Is there anything named dimension?

There may be many dimensions.0,1,2,3,4...etc(according to current ideas).What ever it is,let us contradict higher and lower dimensions exists.now it is a true statement,such that it is a truth.Now let us think what might be its use?what was or is or will be its advantage? and why does it doesn't show really and provided a chance for our brains to think?(only true when our concept of dimension is true)

Do the higher dimensions( what we consider) have a high ability to show theory of conservation? or can it include the most complex structure and processes of universe? or is it which controls the uniqueness of elements and conditionally makes their conversion.Or are they highly unstable but productive?

Reasons have no bounds,but you can share your ideas.

Shadows of a dimesion

Due to the defect of human eyes,we are blessed to see a peculiarity in
the dimension of an object(opaque) and its shadow.We had seen the
shadows of many objects,but had you noticed any specialities?

Let me explain.
What is the shadow of a cubical box? a square.right? or a planar one.Okay?
Now whats the shadow of a squre lamina? or a bangle? a closed
string.Right? that is a closed line segment.

That is a 3-Dimensional object has a 2-Dimensional shadow,a
2-Dimensional shadow has a 1-Dimensional shadow and so on.That is if
the dimension of a body is 'n',the dimension of its shadow is'n-1'

So the 4-Dimension object must have a 3-Dimensional shadow.Even we
cannot give a perfect example there are still some indirect examples
which resemples their example.

1) Image of Rainbow in sky.
2) 3-D images created by interference and superpositioning of light
rays (laser shows).
3) Invisiblity of objects(air,water,glass etc...) even there are no
absolute black bodies in universe.