Chapter 1980: The Truth of Space

"Do you understand the dragon language?" The old man didn't answer Jiang Fei's question directly.

"Understand a little." Jiang Fei replied, he had worked hard in this area before.

"That's good, it's hard for me to express clearly in human language..." The old man changed to communicate with Jiang Fei in dragon language.

Because Jiang Fei had studied the language of the dragon clan for a period of time, he could completely translate the words the old man said next into his own language and understand them.

"What do you understand about space?" The old man asked, and Jiang Fei automatically translated the dragon language into words that he could easily understand.

"Space? I know that we live in a three-dimensional space, and there may be creatures living in a higher dimension than us." Jiang Fei said, but in his heart, it is no longer possible that there are creatures in higher dimensions, because the gang The guy has invaded this universe!

"By the way, senior, is the fourth dimension of the four-dimensional space time?" Jiang Fei suddenly thought of a question.

"Of course not!" The old man shook his head, and then said to Jiang Fei: "Time is a special vector, there is time in one-dimensional space, time in two-dimensional space, time exists in every dimensional space! Time Space and space are two different concepts!"

"That's it!" Jiang Fei nodded.

"Okay, now that the relationship between time and space has been explained, can you tell me the relationship between various spatial dimensions?" The old man nodded, and then continued to ask Jiang Fei in the dragon language.

"Relationship?" Jiang Fei was taken aback, he didn't understand what the old man meant by asking.

"Okay, let me tell you from the beginning." The old man sighed, and then said to Jiang Fei: "The so-called one-dimensional space is a straight line. If there are creatures on this straight line, then in its perspective, There are only one point at the front and back, and it can only move forward or backward."

"Innumerable straight lines form a plane, which is the so-called two-dimensional space. Creatures in this space are no longer restricted to moving in straight lines, but can move freely up, down, left, and right." The old man continued.

"En! That's true!" Jiang Fei nodded. The old man's description coincides with the knowledge he has mastered in the world of science and technology. Although the names of space dimensions in the dragon language are not the same as those of the outside world, they correspond to each other. is a meaning.

"The three-dimensional world we live in is actually composed of countless planes. Layers of two-dimensional worlds are superimposed to form the three-dimensional world we live in." The old man looked at Jiang Fei at this point, and then He continued: "So it is conceivable that the four-dimensional space is actually formed by the superimposition of countless three-dimensional spaces."

"What is the four-dimensional space like?" Jiang Fei asked curiously.

"To talk about this issue, we have to start with our cognition of space." The old man paused here, and then continued: "I don't know if you have discovered that our observation of the world is actually through dimensionality reduction." way."

"What do you mean?" Jiang Fei was taken aback.

"Give me an example." The old man stretched out his hand, and a ray of light appeared in midair.

"This is a straight line, which represents a one-dimensional space. If there is a creature living here, then in his eyes, there is only one point in front and one point behind, which represents the creature living in one-dimensional space. , he can only see a little bit." After the old man finished speaking, he waved his hand, and the light in midair disappeared, replaced by a wall of light.

"Look, this is a plane, which represents a two-dimensional space." Then the old man waved his hand, and many patterns appeared on the light wall, including squares and circles.

"If it is a creature living on this plane, from his perspective, he can't actually see these squares or circles. All he can see is a line facing him." The old man waved his hand again after finishing speaking. , the light wall disappeared, but replaced by a solid wall.

"We live in a three-dimensional world,

Now look at it from your perspective, what's in front of you? "The old man asked Jiang Fei.

"A wall!" Jiang Fei said as a matter of course.

"Well! That's right! But it's also a plane! You can't see what's behind the plane at all, because you are a person in the three-dimensional world, so you can only see the plane in the two-dimensional world." The old man said.

"No! I can see three-dimensional objects, such as this ball!" Jiang Fei said and took out a ball from the ring space.

"Hehe, that's just the answer you subconsciously made up based on a lot of relevant knowledge..." The old man said as he took the ball from Jiang Fei's hand, and with a wave of his hand, the surrounding light instantly dimmed At this time, in Jiang Fei's eyes, the ball only had a faint round shadow left.

"You see, after losing the contrast between light and dark, your brain can no longer perform calculations, and the real image you see in your eyes is just a circle." The old man laughed.

"So that's how it is..." Jiang Fei nodded. It turns out that the three-dimensional world in his eyes is just a supplementary result calculated by the brain based on the knowledge of light and dark contrast and near distance and distance after the two eyes send back two-dimensional images.

"So, a person in a dimensional space can only perceive the space he is in by reducing the dimensionality, and he cannot see the true face of the space he is in!" The old man finally gave a conclusion.

"So that's it!" Jiang Fei nodded. No matter how charming the scenery in the picture is, all the creatures in the two-dimensional space can see are just straight lines, and the colorfulness of the three-dimensional world is nothing in the eyes of people. It's made up of stitching pictures one by one. Although this answer makes Jiang Fei a little bit disappointed, it is the truth.

"So you understand." The old man smiled, and then continued: "The so-called four-dimensional space is the product of stacking countless three-dimensional spaces. Of course, this kind of stacking is not as simple as building a house with bricks. It is still a three-dimensional world, and this stacking is structured in a way that we cannot understand. People there can see through our world just as we see through the essence of the two-dimensional world; 3D images, and because we cannot observe the real 3D world, we have no way to describe their world.”

"Could it be that those of us in the three-dimensional world can't even imagine what the four-dimensional world looks like?" Jiang Fei asked.

"No!" The old man shook his head, and then said, "But I discovered something interesting, which may help you solve some mysteries."

"What's interesting?" Jiang Fei asked immediately.