Here is a gist of an email conversation that happened between Srinidhi and Narasimhanna. You are welcome to participate in the discussion.
Srinidhi wrote:
Peddappa, can you explain what fourth dimension is?
Dear Srinidhi,
I can and I will. It is better when we meet and talk.
In simple terms, dimension keeps track of the number of `factors' we have to keep in mind when we are thinking about any particular matter.
When you walk in a straight line (or when you write), there is only one direction. That is one dimensional.
When we paint a picture or see a picture in a plain paper, there is both length and breadth. So two dimensions in this case.
The space we all exist at any given time has three dimensions : there is length, there is breadth and there is height. The house we live in is in three dimension; the cake you eat has length, breadth and height.
But if you think a little carefully, we really live in four dimensions : we live at a particular place (that is, three dimensions) and at a given time (that is an additional dimension, the fourth one).
All the changing events you see (like your eating, a plane flying, earth rotating, etc.) take place in four dimensions. Just as it is important to know
(i) the length when you buy a string (MALTHADU),
(ii) the length and breadth when you buy a piece of cloth,
(iii) the length, breadth and height when you choose a cake to eat,
when you think of the stars or galaxies, you should think of not only the position of that object but also the time of its existence.
Think of this fact, I was amazed when I came across as a teenager. Many rays of light that is falling on you now (as you are reading this) originated from stars which no longer exist!
When they started, perhaps even our dear sun, let alone our life sustaining earth, did not exist!
It is like you coming across a gift today in your backyard from your fathers, fathers, fathers,... (200 times over)]
So in thinking about such long time phenomena, we should keep track of not only space but also time. You can think of many situations where this may be necessary as thinking about both the length and the breadth is necessary when you are buying a bedsheet.
Think of this: Mudiyanur inhabited by Subbaiahgaru is different than the Mudiyanur inhabited by Subbanna. The space is the space, but time is different.
Think about fourth dimension. I will explain to you some time later why it is important to think of 5 dimensions, 6 dimensions, 7, dimensions, etc.
-Yours affectionately
Narasimha
Srinidhi Wrote:
Peddappa, I understood this. I am eagerly waiting for what is 5th, 6th, 7th etc.,.
Dear Srinidhi,
As you see, we use `spaces' to describe things. Dimension of the space chosen depends on the things we want to describe: dimension one if it is a string, dimension two if it is the site you want to purchase, dimension three if you want to describe the size of the ball you want to describe, dimension four if you want to describe the position of a planet, etc.
But you see, each dimension corresponds to an important feature (`parameter') of the object we want to describe. You can easily imagine many objects/situations where more than four important features are need to describe the object effectively.
Here are some examples:
A. In describing an iron furnace at any given moment (the one used to manufacture iron, like the one in Bhadravathi), the following factors may have to be specified: its temperature, pressure inside the furnace, the quantity of ore inside it, the number of years it has been in use (its age, if you like), the amount of power available to it, number of staff operating that, etc. So you see in describing this we need to keep track of several dimensions.
B. To describe the Bangalore Bus transport system on any particular day : the parameters could be, number of buses available, number of routes, an average number of potential passengers in each route, number of drivers available, number of conductors, amount of fuel available on that day, etc.
The same for a description of Air lines.
The description of the economic profile of a family also needs many dimensions!!
I am sure you can make up many more examples. But, any way, I suppose you get the idea. As the society gets more and more complicated, it is necessary for accurate descriptions (at least as accurate as we can and use that usefully) of various situations.
So, you see, description of space is very important in human life and that is why it has played such an important role in all societies (modern, primitive). The subject that studies it is Geometry. That is why from the old civilizations ( like Aryans, Egyptians, Greek) to the modern era, Geometry is at the core of human thinking and has been very useful.
These days, the computers and Information Theory people are fast developing appropriate geometries to suit their needs.
But the GREATEST ATTRACTION OF GEOMETRY IS ITS BEAUTY.
That is why the ancient Greeks said that God was a geometer.
That is what attracts the indulgence of many thinkers at all times.
-Yours affectionately,
Narasimha
