"First of all, have you ever heard of dimensions?" the baron asked the two of them, "the so-called one-dimensional, two-dimensional, three-dimensional, and four-dimensional space. ”

As a man who has experienced nineteen years of education, Xavier naturally knows what the baron is talking about, even if he hasn't studied it, he should have watched various popular science videos, so he nodded and responded: "One dimension is a point, two dimensions is a line, and three dimensions is three-dimensional." ”

"As for the four-dimensional space, it's time?" he added uncertainly.

Hearing this answer, the baron shook his head at him, looked at Caroline, who did not answer, and continued: "There is no problem with your basic concept, but the four-dimensional space is not time, at least according to the definition of a magician. ”

Is it...... Xavier laughed self-deprecatingly, in fact, he didn't know very well, but in his previous life, he always heard someone say that the four-dimensional space is time, and over time, he believed it.

"What is that four-dimensional space?" he asked the baron.

Actually, the answer is very simple, well, let's start with the basic concept of dimension, which means how many straight lines you can make in a space. ”

"For example, a zero-dimensional space is a point, that is, it has no branches that can be perpendicular to each other, while a one-dimensional space has exactly one, and a two-dimensional space forms a plane, and a square can be made perpendicular to each other at 90 degrees. ”

Hearing this, Xavier tentatively responded, "That three-dimensional space can form a three-dimensional, such as a cube, with three lines perpendicular to each other. ”

The so-called x, y, z axes.

"Not bad. The baron smiled with satisfaction, "You can know a few other things by analogy from one thing you know, and this is the spirit of magic." ”

"As for the four-dimensional space, I think you can already answer, just extend it again in the same way you just did. ”

"So a normal four-dimensional space should have four lines perpendicular to each other......." Xavier replied softly.

In fact, this is a very easy concept to understand, even junior high school students can understand, but Xavier has never been systematically taught these concepts, and when the captain said this today, he naturally understood.

"But. Caroline, who had been listening silently next to her, asked, "Can this exist? Four lines perpendicular to each other cannot be imagined." ”

It should be noted that this aristocratic girl has not experienced Xavier's education, but she can easily catch up, and it can be seen that the aristocratic education in this world is really good for teaching in this regard.

Faced with the girl's question, the baron couldn't help but smile and responded, "So, we don't have to imagine it at all!"

"For example, hypothetical, I mean hypothetical, if there are living beings in the second dimension. They can only understand the two dimensions of length and breadth forever, and can they understand the dimension of height, which is added? No, in the same way, we cannot understand the fourth dimension that is added. ”

"But we can express dimensions mathematically, like through matrices, through vectors...... But that's another topic. ”

"Moreover, high-dimensional space can affect low-dimensional space through projection, such as the current piece of paper. The baron picked up a piece of paper from the table and replied, "I'm tearing it up now, this is to forcibly destroy the two-dimensional space in the three-dimensional space, if there are two-dimensional creatures in it, it will feel that the world is split in half." Of course, this is just a metaphor. ”

After listening to the captain's explanation, Xavier couldn't help but nodded, which was undoubtedly similar to the two-way foil's dimensionality reduction attack.

"The question now is, can people in the low-dimensional space in turn affect the high-dimensional space, or in other words, use the power of the high-dimensional space to attack enemies in the same space?"

"The answer is yes, because magic is such a means, or so is magic. The captain finally spoke this sentence passionately, and then told a story.

"A long, long time ago, perhaps when humans were just learning to use fire, there were some very clever ancestors who discovered that there was a magical power that could communicate with a strange being. ”

"Of course, we later learned that they were actually communicating with elements in a high-dimensional space and releasing them through projection. ”

"Anyway, thanks to their efforts, they have found a variety of effective methods, knowing how to summon the elements, projecting the elements from the higher dimensions, and the power that determines all of them is magic. ”

Hearing this, Xavier couldn't help but wonder, could it be that his own universe in his previous life also had these, but they humans lacked an important trait - magic, and in this world, magic can really exist and affect the entire planet.

If magic is used to communicate the elements, then what is the spiritual power used for?" Xavier thought to himself, and was about to ask a question, when he heard the baron answer what he wanted to ask directly.

"As for the spiritual power, it can be arranged, focused, and dispersed by these elemental projections summoned by magic, releasing them as energy and projecting them. ”

"According to the current speculation of magicians, the elements are roughly divided into four types, namely fire, water, earth, and wind, and perhaps many more, but we have not yet discovered them. ”

From this were born four types of magic, and the seals under them, witchcraft, and so on. ”

Well..... So magic is the foundation, and then mental power determines the upper limit of magicians, so my upper limit is actually quite high, right? I feel like a person who can win the Nobel Prize, but he can't even pass the college entrance examination to enter the university...... Xavier thought disappointed in his heart.

After explaining the basics, the captain let out a long sigh and sorted it out to make sure he was not wrong, while picking up the black tea next to him and taking a big sip.

"Then it's time for the most basic magic test. The baron put down his teacup and said, then took out a sphere beside him, with strange scales engraved on it, as if it had a piece of history.

"It's a magic instrument, capable of measuring your basic mana. The baron explained simply, and then asked Xavier to test it his way, "Xavier, please follow what I have just taught you, imagine that there is a three-dimensional space on top of the three-dimensional space, and there is a space of mind that cannot be understood by us. ”

Xavier's mind suddenly appeared with four axes, they were perpendicular to each other, although they could not be understood, but Xavier forcibly allowed them to exist temporarily, that is, it did not look like an angle of ninety degrees at all, and he also forcibly imagined that it was ninety degrees.

"Next, try to use the power of your body, feel the presence inside, see if you can communicate with it, summon it!" the captain said to Xavier, based on his own experience.