Jun 27, 2005

Artificial Intelligence : A few observations

"A computer can only do what you tell it to do, not what you want it to do." - Greer's Third Law

Artificial Intelligence - The term has been so widely used, overused and hyped about in pop culture that we think of it as something that has already arrived. But has Artificial Intelligence (AI) really come of age yet?

To define AI, we should first define intelligence itself. Intelligence is normally conceived to be the ability of an entity to be aware of itself, to think and to reason, to undergo experiences of varying nature, and to learn from them in order to make a choice among the varying alternatives it has before itself.

"The question of whether a computer can think is no more interesting than the question of whether a submarine can swim." - Edsgar W. Dijkstra (1930-2002)

Thinking comes to us (well, most of us!) naturally. Getting a machine to think is a different ball game altogether. It involves a lot more than pre-conditioned and pre-programmed responses to anticipated situations. It is much more complicated than adding 2 and 2 to get 4.

Yes, I know. You are thinking about how the computer Deep Blue beat World Champion Gary Kasparov some years back. The press declared that the age of the intelligent machines had come. But was Deep Blue really intelligent? It was only a computer, doing what it had been programmed to do- play chess. And it did play very well too. But it was not thinking as Kasparov was. For every possible move, the computer was doing a trial-and-error computation analysis. Simply using the most potent weapon in its arsenal - brute force calculation.

Kasparov, on the other hand, was thinking strategically and forming and discarding options as the game progressed. He didn't have the luxury of trial-and-error; the human brain is simply not designed that way. The machine was not worried about making a blunder; Kasparov was. The machine did not have to think about what it would do to win the next match; Kasparov had to. So, really, it was not a close match by any means. The result was only inevitable.

It does not mean that AI is not here yet. Some dictation software packages can actually 'listen' to what the user says. The accuracy level increases with practice, as the program 'learns' the speaker's voice pattern. Anti-virus software programs using 'heuristics' technology can stop viruses that have not been yet created, which is impossible using conventional packages that can only identify and stop already known viruses. But even then, they do not meet all the criteria that intelligence demands and cannot be termed really intelligent.

Anybody can program a computer to do a task. But a system can be said to possess Artificial Intelligence only if it can transcend its programming and perform tasks that it had not been instructed to perform, tasks which it had learnt on its own. It is a formidable task. And we can only wish the brave men and women working hard to push the limits of computer science and technology the very best in their endeavours. Maybe we may see AI in our own lifetime. The future holds promise.

You can visit these sites for more information on AI:
American Association for Artificial Intelligence (AAAI)
What is Artificial Intelligence?
The AI Depot

Jun 20, 2005

Time travel

One thing that I have always wondered about is whether it is possible for us to travel back in time. Wouldn't it be just wonderful to be back in the days when you were just a little kid, oblivious to all the problems haunting you? I have wished I had a 'Time Machine' of my own, something I could use to go back and undo all the mistakes I have done in my life as a child. Is it really possible?

Einstein says it is. If we can manage to travel faster than light, beating the mind-boggling speed of 3 * 10^8 metres per second, we really could go back to yesterday. It has not been experimentally proven though, for beating that speed will take something really special than jet propulsion and rocket engines.

But suppose you do manage to travel faster than light, what would happen? Would you go back to yesterday and see yourself or would you experience yesterday all over again? The former case will create two of you, and in the latter, you wouldn't even know that you had travelled back in time. Or would you? It really gets confusing over there.

Another phenomenon that is associated with time travel is what is known as the 'Grandfather Paradox.' Suppose you travel back in time to the childhood days of your grandfather. You take a gun and kill him. Now, obviously he died before your father was conceived. That would mean you wouldn't exist. So who killed your grandfather anyway?

There are a couple of arguments against the 'Grandfather Paradox'. The first says that you just wouldn't be able to go back in time. As plain as that. Another one says that even if you do go back to your grandfather's childhood days, you wouldn't be able to affect it in anyway. You just wouldn't be able to kill him. There are no solid explanations as to why this is not possible though.

As always, science fiction has always tinkered with Time-travel. A number of Star Trek episodes talk about the timeline, and how the information from the future can "contaminate the timeline" and so on. There is also the 'Back to the Future' trilogy, directed by Robert Zemeckis which is also an interesting flick. The 'Terminator' series also has some time traveling associated with it, with machines with artificial intelligence sending an agent into the past to kill off their enemy - a human soldier's mother before he is born and later the soldier himself.

Suppose, for the sake of argument, let us suppose that time travel to the past is possible. Then I wonder why we are not seeing visitors from the future visiting us right now? After all, we are past to them, aren't we? :)