Four-dimensional space is different from three-dimensional space. Four-dimensional space refers to the standard Euclidean space, which can be extended to n dimensions. Four-dimensional space-time refers to a misunderstanding of Minkowski's concept of space.

As a three-dimensional object, human beings can understand four-dimensional space-time but cannot recognize and exist in four-dimensional space, because human beings belong to the third-dimensional creatures. Generally speaking, time is the fourth dimension, that is, the time dimension in four-dimensional space-time

The fourth dimension of four-dimensional space refers to a spatial dimension with the same properties as X, Y and Z, but the four-dimensional space-time is not a standard Euclidean space, and the essence of time is to describe the speed of motion.

2. Five-dimensional space:

Five-dimensional space is a space with five dimensions, which is the basic attribute of everything in the universe. From the physical point of view, the five-dimensional space has more dimensions than the three-dimensional space mentioned in daily life and the four-dimensional space in relativity. ?

Five-dimensional space is an abstract concept that often appears in mathematics. In physics and mathematics, the sequence of n numbers can be understood as representing the position in N-dimensional Euclidean space. ? Whether the universe has five dimensions is also a controversial topic.

Extended data:

The method of mutual symmetry and mutual transformation of time, space and level in five-dimensional space architecture. The five-dimensional spatial relationship of time, space and level is the basic attribute of the existence of cosmic things, and everything in the world exists in the five-dimensional spatial structure.

The structure of five-dimensional space is not static, but dynamic. The dimensions of time, space and level are not isolated but mutually transformed, and things develop through the mutual transformation of these five-dimensional spaces. Symmetry analysis of five-dimensional spatial structure is an essential basic method to understand things.

Baidu encyclopedia-Siwei space

Baidu encyclopedia-five-dimensional space