Creating new theories about dimensions is a hard and difficult process because everything must prove by calculating.

  

Creating new theories about dimensions is a hard and difficult process because everything must prove by calculating. 

One of the greatest theories after the Theory of Common relativity is the "Great String theory". In that theory, the key element is that there are one-dimensional strings across the dimension. And those strings are interacting with together. 

So the thing is that the sting, what has one-dimensional structure should be the point, what travels across the universe. In this case the one-dimensional would mean that the string has only length, but not width. The two-dimensional string would have the length and width, and this is the thing, why we have very hard to imagine the form of the string. 

Writing about the dimensions is quite difficult because we cannot make anything else than 3D-models in our dimension. All forms that we are trying to make for demonstrating other dimensions are wrong because we cannot draw the line, what has length, but what has not width at all. And this is the reason, why we must always calculate the angles and other forms of geometrical forms.

When we are drawing the line to paper, there is always width, length, and height because the line of the pen would rise above the paper. So this is the difference with virtually one dimensional and natural one-dimensional line. The in the real-life one-dimensional line must have only the length, but there should not be the body of the line at all. 

If we are thinking that M-theory is a theory of everything, we must always remember that there is always the area, which is so special that the common theories are not fit in that thing. One of them is the black hole, which would curve space and time.

If we would try to create the model of the string, we would draw the line to paper, and suddenly we are facing one of the most interesting things in the geometry. That line is only virtually one dimensional. It has length and width because the pen that is used in the drawing process has an area in the head of it. So why the string theory is interesting? If we think the strings as the things, that are traveling across the dimension, we think that the strings can keep our universe in the form. 

When we are thinking about the difference between the Universe and Dimension, we are not talking about the same thing. If we would create the spacecraft, what is fast enough, it can fly outside our universe, what is the ball-form hypergroup of galaxies. So the dimension continues long behind the farthest galaxy. And our universe is only an area in the thing, what is called as dimension. 

Sources: 

F-Theory:https://en.wikipedia.org/wiki/F-theory

M-Theory: https://en.wikipedia.org/wiki/M-theory

Heterotic String theory: https://en.wikipedia.org/wiki/Heterotic_string_theory

Phys.Org article: https://phys.org/news/2019-07-physicist-loose-thread-theory-puzzle.html

The duality between F- and heterotic string theories: https://scitechdaily.com/explaining-everything-mathematicians-unravel-a-thread-of-string-theory/

Image: https://phys.org/news/2019-07-physicist-loose-thread-theory-puzzle.html