Some small initial warnings:
*This chapter may have translation errors. We are always checking to correct them.
*This chapter uses real scientific terms and others taken from the "canon", but it is only my interpretation and not a real theory, nor in the S.G. fandom or reality itself.
Chapter 9
Wave Function Collapse
Sunday, October 14, 2012
Hashida Suzuha took off her sneakers, went inside and looked around.
"Wow, how disappointing this is."
At the back of the small apartment there was only one window covered with American blinds and a carefully arranged bed. A folding curtain served as a separator between the bedroom and the kitchen, where a round table for two people stood as the most important piece of furniture in the living room. The only interior door was to the bathroom.
"I really expected more from you, but I guess I overestimated you all this time," she added later.
Keitarou looked at her in confusion, not understanding what the harsh comment was about.
"What the hell are you talking about, Hashida-san? This place is very good. In fact, I don't think I could have found anything better."
When he arrived in Wako after his trip back in time, he thought about staying in a hotel, but he found that advertisement on a lamp post. The owner of the apartment was in a hospital and was renting it furnished at an almost ridiculous price, with the condition that his future tenant would take care of the place with everything inside. Keitarou was not able to meet him in person; instead, he contacted an intermediary, a tall, muscular, bald guy with the appearance of few friends. He didn't ask many questions before receiving the money, giving him the keys and leaving, which was a very suspicious attitude. Who would rent a place like this to a complete stranger for so little?
The situation was irregular, but he could not complain. It didn't seem to be a scam, and after all, he wasn't born at the time and had nothing but Shizuka's forged papers. The chances of finding something better were slim, and besides, the original owner seemed to have good taste. The furniture was few but functional, the kitchen was well equipped with various utensils and a large cupboard, and finally, there were enough cleaning products.
He felt at home.
"That's what I mean," said Suzuha. "As much as I like the retrodecoration, I don't see any collectible figures, posters, dakimakuras, or life-size holograms of Hatsume Mirai around here. There isn't even a used handkerchief on the floor, what kind of place is that supposed to be?"
Everything was very clean and tidy. It didn't look like the apartment of an 18-year-old man living alone for the first time. Above all, where were the mountains of pornography? Perhaps the DVDs and Blue-Rays of the time seemed outdated, but considering how cheap the printed paper was compared to 2036, Suzuha could not see any ecchimanga or magazine around.
"Now I understand why Dad always says that Uncle Okarin did a bad job with you: sometimes you act like a normal person. If I didn't know you well, even I would doubt you."
"We are not supposed to accumulate objects, they will not enter the time machine later. Besides, even if I wanted to, I don't have enough money to spend on those things."
"You're a bad liar," Suzuha replied. "You save money almost from birth. You should be a millionaire by now."
He could have told her that he had bought a couple of magazines taking advantage of the low price of paper —who in the world would be able to miss that opportunity?—, but he had taken care of hiding them where she could not find them and therefore, could not see them.
There are things that a man wants to keep secret.
"My point is that Okabe Keitarou is a cheapskate," she continued. "Life is also about enjoying the present. You should learn to have fun once and for all."
"Hashida-san, are you forgetting who pays the hotel bills where you and my sister are staying? Including room service," he added.
Keitarou's savings were paying for all the expenses of the trip. His younger sister had been mining some crypt coins with the technology she brought from the future to help him with the money, but it seems she had run into trouble and almost ended up in the police.
"Hey, I have a job now too. I can pay my share," replied Suzuha, proud of her job at the television store, even though she had already had a full day's pay cut. "But I guess you're right. You've won the battle this time, Keitarou, but I'm not going to lose the wa... Wait!" she interrupted herself when she felt the aroma coming from the kitchen. "Is that curry?"
On the counter there were two dishes served.
"Spicy curry," he replied. "I must admit that it is one of the best versions I have ever prepared. The ingredients of this season are fresher and enhance the flavor better. Even the acidity of..."
Before he could finish his detailed culinary explanation, he noticed how Suzuha was giggling.
"What are you laughing at now? I thought you asked me to cook you curry."
Yes, she had asked for it. In fact, she had literally demanded a "giant pot of curry", but she didn't think he would take it so seriously. It was understandable: since childhood Keitarou had been appointed the Okabe's "official cook" and was used to cooking for his entire family. He had prepared enough to feed a small infantry regiment.
"What do you say we have a competition to see which one of us finishes the dish first?" proposed Suzuha."
"The food is not for playing. Aunt Yuki would be angry with you if she heard you."
Keitarou acting like an obsessive housewife made things more boring, but the curry was ready and had to be eaten soon or it would get cold.
The two sat down and had lunch together.
With her stomach full, Suzuha stretched out her arms. The dish had been delicious. A part of her being —perhaps that which still belonged to "Suzuha beta"— told her that she had been even better than the one served at Go Go Curry.
Keitarou also finished eating his portion and went to wash the dishes, while she watched him from the table.
Had he always been as tall as his father? Suzuha couldn't remember the moment when he had surpassed her, but it must have been several years ago. Time had passed, and her childhood friend, the one who lived in a foreign country, with whom she exchanged messages, with whom she used to play on her vacations, was no longer a little boy, although he was still adorable.
Not everything changed over time.
"You know, when we arrived I thought I would miss technology more, but I think I could get used to living like this," Suzuha said. "I mean, not being surrounded by so many screens makes you appreciate the little things more, what do you think?"
"I must admit it's a nice feeling," he replied, finishing rinsing out the last of the cooking utensils. "However, this is not the time to be lazy. We can't keep letting our guard down now that Okabe Rintarou knows we're here."
"You're still mad at me for telling Uncle Okarin everything, aren't you? You sounded very angry on the phone yesterday."
"I was surprised at first, but I know it's not Hashida-san's fault."
If Keitarou had known that his father had met Suzuha in another world line, he would never have asked her to spy on him in the first place. She was able to resolve the situation as she saw fit, but there was still a risk that everything would fail.
However, why didn't Okabe Rintarou ever tell you about Suzuha's travels to the past? In a way, his son was not surprised. He had grown accustomed to the idea that his father kept more information than he was willing to reveal. That's why Keitarou didn't trust him anymore.
The Okabe family was full of secrets.
"Everything Uncle Okarin said about the world lines was true?" she asked.
At times Suzuha felt that Rintarou was trying to catch her with an exciting story, although it wasn't hard to get carried away with good fiction either. Although some parts sounded exaggerated, especially about World War III and the dystopia created by SERN, which brought credibility to the story.
"There is no way of knowing. If those events happened in other attractor fields, they would not have to be reproduced in this world line. If both the future and the past have changed, it would be logical to think that no one would remember them."
Everyone, except his father. He had the "Reading Steiner" and probably, this ability had given him an advantage to change the previous attractor field and reach the "Steins;Gate".
But what did that story mean to him and what did it have to do with his family in the future?
"The data that SERN published indicated that there were traces of interference between attractor fields in the years 1928, 1991, 2000 and 2010... It is likely that he was referring to the last event. However, shouldn't the intersection between fields have created a new world line with a much reduced wave function... Probably it should have been enough with one millionth of divergence for it to collapse, yet it should have branched out independently... With such restricted initial conditions, wouldn't making small changes make the butterfly effect more relevant?"
Keitarou could see how Suzuha looked at him without understanding anything he was saying.
"I'm sorry Hashida-san, I didn't mean to ignore you."
Talking to himself was a habit of Keitarou when he tried to answer a question, but in general, he tried to avoid doing it in front of other people.
"Don't worry gifted boy, it's not bad that you want to show off once in a while. But I guess now comes a whole lesson in physics, right?"
She would not be content with murmurs, nor with Uncle Okarin's vague explanations. She needed to know how this business of world lines and attractor fields worked.
Suzuha put her feet up and made herself comfortable:
"Well, you have my full attention. Show your worth, future child number 32!"
All your attention? It was Keitarou who could not easily ignore having her feet on the table, but he was not going to scold her.
Suzuha's serious eyes indicated that she wanted to hear what he had to say, and she couldn't waste that opportunity.
"I don't know if I'll be able to explain it like Mom does, but I'll do my best."
Where did he start? There were already more than 1000 scientific articles published with mathematical descriptions of "the attractor field theory". There was a lot of empirical data in favor of it, and some that gave away inconsistencies and points to adjust. How did it synthesize so much information into a single explanation that was long enough not to leave anything important out, but not tedious enough to be boring?
"I suppose it will be better to start from the origin," began Keitarou to expose.
The Big Bang: the beginning of every story that can be told, and of everything humanity could ever know. There was no "before" of it. Space and time were created at that very moment.
Very soon after its creation, the young universe underwent a massive inflationary process that ended up defining its form as we know it. Since then, entropy —disorder—would always increase as defined by the second law of thermodynamics.
"As Uncle Okarin would say, 'the universe is inevitably heading towards chaos,'" said Suzuha.
Yes, his father would say something like that. But it wasn't time to think about that guy yet, it would ruin his explanation.
"But do we really understand what we call 'time'?" he asked.
"I guess you don't ask that every day, do you?" she said. "Time is something that just happens, whatever you do."
As Suzuha pointed out, since the beginning of humanity, people thought that time was omnipresent, a phenomenon that was part of their lives, but they could not define it.
Early theories considered it a straight line running unidirectional from the past to the future, with nothing and no one able to deviate its course. Even Isaac Newton spoke of "absolute time," as an immutable coordinate system that escaped any attempt at physical manipulation.
"It was Albert Einstein who proved that space and time are a continuum, and that they cannot be considered in absolute terms, but rather in relative ones."
The name "world line" was used to describe the path an object takes in four-dimensional space-time. Or, better applied for the purposes of the talk, the path followed by an intelligent observer, such as a human being, through time and space.
According to the theory of relativity, space-time was capable of dilating due to the effects of speed. As a result, the perception of time could change, depending on the inertial reference system of an observer.
His mother thought the latter was romantic and sad at the same time, although Keitarou never understood why. After all, they were just equations.
"In short, Einstein solved the mystery," said Suzuha. "I'm not surprised, they say he was a genius."
The theory of relativity was a great achievement of the human mind, and even justified that they themselves could have traveled into the past through a Kerr black hole.
But that was not all.
"Einstein found an important part of the puzzle, but other theories were needed to form the complete picture," Keitarou added.
Among them, there was one to which Einstein himself had contributed —he even won the Nobel Prize for it— but which he never fully liked: quantum mechanics.
"Hashida-san, do you remember the Schrödinger cat paradox?"
"Of course, there are several anime that mention it. I think everyone knows it."
It was one of the most remembered paradoxes in popular culture, so it was not necessary to introduce too much about what it was.
"You'll know then that when you open the box there are two possible results: one where the cat continues to live, and another where, well, the result is not entirely pleasant."
"The cat fell in action. It's stiff, finished, fried, completely dead," said Suzuha.
What kind of cruel analogy killed a noble animal like a cat? But one could say that the animal was a faithful servant of science.
As formulated, the paradox was intended to describe the state of quantum superposition in which the cat was before opening the box: alive and dead at the same time. Such a counter-intuitive event for the human eye was possible in the microscopic world dominated by elementary particles. It was said then that the cat inside the box was in a coherent state, which could be described by its wave function.
"Wave function?" repeated Suzuha. "What is that?"
"It is the equation that contains all the properties of the superimposed cat and the probabilities of finding it both alive and dead."
When the experimenter opened the box, or in other words, "made a measurement", the whole wave function was no longer valid and gave only one of the two values that were initially possible. The overlap was broken, making it impossible for the cat to stay alive and dead at the same time.
"So there's no chance of a zombie cat?" said Suzuha.
"Who the hell would want to see that?" replied Keitarou.
"Why not? It would resist famine, chemical weapons, air attacks and much more. It would be the ideal mascot to accompany you in case of war."
Her aunt Faris would disagree: there was nothing adorable about a zombie cat.
Before continuing, it was necessary to clarify that pure superimposed states only existed in total isolation, and such a condition was not possible in a world made up of millions and millions of particles interacting with each other. When the box was opened, the quantum cat was no longer isolated and ended up mixing with the outside, thus losing its coherence and giving rise to a mixed state. Scientists called this process "quantum decoherence".
Since humans can only observe non-overlapping mixed states, quantum decoherence was the most accepted explanation for the boundary between the quantum world and macroscopic reality.
"Let's see if I understood correctly: the quantum decoherence modifies the wave function of the zombie cat, making that when we open the box we end up seeing it alive or dead, right?" asked Suzuha.
"I didn't expect any less from you, Hashida-san, you're getting it right," said he, who considered his friend to be a capable person, although he still dislike the zombie cat thing. "But the truth is that decoherence is not enough to know what fate the cat will take when it opens the box."
The decoherence defined a boundary between the quantum and the macroscopic, but it did not explain what happened to the wave function every time the box was opened. The latter was known as "the measurement problem".
"Throughout history there have been different interpretations of quantum mechanics that have tried to solve this problem," said Keitarou. "The two most influential were the orthodox interpretation of Copenhagen, and Everett-Wheeler's many-worlds interpretation."
The Copenhagen performance had been the first historically. The easiest way to understand it was to assume that there was only one solution for each measure. When the box was opened, the cat would probably be alive or dead as defined by its wave function, choosing a value stochastically, as if a coin were tossed to choose its fate.
If the cat ended up dead, the wave function lost information about its live state, and if the cat ended up alive, it lost information about its dead state.
"It is said then that the wave function 'collapses'" said Keitarou.
"The box with the zombie cat broke into pieces," added Suzuha.
He was beginning to feel very sorry for the cat.
On the contrary, according to the many-worlds interpretation, the wave function did not collapse. The measurement process resulted in the creation of two parallel world lines: one where the cat was alive, and one where it was not. Both results were equally valid and no information was lost in the process. Likewise, the observer who opened the box ended up mixing his own wave function with that of the cat, producing mixed states and decoherence.
As many measures could follow each other in time, infinite world lines could be produced as possibilities happening all at once. The level III multiverse was formed.
"Almost like playing a dating simulator," saidSuzuha. "The game has all the information about the route of your waifu and another female character, but you can only see one at a time. However, if you have saved your games well, you can always go back and choose another ending."
This could be a good analogy. Surely Hashida Itaru would approve it with a Titor&Kyouma co.'s stamp.
"The many-worlds interpretation is also a favorite of self-appointed time travelers," added Keitarou.
Such as one that had appeared in 2000 on an American internet forum.
"Anyway, what is the correct interpretation? Let me guess, from everything Uncle Okarin said, it must be Everett-Wheeler's."
"The truth is that they both are," answered Keitarou.
"Both? Is that possible?"
"It is," he said and continued his explanation.
In 2034, scientists agreed that reality is objective for all observers occupying simultaneous space-time, and that only one world line can be active at a time. There was no evidence of a multiverse acting parallel to our own.
Therefore, the wave function collapsed with each measurement.
"Wait! What does it mean that there are no parallel world lines?" she said.
"There are no active parallel lines, but there are probabilistic alternatives," he said.
"I got lost, does that mean they exist or not?"
"To understand it better, imagine each world line as an isolated system," said Keitarou. "As if each world line were a box containing the cat. That being so, you could define an 'initial wave function' to describe everything that can happen in a world line."
But defining a wave function in each world line was not an easy task. To achieve this, scientists had to resort to concepts from chaos theory: the world lines could be considered as chaotic dynamic systems with a deterministic evolution.
"According to chaos theory, the trajectory of a world line depends on its initial conditions. Or put another way, the convergence of a world line depends on its initial wave function."
The convergence of a world line made it always evolve in a manner consistent with the probabilities predicted by the initial wave function that characterized it. Even many events in the history of a world line were defined by probabilities as large as 99.999999%.
This meant that reality developed within very defined probabilistic limits from the beginning, making the system reach a relative equilibrium: past, present and future were related by the principle of causality of events, and the world line passed as dictated by convergence, which in turn, responded to the second law of thermodynamics, seeking to obtain the state of maximum entropy possible.
"Well, the world is heading for chaos, so it's true," added Suzuha.
Yes, but they weren't supposed to jump to the end yet.
"Unlike convergence, divergence is any deviation from the values of the initial wave function of a world line," Keitarou continued.
The divergence acted similarly to the measurement process on the cat. In most cases the divergence was so tiny —something like less than 0.00001—, that it did not produce a real change. Small deviations were well tolerated in the evolution of the system.
However, if a sufficiently "strong" divergence was produced to significantly deviate the initial wave function, then a 'collapse' of the current world line was produced and with it, the re-adjustment of the causality principle to the new initial conditions.
"So, to change a world line you have to generate enough divergence," said Suzuha. "If you are able to modify a part of history, you can make the wave function of a world line reconfigure, by adjusting the past, present and future, right?"
"That's right," answered Keitarou, "but divergence has its limits. The world lines are not totally isolated and respond to even greater convergences than those they possess separately."
In studying the processes of divergence accumulation, scientists realized that collapsing the wave function allowed small alterations in the trajectory of historical events, but the end result was almost always the same. This is how they came to define a "global wave function" for a set of world lines related by a small amount of divergence between them. They called this set an "attractor field" because it behaved like a strange Lorentz attractor.
To define the limits of an attractor field and its global wave function, a relative measurement was chosen: 1% dissimilarity between an initial reference line —also called: the "zero line"— which acted as the core of the divergence accumulation process. Within it, the world lines within it would have certain differences in their course, but eventually their global convergence would lead them to produce the same end.
"If it was already difficult to change a world line, it seems even more difficult to get out of an attractive field," said Suzuha.
"Surpassing the 1% barrier is difficult in theory, but not entirely impossible," he replied.
If a change in events produced a very extraordinary divergence, capable of exceeding that 1%, the world lines that had originated would no longer respond to the attractor and would form a new one, with another final convergence.
"For example, there is speculation today that the discovery of penicillin in 1928 may have been the turning point that caused an entire attractor to collapse, separating a future where antibiotics did not exist, with the future where millions of lives have been saved because of them," said Keitarou.
"It sounds like a very powerful concept," said Suzuha. "Even a small discovery can save millions of lives."
"Even the slight fluttering of a butterfly can change it all."
As Keitarou marked, divergence was mainly responsible for the butterfly effect. Okabe Rintarou was the first to say that the power of serendipity could not be underestimated. A small unexpected change can cause catastrophic effects at the attractor level.
However, chance alone rarely brought about real change.
If one wanted to intentionally collapse a world line, an intelligent observer had to send information, matter, or even himself, into the past, through a black hole, like those created by a time machine. If the process of divergence was done well, he could be able to alter the initial wave function, producing a collapse and with it a change of line, although in most cases, the effect would be minor and would reach another line belonging to the same attractor field, until he could accumulate more than 1% between collapses.
Even in very rare cases, a new world line could arise from the interference of the global wave function of two different attractors. Thus, the resulting wave function would be a product of the interactions of its parents, but without preserving their convergences. This new world line would evolve in a different way.
"That's what Uncle Okarin meant by reaching the Steins;Gate," said Suzuha.
Keitarou also believed that this must have been the way Okabe Rintarou achieved it with the help of Suzuha beta.
"In conclusion, we can say that the world lines and potential attractor fields are, in theory, infinite," said Keitarou.
All world lines and mathematically possible attractor fields existed superimposed within what was known as the universal wave function. According to the laws of thermodynamics, all world lines will converge one day into the state of maximum entropy possible for the universe.
The universe was heading for chaos: Hououin Kyouma could boast of it.
"And that would be all we know as the attractor field theory," he concluded.
The explanation had been longer than he intended, but he hoped that the theoretical journey had been worthwhile.
"I must admit that it was a very didactic talk," applauded Suzuha and lowered her feet from the table. "Now let's get to the point, what does all this have to do with us?"
Above all, there was one thing that interested Suzuha: what did it have to do with what Keitarou was looking for in the past?
"You will see Hashida-san, what I told you before about the world lines does not apply to the Steins;Gate."
She looked at him in confusion, what didn't apply, so what had been the point of all that information?
"Everything you said was wrong?"
"No, that is what should theoretically happen. But Steins;Gate does not behave like a normal world line."
Suzuha was beginning to smell the 'zombie' cat close.
"Leave the suspense and just say it," she demanded, "what's going on?"
"Steins;Gate is unstable," Keitarou said.
"What do you mean?" Suzuha asked.
"That the world line is constantly collapsing."
Scientists intuited that any isolated world line could act as the nucleus of a process of divergence accumulation: a new zero line, capable of originating its own attractor field. Steins;Gate had defined its own "global wave function", and the center of divergence that could give rise to several world lines was in the life of Okabe Rintarou and Makise Kurisu: a change of course, a single decision they made, would be enough to unfold Steins;Gate into several possibilities.
"Under normal conditions, a world line should not spontaneously collapse into an alternative line," he said. "However, the attractor originated by Steins;Gate is unstable and causes the world line to collapse on itself all the time."
Explaining why the active line collapsed into a new one and ended up coming back on itself was complicated. It could be said that the global wave function of an attractor field could define different "levels" of energy, similar to the levels of atomic orbitals, each containing its own world lines.
The first level of all, was that of the active world line: the "1s" level, the most stable of all, and the only one that manifested itself physically. The world line 1s was the one that evolved with the highest level of entropy possible. The 'alternative' world lines of the attractor field were always located at higher levels, which in theory, were inaccessible for people, unless the active line collapsed into a new one.
"However, the world line is capable of making a quantum jump to another line of a higher level without the need of a real divergence event to provoke it."
But since the upper level lines had much higher levels of enthalpy and lower levels of entropy, the jump that took place was transitory and eventually, the alternative world lines ended up decomposing, causing it to return, sooner or later, to the original world line.
"It's hard to believe," said Suzuha in surprise. "It doesn't even sound logical."
"I know it's hard for normal people to believe, because even if the world line collapsed, no one would remember it." Keitarou knew that people were naturally conditioned to readjust to the changes, modifying their memories to match those of the active line. "But the three of us can feel every time the world line collapses. Okabe Rintarou, Shizuka and I... we just know."
The key was that unlike the others, the Okabe family owned the Reading Steiner.
Suzuha had heard it from Uncle Okarin the week before, but needed to know what it was about in more detail.
"The Reading Steiner is the ability to preserve memories of the previous line every time it collapses into a new one," he explained.
Such ability was the product of a series of unusual genetic modifications in a block of genes associated with the process of neuronal plasticity in the brain areas that configured the episodic and autobiographical memory. The large proportion of the human population had polymorphisms associated with this pathway and manifested the ability to a greater or lesser degree, but only very few people in the world —perhaps 8 or 9 people in all— had the haplotype that resulted in a complete Reading Steiner. Among those people, they were three.
"Thanks to Reading Steiner, every time a collapse happens, Okabe Rintarou and Shizuka are able to perceive what is happening in those other lines, until everything returns to normal," Keitarou said. "You could say that they are the absolute observers of Steins;Gate, while I end up forgetting everything that happens during that interval of time."
"Are you talking about your amnesias?" Suzuha asked.
Ever since she met Okabe Keitarou, she knew he suffered from a strange genetic disease: every so often, he would have fainting spells followed by "amnesias" where he would forget a number of minutes, hours, or even entire days in a random way. No doctor was able to give an explanation of his symptoms.
"They are not amnesias, or they should not be," said Keitarou. "In theory, I should also be able to remember what happens in other world lines."
"I don't understand. If you are capable, why don't you do it? Why do you end up forgetting everything?"
"I think it is obvious Hashida-san. Think of it this way: why do you think I did not travel with you to prevent World War III? Or to stop SERN? It is the same thing."
Okabe Keitarou was not born into alternative world lines.
"You're kidding, right?" she asked skeptically. "Because it's not funny."
As absurd as it may seem, that was the real reason.
"I wouldn't joke about something like that," he replied. "It makes sense that I can't remember anything that happens between a shift of world lines. If I wasn't born into any of them, I'm not able to observe them, and if I can't observe them, I can't generate memories."
Every time the Steins;Gate collapsed, he was no longer part of reality. But that was not a problem in itself: it happened when things returned to their normal state. With no memories to keep, Keitarou's Reading Steiner was fully overloaded.
His brain itself resisted the idea of having no memories, producing him a temporary shock. As a child, the shock could be strong enough to leave him in the hospital overnight, but as he grew older, the symptoms diminished in severity and only caused him to lose consciousness momentarily, until his mind could readjust to reality.
Suzuha, as she listened to him, became more and more upset.
"Keitarou, why didn't you tell me all this before?"
Of all the years they knew each other, why had no one ever explained to him what was going on with her friend? Why hadn't Uncle Okarin, Aunt Kurisu, her father, or anyone else? And above all, why hadn't Keitarou mentioned it?
"We never had a chance to talk about it calmly, Hashida-san," he replied. "I mean, this is the first time we are alone like this."
They had been friends from afar. They had grown up in two different countries, separated from each other by the Pacific Ocean. They saw each other occasionally on vacation, but most of the time they ended up playing or hanging out before he returned to the United States. Even if they stayed in touch, phone calls or messages were not a good way to bring up such important issues either.
Keitarou had moved to Japan just 9 months earlier to live with his grandparents, but in that time he was working in the family business, while taking his last exams online and fixing the time machine. Suzuha was a university student, and was busy with her part-time jobs, or with her Valkyrie Resistance meetings. They never spent much time alone.
Finally, the non-birth of Keitarou in other world lines was a secret of the Okabe family. He himself was uncomfortable touching the subject, but sooner or later he knew that he had to tell Suzuha.
He was waiting for the right moment and the meeting with Okabe Rintarou had given him that.
"Well, it doesn't matter now," she sighed, "we'd better concentrate on the future and on getting you born again."
If the problem was that their friend did not exist in other world lines, at least he should exist again in the line where they were now. All they had to do was create the right conditions for it.
"I got it! How about this? We'll travel to the year 2017, and without them seeing it coming, we'll lock up Uncle Okarin and Aunt Kurisu together in a love hotel. But not just any one, but a very romantic one where they can feel comfortable and let their imagination fly. If necessary, alcohol could also help them get rid of their inhibitions, but most important of all, we will make sure that they don't have any protection at hand."
It was a rude, evil and effective plan. A plan worthy of Hashida Itaru's heiress. According to the words her father once uttered, there was no more shameless lust than that of two tsunderes who cannot be contained. Perversion would take hold of them and they would fall into temptation without any resistance.
"What do you think? Do you believe it would work?" she asked her friend.
"Worst of all, it could work," he replied.
Keitarou was not complaining about the idea. He hadn't brought up all his childish beliefs about the biotech stork and mutant cabbages.
Something was wrong.
"Come on, don't tell me you're thinking about that again," she reproached. "You should concentrate on being born again and not bother with that."
But Suzuha had put it into words. The truth that Keitarou himself already knew, although he would rather ignore it: he had been an unplanned child.
"I understand there are many people who expect their OTP to have a happy ending with a wedding first. But there are also others who believe that hentai doujinshis or lemon fanfictions are more authentic and interesting."
In a country as asexual and repressed as Japan, that two citizens gave free rein to their passion could not be blamed. On the contrary, it was a sign of courage.
"You make them look like two teenagers who didn't know what they were doing," he complained.
"Of course not, they knew that very well. I'm sure it wasn't the first time they tried," she said.
Suzuha made the subject even more controversial, but she had a strong point: Uncle Okarin and Aunt Kurisu were not unprotected children. They were adults, they knew the possible consequences, and they took responsibility. Taking charge of one's actions brings a degree of maturity from which they had not escaped. They loved each other, and their child was nothing more than the product of that love.
Keitarou himself did not see it with romantic eyes. It was true that perhaps there were things that could not be avoided and that assuming them was the most mature thing, but he was convinced that his birth was the product of a mistake.
If it had been a mistake of his parents and these can be prevented once they meet… why make them twice?
After all, at the time they were, his parents had not done anything yet.
"Do you know Hashida-san? Since I've been at the RIKEM, I constantly ask myself, what would Mom think if I told her everything?"
"Don't you think it's too much? I don't think Aunt Kurisu is ready to hear what uncle Okarin and she did."
"I don't mean that!" he replied, wanting to leave the intimacy of his parents aside. "I'm talking about what happened next."
About the pregnancy. About the early years. About Canada. About all the economic problems the Okabe family had to face because of having an unplanned child. And about all the other problems that living in an unstable attractor field gave them.
Keitarou never felt that Makise Kurisu reproached him for his existence. As far as he knew, she had never tried to abort him, even though it was legal and perhaps the world line would have allowed it. He always felt that his mother had given him all the love he was capable of. He still remembered the day she explained what happened to him and his sister every time the Steins;Gate made a quantum leap:
"Remember, no matter what world line is active, I will always be your mother," shehad told them.
Keitarou knew it was a pious lie: if he wasn't born, she wouldn't remember being his mother either.
"Mom doesn't have the Reading Steiner like we do, so line changes don't affect her."
Despite all these problems, Makise Kurisu had chosen to be part of the strange Okabe family.
She had even gone to great lengths to reconcile her family and professional life. She had secured a position as a principal researcher at a renowned American university, and was highly respected by colleagues in her field. But in return, she had to work long hours and could almost never be at home with her children. From time to time, she had to make the decision to postpone important experiments to address their health problems, or even just to spend time with them.
High-level science was not a friendly environment for women to raise a family. She always faced challenges and inconveniences that childless scientists did not have.
Would making all that effort once again be worth it for her?
If the passage from one line to another was affected by Makise Kurisu's decisions, what she decided once she knew everything would be the key to changing or not changing the course of the current world line.
Her decision could perhaps collapse the world line into a new one, without so many drawbacks.
"Wait Keitarou, would you be able to endanger your existence?" said Suzuha. "Besides, this is not just about you, there is your sister too, is that what you want?"
"Shizuka will be fine. She will be born anyway, no matter what they decide."
Okabe Shizuka was an absolute convergence within the Steins;Gate. She would always be born, because her birth was determined with certainty in the wave function of the attractor. Even the laws of causality would be rearranged to ensure her birth, however absurd it might seem.
She would be born even if Okabe Rintarou did not want to have children. She would be born even if he tried to have a vasectomy. She would be born even if he walked thousands of miles away from any woman and wanted to become a Buddhist monk. None of those things would work for him. Everything would work against him.
It wouldn't matter what Okabe Rintarou wanted: he would have a daughter by December 2021.
"So Shizuka-chan is a shot that Uncle Okarin will always hit," said Suzuha scratching her head.
It wasn't the most correct way of saying it, but it was the same concept.
Okabe Rintarou had no way out, so it didn't bother Keitarou that his sister wandered around with him in the past. In a way, it would be best if he got used to the idea of being a father.
"Shizuka is a convergence, while I am only a small fraction of divergence."
An unwanted pregnancy was still considered a taboo in Japan by 2017. A wedding caused by it was called "dekichatta kekkon", or shotgun wedding in old American colloquialism.
Due to the influence of their culture, their parents must have followed the same path. However, the convergence of the attractor prevented Okabe Rintarou from marrying before March 2021. He was not supposed to have a formal family before that date.
If Shizuka was the one chosen to exist within the Steins;Gate, why wasn't Keitarou? If convergences preserve all people in the world, why didn't they preserve him?
Not being born in other world lines meant that his birth was an avoidable event. That it was not important. That it didn't change anything.
"My existence probably serves no purpose," he said.
It was dispensable for the plans of the attractor field. So what was the point of being born if he had no 'destiny' to fulfill?
If he was honest with himself, he didn't even know what he wanted to do with his life. As a child, he had become accustomed to hearing that he was "gifted", and he was determined to play the role. He had studied hard in school to skip grades and had even entered college early. He had even chosen a career to prove that he could be as good as his mother, but he finally realized that this was not the case: he would always be inferior. He would always be below what everyone would expect from Makise Kurisu's successor.
That being the case, he would not be angry if she preferred to save herself the trouble of bringing into the world a child who was not worthy of being her son. Besides, that wouldn't mean that his parents couldn't be together either. His sister hadn't told him, but Keitarou was sure that there must be a world line where the three of them could still go on their way without him. A kind of 'R' line where he could disappear without a trace.
Finding that line would be good for him if it was the best for everyone.
Suzuha sighed as she finished listening to him and got up from the chair.
"Keitarou, can you kneel here for a moment?"
The request sounded a little strange, but despite his insecurity, he did it. Then Suzuha knelt down in front of him too and Keitarou felt the green eyes rebuking him.
A moment passed in silence before she spoke:
"You heard everything you said before, right? Did you really mean it?"
"Everything I said is true," he replied. "I know I am unnecessary to Steins;Gate."
She sighed again, resigned.
"All right, you asked for it."
What happened next was so fast that it took Keitarou a while to process the situation.
From one moment to the next, he was on his back against the floor, with Hashida Suzuha's body on top of his.
She had applied a judo immobilization technique. She was holding him firmly by his arm, but as much as he could feel the weight of her hips against him, the situation was far from erotic.
If she was joking, it wasn't funny at all. As much as Suzuha acted like a pervert at times, being on the floor without being able to move was not as exciting in practice as people thought.
"Why did you do that?" he asked.
"I couldn't keep listening to that speech without doing anything," she said, with a voice that betrayed her seriousness. "That your life is worthless? That even your family would be better off without you? Come on, I'm used to your tantrums, but this time you've gone too far."
"You don't understand anything, Hashida-san. I know no one in this world can understand, but for a moment I thought you could."
That Suzuha thought what he said was just nonsense only reaffirmed the little value his problem had for others. He had made a mistake in cutting it off; that being the case, there was no point in continuing with that dynamic any longer.
Keitarou tried to get up on his own, but was pushed back to the ground. Every time he made the effort to free himself, Suzuha was able to give it back to him, holding him again.
"Damn it, that's enough! Get the hell off me!"
He felt very uncomfortable and wanted to stop the game altogether, but Suzuha had all the control over his body. He was helpless.
"I understand that you feel angry, but please try to relax a little," she said. "I'll let you go when I see that you've thought it over and you promise not to do anything foolish."
What was he supposed to think? Yes, what he said sounded a little depressing, but it was the truth, and he wasn't afraid to accept it. He didn't have to decide anything, he hadn't even asked to be born in the first place.
It wasn't as if every time the world line changed he became a ghost: he became nothingness itself. If he ceased to exist and never did so again, he would not feel it. Even he wouldn't realize it, there would be nothing to be sorry about.
"I'm tired of you treating me like a child," said Keitarou. "The last thing I need is your pity."
"Pity? You're the one who doesn't understand anything, future child," said Suzuha. "But I'm no longer interested in what you think of yourself, because unlike you, I do have a life to defend."
Her own life: the life that Suzuha alpha and Suzuha beta had fought for in other attractor fields.
"I love my life as it is now and with all the people in it. I will not allow anyone to disappear easily."
"Even if I disappeared, your life would not change at all, Hashida-san. It would still be the same as it is now."
Suzuha didn't have the Reading Steiner, and like everyone else, she'd forget it too.
"No, I'm sure it wouldn't be the same," she said. "That is, if you didn't exist, who would I play video games with or ride my bike with, or who would accompany me to the movies or karaoke on vacation? Doing it by myself wouldn't be fun."
"Are you telling me that I exist just to entertain you?" he asked.
Did she consider him her personal toy?
"If you like you can see it that way," she answered.
Unlike Suzuha alpha or beta, Hashida Suzuha did not have a world to save. She lacked a true mission and being a "warrior" was just a hobby to brighten up her monotonous existence. The routine flow of life had led her to become a human being like any other: defective, and selfish. A being centered on herself and her own well-being.
After all, that was the life the other Suzuhas would have liked to have. No one could blame her if she concentrated on enjoying it. It would be enough to do what she wanted to do without restraint. It would be enough if she could find pleasure in the little routine things. It would be enough to have a little fun with other people. It would be enough if she could form good memories with her loved ones.
If Okabe Keitarou's existence added value to her own, if those things they do together add a little more joy in her life, then she would not give up so easily. She would defend with all her strength that which made her smile, even if it meant fighting against Keitarou himself.
"What will you do then? Do you promise not to talk any more nonsense? Or else will you try to fight me to get free? If you succeed, I promise that I will not trouble you any more, but you must know that I will not pity you."
He reflected for a moment.
He knew that it was useless to fight against Suzuha. She was stronger than him. Not only physically, her willpower had always been stronger.
Keitarou was weak and not only that, but every day near her, his weakness got worse and worse.
"You win, Hashida-san," he finally said. "I promise I won't talk to Mom."
It was not the answer Suzuha would have liked to hear, but it would be enough for the moment. She wasn't proud of having used force, but he hadn't left her any choice either.
"If you are lying, I promise I will never forgive you," she added before releasing him.
Moment later, the two lay side by side facing the ceiling, while the atmosphere slowly returned to calm.
"It wasn't part of my original plan to talk to Mom," Keitarou broke the silence. "My intention is to fix the future of Steins;Gate, not to eliminate myself."
If he achieved his goal in 2012, what happened after that didn't matter much to him. If his parents made the same mistakes again, it would be none of his business.
"Fix it?" asked Suzuha. "What does it mean?"
"Steins;Gate is unstable, but it shouldn't have been in the first place," he said. "The oscillations in which its energy state moves were caused by an artificial source of interference."
A very stable source, which had not decomposed in more than 20 years.
"Do you what that source is?"
"I don't know. I imagine that some kind of boson, or even a set of them, that has fluctuations. Perhaps a stable half-life graviton, whose waves disturb space-time and cause the world line to change."
Even in the year 2036 the "theory of everything" was not reached that would explain the total functioning of the universe. Keitarou was also not an expert in quantum field theory, string theory, or M theory. His deductions about the nature of inference were only speculative, he could not explain well what the jumps in Steins;Gate were about.
"If you don't know, I don't think there's anything we can do about it," said Suzuha.
"I know someone who does."
The one responsible for creating the inference, and for the world line becoming unstable: Hououin Kyouma
His father was the cause of everything.
"Uncle Okarin did it?" said Suzuha in surprise. "Did he tell you?"
"It was a while ago," answered Keitarou. "He said it happened in the last quarter of 2012. That it was an accident and that other members of the laboratory were involved in the experiment, but that he is the only one who remembers the details."
"A future gadget. That's what we're looking for."
Suzuha could now put the pieces together: if an gadget was the cause of Steins;Gate's instability, and with it Keitarou's amnesias, it was logical to assume that finding it would be the solution to the mystery.
"When he told me, I proposed that we find a solution together. Recreate the conditions of the accident, reconstruct the device and see if there was a way to fix the Steins;Gate. At the time I didn't understand why Mom hadn't investigated the phenomenon yet, but I thought that if the three of us got together, we could do it."
But Keitarou was only a naive child when thinking about it, since his father refused his proposal.
"He claims that everything happened because it was supposed to happen and, being so, there is no other choice but to accept reality as it is."
Not only that, he had apparently also convinced his mother not to intervene, while his sister had already adapted to bear that reality.
Okabe Rintarou wanted to leave everything as it was.
"He even called me 'a fool' for thinking about things like time travel to prevent the problem. It's ironic that we later found that half-built time machine. I imagine he had wanted to try by himself, but gave up."
Keitarou couldn't accept that his father didn't want to do anything. But every time they talked about the matter, he always received refusals, until finally he got tired of trying to reason with him.
"That's why you stopped talking to him," said Suzuha.
She had asked her uncle Okarin why he didn't talk to his son, and he always answered the same thing: that it was Keitarou himself who had asked him. That when his son spoke to him again, he would answer.
But it made sense now: for Keitarou, his amnesias were his father's fault and so he was rejecting him.
"I couldn't keep calling to a guy who prefers to continue this insanity 'dad'."
If there was a God in the world where the Okabe family lived, he either had bad taste in dramatic family stories, or he must have been very bored.
The Steins;Gate was an absurd attractor field.
Suzuha, reasoning everything she heard, could not quite understand Okabe Rintarou's attitude. She sat down on the floor:
"There is something that doesn't add up, why do you think Uncle Okarin would choose to live like this if he could avoid it?"
Even if the world could not notice, why would he drag his whole family into living in such an uncomfortable reality for the four of them?
"He is 'an evil mad scientist', isn't he? The idea of an unstable world line goes well with his discourse of chaos and destruction."
Even Keitarou couldn't bear to think that perhaps his father was taking advantage of the situation. He could not see the other world lines and had no evidence to accuse him. Before knowing the truth, he had always believed in the relationship between his parents, and Shizuka, who if she saw the other world lines, said that Okabe Rintarou was not guilty of anything that could endanger their marriage.
But if he was not willing to fight the divergence, could it be that he preferred it from the very beginning?
"No, I don't see Uncle Okarin indulging in that sort of thing," she said.
It was true that uncle Okarin had the character of Hououin Kyouma, which he executed from time to time, but it didn't mean that he believed all the stories he recited.
"Keitarou, why don't we talk to him and explain everything you just said? Maybe all this has an easier solution."
His childhood friend did not believe what he was hearing. He also sat down on the floor and said:
"Hashida-san, what kind of madness are you proposing? You ask me not to talk to mom, but you want me to tell everything to that guy?"
If there was one other person who could, and probably would, prevent Okabe Keitarou's birth, it was his father. He would reject the idea of having an unplanned child in the first place.
Suzuha knew this was not entirely true. The anger her friend felt had made him forget all the moments they had spent together. Okabe Rintarou had always been Keitarou's father. He gave him his last name from day one, never denying it in front of anyone. He had always been proud of him and even made him the 010 member of the future gadget laboratory.
Although perhaps that applied to the adult man of 2036, and not to the 20-year-old young man living at the present time.
"I guess you're right. Uncle Okarin would have a heart attack if he found out he was having a child that way," she said. "However, we don't have to tell him your identity. I'm sure that if we explain everything that's going on with Steins;Gate, he'll help us find the cause, or at least, he won't let it happen again."
But Keitarou didn't think so.
His father of the future claimed that everything would happen again according to the natural course of convergence: Steins;Gate's will was to initiate its own collapse. If Keitarou wanted to find a perfect plan to avoid it, the cause needed to be found first and the best thing would be to intervene as little as possible in the past.
Besides, he couldn't trust Okabe Rintarou. He had already lied many times, and he would surely do it again.
"We don't need his help. We can find out for ourselves what happened."
Keitarou supposed that his mother must have been involved too, although she said she didn't remember which gadget it was. His father always asked for her opinion when inventing new things for the company, so he doubted that this time it would have been different. He was smart, but she was a genius. If the device was some kind of miniature particle accelerator, he couldn't do it alone.
His mother had written by message to his father that she wanted to talk about a new invention, and Keitarou would have listened to them, if it wasn't for the arrival of his sister. Probably this slight deviation of events would have recomposed itself.
They just had to stay close to both of them. If they continued with the plan to spy on them, it was only a matter of time.
"Are you sure? Because we have been here for more than two weeks and nothing has happened. Besides, Uncle Okarin from this time is different from the future. I feel that we can trust him."
Keitarou didn't want to listen to her anymore, why did Suzuha insist on talking? Why did she defend him?
"Hashida-san, whose side are you on, Okabe Rintarou's or mine?"
He feared that his friend was succumbing to his father's charms. He concentrated some of the divergence on his marriage and the birth of his daughter. So, could there be a world line where...?
No. If that were possible, it would be worse than non-existence, worse than disappearing forever. Worse than death. Worse than any horrible fate he could imagine. He didn't even want to guess the name his sister would receive.
That was never supposed to happen.
Never.
"I don't know what kind of nonsense you're thinking right now," replied Suzuha annoyed, not knowing what was going on with her friend's mind. "You know very well whose side I'm on."
She was on the side of "Hououin Keita", but she was not supposed to pronounce that name aloud. Keitarou would never accept it and she did not want to discuss with him again.
Suzuha got up from the floor, went to the window, and opened the blinds. The languid rays of the autumn sun filled the room.
Sunday was not yet over.
"Hey, don't you want to go for a walk? I don't know this area, why don't you show me?"
Next Chapter: The Future Gadget Lab