THE DIFFERENCE BETWEEN A BRAIN AND A COMPUTER

Difference between a computer and brain can be expressed in a single word, that is, 'complexity'.
The human brain is the most complicated thing known to us.The human brain weighs only three pounds.In these three pounds, there are ten billion nerve cells and a hundred billion smaller cells.These billions of cells are interconnected in a very complicated network that cannot be understood so easily.
  Can a computer think?That depends upon what you mean by "think".If solving a mathematical problem is 'thinking',then a computer can "think",and does faster than man does.Of course , most of the mathematical problems can be solved quite mechanically by repeating certain straightforward processes over and over again.Even the simple computers of today can do so.
   It is frequently said that computers solve problems only because they are programed to do so.They can do only what men have fed in them.One must remember that human beings can also do only what they are programed to do.
Our programme is very complex.We might like to define "thinking"as the creativity that goes into writing a play,composing a symphony, conceiving a theory ,or making a judgement.In that sense computers certainly cannot think.
 The brain is made up of cells in a certain arrangement.The cells are made up of  atoms and molecules in a certain arrangement.To duplicate the material complexity of the brain is ,therefor, to duplicate every thing about it.
 But how long will it take to build a computer complex enough to duplicate the human brain.Perhaps, not as long as some may think.Long before we approach a computer ,we will build a computer perhaps which is , at least, complex enough to design another computer more complex than itself .This further complex computer ca be developed into one still more complex than the previous one,and so forth.
 In other words,once we pass a certain critical point, the computers take over and there will be "complexity explosion".In a very short time thereafter, computers may exist that will not only duplicate the human brain but also will surpass it.Will a time come when man will have to handover the job to someone who can do it better than he can do.
 Yes!Perhaps.But we will have to wait till such a wonder takes place.