As Jin and his companions pondered how to measure such minute intervals of time, Elsa spoke up, having thought of a solution.
"Jin-nii, there is the fact that No. 700672 can measure ten-thousandths of a second."
"Ah, that’s right..."
Since they were in an emergency, she suggested they either ask him for his method or simply have him perform the measurement for them.
"Let’s do that for now."
"Mm. It’s better not to try and do everything on your own."
"That hits close to home... All right, I’m off."
Hanna stayed behind, deciding that she would help Elsa prepare dinner while they were gone.
Jin had Reiko carry the prototype and teleported to No. 700672’s location.
＊ ＊ ＊
"Oh, Jin-dono. Have you made some progress?"
No. 700672 welcomed Jin and Reiko with his usual composed demeanor.
Jin handed over the Persica juice he had brought as a gift and explained the situation.
"I see. Since predicting the occurrence of vibrations is difficult, you intend to deploy a barrier the instant they are detected."
"It’s a second-best measure, but yes."
No. 700672 praised the concept.
"No, I believe it is quite effective. So, what is the problem?"
"We can’t verify if it’s operating correctly. We lack a measuring device for that speed."
Jin explained the technical requirements in detail. No. 700672 accurately perceived his intent.
"I understand. I shall assist you with that."
"Thank you very much."
Thus, with the cooperation of No. 700672, they proceeded to verify the anti-space vibration magi-device.
Because No. 700672’s health would decline if he left the White Room, his adopted daughter, Neige, handled the field experiment.
Jin, Reiko, and Neige used a teleportation magi-device to head to the surface.
The afternoon sun reflected off the lingering snow, making the landscape dazzlingly bright.
Jin and Reiko placed the prototype on a flat patch of ground, and Neige positioned a measuring magi-device immediately beside it.
"Father, preparations are complete."
Using a magi-device similar to a manacam, Neige reported to No. 700672. A reply came back immediately.
『The setup is complete on this end as well. Jin-dono, you may begin at any time.』
Following Jin’s instructions, Reiko threw a small fragment of a magi-crystal and triggered a Mana Explosion.
Despite being localized, the blast was intense, accompanied by a deafening roar.
Since Jin and the others were protected by a solid barrier, they suffered no harm. The prototype was also unscathed, shielded by the barrier it had deployed itself.
However, the aftermath of the explosion triggered avalanches in the nearby mountains.
The heavy, low-frequency thundering unique to full-depth avalanches echoed through the air.
"Whoa..."
Jin paled at the sight.
"It’s all right. It’s nearly the season for full-depth avalanches anyway, so it would have happened sooner or later," Neige said with a calm expression, putting Jin at ease.
『The measurement results are ready.』
No. 700672 contacted them, and the group returned to the White Room.
"These are the results."
No. 700672 displayed the data on a screen embedded in the wall.
It looked remarkably like an oscilloscope.
Two lines were displayed; on one, a flat line suddenly spiked into violent oscillations before attenuating and returning to flat.
"This is the state of the space outside."
The violent wave represented the Mana Explosion.
"And this is the state inside Jin-dono’s prototype."
This was the area the barrier was meant to protect.
The waveform there rose only slightly from its baseline before immediately returning to flat. It had been successfully blocked by the barrier.
"The duration from here to here is approximately one-millionth of a second."
In terms of frequency, that was one megahertz—roughly the clock frequency of early personal computers.
When thought of that way, it didn't seem like much, but for someone like Jin trying to build such a device from scratch, it was a formidable hurdle.
On the other hand, for someone like No. 700672, who had mastered advanced magi-technology, it was trivial. After all, he could handle frequencies up to $10^{16}$... approximately 10 PHz, the frequency of gamma rays.
Technicalities aside, Jin felt a wave of relief at No. 700672’s words. He now knew the device was perfectly functional.
"Jin-dono, to have created something of this caliber in such a short period is nothing short of magnificent."
"Thank you."
Beside Jin, Reiko looked equally pleased.
"I feel like we might be able to manage somehow now. Though we still have a mountain of work ahead of us."
If it was simply a matter of labor, Jin felt they could handle it. The most difficult technical hurdle had been cleared.
"Ultimately, I want to prepare a Space Isolation Barrier large enough to cover Ars and the Moon."
"Indeed, that is a sound goal. In that case, since gravity would cease to act on objects within the barrier, you wish to keep the deployment time as short as possible."
No. 700672 correctly grasped Jin’s intention. If the duration of the Space Isolation Barrier’s deployment was too long, the orbit of Ars could be altered in unpredictable ways.
"However, will you have enough energy?"
Even for an extremely short duration, an object of that scale would consume an astronomical amount of free ether.
"For that, I’m thinking of utilizing the Free Ether Cloud."
"I see. I have heard the concept before; it is certainly a good idea."
No. 700672 praised Jin once again.
"I haven’t decided yet whether to use energy transfer or ethenol."
"Hm? What is this 'ethenol'?"
No. 700672 was unfamiliar with the term—hardly surprising, as it was Jin’s own name for it—so Jin gave a brief explanation.
"I see. Free ether dissolved in water made of magi-isotopes. How truly remarkable."
However, No. 700672 continued.
"The ethenol you have created is an energy source close to the ideal, given that it is a liquid rather than a solid or a gas."
He meant it was easy to handle.
Compared to energy sources on Earth: solids were like coal or charcoal, and gases were like propane. Liquids were like petroleum.
Liquids were easy to store in tanks, transport, and replenish, and their visibility made them manageable. Petroleum—the easiest energy source to handle next to electricity—was used widely on Earth in forms like kerosene, diesel, and gasoline.
Ethenol could be used in much the same way.
"Furthermore, the reason I would recommend ethenol is that we do not know what kind of influence space vibrations might have on energy transfer."
"Ah!"
Jin hadn’t considered that. Indeed, if space itself was warping, it was entirely possible for a transfer beam to be disrupted.
"I understand. Thank you for the advice."
"It is nothing. I am glad to have been of service."
Thus, having concluded a productive meeting, Jin returned to Hourai Island.