“Wolfram|Alpha isn’t really a search engine, because we compute the answers, and we discover new truths. If anything, you might call it a platonic search engine, unearthing eternal truths that may never have been written down before.”(1) I have great respect for Stephen Wolfram. He's one of those guys who not only has been churning out ideas his entire life, but they've had an impressive degree of novelty. Furthermore he's actually instantiated his ideas in workable systems. He's got the spirit of a modern Isambard Kingdom Brunel. (Don't get me wrong, I mostly stick to theory myself. But there's something impressive about ginning up good theory and good artifacts as well.)
Despite his disclaimer, Wolfram|Alpha looks like a search engine, in that there’s a one-line box where you type in a question. The output appears a second or two later, as a page of text and graphics below the box. What's happening behind the scenes? Rather than looking up the answer to your question, Wolfram|Alpha figures out what your question means, looks up the necessary data to answer your question, computes an answer, designs a page to present the answer in a pleasing way, and sends the page back to your computer.
Let me give three random examples. If you enter the query, “3/26/2009 + 90 days” you’ll get a page that gives a date ninety days later than the first date. If you enter “mt. everest height length of golden gate” you’ll get a page expressing the height of Mount Everest as a multiple of the length of the Golden Gate Bridge. If you enter “temperature in los gatos,” you’ll get something like the current temperature, a graph of the temperatures over the last week with projections for the next few days, and a graph of the temperatures over the last year.Wolfram|Alpha can pop out an answer to pretty much any kind of factual question that you might pose to a scientist, economist, banker, or other kind of expert. The exciting part is that you’re not just looking up pages on the web, you’re getting new information that’s generated by computations working from the known data.
(2) A lot of Rucker's questions understandable relate to Google. The difference seems to be that while Google will point you to an already extant page which hopefully contains the answer to your query, Wolfram|Alpha will answer your question itself. I have no idea how well it will answer your questions, or how much better it will get, but it's an interesting context switch. If we're every going to piggyback our intelligence on artificial computing power then it's necessary that we be able to ask a computer a question and get an answer, rather than just being pointed to where we might find the answer.
Note also that Google already does some of this. It already answers one of Wolfram's example queries "temperature in los gatos" by giving the current and predicted weather. A query like "monsters vs aliens showtimes" will give you local showtimes for the movie in question. Airlines are similarly handled. Arithmetic, unit conversion and currency conversion is also all covered already. The difference seems to be that Google, despite these features, is still very much about document retrieval and not answering questions. Without knowing anything about the architecture behind the scenes I can't speculate about whether Google could be made to do what Wolfram|Alpha purports to do.
(3) Rucker also asks about the Semantic Web, another good comparison. I'm with him in thinking that the Semantic Web will never really take off. I have a feeling our natural language processing systems will get good enough fast enough that the Semantic Web will be obsolete before it's formed, if for no other reason than that NLP has so many applications to spur it on. (Of course I tend not to be too optimistic about NLP progress either, I'm just even less optimistic about Semantic Web progress. This isn't a knock on the Semantic Web people -- I know a few of them and they're good, smart folks.)
(4) Wolfram's comment about "the issue is not to emulate humans, but rather to bulldoze a shortest path to an answer" reminds me of a great quote by another CS lumniary Edsger Dijkstra:
The question of whether machines can think is about as relevant as the question of whether submarines can swim.I've always thought of that as the "Quacks Like a Duck" theory of artificial intelligence.
I've seen that misquoted more than a few times as "about as interesting" which I think is quite wrong. It's a very interesting question since it's intimately related to all of cognitive science, and by extension epistemology, metaphysics, psychology, linguistics, AI, moral philosophy, .... Admittedly it's not terribly relevant when we're trying to build the machines that will hopefully be doing our cognitive heavy (or even light) lifting for us. I have no idea if this Wolfram|Alpha system will even qualify as light lifting, but it's an interesting development nonetheless. I'll certainly be tuned in this May to give it a try.
PS Another favorite Djikstra quote: "Computer Science is no more about computers than astronomy is about telescopes." In my pricklier moods I remind people of this when they hear I'm a CS student and immediately ask me what's wrong with their computers. I'd like to see Computer Science renamed Computing Science or Computation Science to better make this decision. I'm not sure it would keep people from bugging me about their out of whack Windows boxes, but it would still be much more accurate.