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"OH WATERS, TEEM WITH MEDICINE TO KEEP MY BODY SAFE FROM HARM, SO THAT I MAY LONG SEE THE SUN." - Rig Veda

15.05.09

Tenho pensado muito em Ballard

David Hockney "American 3"

15.05.09

"When I was writing the NKS book I kept on wondering what the

first "killer app" (to use a phrase from the software industry)

for NKS would be.

I tried to think back what one would have imagined in 1936, when

the idea of universal computing was introduced. Could one have

predicted what the first killer apps for computers would be?

As it was, first there were databases--which drove the mainframe

computer industry, and later there were word processors--which

drove the personal computer industry.

Despite their tremendous practical importance, databases and word

processors are really quite prosaic applications of an idea as

powerful as universal computation.

And both of these applications could probably have been done even

without the full concept of universal computation.

But the point is that the paradigm of universal computation was

crucial in even imagining that either of these applications would

make sense.

And so it is now with NKS and Wolfram|Alpha.

Wolfram|Alpha is, I believe, going to be the first killer app of

NKS.

And remarkable though Wolfram|Alpha is, it is at some level still

prosaic relative to the full power of the ideas in NKS.

Yet without the NKS paradigm, I cannot imagine I would ever have

thought that Wolfram|Alpha could make sense.

There is an immensely complex web of systematizable knowledge out

there in the world. And before NKS, I would have assumed that to

handle something of this complexity would have required building

a system that is somehow correspondingly complex--and in practice

completely out of reach.

But from NKS we have learned that even highly complex things can

have their origins in simple rules and simple programs.

And this is what inspired me to believe that building

Wolfram|Alpha might be possible.

As a practical matter, many algorithms in Wolfram|Alpha were

found by NKS methods--by searching the computational universe for

programs that achieve particular purposes.

And there is a curious sense in which the discoveries of NKS

about computational irreducibility are what make Wolfram|Alpha

possible.

For one of the crucial features of Wolfram|Alpha is its ability

to take free-form linguistic input, and to map it onto its

precise symbolic representations of computations.

Yet if these computations could be of any form whatsoever, it

would be very difficult to recognize the linguistic inputs that

represent them.

But from NKS we know that computations fall into two classes:

computationally reducible and computationally irreducible.

NKS shows that in the abstract space of all possible computations

the computationally irreducible are much the most common.

But here is the crucial point: because those computations are not

part of what we have historically studied or discussed, no

systematic tradition of human language exists to describe them.

So when we use natural human language as input to Wolfram|Alpha,

we are inevitably going to be describing that thin set of

computations that have long linguistic traditions, and are

computationally reducible.

Those computations cover the traditional sciences. But in a sense

it is the very ubiquity of computational irreducibility that

forces there to be only small islands of computational

reducibility--which can readily be identified even from quite

vague linguistic input.

If one looks at Wolfram|Alpha today, much of what it computes is

firmly based on OKS (the "Old Kind of Science"), and in this

sense Wolfram|Alpha can be viewed as a shining example of what

can be achieved with pre-NKS mathematical science.

And curiously, after all these years, it is also perhaps the

first clear consumerized example of universal computation at

work. For now, for the first time, anyone will be able to walk up

to a computer and immediately see just how diverse a range of

possible computations it can do.

So what about NKS? NKS is certainly crucial to the very

conceptualization of Wolfram|Alpha.

And even today one can use Wolfram|Alpha to do a little NKS: one

can type in "rule 30", or ask about other NKS systems that can

readily be specified in linguistic terms.

But in the future there is tremendous opportunity to do more with

NKS in Wolfram|Alpha.

Today, Wolfram|Alpha uses existing models from science and other

areas, then does computations based on these models.

But what if it could find new models? What if it could invent on

the fly? Do science on the fly?

That is precisely what NKS suggests should be possible. Exploring

the computational universe on request, and finding things out

there that are useful for some particular specified purpose.

We started a small experiment a few years ago with WolframTones

(http://www.wolframtones.com) where we use NKS to invent new

musical tunes. But there is vastly more that can be

done--directing with ordinary language, but discovering

automatically with NKS.

Whether today's computers are fast enough to do this well I do

not know. But perhaps by next year, Wolfram|Alpha will not only

be a killer app made possible by NKS--it will also provide an

outlet for the full richness of the computational universe that

has been revealed to us by NKS.

But for now: tomorrow (May 15) is the day we begin to make

Wolfram|Alpha live--the first killer app of NKS.

See the Wolfram|Alpha Blog to follow the launch:

http://blog.wolframalpha.com

-- Stephen Wolfram"