Thursday, September 30, 2004

Special K: Take 2

Upon my arrival home last night:

D: You should help finish the vat o' noodles in the fridge.
J: I'll do that. By the way, what are you going to do about that milk?
D: Milk?
J: Yeah, the bad stuff that's a week past the expiration date. Elena had her coffee before I had cereal yesterday, so I got a heads-up.
D: Oh! I'd never had Special K before, and I just thought that was what tasted terrible.
J: And you bought two boxes!

Around this time, Jim began to laugh, and ceased to communicate effectively for a minute or two. After that, we established that I'd bought the milk at Long's just a day ago; that there was a sale on Special K; and that Jim had bought a replacement gallon which was sitting in the fridge beside the sour milk.

I ate a bowl of Special K this morning. Guess what? It tasted pretty good.

  • Currently drinking: Black coffee

Wednesday, September 29, 2004

Editing fool

I am revising a paper, and I'm in the middle of a particularly thorny section. In an earlier round of editing, I scribbled in the margin that I would like a cleaner presentation of this section; now, I've decided to quit procrastinating and actually clean it. In the process, I've gone from thinking the author is a lot smarter than I am to thinking what was this idiot author thinking? Of course, I'm the author who is the target of this alternate admiration and accusation.

My current method of revising papers involves a fountain pen, a legal pad, and a lot of time writing longhand from a printed page. One advantage of this method is that it's impossible for me to skim, no matter how familiar I am with the contents of the formula; consequently, I catch a lot of punctuation errors, notational inconsistencies, and similar types of mistakes. When I re-write my theorems longhand, I also more easily find places where I've been too loquacious (and my fingers start to ache) or too curt (so that I can hardly decipher what that fool author wrote).

The main disadvantage of this editing method is that I go through ink cartridges quickly. I suppose I'll visit the stationery store when I walk to Soda tomorrow.

Special K

When I went shopping for milk and cereal and machine oil yesterday, I picked up two boxes of Special K. I hadn't had Special K before, but it was on sale, and I'm not a picky eater, so I figured I would give it a try. So this morning, I poured myself a bowl of Special K -- and it was awful.

Have you ever had a multivitamin that makes you feel sick? I have a bottle of them at home, which I bought some time ago with good intentions of taking one a day. It's probably just the brand, but on no fewer than four occasions, I've tried taking them, only to discover that if I have a vitamin pill with my breakfast bowl, the back of my mouth fills with an awful metallic taste and neither vitamin nor cereal will stay down. Special K delivers that same special taste at the back of my tongue, the sort of flavor you might expect to get if you took light corn syrup and dissolved a lot of copper and sulfur and iron into it. It doesn't make me very nauseous, though, so I'll probably finish the box and rinse with mouthwash after each bowl, and never buy Special K again.

Well-intentioned advice can leave an awful taste in the throat, too. I got a dose of Special K advice today (mixed with some pretty good advice). Afterward, I spent a few hours wanting to avoid the world, and so I took my work home. Actually, that's overly dramatic -- I went home because my lunch was there, and because I wanted to sit away from my books and computer resources while I worked on a writing task. But I did leave the office in a markedly anti-social mood, which has fortunately now passed.

  • Currently drinking: Rooibos

Free food

Last night when I left Soda, I took with me a tray of fried noodles with chicken and shrimp that was left over from an IBM recruiting event. Huzzah for free food! Several meals worth of free food, actually.

I think I should go home and eat some of that food now.

Tuesday, September 28, 2004

Mental models

I spent an hour or two yesterday evening correcting a problem in the error-handling code for one of the finite element programs I develop. Today, I spent some hours tracking down a problem in the eigs routine in MATLAB R14. There were two issues, one of them subtle and the other obvious but hard to locate (it resulted in a negative value which would be theoretically impossible -- even in floating point -- if things were working right). This evening, I walked to Long's to buy machine oil so that I could fix the office door lock, which had become nearly impossible to open.

In total, I've spent about half the productive hours since this time yesterday working on fixing problems with one thing or the other. But it's easy to see how those few hours could have become an entire week. So why didn't they?

The reason I'm spending this evening trying to clarify several pages of tedious algebra that I wrote a year ago rather than trying to diagnose problems with eigs and locks and sealing wax is that I have a set of mental models -- of all sorts of things -- that I can employ to find likely problem causes and solutions. My mental model of a lock is pretty crude -- you push in the key and it lifts the pins -- but it's sufficient to tell me that a little oil will probably help things along. My mental model of what goes on inside of eigs is a good bit more sophisticated, and includes a general mathematical component (which is what told me something was very wrong when I got negative numbers for this particular problem), a software architecture component (which told me where to start looking in a thousand line mass of MATLAB code), and a numerical analysis component (which told me why one of the bugs has probably remained undiagnosed for the past several years, and has made little difference to many users). My mental model of my own code is even more sophisticated, since I wrote the thing, and since I've been writing similar codes -- and thinking about how they should be written -- for a few years now.

Now, this collection of mental models is pretty handy for me. Some of those models contain a lot of details that few other people know about, which is probably why people knock on my office doors and ask me questions and then get excited by the simple (sometimes) answers and go off to do cool things (this is how most of my current collaborations got started). But I have not yet figured out how to do a telepathic brain dump to instantly teach another person everything I know about computer arithmetic or real analysis or mixed-language software engineering. I've been tuning some of those skills for over a decade, and while it takes me less time to teach them than it did for me to learn them, it's not an instantaneous thing. But I have more ideas than time, and I would dearly love to give someone enough of my mental models to make some headway on the ideas I end up neglecting.

I suppose I ought to finish being a graduate student before I start aspiring to take on students of my own.

  • Currently drinking: Jasmine tea

Monday, September 27, 2004


Bill Gates is coming to speak at the Berkeley campus this Friday, and the CS graduate student mailing list is full of chatter. There have been several announcements for tickets; and a few mailings about organizing a possible protest, mostly from people who think it is a good idea, but also from at least one person who thinks a protest would be disrespectful to a guest. I have enough on my plate that I don't plan to go to either talk -- I'll go to talks with more information density if I go to any this week -- but all the sound and fury has set me to thinking: why do so many people hate Microsoft?

I do most of my work on Linux boxes, and split the remainder of the time using either Windows or some other UNIX variant (usually Solaris, sometimes HPUX). The tools I use -- LaTeX, gcc (and g77 and g++), emacs, Matlab, and a host of numerical libraries -- play reasonably nicely together under Linux, and I know how to fix things when they don't. My desktop environment is sufficiently transparent by now that I can concentrate on doing work rather than on working around glitches. And I'm happy to be in a situation where I'm encouraged to distribute my software freely, since academic CS departments produce ideas as their primary artifact, and code is just one means of distribution.

Now, suppose I were to change any of the variables involved. What if I hadn't learned a lot about UNIX and related systems through exposure as an undergraduate and through long-time use? What if I didn't spend so much time working with numerical software where the ability to mix languages is so critical? What if I spent less time writing mathematics and wanted to spend more time writing leaflets? What if my presentations included fewer equations and more media clips? What if I was trying to write programs for a mass market? Or -- heavens help me -- what if my favorite game were something other than Tetris?

For me, it takes very little time using a Windows system -- even if something like Cygwin is installed -- before I realize that it doesn't have all the facilities of a well-configured Linux box. I remember this every time I try to recompile and debug my numerical codes for Windows, and find myself missing some favorite tool. There is no valgrind for Windows, and compiling MEX files that combine Fortran and C++ is a lot harder there. On the other hand, if I want to play video games with snazzy graphics, I'm going to use Windows. And as frustrated as I can get during those rare times when I have to use Word or PowerPoint, trying to use OpenOffice is still worse.

Linux is not worse than Windows. Windows is not worse than Linux. If I had to choose, I would probably rather have Linux, since it personally supports more of the tools I use (at least, tools that I use now -- I wrote closed-source Windows code part-time as a high school student and an undergrad, and tools like Borland C++ and Delphi were awesome for the type of work that I did then). I'm also a graduate student in computer science, which means both that I like to read source code sometimes and that I'm fully aware when I pay for software that I might rather be buying food or books or burlap sacks full of Lithuanian gerbil food. Okay, perhaps not the gerbil food, but you get the point. In my present circumstances, using Linux makes a lot of sense. But in other circumstances, it doesn't make so much sense, and I'm not so biased that I'm going to shun all Micro$oft software to make some sort of statement.

Bill Gates is a businessman whose name lends itself to bad puns (of course, I think it's hilarious that Richard M. Stallman is always referred to as rms -- the same initials used for root mean square -- so perhaps I'm a bad judge of name pun-ability). Microsoft is a business, and while I think some of the strategies they use are questionable, I don't think it's a Blood-Sucking Vampire Company (suck you dry in ten minutes or the next death is free!). If you want to be outraged, be outraged at a tobacco company. If you want to ponder questionable business ethics, look at medical insurance operations. For that matter, look at Haliburton. There are bigger fish to fry than Microsoft.

Besides, oh ye open source advocates, Microsoft is good for Linux. Yes, they break standards, and make interoperation a pain in the ass. They also have user interface people who don't think ps -a | awk '/matlab/ { print $1 }' | kill -9 is an intuitive way to stop an errant process. Most of Linux's office software uses interfaces similar to Office products, and in the areas where the two diverge, it's not always the open source version that's doing it right. And LISP may beat VBA hands-down as a scripting language -- it's certainly more elegant -- but do you really want to have to teach recursive thinking to a business major who dropped an introductory CS class after two weeks out of utter frustration (and out of the clever realization that MIS majors might have more time to pursue members of the opposite sex, get drunk, and scope out the Lithuanian gerbil food black market)?

Write useful software that runs on more than one platform. Analyze Microsoft's flaws and tell the world in a way that forces Microsoft to fix the problem or be punished in the market. And when in Berkeley, perhaps, protest, if only so you can tell your grandchildren about it when they start asking embarrassing questions about your past history dealing Lithuanian gerbil food. But really hating Microsoft is probably a waste of moral outrage, and certainly a waste of time.

  • Currently drinking: More rooibos

Sunday, September 26, 2004

For Dummies

Who first said something or someone was too stupid for words? It's an unfortunate phrase, since as English speakers we have a lot of words at our disposal to say how stupid something might be. Whether it was coined out of a (misplaced) surplus of diplomacy or a deficit of creativity, it is hardly as cutting a comment as it might once have been. That is because we are entering The Age of Aquarius for Dummies!

I did not see The Age of Aquarius for Dummies in Barnes and Noble. I did see Chihuahuas for Dummies, and Hockey for Dummies, and RF Engineering for Dummies. If I spent a little more time browsing in Barnes and Noble and a little less time staring at the shelves in the math library or the shelves in my office, I might start to automatically associate yellow covers with the phrase For Dummies; but I have too many Springer math books with bright yellow covers, and a title like Perturbation Theory of Linear Operators for Dummies seems unlikely to yield much profit. I also flipped through an essay in The Philosophy of the Simpsons about Lisa Simpson and American Anti-Intellectualism (it was after the chapter on Homer and Aristotle).

The For Dummies series doesn't particularly bother me -- no more than the woman with the worn pump sneakers making asthmatic-pug-dog noises who dawdled up the hill in front of me this morning. It's more like mushrooms growing after a rain storm, paper mushrooms with virulent yellow covers which are fascinating to observe and perhaps, with some expert guidance to help avoid unfortunate side effects like hallucination and death, good to eat.

I passed the Dummies books by on general principle, but I did buy something from Barnes and Noble this weekend. Actually, I bought two somethings. First, I got the next book in O'Brian's Aubrey and Maturin series, which I will probably put info my fiction reading queue immediately after Count Zero. Second, I bought Joel on Software, a collection of essays much like those on the web site, which is amusing for many of the same reasons most things written by Eric S. Raymond are amusing. The essays are insightful, and possibly relevant to me as a software worker... but who am I kidding? I got it because of lines about carpenters who are only allowed to use nails and they stamp them into the wood with tap-dancing shoes because nobody told them about hammers. The book is funny.

Of course, this may be the same sort of humor that led to Dave, Patxi, and I gasping with laughter over our idea of putting a T-Rex skeleton on a shake table fitting it with sensors, hiring undergrads to wrap wet towels around the joints, and trying to use this to build an experimentally verified single degree-of-freedom model for a running dinosaur. We thought it was hilarious; Winnie and Esther were mildly amused, and most of that amusement probably came from watching us laugh. But while ridiculous jokes, bad puns, and poetry about branch predictors may not be the best way to win friends and influence people, they're still a lot of fun for me and thee (assuming thou hast as quirky a sense of humor as I have).

On an unrelated note: Winnie and I walked to the Pacific East Mall in El Cerrito on Saturday in order to have some pho and look at Chinese language books (I found a book with color pictures of espresso drinks which was pretty, if incomprehensible). There I learned a valuable life lesson: soda drink with preserved plums should properly be translated as carbonated brine with brown lumps. Exploration is good, but perhaps next time we'll stick to lemonade or Thai iced tea.

Thursday, September 23, 2004

Fallacies, fallacies

My office mate sent me this classification of various fallacies from 1962. How many of them have you seen used this week?

Sunday, September 19, 2004

Gardening at night

I'm alone in the office now. Perhaps not so surprising, given that it's 11:30 on a Sunday. I finished what I needed to finish this weekend, if not all that I wanted to finish; and so now I'm taking a few minutes to just enjoy the quiet.

When it's just me here, I can listen to the radio on speakers rather than on earphones (the program right now is World Cafe, a PRI program). I can take breaks to stretch or practice kicks without unnerving anyone. I can pace, or hum absent-mindedly, or gaze into space without unintenionally staring at someone (I'm told this can be unnerving).

I appreciate my time alone, whether it's spent working or playing or just thinking. I think I appreciate it more late in the evening; social graces take some effort for me, and when I start to wind down for the day, I become even more reticent than usual. I'll smile; I'll listen, and even listen actively; but I won't feel like saying anything for myself. So ask early if you want to know what I thought about that REM song, or about the two gentlemen practicing in the park this morning. (A word to the wise: guard your head, particularly if you favor a stance with your weight balanced forward -- and if you're going to use that style of leg block, put some thought into covering your groin, too.)

Mathematical book reviews

In the most recent SIAM News, there is an article on mathematical fiction. I read it and added several more books to my reading list. I was pleased to see that Kasman's list included Clifton Fadiman's Mathematical Magpie, which was one of the books I enjoyed from the Bel Air library when I was in high school.

Actually, most of the SIAM News book reviews make interesting reading. I should add that the books are usually accessible to a non-specialist audience. Quickly browsing through recent issues, I was also reminded of Philip Davis's review of a book of scientist's diaries. And now my reading list is even longer.

Saturday, September 18, 2004

Mathematical Intuition and Millennium Problems

I have been busy juggling these past few weeks. But now the most recent paper deadline is met; the presentation materials for Tuesday are in hand; my computers are stable and mutually consistent; my desk and my home are both clean and organized; and I lack neither staples to attach my papers nor staples to make my meals (man does not live on ramen alone). I've even managed to deal with most of my technical support mail. So this evening I sit with pen and pad and a pot of tea to finish a thought from the start of the month. (As an aside: I wrote most of this, including the previous sentence, on Thursday night -- but I'm just now typing on Saturday morning.)

At Half-Price books two weekends ago, I found Keith Devlin's book The Millennium Problems sitting neglected on a corner shelf. I have a special place in my heart for popular writing by mathematicians like Ian Stewart, Ivars Peterson, and Martin Gardner -- I had their books checked out from the Bel Air library half the time when I was in middle school, and I continue to find them entertaining and interesting today. I know a mite more mathematics now than I did then, but the writing often focuses on history, applications, intuitions, and puzzles centered around some mathematical idea or set of ideas; and so even when I'm familiar with the mathematical idea, I still enjoy the reading. For the same reason, I enjoy reading articles on science written for a popular audicence. Devlin, who may be most familiar as the Math Guy on NPR, has an engaging writing style, and his topic -- the Millennium Problems, seven great unsolved mathematical challenges with million-dollar bounties on their heads -- is something I wanted to know more about. After reading the introduction, I bought the book in happy anticipation of a good read.

Besides, the man has an extinct species of possum named after him. What's not to like?

As I read, I found exactly what's not to like -- at least, I found points in the presentation that I very much disliked. Devlin undertook a monumental task: not just to explain the history and the impact of the Millennium problems, but to give a flavor for the problems themselves -- assuming a reader with only a pre-calculus grounding in high school mathematics. As Devlin puts it,

Even achieving a layperson's knowledge of what [the Millennium problems] are about takes considerable effort. I believe the effort, however, is worthwhile. Aren't all pinnacles of human achievement of interest?

But the challenge was too great. Devlin explained the problems at a lay level better than I could have done; but then, I don't know how someone could think about some of these problems without knowing -- really knowing, not just having some vague familiarity with -- some group theory, elementery number theory, and the basics of differential calculus. Devlin gives a creditable introduction to some of this background, but it is not enough, and by the end he is reduced in his frustration to section titles like The Hard Stuff, Made as Easy as I Can and The Hodge Conjecture: Not for the Faint-Hearted.

For most readers, the description of cohomology classes in the last chapter would probably be impenetrable. For me, it was frustrating. After all the effort of sketching in the technical background, an effort which will likely go unappreciated by most of your readers, why not finish the sketch for me? Just a little more technical detail? Somehow I ceased to react to the book as the popular exposition it was meant to be, and started to treat it as an inadequately fleshed out technical work -- which it was certainly not meant to be.

I was irked. I was sufficiently irked that I wrote a letter to a friend which fell somewhere between a lecture and a tirade, in which I tried to describe what I disliked in Devlin's book. I wondered almost as soon as I sent the letter whether I hadn't been unduly harsh -- but Yi shared an office with me for a while, and had plenty of opportunity then (and since) to become accustomed to the flavor of my unprompted lectures. So I expect she will take it in stride.

After reading Devlin's book, and after spending some time grumbling, I began to think more about the nature of mathematical intuition. In the first chapter, Devlin has a section entitled Why Are the Problems So Hard to Understand? in which he argues that the level of abstraction from everyday reality makes mathematical ideas harder to explain to a lay audience than are ideas from any area of science. At the same time, as he says near the end of the book,

... a trained human mind that has thought long and hard about a particular problem frequently develops intuitions that prove to be correct.

The problem, then, is not that there is no intuitive picture of the ojbects of higher mathematics -- just that such pictures are inaccessible without a lot of patient thought. I disagree with Devlin's assessment only in one point: I believe there are concepts in modern physics and chemistry which require abstractions which are fully as inaccessible to the lay reader as any of the Millennium problems (which is probably why two of the Millennium problems -- mathematical understanding of the Yang-Mills field equations and the solution of the Navier-Stokes equations -- come directly from modern physics).

So why is popular science still so much more popular than popular mathematics? And why does modern math have such a reputation for impenetrability, particularly when -- in contrast to the experimental sciences -- intuition can be had for only the cost of time and thought? Part of the trouble, I think, is educational. Think when the scientific method was first mentioned to you in an elementary science class -- and then think when the idea of a mathematical proof was first introduced. Do you know more names of physicists from the past two centuries than names of mathematicians? Difficulty alone cannot account for the difference in perception; nor, I believe, can the relative distance from everyday reality.

I don't have good answers to the questions why is it so hard to understand? and why should science seem any easier? But I'm still thinking on it. Maybe one day I'll gain enough psychological intuition to understand how people gain intuition -- but I doubt it. Mathematics is easier to understand than people are.

Works considered

This started off longer, and got shorter as I realized I wasn't sure I agreed with my own ideas. Consequently, this list is not a collection of works cited, but rather writings that I looked at during some version of the above.

  1. Nature's Numbers (Ian Stewart); Islands of Truth: A Mathematical Mystery Cruise (Ivars Peterson) -- Peterson's book was definitely one that I kept checking out from the library. I forget which of Stewart's books the library had, but Nature's Numbers is a good one in any case.
  2. Mathematical Association of America -- The MAA does a lot with mathematics education and popularization. Both Ivars Peterson and Keith Devlin write regular columns for the MAA, which are available from the web site.
  3. The Honors Class: Hilbert's Problems and Their Solvers (Paul Yandell) -- Perhaps a natural complement to a book on the Millennium Problems. The Millennium Problems were deliberately introduced 100 years after Hilbert introduced his list.
  4. The Man Who Loved Only Numbers (Paul Hoffmann); A Beautiful Mind (Sylvia Nasar) -- Biographies of two modern mathematicians. I thought both books were fascinating. No, not all mathematicians are so nutty.
  5. Men of Mathematics (E.T. Bell) -- Biographies of some major mathematicians up through the end of the nineteenth century. There are more accurate historically accurate books on the history of mathematics and on historical mathematicians; but it is hard to find another book which is so enthusiastically and charmingly written. Mathematicians were Bell's heros; and he made a few of them my heros, too.
  6. Fermat's Engima (Simon Singh) -- I have intended to finish reading this book for years now. Two of them, actually. But I particularly wanted to mention a quote from the dust jacket, which I repeat here in full:
    Perhaps I could best describe my experience of doing mathematics in terms of entering a dark mansion. One goes into the first room and it's dark, really dark, and one stumbles around bumping into the furniture. Gradually you learn where each piece of furniture is, and finally, after six months or so, you find the light switch and suddenly it's all illuminated and you can see exactly where you are.
    -- Andre Wiles
  7. The Value of Science: Essential Writings of Henri Poincare (Henri Poincare; ed. Stephen Jay Gould) -- Poincare has much to say about the role of intuition and experiment in mathematical inquiry. A profound and prolific mathematician, Poincare turned late in life to writing for a popular audience. His publications were deservedly successful, and are worth reading as a model of accessible exposition, as well as for the ideas they contain on the nature of mathematics and of science.
  8. Linear Differential Operators (Cornelius Lanczos) -- Really, any of Lanczos's books would serve as well, but Linear Differential Operators has a few wonderful paragraphs at the beginning in which he describes the goal of his expository style. In contrast to the very formal presentations of N. Bourbaki (Bourbaki was actually the nom de plume taken by a school of French analysts), Lanczos concentrates less on the details of the analysis and more on high-level intuitions. The Variational Principles of Mechanics is another excellent text in the same style; it was one of my primary texts in learning about classical mechanics.
  9. Catastrophe Theory (V.I. Arnol'd) -- Usually Arnold writes more technical books, and when I found this on the shelf at Black Oaks, I was delighted to find that it was written for a general audience. It's short, interesting, and full of both dry humor and intuition.

Tuesday, September 14, 2004


  • Rooibos is actually pronounced roy-boss.
  • Pico de gallo translates to rooster's beak -- a little peck of flavor.
  • For complex symmetric M, K, the expression (vT K v) / (vT M v) is more accurate than the standard Rayleigh quotient for estimating an eigenvalue from an approximate eigenvector v, assuming vT M v is nonzero.

So now you know.

Sunday, September 12, 2004

Remote thoughts

It was spring or early fall, and the lot of us spilled onto McKeldin Mall, laughing and teasing. We were on the way to Plato's Diner for dinner, perhaps -- I know longer remember. There was a giggle and a charge, and then a weight on my back and shoulders. With no particular thought, I dropped my center of gravity, turning forward and aside just so -- and the weight was deposited in front of me on the grass.

I remember the smell of the grass. I remember she looked up at me from under a tumble of red hair. I don't think I've ever been so humiliated, she said. Have you ever tried to read an ambiguous expression on a face turned upside down? I'm not sure whether she was serious; but a moment later, she laughed, and we all continued our tumble toward whatever our destination might have been.

Nine years later, idly contemplating a laughing gaggle of undergrads sitting at a table across the room in La Burrita, it all came back. It was a minor incident, an acquaintance I saw little in my later undergrad years, and never since I graduated. I don't recall remembering it since. But for a moment, I smelled grass instead of salsa, and I remembered.

Memory's a funny thing.

On an unrelated note, the rdesktop protocol is pretty cool. My desktop at the office runs Linux, and I like it that way, but every now and then I have to work with Word documents or PowerPoint presentations. But since the department runs a Windows 2003 server that supports the rdesktop protocol, I can open a window that acts just like a Windows box. I'm restricted in what I can run on the server, so I can't use it to compile my codes for Windows; but even so, it's mightily useful.

  • Currently drinking: Black tea scented with caramel and memory


Why would someone think that reminding me of a deadline in bright blue capital letters in a large font would be any more effective than sending something politely worded in ordinary text?

Perhaps I could figure out how to use PowerPoint as a mail filter, so that any letters which were intended to be bright blue never actually appeared on the screen; or at least, so that they didn't appear until I restarted PowerPoint.

Wednesday, September 08, 2004


In one of the (unfortunately lost) comedies of Aristophanes the Voice of the Mathematician appeared, as it descended from a snow-capped mountain peak, pronouncing in a ponderous sing-song -- and words which to the audience sounded like complete gibberish -- his eternal Theorems, Lemmas, and Corollaries. The laughter of the listeners was enhanced by the implication that in fifty years' time another Candidate of Eternity would pronounce from the same snow-capped mountain peak exactly the same theorems, although in a modified but scarcely less ponderous and incomprehensible language.
-- C. Lanczos, preface to Linear Differential Operators

Tuesday, September 07, 2004

A tale of three Jims

  1. He taught my first undergraduate math course, a class on real analysis that gave most of us pause. When he explained things, he would lower his head and shake it from side to side, looking at you over his glasses. He gave us problems with the rejoinder That'll keep you out of trouble for the weekend! He constantly broke his chalk; and, like most of the professors I know who break chalk in mid-explanation, it caused him no end of irritation. In irritation, he once tossed a piece of chalk across the front of the room, sidehand, from where he was standing at the door. The chalk bounced four times; each time, the remaining chalk fragments snapped in half, so that a moment later, sixteen bits of chalk collided with the wall. It was all we could do to keep from laughing, but we managed it. He looked at the chalk for a moment, then returned to his lecture.

    He had a chair in his office for visitors: it was a drab upholstered affair, probably as old as I was; it looked like it would probably be comfortable. But it had no bottom to speak of, and so I would sit, precariously perched on the four inch width of board that formed the entire solid seating surface, and ask questions about tensors and algebraic k-theory. I used to ask his opinion on math courses at the start of the semester. That's a good course, he would say; take something with this guy, another time. Number theory! It's an interesting area, but here's the book they use for the undergrad course. You've had abstract algebra, and I know what you know. You could probably cover this material in a weekend, and a weekend spent in a bar, at that. When I told him I was going to graduate school to study numerics, he said numerical analysis!? in the tone most people would reserve for utterances like you're eating cockroaches!? But then he thought for a moment and said there was undoubtedly interesting stuff there, and I would do fine. Just don't forget the math.

    He gave us a homework entitled Eine Kleine Nachtmusik; one problem for each of us. He subbed for the graduate topology course once when I was taking graduate algebra; one of my classmates who took both courses summarized the lecture with the words Who was that masked man? It was in his class that I first really experienced mathematics as I see it now.

  2. He has a beard and glasses, an occasionally owlishly-serious expression, and the ability to cover technical material at a phenomenal rate. I know people who speak faster, but most of them don't really say that much with their words, or become incomprehensible as their rate of speech increases. He doesn't become less comprehensible, but sometimes he saturates his listeners -- too much information, too fast. He covers his book in one semester; most others teaching from the same text only go through half of it.

    The problems in his book are labeled easy, medium, and hard, and it was those labels which first clued me in on how differently we think about mathematics. Some of his medium problems, I find easy or hard; some of the hard or easy problems, I would call medium; and rarely I'll find something that he thinks is hard to be easy, or vice-versa. He is an extraordinary algebraist, far more so than I. His favored languages are Fortran 77 and Matlab.

    He seems to be constantly under threat of a deadline, but usually manages anyhow. He drinks an immense amount of coffee, usually as lattes. I have seen him look stressed, but only once have I seen him look fatigued -- it was in a lecture, and I thought he might have fallen asleep, until he sat up and asked a penetrating question. Each of his students works on something different; but somehow he manages to keep up with them.

  3. He was trained as an engineer, but was not happy working as one. He's a little shorter than I am, and nearly as lanky. I'm not sure he eats much more regularly. His passion is mountain climbing. His accent changes when he speaks with his grandmother on the phone; it changes from an American accent to a New Zealand accent. He's sometimes happy, sometimes brooding, rarely in the middle, always sardonic. He's laid back, with a quirky -- though sometimes ungracious -- sense of humor. He calls me guy, and I call him sir, and we get along just fine even when neither of us have the slightest clue what the other is talking about.

    He plays croquet, likes to have a beer with friends, enjoys rap music but listens to NPR when he's in a car -- which is rarely. He usually bikes or walks for transportation. He sometimes watches classic Star Trek re-runs on the Sci Fi channel, and sometimes I join him. He asked me today whether my shirt (which says Eschew Obfuscation) was geeky or nerdy. I told him I wasn't sure, and then explained what it meant. I wish you hadn't done that, he said, That wasn't the question I asked, was it? I think he was joking; but he delivers his jokes in a deadpan manner: the perfect straight man.

Monday, September 06, 2004

LCD Sunrise

An LCD Sunrise sounds like it ought to be some particularly toxic beverage, doesn't it? Something bright orange, naturally phosphorescent, and capable of stripping paint at twenty paces, perhaps.

I am writing this on my Thinkpad, now restored to normal function. The problem must have been a loose connector, since taking the thing apart and reassembling it seems to have restored it to normal function.

Saturday, September 04, 2004


It is the Way of the German First Person Plural Pronoun. It is not to be confused with the Way espoused by the Jedi Nuns: the Force of Habit. Will this punishing plethora of new paths never cease?

The Pile

The Pile on my shelf is coming of age. It used yo be a cute little pile -- you should see its baby pictures! -- but now it is sullen and wayward. If I do nothing, I fear it might spawn new baby piles, and then where would I be? Buried beneath a host of paper piles, that's where I'd be, or my name isn't Preserved Killick.

It doesn't do to anthropomorphize piles of paper, though, at least not within their hearing. The biological analogy is purely an accident of the s-shaped behavior of a paper pile's growth, so much like the shape of a logistic model. The pile starts modestly enough, then grows at an accelerating rate, until an external concern (like stability of the pile) imposes some restraint. The pile then grows slowly or stagnates until some catastrophe, like a collapse or a spring cleaning, spells doom for the pile as a single entity.

Thursday, September 02, 2004

UPS-y days, eh?

UPS delivered a book for me on August 31 -- but not to me. The customer representative was friendly, and figured out what went wrong.

It took me forever to figure out how to get parallel Matlab running on the local cluster (though Viral did most of the work). Eventually, I discovered it was an error in my .cshrc file. In the process of figuring that out, though, I learned some useful things about ssh, ssh-agent, and ssh-add.

A gentleman using my Matlab interface to the finite element code FEAP has been having persistent problems; I think this is because he is using an older version of the code. But he has done an excellent job in presenting his difficulties -- most people give too much information or too little -- and may go around the problem by upgrading his version of FEAP. And now I know another person interested in using my software.

A colleague is having problems getting results from ANSYS to match results from Sugar on some simulations. I have not yet determined the root of his problem, but I think I have a lead. If I'm right, it's not a bug in my software (hooray!), but a subtlety in the modeling. Modeling issues are much more interesting than software bugs. In addition, we have both learned a few things about frequency shifting due to residual stress -- a topic which I think does not relate to the mismatch between ANSYS and Sugar, but may explain some of the mismatch between the simulated and the theoretical results.

I looked up the warranty information for my laptop. The warranty period ended in May. But from the symptoms, the problem with my laptop is related to the backlight, which may have broken or may have simply become unplugged. Taking apart the screen to find out should be educational; and new backlights are cheap.

I am no Polyanna (though I could pretend to be a polyhedra if that would make a proof easier). But some days the world seems brighter for the bugs in it.

Boat Captain and the World of Yesterday

From O'Brian's The Fortune of War (p. 134), Dr. Stephen Maturin's comments on the merits of monarchy.

Man is a deeply illogical being, and must be ruled illogically. Whatever that frigid prig Bentham may say, there are innumerable motives that have nothing to do with utility. In good utilitarian logic a man does not sell all his goods to go crusading, nor does he build cathedrals; still less does he write verse. There are countless pieties without a name that find their focus in a crown. It is as well, I grant you, that the family should have worn it beyond the memory of man; for your recent creations do not answer -- they are nothing in comparison of your priest-king, whose merit is irrelevant, whose place cannot be disputed, nor made the subject of a recurring vote.

Squirrels cooked in madiera, indeed.

  • Currently drinking: Russian caravan blend

Wednesday, September 01, 2004

LCD Twilight

The backlighting on my laptop screen is no more. The image on the LCD is too faint to be useful, but I can still connect to an external monitor. The screen has been slowly dying for a long time, now; first the image was reddish, then increasingly hard to see, and then... vanished.

A sunset is a much prettier sight.

I've attached my laptop to one of the monitors in the office, and I brought in my CD burner. This evening, I'm backing things up.