Chapter 1:
Childhood
AT AGE SEVEN, I understood what “divorce” was, and when my parents asked me to choose one of them to live with, I didn’t throw a fit.
My father was a celebrated researcher in his field while my mother came from a wealthy family. No matter who I chose, I would have all the financial security I needed, so I was free to let my heart decide—and ultimately, I chose my father. Not because I loved him more than my mother, but because I was afraid she wouldn’t be able to get remarried if I was around.
The root cause of their divorce was poor communication. My father spent many a night at his laboratory, and whenever he came home, he would tell my mother all about his work. Naturally, to her, it was total gibberish. Alas, my father was the kind of man who automatically assumed everyone else understood all the same things he did, and I often watched my mother struggle in conversations with him while he remained blissfully unaware.
Therefore, based on their personalities, I decided Dad was less likely to get remarried. Well, no—I’m sure my thought process at age seven wasn’t quite that clear-cut, but you get the point.
Ironically, the divorce dramatically improved my parents’ relationship, and they cheerfully traded me back and forth at least once a month. Obviously, they had to have loved each other very much considering they got married and had a child in the first place, but it was clear this degree of separation was healthy for them. Personally, I was just happy that they stopped fighting and relieved that it wasn’t because of me.
Once it was just me and Dad, I started popping into his workplace. After school let out, I’d go to his laboratory and wait for him to finish his work so the two of us could go home together. The lab was open seven days a week with rotating shifts, so whenever he had to work on a weekend, I just spent the whole day there.
As part of its benefits package, the lab allowed its employees to leave their young children in the onsite daycare room. It wasn’t a fully-fledged daycare with its own staff or anything—it was just a room where employees took turns babysitting us. As the oldest, I helped look after the little kids, and the busy grown-ups thanked me for it.
Whenever there were no other kids in the room, which was often, I would spend my time reading through the books on the shelves. Instead of picture books, they kept dissertations and scholarly works pertaining to my father’s research. Naturally, I didn’t understand a word of it at first, but some of the books were written in a “For Dummies” way with lots of illustrations, and I managed to power my way through those. The discovery of the unknown made my heart race.
Dad must have been pleased that I was developing an interest in his work. He often came by during his breaks to check on me, answer my questions, and explain his research through simple analogies even a kid could understand.
One day, he pointed at a big tank full of tropical fish. “These bubbles represent the world where you and I live,” he explained.
Unlike my mother, he didn’t refer to himself as “Daddy” when speaking to me, and once it was just the two of us, I stopped using that word myself.
In the tank, I could see big bubbles rising from the aerator pump.
“See how the bubbles get bigger and bigger? Held at a constant temperature, the volume of a fixed mass of gas is inversely proportional to its pressure. This is called Boyle’s law, and—”
“Wait, I don’t get it. What’s ‘inversely proportional’?” I asked.
“You haven’t learned about proportionality in school? When do they teach that?”
“I don’t know, but not yet. Give me an analogy.”
“Hmmm… Okay, let’s say a candy bar is 100 yen. If you buy two, they’ll cost 200 yen, and if you buy three, your total’s 300 yen, right? When both values go up in relation to each other, that’s called directly proportional.”
“Okay.”
“Now, inversely proportional is the opposite of that. If you split six candy bars between two people, each person gets three, right? Split it between three people, and each gets two; between six, and each person gets one. When one value goes up while the other goes down, that’s inversely proportional.”
Dad would always default to using big words, but if I told him I didn’t get it, he would do his best to rephrase it more simply. If only Mom had admitted to her lack of understanding the same way I did, maybe they could have stayed together.
“The deeper underwater you go, the higher the pressure is—that’s the force pushing against you. This means a bubble’s volume—size—goes down the deeper you go. As these bubbles travel upwards, the pressure gets weaker, so they get bigger. That means their volume is inversely proportional to their pressure, which is what we call Boyle’s law.”
“Boyle’s law?”
“Yes, Boyle’s law.”
“Got it.”
“Very good!” he said, praising me.
Satisfied with my response, Dad went back to pointing at the bubbles in the fish tank. Apparently, he had more to teach me.
“In my field, we theorize that our world is like these bubbles, so we’re testing to see if information can be exchanged from one ‘bubble’ to another.”
I remembered him comparing our world to the bubbles at the start of our conversation, but what did it mean?
“See, our world started as a tiny bubble born on the ocean floor. Over time, it floated up, growing in size—and along the way, it split in two. We’re in one of them.”
“What about the other one?”
“We’re in that one too, but it’s not the same as this one. Maybe in that bubble you went to live with Mom instead.”
There’s another me that chose to go with Mom?
“We refer to these other bubbles as parallel worlds,” my father explained.
“Parallel worlds?”
“Yes, parallel worlds.”
“Got it.”
“Wonderful!”
Truth be told, I didn’t grasp this concept quite as well as the analogy about direct and inverse proportionality, but I did my best to soak up knowledge like a sponge. As a result, I never struggled with schoolwork because I was always learning things years ahead of my peers.
“We believe that human beings subconsciously travel between nearby bubbles on a daily basis. The closer a bubble is, the fewer distinctions there are between them, so it’s possible most people simply never notice anything’s different. If that’s so, we first want to prove it. Then, our aim is to control it. This is what our director calls the study of imaginary science.”
At the time, I didn’t fully grasp just how incredible that was. I was a smart kid, sure, but I was still in elementary school. My only real reaction was, “Wow, neat.”
But a few years later, as I was turning ten, that ignorance proved dangerous.