Thermal Noise

“It is in mathematics that our thinking processes have their purest form” - Roger Penrose expounds in “Shadows of the Mind”. The book, which is a sequel to his famous “The Emperor’s New Mind” is a fascinating study that seeks to answer one question - “Can we construct a computational model of the human mind and consciousness ?”

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http://www.informit.com/articles/article.aspx?p=1193856

Paper by Rivest et al:

http://cg.scs.carleton.ca/~morin/teaching/5408/refs/gr93.pdf

And the mandatory sucky applet:

http://people.ksp.sk/~kuko/bak/index.html

Found this out while lifelessly grokking around boost:

http://www.boost.org/doc/libs/1_35_0/doc/html/intrusive/sg_set_multiset.html

Balanced Trees are better than unbalanced because of bounded worst-case O(log n) search time. And AVL is the simplest balanced tree. Red-Black is better than AVL because worst-case O(1) rebalancing during (Updated) insertions are guaranteed. But Scapegoats are even better because they gaurantee O(1) rebalancing AND don’t need the extra field for storing the color of the node. Strange that I have not even heard of a 1993 data structure that sounds practical enough.

Here are the said notes from Knuth’s lecture on Valentine’s Day 2008. There was no specific topic that the Don spoke on. It was more of a Q/A session than a lecture. However there were few short questions and long insightful answers

(A day after the lecture, I did a full transcript which I seem to have misplaced. What follows is a reconstruction from the short-hand notes that I took during the Don’s talk. Due to the peculiar way in which Long-Term memory is reinforced in the human brain, we are capable of making grossly false recollections and delude ourselves into beliving it to be the gospel truth. I have tried best to stick to the words that I took down with no superfluous explanation. But be warned about the limitations of the cerebral cortex. The gist of the ideas and most of the nouns, verbs and adjectives were mostly by the original speaker. But the correctness of pronouns, infinitives, sentence ordering and in general a guarantee of authentic tone are in no way implied.)

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Its 4 a.m in the morning. I haven’t slept in 24 hours. I am still wondering if this is a dream or a dream within a dream.Without much ado, I have just listened to for more than an hour and spoke a word to Donald Ervine Knuth himself, albeit over the telephone on the wrong side of the Atlantic. It was the Don’s Lecture at Sun’s Menlo Park campus on Valentine’s Day and I sneaked in with a friend.

Euphoria is very hard to describe … I will stop !

P.S: I am on a scheduled break from blogging. But this was far too tempting to resist. The transcript of his talk and more details may appear at a later date

http://webcast.berkeley.edu/

From D.E. Knuth’s famous letter to the United States Patent and Trademark Office:

“
I am told that the courts are trying to make a distinction between mathematical algorithms and nonmathematical algorithms. To a computer scientist, this makes no sense, because every algorithm is as mathematical as anything could be. An algorithm is an abstract concept unrelated to physical laws of the universe.

Nor is it possible to distinguish between “numerical” and “nonnumerical” algorithms, as if numbers were somehow different from other kinds of precise information. All data are numbers, and all numbers are data. Mathematicians work much more with symbolic entities than with numbers.

Therefore the idea of passing laws that say some kinds of algorithms belong to mathematics and some do not strikes me as absurd as the 19th century attempts of the Indiana legislature to pass a law that the ratio of a circle’s circumference to its diameter is exactly 3, not approximately 3.1416. It’s like the medieval church ruling that the sun revolves about the earth. Man-made laws can be significantly helpful but not when they contradict fundamental truths.
“

In those words of eloquent truth,
Beat Frost he did, Master Knuth.

India appears in the Top 10 of the Top500 supercomputers list for the first time: http://top500.org/site/systems/2838

EKA, is a Linux cluster of Clovertown based Intel Xeon systems connected via Infiniband. Congratulations to Tata Sons and HP !

Quite shamefully, Solaris runs on only two of the Top500 supercomputers. Blame it on the pathetic HPC userspace and community when compared to Linux !

For the last two weeks, I’ve spent every ounce of my spare time trying to finish “Beautiful Code”. There will be two kinds of people: Those who think its a pointless piece of non-sense and Those who find the book a religious experience . Sharing as they did, some of their most intense experiences of programming and profound insights into the art, were legendary modern day programmers who stand tall to inspire us all: Brian Kerninghan, Karl Fogel, John Bentley, Charles Petzold, Greg Kroah-Hartman, Simon Peyton Jones and Bryan Cantrill.

The two best chapters in the book were: Beautiful Debugging & A Spoonful of Sewage.

I am ordering a hard copy so that I can pray to the book everyday

Continuing from the last article on Hypercomputation, we take a look at the Church-Turing Hypothesis first.

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I recently happened to read in detail about an interesting computational theory called Hypercomputing.

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One of the fallouts of Sun’s historic pact with Intel was that more programmers were needed for Intel device drivers on Solaris. And so, I switched from poking around with userland utilities, libraries and diskless clients to fiddling around with Device Drivers on Solaris.

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I’d interviewed a few folks on Python lately as a favor for a friend. Without laboring into details, there is one question that seems to baffle most candidates consistently. The first time I had to ask this question was because I couldn’t think of anything else “sane” at that point in time - and since the reaction by the (otherwise smart) candidate gave rise to a vicious notion of a entertainment, I kept repeating the question to every single person I interviewed subsequently !

Question: If the expression (0.99 - 0.90 - 0.09) were to be evaluated by the cpython interpreter, what would be the result ?

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One of my friends mourns that I write about technology and other obscure things that 99% of the world would not be interested in. He instead wants me to write more “personal stuff”. I wonder if that will worsen the ratio. Not that it is supposed to signify anything, but then for the heck of not disappointing Sid who threatens to “tag” me if I don’t ….

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Computing is interesting because it is fraught with problems. The argument that those problems are not interesting because they are man-made, is fallacious because problems of living and day-to-day life aren’t created by god either and they are usually more pointless. But that is besides the subject, which is actually something that sounds mundane but is frighteningly complicated to implement: “How to validate an Email Address ?”

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Are you good at Dtrace ? You might have a job in hand ! Here is something that appeared in the Times of India supplement yesterday.

Its a pleasant surprise that DTrace is now a hot job skill in the Indian Market too ! Of course it helps to know the similar family of tools like CodeAnalyst, VTune, oprofile, valgrind, SystemTap, Perftools ….

I was at my alma mater last week to give a presentation on Debugging Tools and Techniques. It was a part of a week long seminar on FOSS Technologies. You can find the presentation here. The talk wasn’t half as scary as the presentation, which looks completely crazy with useless command line options. The “uninitiated” second year students of TCE were the main audience along with a few third year students. It was great to find a lot of wannabe Unix programmers out there.

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Every conversation with geeks not working in Sun this week has been about ZFS and ZFS making it to Mac OS X - Leopard. I get thoroughly drilled on Sun’s financial strategy and how we plan to make money rather than being asked about instantaneous snapshots and self-healing capabilities of ZFS. Thats one of the disadvantages of working for a “Non-Profit Organization” (of which we are very proud, anyway)

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September had been a highly productive month. I ticked off 12 movies from my “Must Watch” list and completed five books. I tried finishing the Sixth - “A New Kind of Science” (NKS) by Stephen Wolfram but ran out of patience.

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My understanding and experimentation of bases other than the decimal number system is fairly rudimentary. I find it extra-ordinary that my friend Sid can perform arithmetic operations on binary, octal, hexadecimal and even trinary! number systems at an amazing speed inside is head. But it takes a true genius (No offence Sid), to invent something as wacky as a Quater Imaginary Base Number System !
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One of the best things about Solaris is that it has got absolutely awesome debugging tools like mdb and kmbd, leave alone dtrace, apptrace, adb, kadb, dbx, truss, proc tools and the lot. One whole week of single stepping in mdb to find the cause of a bug did not result in any Eurekas. In desperation, I tried coaxing Bryan to help me with the problem, and even that didn't work out. So I quit poking around with that bug. But there is an interesting observation that rose out of the whole process …
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Game theory is the most fascinating subject I have ever understood and nothing in Game Theory has the kind of enigmatic history that Chess has. Babbage, Von Neumann, Turing, Shannon - Literally the "4" fathers of the modern computer, all had a dream of creating a chess playing automaton that would eventually beat a master human player. Their dream was achieved only when Deep Blue beat Kasparov on a historic day in February 1996. But ages and ages before that, a guy called Wolfgang von Kempelen, created a mechanical chess playing device that beat human players hands down (Napoleon Bonaparte was one of its victims). What was the secret behind that machine ?

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Its not rare for me to face the question “So, How do you make money ?” when I say that my company gives away its operating system for free. Yeah, Sun did “sell” Solaris a few years back but how many people do you think would have bought the OS alone without buying the Hardware ? That just let me wonder as to why people think you need to sell software at a price to make money.

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For the past two weeks, work became more fun than usual. Anything other than what is classified as work you are normally expected to do, falls under the “fun” category. I was busy doing my favorite job of “talking” (about Branded Zones) to Sun Engineers across the globe. It was a terrific experience ! And the last two days were even more fun - we conducted a hack-fest/trouble shooting contest at the RV college of engineering, Bangalore. I cooked up some interesting unix problems and with the help of the solaris geeks, gurus and geniuses here, we came up with ten moderately tough problems for the students to crack.

One of the simpler problems that we had was this:

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AMD DevCon 2006 happened today in Bangalore at the Taj Residency. This was the first time AMD was conducting a developer conference in India. It was somewhat similar in objective and organisation to the Intel Developer Forums (IDF) that happen every year. System Programmers ranging from BIOS Developers, Device Driver Developers, Operating System developers (yours truly), game developers, enterprise application developers - particularly those concerned about the 64 bit phenomenon were attending the show. To be frank, the morning session was mostly crap. Just some marketing junk spoken by some CXOs who have no clue about technology. But the afternoon session was excellent.

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