The Floating Starlight Bridge Read online

  Chiyuri had already started walking toward the elevator, and her laughter glided through the air to his ears. Sighing, he hurried to catch up with her.

  Outside the windows, white clouds kept up their constant flow.

  3

  Having said good-bye to Chiyuri two floors below in the condo and returned alone to his deserted apartment, Haruyuki had no sooner changed out of his school uniform than he had plopped himself down on the living room sofa and started racing his fingers along his virtual desktop. He first opened a browser and entered the search words through voice command.

  “Social camera export.”

  At the very top of the list of results displayed immediately was the news item: Japanese security system introduced to Hermes’ Cord.

  Security system. Obviously, the social camera technology.

  And Hermes’ Cord was—

  The name of the space elevator above the eastern Pacific Ocean.

  He clicked on the link with a finger, and reading the text of the article, Haruyuki thought ardently about the whole thing.

  In brief, what the article was saying was that the security system for the space elevator, an international facility, had adopted the same technology as the Japanese social camera network.

  The Earth-side station for the space elevator was in the coastal waters of Christmas Island, vastly far away from Japan. If social cameras were set up in a place like that, then that place would be incorporated into the Brain Burst areas, wouldn’t it? Assuming that was the case, was there a way to dive there?

  After cranking away in his head for half a minute or so, Haruyuki quickly abandoned the effort. He just didn’t know enough to figure out the answer. Not about Brain Burst, and not about the space elevator, either. Maybe this was the time to turn to his leader for guidance. Right, she would know much more about both. He closed the browser, launched his mailer, and then hesitated briefly.

  After examining the ratio of the degree of his desire to simply discuss it with her and his desire to talk big, he came to a conclusion of “Right! Sixty–forty!” and quickly typed out a text mail to make an appointment for a dive call. A dive call with this woman of letters who excelled in all subjects, one of the most senior Burst players, and the leader of Nega Nebulus, the Black King aka Kuroyukihime.

  The time specified in the response that came right back to him was twenty minutes later. During this time, Haruyuki finished off a supper of frozen shrimp doria and oolong tea before going into a full dive a minute before the set time and switching the environment data of his home local net for the object set he had downloaded from a site overseas.

  Previously, when he had similarly invited Kuroyukihime to his home net, the only sets he had were either very cold or stank of gunpowder, which had thrown him for quite the loop socially, so since then, he had been collecting things that would create a good atmosphere. Although his mother did complain that he needed to stop filling the home server storage capacity with junk.

  He pushed the connection request button almost the instant he had everything set up and the appointed time came. After a few seconds of the call placement sound, an avatar appeared before his eyes.

  Jet-black dress, silver trim glittering. Folded parasol the same dark color. Spangle butterfly wings on her back with a red pattern.

  This fairy princess, with just the slightest bit more mystique than she had in the real world, looked first at Haruyuki’s pink pig avatar with a smile, and next at her surroundings. She then abruptly opened both eyes wide and let out a cry, clinging to the pole next to her with some force.

  “Wh-whoa!”

  “Huh?! Wh-what’s the matter?!”

  “Wh-wh-what’s the matter? This is the matter! Wh-wh-what is this environment data?!”

  At her consternation, Haruyuki hurriedly took another look around.

  Mountain ridges a hazy purple. An expansive forest and meadow, and a white stone city. The two of them were at the top of a very tall tower where they could see the entirety of this beautiful scene. There was no handrail or anything of the like on the very small watchtower—which was only three meters in diameter, with two chairs placed in the center along with a gas lamp—so the view was exceptional.

  “Uh, um…I-isn’t it beautiful? I found this object set on a German site a while ago—”

  “Before we get to that, exactly how tall is this skinny tower?!” she asked with a pale face, and Haruyuki peered over the edge, straight down. He felt like the distance from the ground was about the same as that of the observation deck at the government office, from which he had fallen in the duel that evening, and so he replied as such.

  “Uh, let’s see…maybe about five hundred meters—”

  “That’s too high, idiot! Or were you aiming for a suspension bridge sort of effect?!”

  “H-huh? What do you mean?”

  “The suspension bridge effect is, well…In a dangerous place like a suspension bridge high up, due to a misunderstanding of the feeling of fear…” Halfway through her explanation, Kuroyukihime stopped talking before lightly clearing her throat and glaring at Haruyuki. “At any rate, that sort of psychological issue has no effect on me! Although…it’s not a duel, so nothing will happen even if I do fall, but at least have the decency to give a little warning in advance at times like this…”

  The end of her sentence lost to muttering, Kuroyukihime finally stood up and sat down in the chair next to him. Haruyuki had also sat down earlier, and he spoke now slightly dejectedly.

  “Um, I’m sorry for scaring you. Should I change it to a different object set?”

  “No, it’s fine. Regardless of how high up this is, you went and searched this set out for me.”

  He saw a faint smile rise to her lustrous lips and breathed a sigh of relief. “Uh, um.” He scratched his head with the rounded hoof growing from his right arm and gave her a belated welcome. “Good evening, Kuroyukihime. I’m sorry for calling you out like this so abruptly.”

  “Good evening, Haruyuki. I’m glad I could see you now since we didn’t get a chance to talk at school today.”

  Umesato Junior High’s school festival was at the end of June, and because this was the last big event for the current student council, Kuroyukihime, being the vice president, was extremely busy every day. Remembering this, Haruyuki took this chance to ask a question that had occurred to him countless times before now.

  “That reminds me. Why did you join the student council anyway? The president and vice president are decided in an election, so does that mean you campaigned for it?”

  “Mmm. Well. Given how fixated I am on simply becoming a level-ten Burst Linker, your question of why is a very good one. The administrative things and conferences take time, leaving me no time for dueling.” Letting a meaningful smile slip across her lips, Kuroyukihime continued. “However, to answer honestly, the reason I became a council member was all for Brain Burst.”

  “H-huh?!”

  “Think about it. For a Burst Linker, the school that you attend is the closest to you, and thus, the most dangerous field. You could even say that having a grasp of all that information and firming up the ground beneath your feet is, in fact, essential. As a student council member, I have nearly full access to the school database. And from that perspective…” Here, Kuroyukihime grinned at him and gave voice to something entirely unexpected. “Speaking of which, there is the matter of after the student council elections next term at the start of the second term. How about it, Haruyuki? You could stand for president.”

  “Wh…Wh-wh-wh-wha-wha-wha—” Jumping slightly in his seat, Haruyuki twitched his pig’s nose at high speed. “N-n-n-n-n-no way, no way! I-i-i-if I did, that would be like giving the whole school a Supreme Court–mandated license to dump on me! Totally!”

  “Mmm, in that case, it might work if I left Takumu to be president and you to be vice president—”

  “That’s! Not! The problem!” Decisively firm in his refutation, speech slightly colored by Frost Hor
n’s tone, Haruyuki decided to force this train back onto its tracks. “Anyway, I fought a duel in Shinjuku today.”

  “Mmm, I heard the talk. A hard fight against Leonids’ starting team.”

  “N-news travels fast.” Haruyuki blinked rapidly and Kuroyukihime’s smile shifted to something a little more sarcastic.

  “Of course I know about it. Apparently, you and Chiyuri are perfectly in tune with each other.”

  “Oh no, that’s…I mean…ummm…”

  “What’s the matter? I’m not reproaching you. As Legion members, the most important thing is for you to work well together, isn’t it?”

  A cold sweat sprang up on his brow at the Kuroyukihime Smile special attack, and he once again reoriented the train. “Right around the end of that duel, our opponent said something like he was going to jump from Tokyo Skytree and kick us, and that’s when it suddenly hit me!”

  Quickly opening his browser, he called up the article at hand and slid the window over to Kuroyukihime. “Um, Kuroyukihime, do you already know about this?”

  “Japanese security system in Hermes’ Cord? Mmm, I feel like I caught a bit of this on the evening news.” She glanced at the holowindow before lifting her face and cocking her head to one side. “So what about this article?”

  “Um, well…It really is just an idea…and maybe you’ll tell me I’m totally, way, way off base, but…I mean, I kinda feel bad for calling you here over something like this at all, but…” After setting up this mumbling guard at top speed, Haruyuki finally got to the heart of things. “That security system is the social camera technology, right? So then that means that the whole of the space elevator in the Pacific Ocean comes within range of the cameras, doesn’t it? So I was just thinking…Hermes’ Cord would show up in the Accelerated World, too…”

  Even after he trailed off there, Kuroyukihime’s eyes were practically popping out of her head, so Haruyuki readied himself for her to burst out laughing at this totally idiotic idea or to get mad at him for calling her over for such a pointless matter.

  However.

  “Hmmmmmmm.” Humming at length, Kuroyukihime placed the fingers of her right hand on her chin and stared down at the browser window one more time. Eventually, she lifted her head and shook it lightly. “What can I say…You really do let your thoughts roam, hmm? But it’s…interesting. Mmm, it is a truly interesting idea.”

  “Uh, uh-huh,” Haruyuki said idiotically, not knowing how he should react, while before him, Kuroyukihime made her avatar get up from the chair and begin pacing in the middle of the narrow observation tower, almost as if she had forgotten her fear of the five-hundred-meter height.

  “Assuming social cameras had indeed been set up there…Normally, that would be a closed net…But I wonder if the Hermes’ Cord central station has the extra space and power to accommodate that enormous image processing system? Either way, connecting with the SSSC in Japan with a satellite circuit and having them process the data would be much more efficient. And cheaper, too. In which case…there’s a possibility that even the Brain Burst program could at least slip past the defenses…”

  “Uh, um,” he somehow managed to interject, moving both of his short hands intently. “I don’t really get it.”

  Kuroyukihime stopped moving abruptly and waggled the index finger of her right hand as if she wasn’t sure how to explain it. “Mmm. All of which is to say, Hermes’ Cord is a low-Earth-orbit space elevator, so the design is incredibly pared down.”

  “What’s low Earth orbit?”

  “…That’s where I have to start?”

  A small, wry grin crossed her lips, and Kuroyukihime sat down once again. She cleared her throat with a light cough and called up a blank window. On the bottom, she drew a circle with her finger and wrote “Earth” in the middle of it in a flowing hand.

  “So then, let’s start with the basics. To put it simply, for a space elevator—also known as an orbiting elevator—you build an extremely tall tower from the surface of the Earth into space, and then you use an elevator that goes up and down this to move people and materials. The transport cost by weight is so low, launching a rocket or a round trip with a shuttle doesn’t begin to compare. However…” Kuroyukihime’s finger moved, and an enormous cylindrical tower shot up from the round Earth.

  “Assuming the same construction methods as Tokyo Skytree, to build a tower that would reach up to space, the base area would have to be on a scale large enough to swallow up Japan entirely, like it is here. Constructing such a Tower of Babel is utterly and entirely impossible in practice. Here, we change our way of thinking.”

  The tower immediately disappeared, and next, a small square was drawn in space, far away from the Earth.

  “We build a station like this in stationary orbit thirty-six thousand kilometers away from the Earth. We then suspend from there a strong and lightweight cable toward the Earth. Since the speed of objects going around in geostationary orbit is basically perfectly synchronized with the rotation of the Earth, for all appearances, it never moves from that one spot in the sky above the Earth. Just as the name says, it’s stationary. Thus…” The line coming straight down from the square—the station in geostationary orbit—hit the Earth. “If you attach the end of the cable to the Earth, you get a tower like this. Or rather, a ladder that reaches from the Earth to space.”

  “Oh! I get it!” Impressed, Haruyuki slapped his knee with the hoof that was his right hand. But he soon furrowed his brow and popped his head sideways.

  “No, but…Hold on a minute. No matter how light the material is, if that cable is thirty-six thousand kilometers long and thick enough to set up an elevator in it, the total weight has to be incredible, right? They don’t pull that up and drop it on the Earth from the station in orbit, do they?”

  “They do!” came Kuroyukihime’s immediate reply, and he slid back in his chair.

  “That’s…”

  “As to how they do it, here’s how.” This time, she had a line stretch out from the top of the station and circled with her finger to draw a dot at the end of it. “All you have to do is stretch out a cable from the top as well and attach a weight to act as the center of the station’s load—its center of gravity, in other words. Once you do this, an upward vector is generated due to the centrifugal force of the rotating weight, and that balances the downward load the cable creates.”

  “Oh! I get it!” After being impressed once more, Haruyuki craned his neck yet again. “So where do they get this weight from?”

  At this, a meaningful grin made its way across Kuroyukihime’s lips, and some fairly unexpected words came out of her mouth. “The concept for this geostationary orbit space elevator actually was announced by NASA in the United States more than forty-seven years ago, in the year 2000. But at the time, it was projected for completion in 2062.”

  “Huh?! B-but that’s still…way ahead?”

  “Mmm. So why did they set a date so far in the future? Because in NASA’s plan, they were going to catch an asteroid passing close to the Earth and attach that to the tip of the cable stretching out above the station in geostationary orbit and use it as the weight.”

  “What?! They were going to catch an asteroid?!”

  “Exactly. The idea was that if they waited until ’62, a reasonable-size asteroid would luckily be flying by, and they would have developed the technology to catch it by then.”

  “That’s fifteen years from now, right?…Isn’t that kind of impossible?”

  “Mmm, it is.”

  Not understanding anything about anything, Haruyuki simply flapped his jaw open and shut. “B-but…The space elevator—Hermes’ Cord already exists, right! I’m pretty sure they finished it five years ago, so that would have been in 2042. So what changed?”

  “Well, that…,” Kuroyukihime replied as she wiped away the illustration in the window with the palm of her hand. “Compared with the initial concept model for the geostationary orbit space elevator I just explained to you, Hermes’ Cord
is a low-Earth-orbit space elevator, based on plans revamped from a more practical standpoint.”

  “Low-Earth…orbit.”

  “The basic idea is the same as geostationary orbit. But the scope is different. The central station for Hermes’ Cord is suspended much lower than geostationary orbit, two thousand kilometers above the ground…That said, it is still outside the atmosphere.”

  “Uh, um. Geostationary orbit’s thirty-six thousand kilometers, so…that’s like crazy close, isn’t it?”

  “It is. And because of that, the cable can be shorter and lighter, so you can get by without using an asteroid or something like that for balance.”

  “O-ohhh…I get it…” Haruyuki nodded deeply before giving voice to the obvious question. “So then why didn’t they just use this low-Earth orbit right from the start?”

  “Because this method has its own problems. In order for this man-made object inserted into low-Earth orbit—that is, two thousand kilometers above the ground—to gain the centrifugal force needed to balance against the pull of the Earth—which is much stronger than in geostationary orbit—it has to go around at a speed that far exceeds the Earth’s rotation. With geostationary orbit, the speed at which the station goes around is synchronized with the Earth’s rotation, so the end of the cable can be attached to the Earth, but that’s not possible with low-Earth orbit.”

  As she spoke, Kuroyukihime stretched out a finger and made a small mark in a spot fairly close to the circle representing the Earth.

  “This is the Hermes’ Cord central station, constructed in an orbit two thousand kilometers in the air. From this, a cable made from intertwined carbon nanotubes, or CNT, stretches out upward and downward to connect above with the top station and below with the bottom station, which act as weights.”

  The bottom tip of the line stretching out from above and below the mark was just a little separated from the outline of the Earth. Kuroyukihime tapped this gap with a finger and continued.

  “This bottom station hangs a hundred and fifty kilometers above the Earth’s surface. Any lower than that and the atmosphere becomes too thick, and the entire elevator would be pulled down because of the friction, eventually falling out of the sky.”