Windowless Building

As they climbed higher, the scenery changed again.

Footing was still sparse. The mountain climbing route was still devastating and consisted entirely of objects hanging from the heavens by wires. But instead of window cleaning gondolas and crane hooks, Kamijou and the others saw fairy tale 5-pointed stars and cradle-like crescent moons. They were all a few meters across and it felt like jumping between gorgeous chandeliers. If not for the terrible fear of heights, they should have provided enough footing, but…

“How high up are we now…?” Kamijou wondered aloud.

Unlike true mountain climbing, the air did not seem to grow thinner and colder as they climbed. No matter how strange it seemed, they were still inside the Windowless Building, so the temperature, pressure, and humidity may have been kept at a certain value.

The giant tower ignored three-dimensional space as it rose toward the heavens.

And they had finally reached fake stars and moons.

…This should have been an impossible height. Checking the distance from the surface to the outer atmosphere in an online encyclopedia was enough to know that. That was not a distance that human legs could clear in a day. But at the same time, this was an alternate-dimensional space where Euclidean geometry did not apply. The distance of each step did not necessary match up with the distance they had actually traveled. Plus, they were surrounded by giant walls on every side. With no view outside, there was nothing to judge the distance by.

Would they really make their way to outer space like this?
[-]
Confused, Kamijou asked a question.

“Eh? Eh? What just happened? Some kind of adhesive? Or a magnet???”

“I don’t know…but it felt like I fell toward the star…?”

On the boy’s shoulder, Othinus crossed both her arms and legs as she sighed.

“Artificial gravity? Curse that ‘human’. Is he working to acquire even the forces of the planet?”

Kamijou did not understand how this worked.

Artificial gravity brought to mind a small room spinning around to produce centrifugal force, but he had no idea how people or objects could be pulled toward the surface of a small sphere like this.

Or…

If the actual matter was far denser than the apparent volume, could it be given the same powerful universal gravitation as a normal planet?

“No, that wouldn’t work… It wouldn’t make sense for it to be dangling from a single wire then. And if it was that dense, it would be a scorching hell like the earth’s core.”

There were exceptions such as a black hole that created gravity powerful enough to distort the surrounding space and had no material core, but that too could not explain this. Or rather, that would not allow one to adjust the gravity to the desired level. There were only two options: a micro black hole that could only be observed through data or a macro black hole that would swallow up the entire solar system if it formed. Even an esper who could directly manipulate gravitons had only been able to produce explosions.

“Being able to convert the proper methods into any universal power does sound like his kind of theory. I doubt you will find the answer with the knowledge found in a high school textbook, human.”

“I’m not interested in being an intellectual. I just want to know if Imagine Breaker will destroy it or if it can support me.”

With that, Kamijou reached his hand out toward the closest crescent moon.

And that acted like a trigger.

He had already had a hunch... it was about time.

Reality and illusion crossed over, the crescent moon crumbled away without warning, and Kamijou Touma was overcome by a far too real sensation of falling.
- To Aru Majutsu no Index NT18 Chapter 3 Part 10
[-]
Kamijou Touma once more climbed to the top of the transparent spiral staircase.

He had reached the summit of the mountain.

A vast space awaited him. There was no concept of a floor or stairs here. Everything was transparent. After taking just one step into it, he was unsure where the stairs he had climbed were. No, perhaps the exit really had disappeared once he arrived.

And now that he had climbed the heavenly staircase, he was in outer space.

He had no idea how the dimensions were distorted inside and out, but the giant blue planet spread out endlessly below his feet.

“It is simple.”

For the first time, he heard a physical voice instead of a staticky fake.

Kamijou Touma was not about to let any absurdity or unreasonableness surprise him now. That “human” stood in the center of that space which had nowhere to hide. He had ankle-length silver hair and wore a green surgical gown. He looked like both a man and a woman, like both an adult and a child, and like both a saint and a sinner. And he spoke as if he had been standing here for an entire century.

“A field ruled by the ley lines running through the ground. The directionality and intensity of the various forces arriving from the cardinal directions and from other heavenly bodies… The magic born on earth is bound to earth. And unfortunately, humans will fill in seas and shave down mountains to achieve their goals. Yes, the very same people who are affected by the many sparks. So I thought I might be able to achieve a ceremony worthy of my goal if I escaped the limited possibilities of the earth. I will admit I panicked somewhat when that space elevator got there ahead of me.”

That was the purpose of the powerful walls, fully-enclosed environment, and rocket boosters.

And it did not matter if those conditions needed to escape the earth were destroyed. He had ignored Euclidean geometry to extend space, raise his tower in another dimension, and free himself from the bonds of the heavens.
- To Aru Majutsu no Index NT18 Chapter 4 Part 1