kscans

Chapter 277 - The Inverted Shadow in the Mirror

We entered a "building" several times taller than the castle, so high it felt like my neck would break just looking up. Astonishingly, and perhaps inevitably for a place this tall, Senpai and I were carried upward in a square gondola.

Unlike the first floor, which had been bustling with noisy crowds, the top floor was quiet. It was an elegant space, one you might expect to find in the home of the city's lord.

Senpai explained it was a place like Central Garden's convention center, where various exhibitions are held.

"The exhibits change with the seasons, more or less. I think it was foreign oil paintings until last month. At least, that's what I remember."

"So, what is on display now?"

"That is a surprise for when we get inside."

Senpai bought tickets at the entrance. The admission fee was about the same as our lunch earlier. I tilted my head at his comment, "It is an academic event, so it probably gets some kind of government subsidy."

We walked down a dimly lit passageway with a red carpet. I could not help but touch the wall. It was so smooth I wondered if it had been made with alchemy.

On the glossy paper posted on the walls were strange patterns. Paintings, maybe? They had a translucent, vivid coloration. But they depicted neither people nor scenery.

One shape looked like two circles overlapping. It resembled the number 8, but it was twisted along its central axis. I stopped in my tracks. If this shape were three dimensional…

We went from the passageway into a room. As expected, there were few people. Apparently, it gets quite crowded when they exhibit foreign paintings or sculptures. This meant the current event was unpopular. I had to admit, I could not imagine a painting like the one I just saw drawing the interest of an ordinary person. Though I am not sure what ordinary is here.

Inside the first exhibition room were many transparent cases. The cases were shockingly well crafted and clear. Inside them, a glittering liquid was flowing. It was a bizarre sight.

"It looks like the fish tank you want to make, Senpai…"

As I said that and peered inside, I froze. The things inside were not fish, and what was flowing was not water. The patterns from the posters outside were on display as three dimensional objects.

"Wh, what is this…"

My voice cracked. The question that had occupied my mind until just a moment ago, the one about this being a dream, was completely blown away.

It was the beauty of an impossibly beautiful illusion. Something that existed only in my mind, something I sometimes mistook for reality because it felt more true to me. And here it was, existing in a visible form. It was truly a scene from a dream.

I instinctively reached out. But as my hand drew near, the illusion collapsed. When I hastily pulled my hand back, the illusion swiftly reformed. It had no form…

"This is called a hologram. Um, let’s see, the explanation said…"

Senpai had a triumphant look on his face. He looked at a nearby panel made of a material I did not recognize. It was incredibly frustrating that I could not read it.

"Okay, so, what’s creating this three dimensional image is the pattern on the flat surface below it. When light hits that pattern, what’s projected is this solid object."

I looked at the floor. Our shadows were there. Our shadows, which came from our three dimensional bodies, were flat. This was the opposite phenomenon.

The next exhibit allowed you to control the angle that created the shadow yourself. Each time you changed the angle of the light hitting the flat pattern, the projected pattern transformed. It was just like how the shape of a shadow changes according to the direction of the light.

"Like a three dimensional shadow…"

"That’s our Mia. You’re probably right about that."

Senpai nodded in admiration at my unintentional whisper. The concept of projection across dimensions. Understanding of it crystalized in my mind in an instant. Amazing. Amazing. Amazing. But, this is strange. In the case of a shadow, one dimension of information from our solid bodies is lost…

Besides, what is a technology like this used for?

With this question in mind, I moved on to the next exhibit. It was a portrait of a person. However, the number "10000" was written on the top left and right. It looked like the payment certificates Senpai had taken from his wallet earlier. And in the bottom left corner was the same strange, glowing pattern as before.

"It’s not exactly an everyday thing, but it’s used like this as a countermeasure for counterfeit currency."

"I understand that printing a large amount of information onto a flat surface would make it difficult to forge, but…"

I thought it was overkill, but I reconsidered when I saw the same glossy paper from before on the wall. If printing technology of this level exists, then this is necessary. It is still astounding, though…

I questioned Senpai, and he, prompted by me, read the explanation. The wrinkles on his brow deepened.

The next exhibit was even stranger. There was a curved surface, and projected from it was a sphere.

"It’s a globe, a map of this world. Uh, the meaning of this exhibit is…"

Senpai looked at the explanation, his brow furrowed.

"This is too difficult for me to understand, so this is just a vague impression, okay? This universe, well, this world. There’s a theory that the highest possible information density of the world itself is a flat plane. The true form of the world is…"

"Yes!"

"So, let’s say this sphere is the three dimensional space we perceive as the world. But all the information for this three dimensional space exists on the curved surface behind it, a two dimensional plane. The idea is that the three dimensions we perceive as the world are just a facade, like this hologram."

When Senpai reached out his hand, part of the sphere blurred. A portion of the true information on the surface behind it was blocked, causing the three dimensional image to lose its integrity.

"I understand."

In other words, the mathematical equations are the reality, and this world is merely their projection. That is the very idea I have always found strange yet could never deny.

"You get it?" Senpai said, looking a bit taken aback by my excitement.

"Well, if you were to shine a light on this plane from another direction, let’s say from the back, then the same information would create a completely different world."

"Ah, does that mean…"

I knew what Senpai was trying to say. In other words, the reason Senpai crossed over to another world…

"My head is spinning."

I shook my head, which had grown hot from taking in too much information. Somewhere along the way, my worries about this being a dream had vanished.

"You’re focusing too hard. Well, it looks like this is the last exhibition room. Hey, Mia."

My eyes were drawn to a single display. It was a particularly small case. Inside was a pattern like a ring, yet it seemed to be formed by multiple complex circles interwoven in three dimensions.

"Ah, that’s a mathematical formula given form. Let’s see, this formula is…"

"This formula is?"

I gulped as I watched Senpai look at the explanation.

"Perturbation by a quantum information model using a manifold torus. Sorry. This is completely beyond my abilities. It seems to be connected to that explanation about the hologram and the world."

"……………………………………"

I looked at Senpai reproachfully.

"Uh. Let me try to explain just the elements, as far as I understand them…"

Senpai took a notepad out of his breast pocket. It was his essential tool.

"If I convert it into numerical arts as much as possible, it looks something like this."

I stared at it intently. Then I compared it to the illusion, no, the true form before my eyes. This part here is pi. If I swap this term and this term. Ah, an infinity canceling another infinity. So, if I convert this part and this part…

"And if you do this, it becomes a slightly easier form to understand."

I returned the notepad to Senpai. There have been times when Senpai remembered only the formula, and I was the one who taught him its meaning. I never thought I would be doing it in a dream…

"I can just barely grasp it. I see, so it’s like creating a repeating pattern with another repeating pattern…"

Senpai looked at what I had written, though his expression said his head was throbbing. He was trying his best to understand my thinking. It reminded me of when I first met him.

For a moment, I forgot about the formulas and just looked at Senpai. To me, he is the only person in the world who understands. Of course, I have Noel and Maytyl now, but even so, he is special.

Right now, the two of us are standing side by side, surrounded by the world of ideal numbers. It is just like a dream…