Tensei Shitara Ken Deshita - Chapter 92

I was listening to the audio book for this arc (from the web novel version) and this part of the battle was very unclear. Definitely, no detailed explanation about the mechanics of the sword technique. This is fascinating that this sword tech explanation is coming back too.

Ever since Zoro of One Piece invented the idea of simply screaming-fancy-name style of sword tech, it seems like this old style of actually trying to explain things have gone away. It’s cool that someone is trying to revive this.

I believe the first artist to do this for swords, not magic, is Dragon Quest: Dai’s Adventure. In that manga the original hero, who was the protagonist teacher, created 3 sword styles which he name the Earth-style, Sea-style, and Sky-style. And when combined they can be used to create the ultimate sword tech, Avan Slash which was further divided into A and B styles. Anyway, part of the fun of reading DQD was him recovering these old sword techs through the adventure since he only learn the Earth and Sea in the prologue before the old hero was killed but who turned out to have been resurrected.

I believe the mangaka in this chapter is trying to recreate the Sea-style of the the hero’s sword techs but using the image of *air* instead of “water.” If I am right, the original Kanji is probably “VACUUM” and not air which funny enough is the same kanji because they are all the same kanji as “sky” or “sora” but they all have different hirogana designations. Sadly, i don’t remember what the others were. So, don’t quote me on this.

What happens when an object falls is that a high pressure is created at the bottom of the object and a vacuum (or lower pressure) is create at the back. This actually slows your fall and is the source of “terminal velocity.” The faster you fall the greater the differential and so this mechanism slows you fall due to the negative pressure “vacuum” until the gravity balances against this

That’s why the direction of the flow is going into the sheath and out. However, since this is a world of magic, the Master hypothesizes that he can work this process in reverse and create at vacuum at the front of the sheath and a boost at the back by reversing the flow. And this should increase the sword speed tremendously. Fast sword is the Hero’s Sea-style’s basic component. So, this can be named “Vacuum Sword”

Now, there is already a sword-man in manga history who utilizes “Vacuum Sword” but his is explained through pure physics: Imaginary pure physics of course since no human can possibly do this. But its still better than screaming imaginary physics, right? That person is Kenshin in Ruroni no Kenshin (aka Samurai X). He also has a vacuum sword draw technique, and I suspect this is the one that this mangaka was actually thinking of and not Dai’s Hero Sea-Style.

In this version, the way it was explain is just pure human speed of the draw, but all the speed is at that instance of the first draw which is impossibly fast that it creates a vacuum, technically a space with nothing in between the scabbard and the sword protector. It’s technically not a “vacuum sword” but a “space distortion sword draw”.

You see, this is what happens when you are a Chunibyo. You end up studying physics to try to recreate these sword techs, and sometimes even magic-tech.

Don’t underestimate the imagination power of the mangakas. One of the tech I was trying to figure out was the instant-double-punch of the Sagara Sanosuke, also in Rurouni Kenshi (Ni-Chou-no-Ken). I was trying to use this idea to calculate what happens when you fire off two atoms (or photons) at say a wall or a mirror, but one at a slower speed and the second one higher thus it has a chance to catch up. Obviously, you can’t do this with photons as I later learn because photons only travel at one speed so there is no catching up. But, with atoms, who knows maybe this is all you need to create fission without having to accelerate them to too high of a speed.

Anway, this thing turned out to be very useful in studying materials and had already been invented by others called double two point correlation analysis. So the atoms are phonons and the “wall” is a probe in this case. Sadly, you can’t shatter walls with this method yet, but maybe one day.