January 2, 2021—August 8, 2021
“Consider the double-slit experiment. A coherent light source such as a laser beam radiates towards an opaque screen with two parallel slits. The width of a slit is not much bigger than the wave length of the light; the distance between the slits is however considerably bigger. Behind the screen a photographic plate for registration of incident light is placed. Blackening of the photographic plate is a quantum process, a chemical reaction at a certain concrete point-like position produced by absorption of a single quantum of light, photon. If we could speculate about what happens to a photon between its emission from the light source and its absorption in the photographic plate, we could argue as follows: the photon can come either through the first slit or through the second slit. If it comes through the first slit, its probability distribution for being absorbed at a position on the photographic plate cannot depend on whether the second slit is open or closed. Similarly, for the second slit, the probability distribution cannot depend on whether the first slit is open or closed. If so, it appears logical that when both slits are open the blackening of the photographic plate should be the superposition of the patterns produced by the photons coming through the individual slits. Yet, this is not what happens in nature. When one slit is open, a continuous area on the screen is affected: the blackening is most intense in the middle, as one would expect, gradually fading out at the sides. When both slits are open, however, what one sees is the characteristic interference pattern consisting of alternation of light and dark bands.
“To explain this phenomenon we could turn to an analogy involving propagation of waves. In that case, one could say that the primary wave penetrates through the slits and results in two secondary spherical waves which overlap and produce alternating regions of cancelled out and reinforced perturbations. Thus, it appears that light exhibits properties of a wave when it comes through the slits and properties of a particle when it is registered on the photographic plate.”
Pavel raises his head from the smartphone and his mind returns into the embrace of the August night. It has grown deep, hot, and stuffy. Somewhere far away, on the verge of a dream, leaves rustle languidly, but here, inside, the air remains stagnant. The gloom of the room is almost total, almost velvet-like, except for an old electronic clock that radiates a flickering neon glow and stands out like a lurid lighthouse. Its big green digits indicate three fifty-two AM. Pavel puts aside his smartphone and listens to the sounds of the night; his gaze fixes inertly on the center of the room. A ray of amber light enters through the open window and falls on the floor where it gradually disperses without exposing details of the interior. The light is dim and shimmering; it lacks a clear origin and appears to be only a side-product of the ambient heat.
A few seconds pass in silent darkness before Pavel rehears the sounds that made him interrupt his reading. Loud metallic clangs are wending through the floors of the condominium. They appear to be coming from afar, garbled by reverberation, rising all the way from the ground floor. Pavel finds the noises unsettling. He lies in the supine position and watches the dark ceiling while waiting for them to stop. He cannot say how many seconds or minutes pass before everything calms down. When silence is restored, Pavel exhales slowly and takes his smartphone.
“It is possible to do a variation of the experiment by emitting one photon at a time. In that case, a single point of impact per photon appears on the photographic plate, as expected. Remarkably, however, the same interference pattern emerges when these particles are allowed to build up one by one. In this way the fundamentally probabilistic nature of quantum phenomena is demonstrated: it is impossible to predict the position of an individual impact on the photographic plate, but the probability distribution of these impacts over the surface of the plate is always the same for a given configuration of the experiment.”
Now it is certain that the lift in the stairwell is moving. It is rising slowly somewhere in the background, but its quiet screak does not fail to attract Pavel’s attention. He feels an impending panic attack which makes him put his smartphone down on the nightstand and cover his face with his palms. Suddenly, a dull mechanical click comes from behind the entrance door and in the absolute darkness the slits around the doorframe turn into lines of light. Pavel props himself on the bed with his elbows and looks at the lucent rectangle. He gulps; from this moment on he cannot help but notice the sounds of his own breathing. The electrical buzz of the working lamps in the stairwell seems dry and surprisingly resounding. Seconds pass; there is no sign of life behind the door, but there must be something that has caused the light to turn on. “There are only two flats on this floor: mine and the one where the old lady lives. There is no reason why a stranger would come here at this ungodly hour,” thinks Pavel. Finally, after what seems to have been an eternity, he hears footsteps—they approach slowly and stop in front of his apartment.
An audacious wave of sound comes and brings an adrenaline rush and cold sweats. The ringing of the doorbell is so loud, so illogical at four in the morning that the only sane explanation is an emergency. Pavel experiences a choking feeling; he touches his throat to make sure that there is nothing around it. “Of all people, why me?” he thinks. “It may be an emergency, but it may be harassment, too. I’m not expecting guests. Until this moment I was safe. Now the finger of a stranger is pointing at me. I’m arraigned without a case.” The ringing repeats again and again while Pavel waits with bated breath for it to stop. Finally, it does stop, but in the restored silence, in the total darkness, many minutes pass before Pavel notices that the light behind the entrance door has ceased.
In a brightly lit room with darkness instead of walls everything is sturdy and impressive. There are devices for conducting physical experiments with radiation and matter: coils of thick copper wire, industrial electromagnets, brass tubes, high-voltage transformers, ultra-precise scales, polished spheres made of metal and glass, imposing gray screens, levitating superconducting alloys, automated retorts. Some instruments are placed on the floor, others—on solid oak tables. Everything is new and perfectly clean; the shiny surfaces look dazing and impatient.
Pavel walks around in the laboratory and sees many appliances that arouse his curiosity. Many times he considers trying out one of them but always stops in hesitation not knowing what experiment to conduct. Finally, he notices two massive treasure chests made of brass and galvanized steel. Beside them, many different keys lie on a table. Designs and sizes of the keys vary as do their materials: brass, tin, silver, nickel, copper, and even gold. Pavel picks a key and attempts to insert it into the key hole of a chest—this experiment appears straightforward enough. The key fits and yields a full turn. Something clicks inside the mechanism indicating that it is responding. However, the lid of the chest remains locked. Pavel tries to give the key another turn, but discovers that it is now blocked and will not turn anymore. The same happens with other keys. They all seem to fit but get stuck after one or two turns without unlocking the chest.
Suddenly, Pavel feels that he is being watched. He turns his head and sees, to his surprise, that he is no longer alone in the laboratory. An elderly man with a long gray beard stands still in the center of the room. His face is completely expressionless and looks rather like a pale plastic mask. He is dressed in a gown that fully covers his feet; as for the arms, only fingers are visible. The base material of the gown is perfectly black and appears to be very thick. It is adorned with intricate patterns of what seems to be massive electronic circuits made of electroplated copper.
Pavel feels respect for the mysterious man whom he recognizes as the head of the laboratory.
“How have you achieved all this?” he asks.
“I hoard light,” answers the man.
At this moment it becomes clear that the walls of the room are non-existent and the whole scene is suspended somewhere in space not far away from Earth. Sun and other familiar celestial objects can be readily observed in the background. The man lifts his hand and beckons Pavel with his index finger, supposedly to demonstrate the process of light hoarding. Pavel comes closer and notices that the man’s gown is now connected to the treasure chests with thick bundles of wires. Unlike before, there is distortion of light around the chests which seems to be caused by nothing but the optical qualities of the surrounding air. A resounding electrical buzz suggests that some sort of a high-energy experiment is now in progress. Pavel comes near to look into the chests expecting to find inside them, for some reason, photographic plates. However, when a chest is opened he sees only absolute darkness inside. He realizes that it must be a black hole and that the optical distortion around it is nothing but the effect of gravitational lensing. Pavel finds it strange that he is able to stand so close to a black hole without falling into it. Immediately after this thought is finished, the process of spaghettification starts taking place—his hands stretch into long and narrow bands of matter as they fall into the darkness and disintegrate. Pavel looks around in terror, not understanding what is going on. A bizarre glowing device levitates nearby, but Pavel cannot make sense of it. Only after struggling for ten seconds or so he realizes that he is looking at his old electronic clock. It shows that it is now six fifty-seven AM, three minutes before the morning alarm.
Half an hour later Pavel stands on a metro platform, in the center of an artificial network buried deep underground, with its wild air currents, immense hollow cavities, noises distorted by reverberation, overlapping vibrations and pulses. Pavel watches trains come and leave. As they move away, their noises faint, glide upwards, and gather somewhere under the ceiling. The heat of the day is ripening here; in two hours it will smother the city. Finally, the train Pavel is waiting for arrives. He boards the train, finds a seat, and concentrates on his smartphone. The surrounding world ceases to exist.
“Consider further the delayed-choice quantum eraser experiment. An argon laser generates photons that pass through a double-slit apparatus and then through a nonlinear optical crystal, beta barium borate. That crystal converts a photon coming from either slit into two identical orthogonally polarized entangled photons. These photons are caused to diverge by the Glan-Thompson prism, so that one of them ends up being absorbed by the detector D. The other passes through a series of beam splitters that allow us to infer in fifty percent of the cases through which slit the photon generated by the laser came. If we filter out the photons recorded at the detector D for which we know the trajectories of their parent photons, we do not observe interference patterns. It appears that the knowledge of the trajectory of a photon determines whether it behaves like a particle and passes through one slit, or whether it behaves like a wave and passes through both slits simultaneously, interfering with itself.”
Pavel rereads the description of the experiment several times, takes notes, and adds a few entries to his list of topics to study. Then he closes his eyes and tries to visualize the experiment and develop intuition for the physical phenomena it involves. Finally, he opens his eyes and observes the passengers. He finds it amusing that even though they all live in the same physical world, only he, Pavel, is closely familiar with its deepest mechanics.
At eight-thirty AM, Pavel enters a large shop, part of a well-known retail chain of electronic products. He makes himself presentable and attaches the badge of a shop assistant to his shirt. After that, he restocks some shelves and carries out a couple of chores to ensure an acceptable and welcoming appearance of the area he is responsible for. When everything is taken care of, Pavel ensconces himself in a chair and takes his smartphone intending to enjoy a brief reading interlude before the first customers begin to arrive. At that moment his colleague Vova approaches him.
“Hey, how are you doing?” he asks casually.
Pavel is irritated by the fact that someone is stealing time he could use for learning. “Hi, I’m fine,” he says, trying to appear calm and professional.
“Look, there will be a little team building event after work this Friday. We hope you’ll come.”
“I’m doing my job well, I’m not obliged to waste my free time after work with these people,” thinks Pavel. He looks away and replies, “I’m rather busy, I think I’m going to skip it.”
It seems that Vova was expecting this kind of response. He quickly perches on a table in front of Pavel and starts talking quieter as if they were good friends sharing a secret.
“Look, we all have noticed that you keep aloof. I’m cool with that, but we want to get to know you a little bit. This is how teams work, you know. Working with friends is much easier than working with strangers, right?”
A few seconds pass in awkward silence.
“I’d like to participate, but I’m really very busy,” says Pavel.
“What are you busy with?” asks Vova.
Pavel hesitates for two seconds or so, then he says, “I’m doing scientific research.”
“Ah! This explains a few things about you,” says Vova and chuckles. “Are you studying at a university?”
“No, I’m studying on my own,” answers Pavel quietly, looking somewhat ashamed.
“In that case, surely you could skip a lesson on Friday?” blithely suggests Vova.
“I can’t skip my studies, I must make progress quickly. I cannot waste time,” replies Pavel.
“What kind of research is this?”
“It is… advanced.”
“Oh, come on! Try me!”
“Well, this morning, for example, I was reading about light. As you probably know, it’s made up of photons. So, it turns out that when their trajectory is known they travel in straight lines and it is easy to predict where they will end up. However, when their trajectory is not registered, they start interfering with themselves,” says Pavel and pauses as if trying to remember something. “Like, a photon can interfere with itself,” he finally adds.
“What do you mean by that? How can it interfere with itself?” asks Vova.
Pavel tries to formulate a good answer. Different terms and concepts all come to his mind together, tangled and fuzzy. Beta barium borate, quantum entanglement, prisms… Pavel repeats the question in his thoughts again and again, but no adequate replies come to his mind. Finally, he says, “When a photon interferes with itself, we can see… we can observe dark and light bands of light instead of normal light.” Immediately, he realizes that this response does not really answer Vova’s question. Pavel starts blushing and squirming in his chair.
“So, when I’m not looking at light it becomes like a zebra? Or maybe when no one is looking it does that?” sneers Vova.
“No, you don’t understand,” says Pavel in a feeble voice, feeling that he wants to run away.
“I surely don’t!” retorts Vova.
Pavel starts mumbling. Seconds pass, but nothing understandable comes out of his mouth, until he declares, “It must come through slits.”
Vova laughs. “Well, that makes sense to me. If light comes through slits it will have dark and light bands. That’s no rocket science,” he says, completely red from laughing. “What’s to study about it?”
“I don’t know, leave me alone,” whimpers Pavel.
“It looks like you need to study harder!” says Vova as he turns around and walks away.
Pavel feels dizzy, his hands tremble. If only he spent these ten minutes reading instead of wasting time in a pointless conversation, he would be more prepared to answer questions about propagation of light. Pavel wants to go out and breathe a little bit to calm down, but he notices that the first customers have already entered the shop. The busy work day has begun.
In the evening, at home, Pavel decides to take a bath—the heat is unbearable. He enters a small and poorly lit room with painted walls abundantly covered by cracks. The bathtub is installed in the corner. It is quite wide and joins the walls seamlessly on three sides taking up the whole width of the bathroom. Pavel starts cleaning the tub, but his mind wonders. The volume of the tub and the shiny metallic surface of the faucet make him think of improvements to industrial processes like electroplating, but his mind refuses to produce sensible ideas. Before long, Pavel finishes cleaning, plugs the drain, and opens the tap almost completely. He performs a series of adjustments in order to make sure that the water temperature is right. The loud noise produced by the strong current cheers him up; he leaves the bathroom and starts running nimbly around the flat.
Through countless arguments Pavel convinces himself that despite his lack of formal education he is about to make a breakthrough and establish himself as an eminent figure in the scientific world. He imagines temporary setbacks and even outright malice on the part of his competitors that strive to impede his progress and gain complete understanding of the world before him. But all this only makes Pavel work harder and eventually his results are accepted. He becomes an accomplished physicist and all people who presently snub him recognize his genius. The moment comes when there is nothing else to study and nothing else to prove. There is no question anymore about Pavel’s worth. He feels liberated and happy as if a heavy burden had been lifted from his shoulders. As Pavel goes on with these fantasies, he starts moving more and more erratically and playfully, capering and gamboling in circles in the living room. Time and again he flaps his arms like a gigantic bird that is about to take off, until finally he sprawls on the floor exhausted. The sound of running water reminds him that he should check on it.
Pavel returns to the bathroom and sees that it is now filled almost to the brim. A rapid stream of hot water keeps falling down full of noisy energy—a minute more and there will be an overflow. Pavel dashes to the tap and hastily rotates it until the current dies out. Within two seconds the surface of the water becomes flat and unstirred; barely noticeable ripples traverse it two or three times before petering out. Immediately, Pavel finds the abrupt silence uncomfortable, as if the absence of noise has left him alone with something he would rather not confront. He remembers reading somewhere that an average bathtub has the capacity of one hundred liters. That amounts to about one hundred kilograms of liquid matter right in front of him. It is hot and appears calm, but Pavel knows for a fact that it is swarming with hidden activity. The number of water molecules in the bathtub is staggering. They glide and mingle incessantly at startling speeds and with uncanny fluidity. An individual molecule is elusive and impossible to locate. Does it even have a trajectory? It moves by quantum laws no different from those that govern photons in the double-slit experiment. Physics at this level cannot be intuited. And yet, from the movements at the micro level somehow the textures of the macro reality emerge. Pavel scoops up some water with his palm. It quickly seeps through his fingers and flows back into the bathtub. The appearance and fluidity of the liquid amaze him, as if he had never seen it before. “This is a miracle,” Pavel whispers. He considers immersing his forearm in the water but does not dare. Instead, he looks at the old shabby walls of the bathroom and thinks about the intricate interplay of different forces of nature that makes all this possible. Minutes pass in the abstraction. Finally, Pavel forces himself to return to reality. His plan was to take a bath. But now the water appears alien, dangerous in ways that are not easy to formulate. Pavel involuntarily pictures how he gets into the bathtub and how a peculiar collision between two water molecules initiates a chain reaction, perhaps yet unknown to humanity. The water gradually turns into something black, viscous, and strongly acid, and that something corrodes, irreversibly destroys his body. “This is nonsense, nothing of the sort can happen,” he tells himself trying to fight growing dizziness. His hands tremble.
At this moment the doorbell rings. Pavel flinches—he is not expecting guests. Moreover, there is a probability that the visitor from the last night has returned. “If he had the audacity of coming so late, who knows what he might want from me,” thinks Pavel. He decides to freeze in place and wait out. Soon, the ringing is succeeded by muffled sobs and murmuring that continue for some time, until suddenly, a distinct call full of desperation comes, “Vera!” Pavel realizes that the uninvited guest has confused apartments and it is possible to put an end to his irritating visits once and for all by letting him know about the fact. The plan appears tempting; Pavel comes to the hallway intending to put it into action. He listens carefully to the sounds coming from the other side of the door and becomes convinced that the intruder is heavily drunk. Nevertheless, Pavel chooses an auspicious moment when the babbling of the visitor calms down and says as confidently and as loudly as possible, “Vera doesn’t live here. Please, stop coming.” A pause follows, but soon enough the noises resume.
“Was it you who came yesterday at four in the morning?” Pavel asks.
“I’m so sorry…” says the man on the other side of the door, apparently having great difficulty pronouncing the words.
“You are disturbing me, stop coming here,” says Pavel.
Muffled sobs continue behind the door, but no answer comes.
“Misha, is that you?” the man finally asks. Without waiting for a reply he starts crying bitterly.
“It is not Misha,” says Pavel. “Stop coming here.”
“Can you forgive me?”
“I’m not Misha and I don’t know Vera. I’m renting the flat. Do you understand that?” shouts Pavel. The man’s crying starts getting on his nerves. Valuable minutes of the evening are being irrecoverably lost. Suddenly, it seems certain to Pavel that he will never be able to achieve the goals that he has set for himself. Not with a full time job dragging him down. Not with all these people constantly distracting him. He simply does not have enough time for his studies. Meanwhile, there are plenty of professional scientists doing research at this very moment. They have the right education and resources. Their names are already well-known. There is no way for Pavel to rival these people. His dreams and his time investment are not meritorious but preposterous. Pavel feels a void swelling in his chest. He slumps against the door and tears start running down his cheeks.
“Misha, tell your mom that I’m sorry,” cries the drunk man behind the door. He seems to lean on it from the opposite side.
“Go away!” cries Pavel.
The uninvited guest starts knocking on the door. “Mishenka, I’m back for good!” he howls. Pavel cannot continue the conversation any longer. He feels that he is not much different from this repenting drunkard who was missing out on something important for so long. Pavel runs to his room and throws himself onto his bed.
Hours pass. The sounds of the evening fade and disappear, except for the barely noticeable rustle of leaves somewhere far away. The torrid August night grows dark and quiet, permeates the city, comes into each and every room. It settles in Pavel’s room, too, and little by little fills the void in his chest. Tired and exhausted, he falls asleep and has no dreams.