Komoreby

8 | A Rabbit Hole

"What!" She blinked. "That's insane."

"An apt way to describe the subatomic world," Inoue said, her eyes twinkling. "What's even more fascinating is that superposition has been tested and observed in large molecules as well. Now, according to the many-worlds interpretation of quantum mechanics, all the possible states diverge into different universes. So it's like in one universe, the cat's alive and in the other, it's dead. Similarly, there might be one universe where you didn't come to school today or another where you never left Nuara. There can be infinite possibilities."

"What about time? Can you travel in time?"

The teacher gave her a matter-of-fact nod. "Yes, you can, and it has been done."

"Huh?" Evanna gaped, her pulse racing while she yet again experienced an upheaval of everything she knew.

"In our day-to-day lives, with our limited experience, we feel as if time is rigid...that it ticks the same for everyone. You feel like the time that elapses for you is the same as that for a student who walks out in the corridor as we speak. It's not. Time ticks slower for the person in motion. Imagine that you ride your bike close to the speed of light for a couple of hours. Years would have passed for the rest of us. You've essentially traveled into the future."

Evanna stood stock-still. The brightness in the room dimmed as her unwavering stare focused on the teacher. The earth seemed to wobble, making her grip the edge of the table.

"Then there's gravity," Inoue went on. "Many people think of gravity as a force that pulls things. Gravity is not a force—it's a distortion of space-time caused by objects with mass. It's noticeable around planets and stars, since they have great mass. Higher the gravity, the slower time ticks. Time is slower for someone on the ground floor of a skyscraper than for someone living in the penthouse, because gravity is stronger the closer you are to Earth. The effects are more drastic if, for instance, you spend an hour or so near a black hole—where gravity is very high. Once you get back, you could've traveled fifty years into the Earth's future."

"What about traveling into the past?" Evanna managed to croak.

"That...is a bit tricky. We are delving into pure speculation. If a future technology involving, say, wormholes, enables us to create a checkpoint in time. You can return to that point whenever you want. But will your future be the same? Let's think of what is known as the Grandfather Paradox. You can go and kill your grandfather before he had your parent, but that means you would not be born. Are you with me?"

"Yeah..."

"The universe would either prevent you from creating such paradoxes or...it would be a different universe once you've traveled back, so there would be no paradox no matter what you do."

Evanna resisted the impulse to sit down. "What if you don't travel physically, but you sort of wake up as yourself in another universe, in the past?"

A beat of silence elapsed.

Inoue chuckled. "Then you better wish that life is good for you in your new universe. You should run along to your class now. You're already late."

When Evanna burst into Math class, the teacher Manasie Mori finished taking attendance.

"I'm sorry I'm a bit late, Miss Mori!" Evanna panted, avoiding all eye contact.

"Just take your seat," Mori said in a dismissive tone. "And remind me later to mark you present."

Math was now her least favorite class—not just due to the presence of those whom she wanted to avoid, but also because of Mori's teaching style with her solemn demeanor.