Simply put, a tesseract is a cube in 4-dimensional space. You could also say that it is the 4D analog of a cube. It is a 4D shape where each face is a cube.

If you’re an Avengers fan, the first thing that comes to mind when you hear the word “tesseract”:

For fans of the Marvel Universe, the Tesseract is the bright blue cube that not only people from Earth, but also from other planets are crazy about. That’s why all Avengers joined forces to protect Earthlings from the extraordinarily destructive powers of the Tesseract.

But let me tell you this: The tesseract is an actual geometric concept, or rather, a shape that exists in 4D. It’s not just a blue cube from the Avengers… it’s a real concept.

But before we explain a tesseract in detail, let us start from the bottom.

## What are “dimensions”?

I am sure that you have heard the terms 2D and 3D, which represent two and three-dimensional objects of space respectively.

A dimension is only one direction you can go in. For example, if you draw a line on a sheet of paper, then you can go in either the left/right (x-axis) direction, or in the up/down direction (y-axis). So we say that the paper is effectively two-dimensional, since you can only go in two directions on it.

Now in the real world, in addition to the two directions mentioned above, one can also go in/out. Therefore, in 3D-space, a feeling of depth is added. Therefore, we say that real life is three-dimensional.

A point represents 0 dimensions because it does not move in any direction, a line represents 1 dimension (length), a square represents 2 dimensions (length and width) and a cube represents 3 dimensions (length, width and height).

Take a 3D cube and replace each face, which is currently a square, with a cube. And lo and behold! The shape you get is a tesseract.

## What is a tesseract?

Simply put, a tesseract is a cube in 4-dimensional space. You could also say that it is the 4D analog of a cube. It is a 4D shape where each face is a cube.

A square is a 2D shape; therefore, each of its corners has two lines that separate at a 90-degree angle from each other. A cube is 3D, so each of its corners has three lines that separate from it. Similarly, a tesseract is a 4D shape, so each corner has four lines that separate from it.

## Why is it difficult to *imagine* a Tessseract?

Since we as humans have evolved only to visualize things in three dimensions, anything that is part of other dimensions, such as 4D, 5D, 6D, etc., makes no sense to us because we cannot visualize them at all. Our brain cannot make sense of a fourth dimension in space.

But just because we cannot visualize a concept does not mean that it *cannot* exist.

Mathematically, a tesseract is a perfect shape. Likewise, all shapes in higher dimensions, i.e. 5D and 6D, are also mathematically plausible.

Just as a cube in 2D space can be unfolded into 6 squares, a tesseract in 3D space can be unfolded into 8 cubes.

Incredible, isn’t it?

So a Tesseract is a real concept (which is mathematically absolutely plausible), and not just a bright blue cube, which they fight over in *The Avengers.*