In the ancient ruins of Qingshan Temple in Fanyu Village, Ji Haotian chatted with three men for a while, then flew out of Qingshan Temple Valley and came to Shuangshanjiangu, another valley in Fanyu Village.

Shuangshanjiangu is the largest and deepest valley in Fanyu Village. It is located at the foot of Shuangshanjian, the highest peak of Fanyu Mountain, so it is called Shuangshanjiangu, or Shuangshanjian for short.

Ji Haotian stood at the foot of the peak of Shuangshan, the highest peak of Fanyu Mountain in Fanyu Village, and looked around.

Not long after, a yellow man in a blue robe flew out of the forest at the top of the mountain and landed in front of Ji Haotian at the foot of the mountain. His cultivation was the same as Ji Haotian, and he was also in the supreme realm.

What surprised Ji Haotian was that there were many rare and rare space-dimensional divine crystals in the multiverse of this person's body. Obviously, this person had a lot of adventures.

The space-dimensional divine crystal was born in a high-level space-dimensional energy field, which is quite rare. Ji Haotian only has only a few dozen pieces, far less than the blue-robed man. He saw that the blue-robed man went to a high-level space dimension, only this adventure.

Spatial dimension: each dimension is a trivial section of a higher dimension, if the multiverse of the four-dimensional world is divided into endless three-dimensional spaces according to certain rules, then each of these three-dimensional spaces is a closed space structure, is an independent three-dimensional multiverse. In the eyes of these four-dimensional creatures, countless legendary stories are staged in the insignificant "three-dimensional membrane", and then countless civilizations have created their own epics in these "membranes".

Although the four-dimensional world is filled with the three-dimensional world, the matter in the four-dimensional multiverse and the matter in the three-dimensional multiverse are independent systems that do not interfere with each other, and are spaces that overlap and can exist at the same time. And the relationship between the four-dimensional world and the fifth-dimensional world is the same as three-dimensional and four-dimensional...and so on to infinitely higher dimensions. The multiverses and various fields mentioned above belong to the three-dimensional space, and the three-dimensional worlds outside the multiverse are all in the sandwich between different three-dimensional multiverses (these sandwiches are also contained in the four-dimensional space occupied by the four-dimensional multiverse. , and is just another form of "three-dimensional membrane" for four-dimensional space).

For living beings living in two-dimensional space, three-dimensional space is the whole superimposed by infinite layers of two-dimensional space. The two-dimensional world has always existed in the three-dimensional world, but the latter has one more coordinate axis than the former. If you make a two-dimensional creature move along that coordinate axis, that is, let it move in a direction where the two-dimensional world does not exist, then for it, it is just traveling in infinite planes, in countless two It's just a flash in the dimensional world, and it can't make it see the whole picture of the three-dimensional world (if it is made to observe a three-dimensional object, then it only sees the edge of an infinitely thin section of that object), although it is also in the in the three-dimensional world. Isn't that the relationship between three-dimensional creatures and the four-dimensional world? The so-called "going from three-dimensional space to four-dimensional space" is nothing more than moving in a direction that exists in four-dimensional space but does not exist in three-dimensional space, and then crosses countless cross-sections of four-dimensional space (three-dimensional space).

Sometimes, humans use pieces of paper to compare two-dimensional space, and compare the three-dimensional figures formed by stacking these pieces of paper to three-dimensional space. relation. What is the three-dimensional image of a two-dimensional creature? Maybe it will also use the method of analogy to compare the lower dimension with its own dimension, and roughly understand the concept of "three-dimensional", but its two-dimensional brain has a three-dimensional image that cannot present three-dimensional objects (fact On the other hand, what our three-dimensional brain presents is only a flat image, and the images in paintings and photos can also be understood as two-dimensional images, but the visual effect creates a three-dimensional sense of space.

In the eyes of two-dimensional creatures, the world is a straight line connected by one-dimensional line segments. These line segments are actually the edge parts of different plane figures. All they see are the edges of those two-dimensional objects, just like when looking at the thickness of a thin film, except that objects in that world have zero thickness and are solid to two-dimensional creatures. In the true sense, it is the creatures in the four-dimensional world that can see the "three-dimensional image". Every angle, every position, and the structure of every layer of a three-dimensional figure is completely exposed under the gaze of a four-dimensional creature, while a three-dimensional creature can only see the surface of an opaque three-dimensional object. ).

Make a straight line perpendicular to it on a two-dimensional plane, and then place a plane penetrated by the straight line at each point of the straight line. The whole composed of countless planes is three-dimensional space. Although some two-dimensional creatures understand that the three-dimensional world is actually the product of the superposition of the two-dimensional world, all they can do is imagine many scattered plane figures, and then piece them together into a larger two-dimensional figure, which is impossible to break through. Its own level, superimposing two-dimensional in the direction of three-dimensional. The same is true between three-dimensional creatures and higher-dimensional worlds. Human beings have tried all kinds of methods to describe the specific images of four-dimensional objects. They can only use analogies to help themselves roughly understand.