29-Aug-2011, 07:42 PM
(This post was last modified: 29-Aug-2011, 07:57 PM by Vinod Wadhawan.)

(09-Aug-2011, 02:33 PM)Kanad Kanhere Wrote: Ajita, Dr Wadhawan,

I have some queries for you. I went through the TED talk and then the link sent by murthmail. I am absolutely novice in this field and my knowledge in this field is next to nothing, so Sorry in advance if my queries sound stupid.

The link, as per me, had two strong points

1. "Wolfram is just proposing a new kind of computational method, not a new kind of science"

2. "Wolfram's theory lacks explanatory power. Not everything that is useful is explanatory"

What is your take on these?

Doesn't this method sound like a brute force method of figuring out fundamental laws of nature?

The answers to your questions are discussed in detail in Chapters 12 and 15 of my book 'Complexity Science'.

http://www.amazon.com/COMPLEXITY-SCIENCE...108&sr=8-1

Trying to give a brief and simplistic answer would be unfair to Wolfram's work. So I shall just give you a feel for what is at stake here.

There are 'simple' (or simplifiable, or computationally reducible) systems, and there are 'complex' systems. Practically all our present science deals only with simple systems. For such systems it is possible to make models, and make testable predictions. Most of the complex systems are such that it is impossible to model them sensibly. Any model involves approximations, and for complex systems approximations usually lead to disastrous, runaway, consequences (e.g. in chaotic systems). Real Nature is mostly about complex systems. Mathematical equations are not good enough for modelling them sensibly. So what do we do? Wolfram's 'New Kind of Science' (NKS) offers a way out.

His approach is born out of a question he asked long ago: 'What secret it is that allows Nature seemingly so effortlessly to produce so much that appears to us so complex?' His answer is that all natural processes are just computations, i.e. the running of what he calls 'simple computer programs'. Any process that follows definite rules can be regarded as a computation. Thus cellular automata (CA) can carry out computation, as can Turing machines, and many other systems in Nature. In computations carried out by humans on computers, the computer programs define the rules of computation. In Nature, the rules of computation are nothing but the laws of Nature.

As Wolfram emphasizes, the whole idea of doing science with mathematical formulas makes sense only for 'computationally reducible' systems. For other systems there are no computational shortcuts; practically the only way of knowing a future configuration is to actually run through all the evolutionary time steps. And Wolfram’s NKS is ideally suited for that purpose. Exploiting the immense power of modern computers, one can generate a huge repertoire of the consequences of all sorts of simple programs as embodied in the corresponding CA. For understanding the basics of a given complex system observed in Nature, one can try to see if the observed behaviour pattern can be matched with any of the archived CA. If yes, then the simple program used for generating that particular CA pattern is the explanation of the time or space evolution of the complex behaviour observed in the actual physical system under study.

Whether we like it or not, there are not many other ways of understanding complex systems. That is why Wolfram's NKS cannot be ignored. It is important.