Sunday, December 28, 2008

Are you Indian enough?

Newspaper reports in the Indian Express and others have mention that the sports ministry has decided to ban players not holding Indian passports from competing for India. Remember, that this is the same ministry which asked Sachin to remove the tricolour from his helmet some years ago. This is the same ministry that could not handle the false doping issue of Laishram Monika correctly. And of course, as I said earlier, if you are incapable of fixing the real issues in a field, you take something insignificant, blow it up into a big issue, and then make crude attempts at hacking a solution for it. Our health minister is the best exponent of this craft in this government, but it appears that the sports minister has decided to give him competition.

What is wrong in PIOs playing for India? They are allowed to buy land in India, they can carry on any occupation in India, and they have every right that a citizen has except the right to vote. Then, why create another class of citizens there? Isn’t it enough that we’ve created separate classes of citizens for flying the flag, separate classes for healthcare, for education, and for every social service? Why do it in sports as well?

This is exactly the sort of megalomania that ministers in India are prone to. Ban live bands, Ban parties, Ban flag-flying, Ban sportsmen.

Thursday, December 25, 2008

Technology Notes, Vol 1 Issue 7: Computation and Philosophy (Part 2)

See my report on the first day here. Unfortunately, it has been a while since I attended the conference, and too many things have happened in the interim, so this part of the report may not be as crisp as I’d like it to be.

I could only attend the afternoon session on the second day of the conference, and only one talk on the third day. I did miss a few (possibly interesting) talks in the process – I have abstracts and contact info of them, so if you are interested, talk to me.

The first talk in the afternoon session on Day 2 was “Mathematics, Computation and Cognition” by Rajesh Kasturirangan of NIAS. His premise was that the study of cognitive basis of mathematics and computation is best done on experienced mathematicians as opposed to children or chimpanzees as is usually the case. He talked about the classic Turing papers on Computational machinery and intelligence and George Lakof’s work which said that computational thought is essentially metaphorical. The question that we must ask, Rajesh said, was of the origins of that metaphorical ability. After this point, I lost him, and the discussions on what should be done got mixed up with what is already done (at least in my mind). He gave some characteristics of mathematical phenomena (like precision), and said that some interesting questions in the area were understanding the cognitive capacity for induction/recursion, and formulating theories for mathematical understanding. In conclusion, he advocated taking a holistic interpretation of the metaphor-mathematical thinking link, to see if they mutually interact and benefit each other. Q&A was OK, and there were some theories that floated around natural language and natural numbers, but I didn’t understand most of the discussion. Important reference here is “Number sense” by Daheane.

Next came what I thought was the least interesting talk of the conference, “Marr’s three-level typology for Cognitive Science”, by S. Pannerselvam of the University of Madras. The speaker simply read out the paper he’d authored without bothering to look once at the audience, or pausing to see if people understood what he was trying to say. Anyhow, Pannerselvam started with the Vision module that Marr describes, where he gives a three-level typology for cognitive science, each level corresponding to one of the three, why, what, and how questions of implementing such a module. He then appeared to contrast it with a connectionist approach pioneered by Jerry Fodor (See "The Elm and the Expert”). In that approach, as opposed to the “implementationist” approach of Marr, there is no central CPU processing information – instead, there is a more of a neural net that has parallel “total cognitive states”. A “Cognitive Transitive Function” would define state changes, although the characteristics of that were not explained by the speaker. The most interesting part of this talk was when Pannerselvam mentioned Jerry Fodor’s Somehow, amongst all these, he mentioned a “Language of thought”, which he said was not a natural language. During Q&A, many in the audience asked him about the characteristics of the language, but he didn’t say much. If you are interested though, go through the link above, and it has quite some information. Dan Dennett and Don Davidson both support the “no thought without language” thesis.

What does a cognitive agent have to do to develop meaning/understanding, or what is called a “grounded representation”? The next talk, by Nagarjuna G of TIFR was on this topic. He introduced Taddeo and Floridi’s (TF) criteria to solve the “Symbol Grounding Problem” (paper by Harnad here) and explained that the drawback of the system was that it did not specify a filtering mechanism to select the states that the cognitive entity would process. Other models were discussed, for instance, the Symbolic model (where the brain was a CPU that had sensory I/O), and the Connectivist model (that of neural nets and parallel states). The other shortfall, btw, of the TF criteria was that the entity under observation was assumed to have an abstracting ability that evolved from evolution! From what I understood, these models assumed something like the following: the eye only let light through, and the brain and its structures decided what we were seeing and equally importantly, what was the importance of what we were seeing. The alternative model that the speaker proposed used “Active perception” and a sensory system where inputs collided with each other (think seeing and hearing at the same time),  and not everything that was perceived was processed. There was more information on this, but I’ll let you read his paper: “Muscularity of the Mind”. The talk seems to make more sense, the more I chew on it, so I’ll try and post an addendum here later.

The final talk of the day was on the "Status and Justification of the Church-Turing Thesis (CTT)”, by Jonathan Yaari of the Hebrew University. The premise of this talk was that CTT was a contingent (i.e. aposteriori and necessary) thesis and one that didn’t require proof (or was unproveable) – similar to the fundamental axioms in geometry. The speaker wanted to use Kripke and Putnam’s theory of the existence of scientific ‘sentences’ that are both aposteriori and necessary to show that CTT was both a posteriori and necessary. See this article for more on the theory itself. What he failed to give though was a proper ‘reduction’ from CTT to the K-P theory. He also described CTT, attempted proofs for CTT, and K-P theory for too long to have time for a proper explanation of his ideas. Q & A focussed on this and other questions on computability, and while there were some good points raised, I don’t remember any of them now :(.

The last talk I attended was “Modularity revisited” by Pritha Chandra of IIT-D. The question Pritha raised was whether FL(N),  the Faculty of Language (Narrow) was modular as Fodor defined it. I didn’t really get the point of the talk, except for her conclusion that FL(N) was modular. I’ll put some references here if you are interested: Chomsky’s Minimalist Program, Spelke’s work on why FL(N) isn’t modular, paper talking more about FL(N) by Hauser, Chomsky, and Fitch, and papers defending modularity of FL(N), by Fodor and Butterfill

I’ll post my conclusions on the conference in a separate post. :)

Tuesday, December 16, 2008

Of love, leagues and relationships 7: Page rank

Previously in love, leagues and relationships…
…New samvat's, the festival that celebrated 60,000 years of human existence. Would he be able to enjoy the day?

Arthur felt a light feeling in his head. His feet weren’t on solid ground. Trying to piece together what had happened, Arthur recollected drinking heavily on Samvat, getting into a car and driving off into a dark highway. He could recollect seeing two big lights, growing ever larger, swaying from side to side, approach him. What happened next was no mystery. As Arthur struggled to get a firm footing on the ground, he realized that he was no more.

Arthur kept feeling lighter, he felt himself being sucked up as though a power vacuum was running up in the clouds. In seconds, he flew through the clouds, through the solar system, outside the Milky way, and landed in a long queue that led to a train station.

A large board in the distance read “Pearly Gates”. A smaller board indicated that the Pearly Orient was due to start in half an hour.

The queue progressed forward at a rapid pace. Soon, Arthur was only a few feet away from what he thought was a ticket counter. To his surprise, he saw most people disappear once they reached the counter, and only a few were let through. Intrigued, as Arthur waited for his turn, he overheard this conversation:

But I have been a man of god all my adult life! And how can you let this terror on the street through while preventing me from entering?”

The TC replied: “God is not only concerned about your means, but also your ends. This auto driver from Bangalore made more people pray to God while he was driving, while all you did was put people to sleep with your sermons! Three years in Hell for you!”

With a poof of smoke, the preacher disappeared.

Arthur was next, and the man at the ticket counter pulled up what looked suspiciously like Arthur’s favourite search engine and typed his name in. In seconds, Arthur’s life flashed on the screen. Images from his life, videos of acts he’d done, reams of text of things he said or thought, profiles of his friends, in short, his entire life appeared on the screen. Finally, at the bottom, there was a single score in large bold letters: a small negative number with the title “LifeRank score”.

The ticket collector’s face darkened.

“You will have to go to Hell.” he said.

Arthur was terrified. “But I’ve done nothing wrong!”, he exclaimed. “I was god-fearing, did the right things always, was pro-environment, kind to animals and was helpful to people! Why should I go to Hell!?”, he asked. Unable to contain his curiosity, “What is that LifeRank score?”, he added.

“Ah, a software engineer, aren’t you?”, replied the TC. “Always curious, but never doing anything useful.” Arthur was peeved by the judgment. Still, one doesn’t argue with a man who decides your time in eternity, so he let the TC continue. “LifeRank is a score computed by weighing in your accomplishments in life, your carbon credits, animal credits and other factors. However, the most important factor in the LifeRank score is the rating given to you by the people you know, and their LifeRank scores. You see, in eternal life, as in real life, where you end up depends mostly on who you know.”

Arthur was amazed. “Why is my score negative? Is that bad? What _are_ the components of my score?”, he enquired.

“Sorry, that is a secret”, replied TC. “The precise weights given to each component is only known to the One. What I can tell you is that you seem to know many people with a negative life rank score who think you are a great person. And that is BAD.”

“What!?”, exclaimed Arthur. He could not believe what he was hearing. “Why should I get a bad score because some bad folks think I’m good?”, he asked in an agitated voice.

“Simple, my man.”, replied TC, with the patience that only eternal life can bring. “Who do you think would Adolf, the patron saint of Hell, rate highly, Mussolini or Gandhi? Who would Gandhi rate highly? Stalin, or Lincoln? If you are rated highly by someone with a negative score, your score becomes negative. ”

Arthur couldn’t believe what he was hearing. His mother always told him to be careful of the company he kept, but little had he realized that her advice could come to haunt him this way!

“But I must know a few good people”, he said, defensively. “Yes, you do”, replied TC. “However, none of them rate you as highly as the negative ones do. Sorry, I must let you go.”

Dejected, Arthur took one last look at the screen, and saw the hint of a familiar multi-coloured logo. Suddenly, with a smile, he said, “Are _you_ using the PageRank algorithm developed by Search., Inc? Wait, this even looks exactly like their home page!”. TC was taken aback. Clearly, he hadn’t met many software engineers, particularly not those with Arthur’s keen eye. Recovering, he said “PageRank? That is just a prototype of the real algorithm. What we use is LifeRank – which the One created. He did give away an early prototype to Lerry Brim and Sogay Page. However, PageRank is ages behind LifeRank – it doesn’t scale, it requires expensive computers, and a whole lot of energy. LifeRank, on the other hand is IJW. It Just Works.”

“So, _you_ guys started the greatest battle of 21st century computing!”, exclaimed Arthur. “But why did you give Page rank to Search., Inc, and not to their rivals, Myahoo?”. Arthur knew he was on to something exciting. “Oh, that is because of their motto – don’t be evil.”, replied TC. “And yes, we know, they haven’t really stuck to their ideals, but hey, they’ve served as a brilliant marketing tool for God. Remember, everyone does marketing all their lives. Even God.”

Arthur could not believe what he was hearing. He managed to ask: “What about their rivals?”.

TC replied, with a huge smile: “Oh, they went to heaven. After all, haven’t you heard of the Vista operating system? By making people wait for long minutes during reboots, the company gave people, particularly, a community as under-devoted as software developers, time to think about the true meaning of life. Would such a deed go unrewarded?”

Arthur had no more questions. He closed his eyes, expecting the worst.

(PS: A number of statements and anecdotes here are not my own. Full credit to the authors - Vibhuti for the "marketing statement", and Anon for the autorickshaw joke.)

Monday, December 15, 2008

Technology Notes Vol 1, Issue 6: Computation and Philosophy (Day 1).

This issue of Technology notes is dedicated to the "Computation and Philosophy" conference held at the National Institute of Advanced Studies. There were more than 25 talks (of which I attended 13), and although I went in with some degree of trepidation, I must say I wasn't completely lost. I am still chewing on what I heard and on my notes, so what you see here is a half-cooked report on the three day conference.

A few caveats first: As I don't have formal training in philosophy, everything I say here is what I understood from my low perch in Computer science, so please take everything in this post with a healthy dose of skepticism. Further, conclusions I draw here are my own, and they may not be what the speakers intended.

The one big lesson I drew from the conference is that a reductionist approach is grossly insufficient to describe many complex systems, one of which is our own ability at computation, which includes the ability to learn language.

The first hint towards this came from the talk on Templates, Complexity and Autonomous systems by Paul Humphreys. Prof. Humphreys is an authority on emergent behaviour, and he contrasted reductionism to a constructionist approach to explain higher-order properties. While reductionists argue that all higher orders of properties can be explained by interactions amongst lower-order properties, constructionists believe that there are levels in the reductionist hierarchy which are not algorithmically accessible from the previous levels. That is, there are higher-level properties that cannot be reduced to the interactions between the properties that exist at lower-levels (think genes->proteins->organs). The question Prof. Humphreys asked was whether this irreducibility was provable. He explained his results using Ising models and Cellular Automata, but I was unable to understand the gist of his discussion, as it assumed that one knew these concepts apriori. Overall though, I think his point was that it can be proven that it is not possible to have models of sufficiently complex physical systems where every property can be computed. I'm still reading up on some of the papers he mentioned, so if you are interested, Sorin Istrail's paper at STOC 2000 is one suggested for reading. I'm still trying to figure out what he said, and once I do, I'll put it up here for more discussion.

The next two talks, "Algorithms in Indian tradition" and "Mathematical, Algorithmic, and Computational thinking in the Indian mind-scape" were rather boring. Both speakers talked about the glorious Indian tradition of science, and while the first speaker, M D Srinivas, gave an illustration of how Aryabhata and other Indian mathematicians wrote maths in poetry, and were able to compute functions like sine-inverse, Veni Madhavan who gave the second talk said that the notion of proof and generality didn't arise in the Indian mathematical tradition because of the poetic way in which mathematics was passed down. The first talk was a repeat of a talk I'd attended at MSRI, and the second had zero proof and lot of hand-waving as to why poetry caused Indian mathematicians to miss a glorious opportunity to own, for example, the "Chinese remainder theorem". The speakers tried hard to avoid being patriotic, but that feeling somehow snuck in, and in addition, beyond making an unproven statement that poetry is some sort of an enemy of generalization, was completely unrelated to the topic at hand.

Some of the Q&A here was good though, with some people debating whether notations freed or constrained thoughts of people - Greeks, for instance, not going beyond the third power simply because their mathematics reduced to geometry, and they were unable to visualize a fourth dimension. No conclusions were drawn though.

These talks were also the started the trend of poor presentations in the conference by many of the speakers. So many of them came unprepared, many didn't have slides and read from papers or books they'd written, and one person literally recited his paper during his presentation.

Anyhow, the next talk was by N. Raja from TIFR, on the "Philosophy of Software Artifacts". This talk was another disappointment, particularly because I was really looking forward to what he had to say. N. Raja spent a LOT of time talking about denotational v/s operational semantics, explaining the lambda-calculus, and quoting books (for instance, "Meaning and Interpretation" by Charles Travis). I didn't get the point of his talk, however – I guess he was trying to introduce the different approaches to semantics in Computer Science. Some of his references though are interesting reads, notably the Scott-Strachey paper "Towards a mathematical semantics for computer languages" and Peter Landin's work on a lambda-calculus-based abstract machine. Overall, the talk wasn't crisp and while the speaker had slides, there was a lot of back-and-forth movement, and not enough time devoted to making a single, "take-homeable" point. The one thing I remember about the talk was a flat joke about how computer scientists are formalists on the weekday and 'something else' on the weekends, but I forget what.

The next talk was post-lunch, and it was by Amba Kulkarni on "Panini's Ashtadhyayi", on Sanskrit grammar, which incidentally is the first generative grammar known to us (think Chomsky's hierarchy for what a generative grammar is). Kulkarni made the point that Panini was aware of information coding abilities of language, and the need for brevity while defining grammar, and she explained how Panini used anuvrutti or factorization to get brevity in his definitions. (See the section on "IT markers" on the wiki page.) There was a lot of room for ambiguity, and in such cases, he took refuge in meta rules and akansha (what the listener expected) to resolve it. Essentially, there were phonemes, called shivasutras and rules called anubandhas that mimicked Niklaus Wirth's famous book: Programs = Data + Algorithms, with shivasutras playing the role of data, and anubandhas, the algorithms that defined the composition and behaviour of these data items. Kulkarni also gave some 'proof' (quotes intentional) for how the system is similar to OO programming, and quoted a paper by a Yale professor on inheritance in ashtadhyayi which had dealt with this issue. I only realized later that she meant a completely different inheritance - the paper here says

"What distinguishes Panini's approach is not only temporal priority, but a novel method of interleaving formal and semantic specifications along a single inheritance path to model many-to-many correspondences between the formal and semantic properties of derivational affixes"

leaving me clueless. Maybe a linguistics person can clarify this? Meanwhile, it was time for Q&A, and when there is talk of Sanskrit, how can talk of programming be far behind? Quickly, a consensus formed, excluding the two Microsofties present, on the suitability of Sanskrit for computer programming. Never mind that the grammar itself is ambiguous, and requires human understanding (see the point about akanksha) for interpretation. Of course, I'm NOT a qualified linguist, and it may indeed be possible to program in Sanskrit. One does wonder though why a compiler hasn't been built to translate Sanskrit into say, English.

Next was a talk on "Computation and the Nature of writing" by Sundar Sarukkai. This was an interesting talk, where he first defined computation as the manipulation of symbols leading to a conclusion. Then he asked the difference between writing and computing. Quoting from a reference I didn't record, he mentioned that the essential characteristics of writing were temporality, progressivity, and that it was a representation of speech, which itself was a representation of thought and was a second order copy of information. He then introduced cognitive models of writing favouring the "planning, organizing, goal-setting" model, and was emphatic that all three occur in parallel. Writing was also goal directed, he said, with process and content goals being satisfied through a process of translating thought to symbols. Coming back to computation, he mentioned semantics was the bugbear for math, and that removing meaning from symbols gave it a certain purity, and allowed 'logic' to operate on them. Thus 'symbol-centrism' became central to computation. Ultimately, his conclusion was that the two were similar, as both did translations of thoughts into symbols on a medium. He did leave a few questions open, for instance, the rules for a "metaphysics of computation", or the difference that writing and speaking make to the computability of mathematics.  Considering how the talk concluded, I must say that while the talk itself was well presented, the conclusion was something anyone with very little knowledge of philosophy would have come to. But I guess that is the challenge of philosophy - to provide theories for understanding even those things that we think are obvious.

The next session of three talks was dedicated to Biology. It started with a talk by Vijay Chandru of Strand genomics on a "Systems View of Biology". Vijay started by saying how a reductionist approach to biology has failed to describe higher order behaviours like organ function, (See "Music of Life" by Dennis Noble for more on this), and gave an illustration of the work Strand is doing in their field by the example of hepatotoxicity detection. Strand seems to be doing very well, and they appear have teams of PhDs and MDs tackling every problem in a co-ordinated way. The talk though didn't have too many insights beyond telling us that computation will change the way biology is done in this decade or the next.

Next in the biology series was Dr. Raghavendra Gadagkar's talk, "Decision making in Animals", by far the best talk of the conference: well presented, with a lot of content, and independent research backed up by evidence. The subject was apparent intelligence of decision making in bees and other social insects - for instance, bees are known to convey both the distance and direction of food accurately, and other bees are known to follow up taking into account the rotation of the earth. Ants find what is usually the shortest path to food. His conclusion was that all this is done by following certain simple heuristics - for instance, ants set off in all directions in search of food, leaving pheromones on their path. When a food source is found, the ant finding it traces its way back to the nest. If two ants find two different routes to the same food, the ant which returned first would leave a stronger pheromone trail (as it has passed the route twice). An ant that sets off after the first one returns will simply follow the path of the stronger pheromone, increasing its strength. Ants that come later continue to follow the same rule, making the path the standard one. The experiments suggested were simple, and brilliant (at least to a layman), and this was clearly the best talk of the conference. [May I make a recommendation that he be invited to give a talk at MSRI?]

The final talk of the day was by M G Narasimhan of NIAS on "The Genetic Code as an Information Entity". The speaker spent a lot of time talking about DNA and Watson and Crick and the whole history of the study of DNA, and by the time he came to his conclusions, his time was up, and so was our patience. We left without waiting for the Q&A.

Will write about Days 2 and 3 in the next post.

Sunday, December 07, 2008

The Google OS.

It is so gratifying when a prediction you make comes true (or nearly true). Internetnews says that Google is hiding OS signatures for packets coming out of Wonder why. Remember though, that you heard it first here, a few months ago, when I'd speculated that the ultimate Google weapon against Microsoft would be a Google OS - this report says that they may actually be working on one, even as we speak!


Tuesday, December 02, 2008

On Open Source

I am a big fan of Open Source. I think it is the greatest ode to teamwork: Just imagine, getting people from nearly all over the world, with completely different interests, who've never seen each other, to work on a common project! Simply amazing. The sophistication of processes that open source teams (well, at least in Linux development) have achieved deserves kudos. Not to mention the opportunity it gives for students and amateurs to learn both by doing and by actually seeing what goes on under the hood of any software application. Being open to scrutiny, bugs get fixed relatively quickly, and security flaws are fewer - well, that is at least what I've heard.

However, what bugs me is the simplistic formula - "Open source = good; Proprietary software = bad." That is, anybody, any entity that supports open source is cleansed and becomes pure good, while any entity that doesn't becomes an incarnation of the anti-Christ.

Take, for instance, this comment on a page debating the virtues and vices of Google:

"Google is not evil. They encourage open source software. They have effectively counteracted Microsoft and Apple closed source systems to the benefit of the public. ..."

(Ed: I've removed the part of the comment talking about text ads - those are great innovations and have nothing to do with evil or good.)

Of course, the author of this comment wasn't probably aware that Google's search algorithm is still secret. (Don't pop the PageRank paper at me now - Google hasn't open-sourced it's actual search algorithm that runs on production machines - a lesson they learnt after publishing the page-rank algorithm as grad students.) Or that Google has been sued many times for violating someone's patent (this maybe simply for money), or someone else's copyright. Or the fact that Google submitted to the Chinese censors without as much as a whimper.

If you are not giving out secrets that matter most to your company, then you are no different from all the companies that work with closed source. Why isn't this obvious to people? Why are we always on the lookout for a white knight that battles the dark satanic forces of commercialism?

Open source software is no longer groups of individuals creating world-class software for nothing but fame or their love of software development. Open source is now backed by companies with millions of dollars - think Google with Mozilla/Linux, IBM and HP with Linux, and the countless others that pay developers good money to write Open source software. None of them are doing it out of the good in their hearts. They are doing it because it gives them a competitive advantage, good publicity, or the chance to shoot at a rival over the shoulders of 'Open source' developers.

(Been unable to write anything on the Mumbai attacks yet. Still trying to formulate a sensible post.)