Isekai Taneuma

We live in four-dimensional space-time with three spatial axes of vertical and horizontal height and one temporal axis.Most people will know this as knowledge and intuition, but perhaps few people can explain exactly why space and time are integrated.

However, if you link Einstein's theory of special relativity, I think you can understand it if you have high school mathematical knowledge, so I will omit it here.Since it is undoubtedly one of the most beautiful theories in the long history of physics, it is much better to read one or two of the commentary books that exist in the alley than to receive a shitty explanation.So anyway, all you need to know is that our world is in four-dimensional space-time, represented by three spatial axes and one temporal axis.

Now, we live in such four-dimensional space-time every day, but when it comes to whether the universe also exists in the same four-dimensional space-time, it seems to be different.Strangely enough, there are ten dimensions of space-time in the universe, and we seem to recognize only a fraction of it.

How do you know that?That said, it's not really clear that it exists... but since the 20th century, as science and technology progressed, we've found evidence that it's convenient to think that the universe has more dimensions than four.

It was pioneered by the Karza-Klein theory, an integrated theory of electromagnetic forces and gravity.The integration of electromagnetic forces and gravity was a very difficult problem, and even Einstein, who had been working on it for a lifetime, could not solve it.Theodore Carza said that it is possible to unify space-time in more than five dimensions.

But what does it mean to bring out something you don't know about five-dimensional space-time?That's a bit difficult to explain... but in physics, it's very important to integrate those forces.

The universe is thought to have begun with one point, so it would be strange if all the particles present in the universe were not integrated back in time.Gravity and electromagnetic forces (strong and weak) were all the same at first.But even if you think about it in four-dimensional space-time, they're not very well connected.

However, if we think that there is more than five dimensions of space-time like Karza, it is likely to work.Therefore, the theory of surplus dimensions was thought to be just a mathematical play at the beginning, but gradually became accepted.

And finally, a superstring theory was born that thought that the universe was made of 10-dimensional spiders.I wonder if this name will accept the Nobel Prize winner and those who were half-hearted in the high dimension....

This superstring theory, by the way, is still an excellent theory in the 21st century, but it is not a theory of all things.Because, after all, no one can confirm whether there is really time space in more than five dimensions.Because we live in four-dimensional space-time, and it's impossible to recognize the space that deviates from it.

Let's forget about time and think about three-dimensional space and four-dimensional space.

We can intuitively understand a three-dimensional space, but even a four-dimensional space can't imagine what it is.I know the vertical, horizontal, and height, but which direction is the four-dimensional axis?You can't even imagine what the space is like in your head.However, a theory based on the assumption that it exists is hard to accept.

But still, the universe is in ten dimensions, so it seems like a lot of people are deciding.Perhaps this will not cover us in the future.We live forever without being able to recognize it, knowing that there are six more dimensions in addition to the four dimensions of space-time that we can recognize.It doesn't feel refreshing, like a fish bone in my throat.

... but we certainly can't recognize the four-dimensional orientation, but we can understand it.When things are complicated and you can't understand them, you just have to simplify them and think about them.

For example, residents living in two-dimensional spaces should not be able to recognize three-dimensional spaces so that we cannot recognize four-dimensional spaces.So first of all, if we think about the feelings of the inhabitants of the two-dimensional space, we will know what lies ahead.

Mr. Delta, who lives in Flatland, is a two-dimensional resident.

Flatlands are not tall and have only two spatial axes, vertical and horizontal.If you think of the drawing paper, there is no doubt about it.Mr. Triangle is a person who is wandering around in his flat picture paper (Flatland).

Then Mr Square came from afar.Mr. Triangle and Mr. Square are friends of the bamboo horse, but even if they come close, they don't know each other.The way Flatland residents look at each other is because it's just a line, so you can't get close enough to know who it is.

So in order for Flatland residents to know each other, they have to touch each other and see what it looks like.Mr. Triangle circled around and touched Mr. Square's body, knowing that there were four corners there, he said, "This is Mr. Square."In the same way, Mr. Square touches Mr. Triangle's body and decides, 'This is Mr. Triangle', and they finally realize that they are friends with each other.Very detour, but this kind of communication is common in Flatland.

On such a flatland, one day, Mr. Sphere came to play from a three-dimensional world.

Sphere tries to "go up and down" through flatlands that are only vertical and horizontal.How does Mr. Triangle look when he happens to see it in front of his eyes?

The moment Mr. Sphere touched Flatland, it would appear that a dot had appeared to Mr. Triangle from nowhere.As the sphere passes further through the flatland, his body, which was initially visible as a dot, gradually turns into a large circle, the circle being the largest at the mid-point just as the sphere passes through the flatland, then gradually smaller, and finally disappearing as a dot.

In this way, a two-dimensional dweller should look like a strange object that changes in size, emerges, or disappears.

Regardless, Mr. Triangle was surprised at the emergence of three-dimensional residents and said, "Who are you?'. Then Mr. Sphere says, "I am a sphere."Triangle couldn't understand the sphere and said, "Circle?'. "The circle is a part of me," replies Mr. Sphere.

Sphere says to Triangle."I can't expose everything to this world, so I can only see a part of my body."Still not convinced, Triangle said, "Where are you from?'' said Mr. Sphere, 'coming from above.'However, Mr. Triangle does not know the "upper" direction.

Top is vertical or horizontal? It may be strange for Mr. Triangle, but even if he asks, it is only up for Mr. Sphere. Up is up I don't know.Right or left?"" Neither right nor left. "" North or east?

After a conversation that didn't mesh with him, Spherical finally got impatient and had a tantrum. It's this way up there Sphere pulled Triangle's body and jumped out of Flatland.

By jumping out of Flatland, Triangle found out for the first time what the sphere looked like.

"Is that what you were in?"

And from the three-dimensional direction, he was able to overlook the flatland that he had lived in.There lived a lot of friends, Mr. Square, family and friends, but it was clearly different from what he was always seeing.

"I can see the contents of the human body."

Usually I can only see a line, but now I can see the full contents of the body tied to that line.By jumping into three dimensions, Triangle became uncomfortable realizing that he was also completely visible in his body.

"Did you see everything?"

Eventually, when he returned to Flatland, Triangle left Sphere and returned home, recalling his exciting three-dimensional journey.This world is not closed in two dimensions, but outside it is a three-dimensional world.He wanted to tell his family and close friends about it.But no matter how much he explains, no one will believe him.

You say that there are three dimensions, but which direction is the three dimensions?

It's up, it's up!

... this is a novel by the nineteenth-century poet Abbott called "Flatland", but it is suitable for explaining the high dimension that is difficult for us to understand, so it is often quoted.

When we imagine the inhabitants of a three-dimensional space as a four-dimensional space, we should think the same way as this pathetic Triangle.Like Mr. Triangle, we can only see the outside of man.If a four-dimensional presence appeared before us, it would appear as a weird object that changes shape with time, as the sphere looks like a variable circle.We cannot recognize what it looks like in general, being trapped in three-dimensional space.

However, if it jumps out into four dimensions, you can understand what it looks like.And we're surprised to see the three-dimensional world we've been living in."I can see what's inside of you."It's not like you can see a human specimen stuffed with organs, it's like all the molecules that make up the human body at first glance.Every molecule that makes up us is connected in four dimensions in the micro part.

However, when we intuitively understood the four dimensions, we also lost sight of them the moment we returned to space in the usual three dimensions.Which way is the four-dimensional direction?That's probably because Mr. Delta said, "Up you go!Like I said, I can only say that it is four-dimensional... We should have understood that there are four dimensions, but we can't explain it with our mouth.

Well... I've been explaining it for a long time, and all of a sudden I started talking about things like four-dimensional space, because I recently saw an anime that deals with surplus dimensions.I don't know what the title is... but one day oniisama will be attacked by a virus or something coming from a higher dimension.

Oniisama and her allies use their instincts to attack, but we don't know where the enemy is coming from.I'm poor as it is.Gradually, there's a rush.And at that time, my friend's glasses said, "That way!'. Then, a hole like that created by some skimmer monster was punctured in the eyeglasses pointing at it, and a strange radio wave popped out from it.

This strange radio wave coming through the skima is an attack from a high dimension, but now that I've heard Flatland's story, do you realize that this is strange?

As the contents of the residents of Flatland were visible to Mr. Triangle, who jumped out in three dimensions, the contents of our three-dimensional creatures were visible from the surplus residents looking over the three-dimensional space.In that case, it would be more efficient to aim directly inside the body without passing through the skimmer.

Let's go back to Flatland and think about it.In this one-sided situation, if you were Mr. Sphere, how would you attack Mr. Delta?For example, why don't you bring the magnifying glasses and sit in Flatland's Triangle's head and collect the sunlight.I'm sure Mr. Triangle will die without realizing who attacked him or how.High-dimensional attacks are irrational.

That's why it's a mistake to say that if you're attacked from an extra dimension, the skyma of space opens up in this world.Having said that, I do not mean to say that the skimmer is bad.Since it is more persuasive to show something like that as a video than to explain the invisible force in the mouth, I guess I had no choice but to do it in the production.If I were a director, I would still choose the same method after all the trouble.That's why I'm not going to criticize Skima.

Speaking of what I want to say, the protagonists of this story... Feng and Jeanne are subjected to such irrational forces on a daily basis.

And if there is a "God" outside the four-dimensional universe where we live, how unilaterally and enormously powerful it is... I hope you understand that at all.