The Fourth Dimension

  Scientists proved that fourth dimension really exists. The idea of adding fourth dimension began with Joseph Louis Lagrange in the 1700s and formalization of concept in 1854 by Bernhard Riemann and also in 1915 Einstein's theories of special and general relativity.  

  First, we have to know- What is dimension?

Dimension is a direction which we can picture as a line. In the photo there are 4 types dimension which we think that we know about them.

    

A point is zero dimension and if we have 2 dots and combine them, we will have line is a  one dimension. We can only move right and left depend on the direction of line. If we stretchthis line , we will have square. The square has 4 side. We can move right, left, forward, back. It is 2 variable because square has width and length. If we drag this square, we will have cube which is combine 6 square. It is 3 variable because cube has width, length and volume. So if we drag cube, we will have new figure.

Here fourth variable is time. It combine 8 different cube. We can move every side and definite time.

Now I want to explain How 3 dimensional sphere impact and passing through 2 dimensional Flatland. 

 This idea created by Edwin Abbott in 1885 who was student of W.Shakespeare. This concept means in 2 dimension everything is flat and there is no idea about up and down. 

 So here square is in 2 dimension and sphere is 3 dimension. Sphere can see middle of square and all 2 dimensional system, but square can't see it. If sphere want to go 2 dimension, square see sphere that suddenly something appear and its size change when sphere move. It is also shadow of sphere in 2 dimension. We are living 3 dimensional system. Then the projection of sphere is circle for us. But for 2 dimensional creature it will seen point and line when sphere move. 

 This assumption make idea about 4 dimesional. It means that we can make the shadow of 4 dimensional figure in  3 dimensional system. 

 Here the shadow of 3 dimensional cube in the 2 dimensional. We can easily see that, all side of cube is equal but shadow is not equal. So, it means that shadow form of figure have mistake about size. Using this figure, scientist find the shadow of 4 dimensional figure in 3 dimension. 

 This figure called Tesseract or Hypercube. I can't show you tesseract because we are trapped in 3 dimension. But i can show you shadow in 3 dimension of 4 dimensional hypercube. In reality all side of hypercube is equal but not in the shadow as a cube. 

                                                                                                                

And this photo is open form of cube and hypercube

For some assumptions, in 4 dimensional system we can touch the inside of figure without to touch outside. It makes some ideas; human body, our organs is active without something influence or some illness suddenly occur. If we can move it means that time is exists. So are we 4 dimensional creature living in the 3 dimensional system? These types of unknowns things occur a lot of questions.
  
 You can also get information about dimension from  "Intersteller" film which is film of Christopher Nolan. You can watch from this link: https://123movies.la/movie/interstellar-6y7je2y/watching.html

"The cosmos is within us. We are made of star-stuff. We are a way the universe to know itself."

          Carl Sagan

Resources;https://www.youtube.com/results?search_query=carl+sagan+4+dimension

                      https://www.youtube.com/watch?v=-TNvUCOTDlQ

                    https://en.wikipedia.org/wiki/Four-dimensional_space