One-dimensional space is a line. Two-dimensional space is better understood. These are two lines. These two lines intersect. In which a space having a width and a length is formed. Just like our rectangles, squares and circles. Simply put, two-dimensional space is a world with only one plane. Scientists say that ants can best express this two-dimensional space. Because ants see a flat world. Because in this world, no matter what animals you meet, you can only treat them as an airplane.
For example, ants look at human beings and see people like posters, not three-dimensional people with noses and eyes. But why can humans and other animals see ants or other animals? Actually, because we are all three-dimensional. There is another thing in this three-dimensional space. It's depth. The appearance of this depth makes us stereoscopic, we can touch everything, and we can see the difference between the back and the front. Special relativity unifies space and time, which is called four-dimensional spacetime. Time and space are no longer independent. In some cases, time and space dimensions can be compressed, lengthened or even interchanged.
With the development of scientific theory, scientists began to think that there is no higher dimension except four-dimensional space-time, and there is an essential difference between time dimension and space dimension, so it is generally not called multidimensional space, but multidimensional space. Many novels and movies also mention the concept of multidimensional space. The mathematical model of multidimensional space is to add dimensional variables, but it is difficult to refer to physical concepts. For example, the famous Calabi-Qiu Cheng cave space is a six-dimensional space mathematically proved by mathematician Qiu Cheng Cave. Calabi-Qiu Cheng cave space is a dormant high-dimensional space, which physically predicts the existence of Planck scale space, so it is impossible to detect the existence of this space by physical means at present.