# Zero-transportation in space

On the pages of science fiction novels, you can often meet with an almost instantaneous overcoming of huge cosmic distances, where "zero-transportation in space" - "jump" in space through millions and hundreds of millions of light years plays a major role. But what is zero-transportation in space and is it really possible? It turns out that it is based on rather interesting considerations.

To begin with, in one-dimensional space there is only one dimension - length and only two possible directions - forward and backward. In two-dimensional space, in addition to length, there is also a width. If we lived in such a space, we could come to a theoretical conclusion about the possibility of the existence of a larger number of dimensions, but the path to the next dimension would be closed to us. Exactly the same arguments are valid for our three-dimensional space, if it were enclosed in some even more extensive, four-dimensional space.

In three-dimensional space, there are three mutually perpendicular "basic" dimensions - "length", "width" and "height". If a fourth one could be added to these three directions, also perpendicular to each of them, then the space would be four-dimensional.

In a two-dimensional world, thanks to the presence of an external three-dimensional world, some phenomena, in principle, can proceed with the emergence of the third dimension. This circumstance in a number of cases makes possible such processes, which in the very two-dimensional world itself could not occur. For example, if you need to overcome the distance of 50 km between two points of the flat world A and B. Imagine that the two-dimensional surface is collapsed in three-dimensional space in such a way that the points of the beginning and end of the route turned out to be one meter apart. Now they are separated from each other by a very small distance, which can be overcome very quickly, making a "jump" in space. But this meter lies in the third dimension! It would be zero-transportation.

If the four-dimensional space and the way out to it really existed, surprising possibilities would open up, and a similar situation could arise in a twisted three-dimensional world...

As shown by the general theory of relativity, our world really has curvature. And if there was still a four-dimensional space in which our three-dimensional world is immersed, then to overcome some giant cosmic distances it would be enough to "jump" through the four-dimensional gap dividing them. That's what fantasy writers mean - in their works, zero-transportation is feasible.

In the theory of relativity, we are talking about the four-dimensional space of the universe. But this is not exactly the four-dimensional space that was mentioned above. The fourth dimension is time. The four-dimensional "space-time" of the theory of relativity is just a mathematical device that allows us to describe various physical processes in a convenient form.

So, zero-transportation, at least on the modern level of the development of science, unfortunately, is feasible only in the pages of fantastic novels.