was thinking of Penrose. What if being in a quantum superposition affected your consciousness, which in turn affected the experiment?”

“Copenhagen for conscious observers?” Brian said, referring to the now extremely unfashionable interpretation of the weirdness of quantum mechanics.

“Yes, but more than that. You get conscious memories of different paths.”

“Conscious memories and wet pants.”

“I'll admit it — that's a puzzle piece that doesn't fit.”

They reached a door to the Duane Physical Laboratories complex. Geneviève used her staff key to open it and they climbed the stairway.

“Occam is definitely saying long term hypoxia from a Nitrogen leak.”

“But we haven't had any other symptoms. No shortness of breath.”

Once in the lab Brian checked the oxygen sensor and Geneviève searched the cabinet for the portable unit. Brian pressed the test button and a piercing tone reverberated in the test chamber. Geneviève found the unit and switched it on. “Twenty percent at a pressure of eighty percent of sea level. Normal for Boulder.” Brian checked a valve on the liquid nitrogen supply to the laser. The flow is zero. Geneviève checked the date on the tank alongside her lab notebook, and walked over to the whiteboard for a quick calculation. “If there had been a significant leak for more than a day, the tank would show more than the usual rate of depletion. We have closed the valves whenever we have shut down — otherwise we would have seen a great deal more loss.”

Brian's heart sank. Was it stress? Was he imagining things? His pant leg was no longer wet — the one piece of physical evidence had evaporated. Out of the blue, the voice of his high school track coach went through his head. Go for it! Give 110%. The memory of that voice often surfaced when he was making a conscious choice; in the past he’d listened to it less than half the time.

“Let's try it again.”

Geneviève lit up at the suggestion. The two reset the apparatus, and Brian stepped back into the blue light of the chamber. He watched the timer. The AI was doing the measurement again. He heard the stepper motor. He took a couple deep breaths, and slowly counted down from ten. Yellow; no red.

Geneviève opened the door and helped Brian out of the seat. “Anything different this time?”

She was still wearing her white hoodie. Maybe he just thought it was gray. His coffee cup was still empty. How can you check for things out of place when you don't know what to look for?

“Fringes?”

“Like last time — they disappeared.”

Brian grabbed on to a new narrative.

“Maybe seeing things changing was stress. Maybe doing a shot with you loosened me up. Maybe the conscious observer effect on the interference pattern is real.”

“Maybe we should close up and get some rest,” Geneviève said. “We’re not going to solve it tonight.” Brian nodded.

III. Tau Ceti

Brian started to realize Poisson distributed pulses of buzzing from his phone. It was still dark in his apartment; a faint blue-pink light was streaming through the slats of the mini blinds. The pulses indicated text messages — text messages from a grad student friend who had taken a postdoc with the European Space Agency a couple years before Brian finished his PhD and moved to Boulder. The first one just said “duuuude”.

The second was a picture; it looked like a Matlab plot of a background of noise with two fuzzy dots on a circle at the 2 o’clock and  8 o’clock positions. No axis labels. The tick marks appeared to go just beyond +1 to −1 on both the x and y axes. Brain rubbed his eyes and grabbed his glasses from his bedside table.

The third was in all caps “BPSK” with an alien emoji.

The fourth was “greenbank ftw”.

There probably had been some kind of protocol put in place for an event like this, but Breakthrough Listen was funded through the whims of a billionaire so the detection spread on social media immediately. Brian hadn't even heard of the program. He tapped a link.

BREAKING NEWS: An all night listening session at Greenbank Telescope funded by billionaire Yuri Milner's Breakthrough Initiatives detected incontrovertible signs of extraterrestrial communication coming from Tau Ceti. As the weak signal had to be collected for several hours to detect it at a range of 12 light years, no details of the contents are available. 

The signal shows signs of digital information with 1's and 0's accumulating into the distinct pattern of Binary Phase Shift Keying (BPSK) modulation. No terrestrial signal uses this modulation at the radio frequency the signal was detected and the Doppler shift corresponds to the orbital velocity of one of the planets of the Tau Ceti solar system.

Frank Drake, famous for the Drake equation, had scanned Tau Ceti with Greenbank radio telescopes as part of Project Ozma back in the 1960s finding nothing. However, Project Ozma focused on a much more limited range of frequencies than Breakthrough Listen so this signal would not have been seen.

Updated 3:05am EST: The President is expected to make remarks at 12pm EST today.

Brian’s head was reeling. This was definitely out of place. However, it didn't make sense that an experiment on Earth last night would cause a change such that a signal that needed to start its journey 12 years ago would show up today. Aurel’s lab had only gotten started three years ago. From the spacetime perspective of the test chamber, this alien signal had come from elsewhere.

Brian was in the process of tapping out a message to Geneviève when a message from her came through. “Look what you did.”

The two postdocs spent the morning passing breaking news items back and forth. What appeared to start as a unifying human event slowly and then all at once decayed into factions. Alien deniers accumulated on social media. Riots broke out in DC, Paris, and Moscow. The Presidential address was pushed back an hour, and then two.

Brian plugged in his phone charger and started the live stream. Just as the President walked out to the podium, loud bangs could be heard in the background coming from the National Mall and the secret service whisked the President away. The news network rotated its camera around to see four to five columns of smoke coming from different locations around the mall. Within an hour, city-wide curfews had been announced across the United States.

Brian called Geneviève. “I think the conscious observer does have an effect — and not just on the interference fringes.”

“Are you saying you may be from a different quantum history? One where I was wearing my gray hoodie, you spilled coffee on yourself, and aliens weren’t just about to be discovered?”

“Think of it — if conscious observers collapse the wavefunction, then aside from a few quantum parlor tricks there’d be a single universe for those conscious observers. At least until they develop the ability to put a conscious observer into superposition — in this case, it’s me.”

“But why do I remember doing the experiment again because you saw my hoodie change?” Geneviève was quiet on the phone for a minute. “Oddly, this would also a solution to the Fermi paradox. Conscious species that evolve on a causally disconnected world would almost certainly progress through a slightly different quantum history — one that wouldn’t intersect with the quantum history of another conscious species. But that means my universe, the one with me in it, might not have existed except as a path not taken until you visited.”

“Does it mean my old quantum history no longer exists? Or did it split off?”

“Is the entire universe outside the chamber becomes the quantum superposition for the observer in it?” The two postdocs were in a state of having more questions than answers — usually the exciting part of science, but now ominous.

“Do you think I can go back?” Brian asked.

“We can try,” Geneviève said.

Neither of them lived very far from campus, so could each walk. A few other people could be seen challenging the curfew along the way — having been hastily set up and consisting of only roadblocks and vehicle patrols it was porous.

The pair met up a block away from the Duane Physical Laboratories Complex, and covertly made their way to a side door. Brian put his key in the lock, but it wouldn’t turn. Geneviève tried hers; it opened easily. She hurried him inside so they wouldn’t be seen.

“Hand me your key,” Geneviève said.

Brian handed his whole keychain over. She held her staff key up next to his and examined the bitting. “Whoa. They’re different. You really are from a different quantum history.”

“I mean, it’s a random assignment of a number,” Brian said. “The tiniest fluctuation could change something like that.”

There was a pause. “Not sure I want to find out what else is different here.”

She handed him back his keys, and they headed up the stairs to prepare the experiment.

Brian paused while halfway in the door of the chamber. “What if you don't believe me? You know, the Geneviève in the other universe?”

Geneviève went over to her notebook on the desk, wrote a short paragraph in it, signed it, and handed it to Brian.

“The whole notebook?”

“Harder to rationalize than wet pants. You should have some of our text messages on your phone, too.”

Brian got into the cramped test chamber seat. He looked up at Geneviève. “Something is bothering me. I mean, it made some kind of sense for you and I to be in the lab last night working on the mystery of the disappearing fringes, the missing coffee, and the color-changing hoodie.”

“But what kind of past history of the universe outside the chamber would be consistent with us being here tonight, running the experiment again?” Geneviève asked, rhetorically.

“It might be worse. And even if it’s not, what about you?”

“Humans are terrible to each other in every possible universe. And you’re forgetting —this one is mine. I don’t want to step in there and learn that my parents are dead when I get out. This experiment is an existential horror.”

A short silence before Geneviève adds “I feel so bad for Wigner's friend.”

“I'd rather be Wigner forgetting than his friend remembering.”

“True. I guess this is a goodbye of sorts?”

“At least between these versions of ourselves.”

“Versions in the same universe that both know.”

Brian gave a salute, and started to close the door; Geneviève sealed it shut. The timer started counting down from three minutes.

Brian sat for several seconds expecting the chamber door to be opened. Nothing. He pulled the safety release latch and climbed out. As he did, a small mechanical device broke off from the edge of the door on the outside. What is this?

The lab was dark. He saw a tripod with a digital camera — its red record light radiating. There were some random objects on the floor — a soda can, a flash drive. Each were labeled with tape X’s under them. Everything was quiet except the hum of the fans on the electronics racks. He picked up a notebook on the desk near the tripod and held it on top of Geneviève’s, opening it to a random page. There were some familiar space-time diagrams, but the math was new to him. Still, it was his handwriting: scribbles, cross-outs, and all.

Integrating over all possible coarse-grainings of the elsewhere causal diamond results in an oscillating oscillatory function due to a ‘moire effect’ — the interference pattern we seek.

Putting down the notebooks, he pressed the button to stop the recording. It was the digital camera he had gotten for his 21st birthday. It even had the dent from being dropped on a hike up Mt. Etna. Only one file was on the SD card; he pressed play. The field of view included the test chamber, the taped X’s, and the interference measurement output monitor. His own face popped into view from off screen.

“Not sure if I am talking to myself. The Brian doing the previous run felt like me. However, it seems the longer I stay in the chamber in superposition, the further I move from the progenitor casual diamond. I only noticed the change in the objects I randomly placed on the ground the first few times tonight. The flash drive moved. The lab coat was there instead a can of soda. Nothing as dramatic as the presentation poster changing in the first test this morning where I spent twenty, maybe thirty seconds checking everything before making the observation in the chamber. This session, I will set the timer for longer. Also want to give a shout out to the Nobel committee. Let’s go! 110%!”

Brian saw his own face smile right into the camera. That Brian was wearing sweatpants and a Duke t-shirt. Did that Brian go to the Tau Ceti universe? Did he go elsewhere? A pang of guilt hit him in the stomach. Watching the video, he could see the interference fringes on the monitor for several seconds before they disappeared in accumulating noise and the light indicating the measurement had been made came on. Several more seconds passed. I was expecting Geneviève to open the door. Then he saw himself, his current self, emerge from the chamber.

Something else seemed out of place. Brian scanned back though the video, watching himself get in the chamber again. He paused it. No chair. And that mechanism attached to the side of the door. He looked up at the chamber — chair and AI system from his universe were in there. This universe’s AI system was pulled out and was sitting at the side of the lab. The conscious observer experiment, the chair, had been Geneviève's idea. 

Geneviève.

Brian jumped into a run and bashed the lab door open. He ran down the hall to their offices, checking the name plates — almost all familiar names. Almost. Nelson? Brian sank to his knees in the hall in front of an ordinary office. The emotional oscillations of the past two days had reached the point of shaking him apart. He started to cry. He sat against the wall of the hallway for half an hour, staring into the void.

Deep into the night Brian got up, went into his office, turned on his computer with a shake of the mouse, and opened a browser.

Geneviève Georges

Geneviève Georges physicist

Yes; papers; she exists. He pulled up her Google scholar page. No publications in the past three years. He pulled up his social media. No Geneviève Georges. She had disappeared — at least from his universe. He checked the news. No Tau Ceti. Brian put his head in his hands.

It was now very late, almost early. This was a universe where no one but he had hit on the conscious observer experiment — at least in Aurel's lab. It was missing its inspiration; Geneviève had suggested it in jest but Aurel ate it up to keep the publicity machine going. Brian cleared out the extra equipment in the lab and re-installed the AI system — taking the one from one of the previous universes and hiding it alongside Geneviève’s notebook in a box in his office.

He looked at the door mechanism. This was to open the door because no latch was installed in his universe. He remove the internal latch and the door mechanism, putting them in the box in his office. The chamber chair looked like bondage equipment outside its usual environment. Brian disassembled it.

How far was this universe from his own? Did he live in the same place? Does his phone work? He checked it. Signal. Network. He opened his Amazon app. It works. Ship to ... yep, same address.

Brian walked down the stairs. Before leaving the laboratory building he checked his key. It works. He started walking towards the road when he caught sight of his own car in the parking lot. Makes sense. Had to bring a camera and tripod. No curfew, either —  an added sardonic thought.

This universe is so close, but so far, Brian thought. He drove home.

IV. Wigner’s friend

Brian was packing up his office. His two-year postdoc was over. He’d gotten a tenure track position at MIT on the strength of his series of papers on the elsewhere interpretation along with the experimental work in Aurel’s lab. Imposter syndrome was still hovering over his thoughts. It had taken months for him to master the material his other self had derived. It had taken months more to be able to make additional progress. He’d had lots of time, however. Only the occasional social gathering for a grad student’s defense or a professor’s retirement had broken the string of dinners home alone.

Aurel’s head emerged from around the corner of the ajar door. “Professor Wigner’s flight got in early; we're having an impromptu meet and greet with the group. You should join us.”

Deep into preparing to move, Brian had forgotten the department would move on without him.

“I'll be there.”

“It’ll be in the big conference room.”

“Ok, thanks.”

A few seconds later, there was a knock on the partially open door. “Brian? Not sure if you remember me from Duke.”

Brian's breath stopped. His heart filled with so much joy, but his brain was vetoing the emotion as socially inappropriate in this universe. 

“Professor ... Wigner?”

“Geneviève. We were in quantum mechanics together as undergraduates.”

“Yes, of course I remember!”

“You have done well — you are going to MIT? Your papers on the elsewhere interpretation were great.”

Geneviève’s French-accented English reminded Brian of when they first met years ago in that other universe.

“Thank you. You’re at …” Brian couldn’t remember the colloquium announcement email. Oh, no — so rude, he thought.

“Liege. They said they would also offer my husband a position in maths if I would take a position there. It was too good to pass up. I have been there ever since.”

"Nice. MIT is barely covering my moving expenses." Brian laughed.

“I was wondering if you had some time this week to discuss a strange idea. Sorry I did not email ahead of time — I did not realize you would still be here instead of MIT.”

“Strange idea?”

“Do you think, if you were somehow to get into your test chamber, you would, as a conscious observer, see Schrodinger’s cat both alive and dead?”

Brian’s hands became cold and clammy; his eyes widened. “The red and green photons as yellow.” A pause.

“Have a seat. I’m going to show you something that might be difficult to take in.” He reached into a nearby box, and pulled out a lab notebook. He hesitated, holding it in his hands with reverence, before opening it to the final handwritten page and handing it to Geneviève.

Geneviève, it’s me Geneviève. Brian is likely giving you this notebook because I — you — don’t believe him. It should be more convincing of the possibility of universes with alternate histories than color-changing hoodies or coffee stains. You can check the handwriting and all your — my — notes from the past year. You might even have your own copy. The conscious observer experiment must be a nightmare for the test subject, for Brian. Although my universe is starting to go through a pretty tough time, I wouldn’t want to arrive in another where my — our — parents had died or worse. Brian probably feels bad about leaving me here, but you should reassure him that you’d make the same choice. He’s my good friend and I care about him — every version of him.

Geneviève Georges

While Geneviève was reading, Brian had taken out the SD card and plugged it into his computer — pulling up the video file. She looked up from the paragraph to see Brian’s quantum clone giving his monologue. She watched him go in, and she watched him come out — dressed differently and holding a notebook. This notebook.

Brian sat down in his chair. “Our billions of conscious observations of the universe and the very small scale of Planck’s constant tend to limit the size of the elsewhere causal diamonds. Collectively, our human consciousness creates an objective reality with only hints of many worlds. Our human ingenuity has gradually allowed us to construct bigger and bigger diamonds. And if you create a large enough elsewhere causal diamond — a pocket of elsewhere big enough to fit a conscious observer, a person — all that matters are the boundary conditions. The surface of that test chamber is the only constant. It’s almost as if there is a duality — outside the chamber becomes the elsewhere for the inside — and the different universes can mix. Actually, you gave me that idea. For Wigner, his friend is from an alternate universe. For Wigner’s friend, Wigner and his universe is the alternate. The longer you stay in superposition, the longer the winding of the wavefunction’s phase, the longer the spin on the wheel of fortune, the further you’ll get from where you started.”

Geneviève sat in stunned silence.

“A preview of my next paper,” said Brian. “I still have to work it out completely before putting it out there, but I’m going for it. My high school coach would be proud if he were alive in this universe. No one else is working with so large a test chamber, so I have time before someone else subjects themselves to it. Did you know that in my universe, the one that I started in, it was you who suggested the conscious observer experiment? I was going to put you — her — as co-author on the paper thinking that something had happened to you in this one. But here you are, and you’re suggesting the conscious observer experiment again.”

“This is a lot,” said Geneviève. “And I feel like I have opened a wound for you.”

Brian smiled. “I’ve had a lot of time to process my experiences. I just want to make sure no one else has to go through it.”

“I could not imagine her universe where my son did not exist. She — I — made the right choice. However, I am sure there are some people who would chose another world from behind the veil of ignorance.”

“At the very least I can make it an informed choice.”

© Jason Smith

1. Short story outside of the Inner Horizon universe. Current version is a draft.