Tumbolia

Courage now

2012-01-23T14:31:00.000-05:00

A. What is virtue? Perhaps the question is wrong, but suppose you were to characterize the habits and behavior you wish everyone would cultivate. What would make your list? There are many considered answers. For example, the ancient Greeks listed prudence, justice, fortitude, and temperance. Catholic catechism takes those and adds faith, hope, and love. The YMCA promotes caring, honesty, respect

Why do we indent code?

2012-01-23T13:58:00.001-05:00

Apparently one of the rules of Stack Overflow is that if enough people read and like a post, it gets deleted. Here is one of mine from two years ago. For a time, it was my top-voted answer. Q: The firm where I work has programmers who still don't seem to understand the importance of indentation and write all the code aligned to left margin. What arguments can I put to convince them of the

Opposing thoughts on teaching

2011-11-28T12:08:00.001-05:00

Some thoughts on teaching by Bret Victor. I used to think that to be a good manager of engineers, you first had to be a good engineer. I could name several particular managers in support of that theory, but that’s anecdotal evidence, right? And believe it or not I have a few counterexamples too. Now I think that management is many things, and there is more than one way to be great. Bret says that

Khan Academy

2011-11-21T16:17:00.001-05:00

Before reading this post, go to khanacademy.org and click on “Practice”. Play around with it for a while. Neat, huh? I turned J loose on it for a few hours. (J is eight years old, homeschooled, and way ahead of his age cohort in math.) He was absorbed for a surprisingly long time, he said it was “kind of fun”, and he learned a few things. Not bad! A few points to curb your enthusiasm: Khan

Nashville

2011-10-27T23:57:00.002-04:00

I didn’t know there was an Occupy Nashville, but there is. Protesters have been camped out in the Legislative Plaza since October 7. There are dozens there around the clock. And if you’re homeless in Nashville it is totally the place to be now. :-\ Amazingly, the state is trying to ban this protest. Effective today, there is a new curfew. Nobody is allowed in the plaza at night. If you want to

Oakland

2011-10-27T17:39:00.001-04:00

what it looked like to be there (warning: contains loud swearing and people acting like they’re in a movie) NYT blog Well, firing any sort of weapon at peaceful protestors is just wrong. People who would do that or order it should not be cops, because cops should have a level head and a sense of what amount of force is appropriate. The Oakland PD says some individual protestors were throwing

Ozymandias

2011-09-28T11:45:00.000-04:00

“Because limited written historical sources have survived, much of what we know about the Parthians”—a powerful empire that ruled Persia and neighboring countries for five hundred years, from the collapse of Alexander's empire to the heydey of Rome—“must be deduced from coins.”

Reasons for parental censorship

2011-09-28T11:33:00.003-04:00

Follow-up to Censorship. There are a lot of ways to be a dad. As always, what I’m writing here is meant as a partial explanation of what I do, never a rebuke of any other parent. 1.The Merch. Unfortunately this graphic got squunched when Penny Arcade redesigned their web site. This is, of course, not to be taken seriously. It’s an insane exaggeration of American kids’ media diet. But it’s still

Censorship

2011-09-08T20:02:00.002-04:00

We bought Apples to Apples Kids. I don't reflexively buy the “For Kids” versions of things, but Apples to Apples has enough political and pop culture references that it's not really a game four-year-olds can play. Anyway, the game comes with 216 noun cards. Olivia and I looked through them and threw away eleven cards. One was Recess. I've got nothing against recess, but the kids have no such

Bribes and rents

2011-09-08T19:55:00.001-04:00

Here’s a bit of a twitter conversation I saw this morning: @ModeledBehavior I prefer a politician who buys support with crooked land deals to one who does so by embracing obviously bad populist policies @mattyglesias In a non-agricultural society, crooked land deals are probably the optimal form of corruption. @ModeledBehavior Just transfer of rents right? In general, I'd prefer leaders who

The Blob

2011-08-22T12:29:00.006-04:00

Last week, my six-year-old daughter hopped on a bike and took off. Well that was easy. I’m pretty sure when I learned to ride a bike my dad had to exercise more patience than that. I don’t really remember, but let me just say with absolute confidence: there was blood. Probably some pants had to be thrown out. I don’t think my daughter even skinned a knee. It was ridiculous. The same week,

Appalachians

2011-07-08T11:15:00.004-04:00

I've been reading about geology, the most epic of the sciences. Long ago, the continent of Africa collided with what’s now the east cost of North America. The collision lasted for, oh, eighty million years and left behind... the Appalachian mountains. The Appalachians you see now are not the originals, though. Those were some serious, Himalayan-scale mountains, but time and water wore them away

Powerful stuff

2011-01-18T02:44:00.006-05:00

Martin Luther King’s I Have a Dream speech is full of poetry, metaphor, and allusion. Twice King quotes Scripture. Amos 5:21-24 is one of the few places in the whole Bible where God is actually said to hate anything. It is nonetheless my favorite passage in the entire Old Testament, the one that I think comes closest to reconciling fire and brimstone with love and mercy. The verse King quotes

Dangerous eggs

2011-01-13T10:22:00.004-05:00

Among the dangerous contraband items U.S. border officials look for when they search your car are Kinder Surprise candy eggs. The CBC has an account of one seizure. Punchline: As trivial as the border seizure may seem, Bird said the U.S. government has sent her a seven-page letter asking her to formally authorize the destruction of her seized Kinder egg. “I thought it was a joke. I had to read

Wikileaks, journalism, and espionage

2011-01-11T17:09:00.001-05:00

WOLF: Jeff, can I talk about the Espionage Act because that's really what's at stake now that they've invoked it. I predicted in my book The End of America that sooner or later, journalists would be targeted with the Espionage Act in an effort to close down free speech and (INAUDIBLE) of government. And we have a precedent for that. In 1917, the Espionage Act was invoked to go after people like

Things I learned recently

2011-01-11T08:56:00.001-05:00

Handmade paper does not have a grain. The fibers stretch out in random directions. But factory-made paper uses a process where water flows across the surface of the paper as it forms. Take any sheet of printer paper and you'll find that you can curl up the long vertical edge over using less force than the shorter horizontal edge. Even though you're bending more paper the long way, you're bending

The Aztec merchants

2010-12-20T20:07:00.004-05:00

Trade in the Aztec empire was mostly barter, but I'm surprised to read that a few commodities were plentiful, portable, durable, interchangeable, and stable enough to serve as money. “Cacao seems to have been the most common form of money, and it did, indeed, grow on trees. It was widely accepted as payment for both merchandise and labor.” There were even, this book claims, cacao counterfeiters.

Easier said than done

2010-08-31T01:09:00.003-04:00

Epictetus wrote: 15. Remember, you must behave as you do at a banquet. Something is passed around and comes to you: reach out your hand politely and take some. It goes by: do not hold it back. It has not arrived yet: do not stretch your desire out toward it, but wait until it comes to you. In the same way toward your children, in the same way toward your wife, in the same way toward public

2010-08-17T02:19:00.000-04:00

In prose these days, the style is to be plain. Use common words; be forthright and succinct; Avoid formality; use active voice: In short, say what you mean and nothing more. These rules apply whatever you may write, To traffic signs and novels just the same. And in return for hewing to these rules, The writer gets free rein, a blank white box In which to dump his brain without a care For form

Problems that are too hard

2010-08-17T01:56:00.000-04:00

I am self-conscious about homeschooling. It's not something I would have thought to attempt, if it were just me. I believe teaching, like any skill, improves with practice and study; and I have neither practiced nor studied teaching young children. I think most kids learn more when they spend more time studying; and my six-year-old spends a lot less time “at school” than I did at his age—by a

Homework

2010-08-16T06:14:00.000-04:00

Earlier this year I suddenly remembered being taught in school to answer questions of the form “What is the difference between a delta and a wetland?” by copying the definitions of the two terms out of the book and putting the word while between them. Imagine writing this out in cursive on notebook paper: A delta is a low triangular area of alluvial deposits where a river divides before entering

2010-07-07T01:23:00.004-04:00

Near the beginning of The Port-Royal Logic there is a brief and somewhat odd discussion of the Pyrrhonists and the Academics, and I guess Michel de Montaigne: We may indeed easily say outwardly with the lips that we doubt of all these things, because it is possible for us to lie ; but we cannot say this in our hearts. Thus Pyrrhonism is not a sect composed of men who are persuaded of what they

Questions about net neutrality

2010-05-06T11:22:00.000-04:00

(I originally wrote the following in October 2009, but did not publish it because it seemed likely that I just didn't know what I was talking about, and everything was OK. That's still likely, but recent events suggest I could be wrong about that.) This video starts out great. It's about what makes fertile ground for innovation. After about 2 minutes, it goes off into “I have a right to Internet

A story with some scary parts

2010-04-19T14:35:00.004-04:00

My four-year-old and I decided to collaborate on a book. I was surprised when she decided the story should have some scary parts in it. Like a dragon, she said. Or the dark, I said. Like a dark cave, she said. Here's what I ended up writing. The snow fell harder and harder. I remembered that polar bears dig dens in the snow. So to escape the biting wind, I begin to dig. Suddenly the ice and

Infinity, part 2: Zeno's paradox

2010-01-21T11:36:00.001-05:00

(An ongoing series. See part 1.) In this capricious world nothing is more capricious than posthumous fame. One of the most notable victims of posterity's lack of judgement is the Eleatic Zeno. Having invented four arguments all immeasurably subtle and profound, the grossness of subsequent philosophers pronounced him to be a mere ingenious juggler, and his arguments to be one and all sophisms.

Perfect cinnamon twists

2009-12-22T11:42:00.005-05:00

This is a great recipe for beginning bakers. They come out light and fluffy. If I can make them, so can you. Bring to boil in large saucepan: 1 cup sour cream Remove from heat. Stir in until well blended: 3 tbsp shortening 1/4 cup sugar 1/8 tsp baking soda 1 tsp salt Cool to lukewarm. Add: 1 large unbeaten egg 1 package of dry yeast Stir until yeast is dissolved. (At this point you

Mathematicians in training

2009-12-06T08:55:00.004-05:00

First off, if you haven't played Set, you really should, because you're just the sort of person who would love it. It's a clever idea elegantly executed, and it just happens to be great competitive fun. I taught the kids to play, and the four-year-old has a definite edge on the six-year-old. I couldn't be more pleased. We had a bit of a drive yesterday, and along the way we gave the kids some

Milestone

2009-10-14T10:34:00.002-04:00

I probably learned about variables from playing around with a Commodore 64 when I was about the age you are now. But I didn't see them used in mathematics for many years, until they were finally introduced, in about 7th grade, as a tool for solving problems. Take a problem, write down the equation, putting variables for the unknown quantities, and then you have something you can solve. A little

Prehistory, continued

2009-09-13T09:48:00.002-04:00

I guess I always thought of technology as strictly cumulative, but reading a little about the Stone Age dispelled that notion. Archaeologists have had to reverse-engineer, from the artifacts they left behind, the toolmaking skills and technology of extinct cultures. How did Cro-Magnon mammoth hunters store meat? Wouldn't it spoil? Well, we really don't know that sort of thing anymore, but there's

This week I learned...

2009-09-11T06:05:00.001-04:00

It's prehistory week at the jorendorff household. This week I learned: The fossilized skeletons of a 14-foot Xiphactinus (a mean-looking Late Cretaceous fish) and its last meal, a merely 6-foot bony fish which it swallowed whole, are on display at the Sternberg Museum of Natural History in Hays, Kansas. Woolly mammoths had a three-inch-thick layer of fat underneath thick skin, fur, and

Steampunk 4 life

2009-08-25T08:26:00.003-04:00

“But surely (said I) that would make us Slaves to these Automata, if indeed they did not destroy us altogether.” “Nay (quoth Doctor Albertus), it is not the Extinction or Enslavement of our Race that I see when I gaze into the Future of Mankind. On the contrary, I see naught but Liberty. There are some among us destined to be Monarchs, but how many are they? Each Country admits of but one

Lockhart's Lament

2009-07-02T15:52:00.005-04:00

Lockhart's Lament (PDF, 25 pages) starts out like this: Everyone knows that something is wrong. The politicians say, “we need higher standards.” The schools say, “we need more money and equipment.“ Educators say one thing, and teachers say another. They are all wrong. The only people who understand what is going on are the ones most often blamed and least often heard: the students. They say, “

The ring Z[i]

2009-07-01T08:08:00.006-04:00

This is a little self-portrait, "The Artist Trying to Learn Abstract Algebra", probably of no interest to anyone else. I read an introduction to rings (in Gallian, fifth edition, which I enthusiastically recommend). Now I'm trying to come up with some conjectures and prove or disprove them before I start on the exercises. (This book has great exercises, and doesn't bother teaching anything in

A storytelling game

2009-06-22T12:35:00.004-04:00

I've played this game a few times now and have really enjoyed it. I've only tried it with two players. It might work with more. Rules Each player starts by jotting down a very brief story outline: just five lines. Each line should be seven words or less. It's OK to steal the outline of a familiar story, as in the example below. a girl in red a wolf with a plan the wolf eats grandma the

Stoicism, Christianity, and Mother Goose

2009-05-19T22:17:00.001-04:00

I read the Handbook of Epictetus. It's very brief, just a few pages really. I'll quote a few paragraphs that should make it clear what Stoicism is about. (I'm quoting a recent translation by Nicholas P. White which I really like. The translations I found on the Web seem stilted, or florid, by comparison; though Higginson isn't bad. Of course you can try the original Greek.) Some things are

Sonnets

2009-05-18T05:00:00.000-04:00

Once I wrote two lines of what would have been an awesome sonnet. Shall I compare you to my friend Matt Jones? You are more lovely and not half so drunk. In San Francisco, while everyone else was napping, I managed to sneak out to City Lights Books. There I stumbled on Sonnets by Giuseppe Gioacchino Belli, translated by Mike Stocks. Translated. Imagine translating sonnets. I opened it up and

Recently I learned...

2009-05-09T13:08:00.001-04:00

Your browser uses the public suffix list to determine whether two web sites may share cookies. This is not very robust but better than the previous strategy. If you take a long strip of paper, fold it in half as many times as you can, and unfold it, it'll make an approximation of the fractal shape called the Heighway dragon. If you take two fractions, say 1/2 and 1/3, and add the numerators

Learning in games vs. applications

2009-05-09T11:05:00.002-04:00

I was talking to one usability expert and he was describing how they measure task completion. Did the user press the buttons in the right order? Their ideal app resulted in new users completing tasks 100% of the time. This isn’t exploratory learning. You need to be able to fail and explore the possibility space of a particular tool. Through repeated failure and success, users build up robust

Handlebars

2009-04-06T14:39:00.004-04:00

Hey, listen to this song: Listening to the first 15 seconds, I didn't think I was going to like it. The reasons I like this song are interesting enough to write about at length, but... oh, just hit the button.

In which something is beeping

2009-04-05T06:05:00.005-04:00

Several years ago I predicted that in the future there will often be a mysterious beeping which no one can identify or locate. This has happened to me several times since then, but tonight was special. Something kept going BEE-doo loudly, about once every two minutes. I suspected the smoke detector and my laptop before tracking the noise to a cell phone. It was 3 AM. My house is full of

J. listens to a story

2009-03-11T08:22:00.005-04:00

I started to read J. the story of Moses last night. As a kid I probably scorned story bibles, but someone gave us this one when J. was a baby, and flipping through it I was pleasantly surprised. Now I think you can probably do a whole lot of deleting and clarifying without hurting much. You do lose the texture of the Bible. But we've already read the kids D'Aulaire's Greek Myths (miraculously

J. writes a song

2009-02-26T17:56:00.001-05:00

The handwriting is our babysitter's.

Junk and your unconscious mind

2008-12-31T19:22:00.002-05:00

It's wonderfully easy to contribute on the Web, and as an unfortunate side effect of this essential fact, hoaxes, cranks, and general nonsense abound. I'll euphemistically call this stuff “junk”. Because so much of what you see online is junk, smart people such as yourself develop a finely-tuned junk detector. This is fine—in any case it's important to have one if you plan to use the Web for

Structure

2008-12-31T18:46:00.005-05:00

On the Web, alternative reading to whatever you're looking at is never far away. There are even links in most Web pages, forever calling you to random-walk. The result, for the reader, can be a haphazard adventure of reading, interesting at every point but without overall purpose. The result for writers is that time spent organizing thoughts is usually wasted—nobody wants to read all that.

The School Mathematics Project

2008-12-17T09:41:00.005-05:00

JJ had me look at a set of old mathematics textbooks, and I found this. 4.1 Division and repeated subtraction We can write 7 + 7 + 7 + 7 + 7 + 7 + 7 + 7 + 7 = 7 × 9 = 63. (a) What is 63 - 7 - 7 - 7 - 7 - 7 - 7 - 7 - 7 - 7? (b) What is 63 ÷ 7? (c) Explain the connection between the last two questions. (d) If you were to work out 65 - 7 - 7 - 7 - 7 - 7 - 7 - 7 - 7 - 7, what would you find? How

The very best of jorendorff?

2008-12-09T08:27:00.009-05:00

I like Language Log, but I would like it even better if there were less of it. Wouldn't it be keen if there were a site where you could enter the URL of any blog, and it would give you back a feed containing only half the entries—the best ones, according to whatever metric of popularity the service could find (links, diggs, whatever). I proposed this on IRC, where mhoye and humph reacted with a

Arms

2008-11-21T10:11:00.005-05:00

I am flushing the buffer of old posts. Here is one I delayed posting because it's just too boring. Well, I'm posting it anyway. Sorry. xkcd has a provocative comic about cryptography. I imagine many geeks are moderately in favor of gun control but staunchly opposed to cryptography control. The two issues are very similar. Having a gun lets you do two basic things: intimidate unarmed people

Recently I learned...

2008-11-18T13:48:00.003-05:00

Some people are, at this moment, running around the world. As of this writing they're about 16% done. Seattle is farther north than Montréal. It is in fact farther north than all but the northernmost tip of Maine. Someone with a browser history like mine is more likely female than male. (My history includes a lot of pages on bugzilla.mozilla.org and developer.mozilla.org, which should peg

Commonwealth of Kentucky v. 141 Internet Domain Names

2008-10-23T09:09:00.004-04:00

Bill Poser is annoyed that the state of Kentucky has decided to seize a bunch of domain names on the unlikely theory that they are “gambling devices”. Among the silly things going on here is the name of the case, which Bill explains in the comments: Yes, the nominal defendants are the domain names. This is an example of a lawsuit in rem "against a thing". It is the typical form of action in

Who buys this stuff?

2008-09-30T12:47:00.003-04:00

My search continues for something substantial to read from an economist in favor of the bailout. On TV, they all appear to favor it (using vague language and lots of clichés), but on the Internet, they all seem to oppose it (with compelling economic arguments). I thought I may have found it when I ran across a dire quote from Nouriel Roubini in a newspaper, warning of economic woes to come.

My Representative

2008-09-30T11:57:00.006-04:00

I wrote to my Representative, Jim Cooper, and three days ago, he wrote back: ...I hate the thought of paying ransom to Wall Street, especially when Main Street is struggling. I am furious that our financial situation has been allowed to get this point, and that Treasury is considering bailing out the lenders who helped caused this to occur. Then he voted for the bailout. According to this

Squares

2008-08-12T19:21:00.003-04:00

Yesterday, apropos of nothing, J. announced that 9 is not the only square number. 4 is, too. Even 1, he added. It turns out he didn't hear the phrase “square number” anywhere. He's just been playing with blocks. Today I got out some extra blocks and showed him that 16 is a square number, too. He wondered, apparently at random, if 100 was a square number. So we counted out one hundred

Last week I learned...

2008-07-24T09:07:00.010-04:00

When volcanic eruptions created the island of Ferdinandea in 1831, it was quickly claimed by Italy, France, the UK, and Spain. While they were arguing, the little island eroded away. How to put this? Language isn't what I thought it was. (This definitely falls into the category of thought-provoking stuff I won't pretend to understand.) A little background. Before your third birthday, you

Stuff I learned recently

2008-07-23T23:53:00.000-04:00

Twelve thousand years ago, a gigantic dam of solid ice blocked the Clark Fork River, creating Glacial Lake Missoula. The lake was almost 2,000 feet deep. And periodically the dam would explode, laying waste to parts of what's now Montana, Idaho, Washington, and Oregon. Thundering waves and chunks of ice tore away soils and mountainsides, deposited giant ripple marks, created the scablands of

What is a noun?

2008-07-02T00:28:00.001-04:00

But what about earthquakes and concerts and wars, values and weights and costs, famines and droughts, redness and fairness, days and millennia, functions and purposes, craftsmanship, perfection, enjoyment, and finesse? —Ray Jackendoff, Foundations of Language: brain, meaning, grammar, evolution I learned in school that a noun is a word that names a person, place or thing. A few years after

Barleycorn Bay

2008-06-14T11:19:00.002-04:00

See earlier puzzles for, er, something of an explanation. “Now listen close-like,” said my new friend, “'cos I'm only going to say this once. All the inhabitants of Barleycorn Bay, and I've met them each and every one, are either heroes or vagabonds. Or both. Every one of the heroes is blonde; every one of the vagabonds is a magician, except for any that be Quakers; and all the magicians are

Facts

2008-06-01T13:47:00.000-04:00

David Macaulay wrote and illustrated a book entitled Castle. If you have a child four or older, you have a perfect excuse to buy it. Mill is fascinating, too. That “if Microsoft designed the iPod package” video was commissioned by Microsoft. To my mind, that makes it even cleverer. In an underground passageway somewhere near Shinjuku, there is a machine that cleans your glasses. A hot-air

Crowd vs. Committee

2008-05-28T12:31:00.006-04:00

I just found this in an old notebook. Apparently I wrote it a couple years ago. Most of it seems to make more sense to me now. Wisdom of Crowds Design by Committee Both: Participants may be biased. Bias averages out Bias creates “riders” Not much work Lots of work No consensus required Seeks consensus. Decisions may be postponed to avoid stirring up trouble. Minority (“

Curlicues

2008-05-23T10:18:00.003-04:00

J was writing his sister A's name for her on a piece of construction paper. J is 4 years old and A is 2, and somebody recently taught J that he can decorate his letters with outrageous curlicues. So J says, “Do you want me to put curlicues on it?” And A replies, in her tiny stern voice, “There are no Qs in my name!”

Firefox 3

2008-05-10T12:04:00.004-04:00

Firefox 3 is nearing release. Check out what's new, especially the Awesomebar, which has changed my life. (Awesomebar itself is the work of superhacker Ed Lee, but it relies on Places, the new bookmarks and history system, 2+ years in the making.) If you're interested in security, especially the difficulty of giving users correct, actionable security-related info at a glance, read about

This week I learned...

2008-04-06T00:56:00.003-04:00

In the children's section of the Nashville public library, the mother lode of folk tales is in the nonfiction section. Aha! There's a whole family of egg-eating snakes that swallow eggs bigger than their heads, squeeze out the insides, and spit out the shell. According to this blog post, native speakers of Chinese are gradually forgetting how to write. According to Jared Diamond, out of 148

This month I learned...

2008-04-04T15:06:00.000-04:00

The past three or four weeks are a bit of a blur, but: Just before he died, Beethoven claimed to be working on a Tenth Symphony. Fragments of this were discovered among Beethoven's sketchbooks in the 1980s (!), and musicologist/composer Barry Cooper stitched together a highly speculative, but performable, first movement. I knew that John Harrison invented the first clock that could keep

A bad guy in a lose-lose situation

2008-03-14T20:08:00.003-04:00

I guess there's no point denying that J, my four-year-old, has a bit of an aggressive streak. Paraphrased from memory: J: I'm going to try and splash him into that swimming pool. He's a bad guy. (The “bad guy” is a toy car.) If he misses, he's going to be shot out of a cannon that will shoot him so hard, he will crash into the sun, and then he will blow up and his car will blow up. (J.

This week I learned...

2008-02-29T17:26:00.003-05:00

I spent most of this week sick in bed, but I did discover that: According to the Jameel Poverty Action Lab at MIT, the cheapest way to improve attendance in Kenyan schools is mass deworming. There's a guy removing Garfield from Garfield comic strips. The result: “an even better comic about schizophrenia, bipolar disorder, and the empty desperation of modern life”. Guy Steele wrote The

This week I learned...

2008-02-23T18:20:00.004-05:00

A shibboleth is language that sends cultural signals beyond its plain meaning. The word comes from a fairly amazing Bible story. Now I want a word for language invented to annoy, like “Democrat Party”. Aristotle believed slavery to be “expedient and right”. All the best arguments by learned apologists for slavery in the U.S. South were from his writings, particularly in the Politics.

This week I learned...

2008-02-08T13:37:00.000-05:00

Special double issue! Two weeks' worth of trivia, including a week spent in Mountain View. Most Japanese streets do not have names. With GNU Radio, you can buy some cheap hardware, plug it in, and your computer becomes a GPS receiver, a garage door opener, an HDTV tuner, an AM/FM radio, a cell phone. This is subversive technology. Hollywood wants regulations that would ban such nonsense.

This week I learned...

2008-01-25T18:02:00.000-05:00

NestedVM can take any program that GCC can compile and run it in a Java VM. It does this by compiling the program to a MIPS executable and then translating the MIPS machine code to Java bytecode. Now, there isn't any high-level type information in a MIPS binary, so there isn't any in the bytecode. Instead each instruction is translated to something that bangs on some large int arrays that

This week I learned...

2008-01-18T22:53:00.000-05:00

The Phaistos Disc is a mysterious clay disc, about 3400-3850 years old, discovered in the basement of a Minoan palace. It is imprinted with hieroglyphic symbols. It is the earliest known instance of movable-type printing, which would not be seen again until woodblock printing appeared in China some 1600+ years later. Poseidon was believed to have created the horse. (I didn't even know that

This week I learned...

2008-01-07T14:11:00.001-05:00

Before desktop computers were widely used in China, telegraph operators there had to memorize every Chinese character's GB 2312 character code. Moleskin is made from cotton, not moles. (In other news, guacamole is made from avacados.) Garbage collection in Erlang is per-process. This seems weird—are messages copied from process to process?—but as that article explains, there are advantages,

This week I learned...

2008-01-04T21:21:00.000-05:00

A chipotle is a jalapeño that has been smoked. There are lots of ways to tile a regular dodecagon with sides of length s using only rhombi with sides of length s. My favorite so far: I speculate all such tilings use exactly this many rhombi of each shape—six skinny diamonds, six fat ones, and three squares. It would be really cool if I were wrong. Calculate the area of each shape to see

This week I learned...

2007-12-21T08:32:00.000-05:00

A five-step checklist saved about 1,500 lives in Michigan intensive care units in 18 months. It lists the five steps a physician should take, when putting a tube into a patient, to prevent infection. Simple array lookups like arr[i], where i is an int, are troublesome for x64 compilers. This is because int is a 32-bit type, while arr is 64 bits. To generate the fastest possible code, the

Today's recommendations for me

2007-12-20T13:59:00.000-05:00

Amazon thinks I might like the following items: György Ligeti Edition 2: A capella choral works Galois theory for beginners General topology Infinity and the mind Banana Banana? It turns out Amazon recommended Banana for me because I purchased Fried Egg. So that's all cleared up.

This week I learned...

2007-12-14T23:31:00.000-05:00

This T-shirt claims that “Under extreme stress, an octopus will eat its own arms.” According to Wikipedia, this is a “common belief”, though I'd never heard of it. I'm suspicious. Thanks to johnath, I now know that self-actualization tops Maslow's hierarchy of needs. The Internet, incidentally, is all about self-actualization. Depending on my mood, this strikes me as either dumb or

This week I learned...

2007-12-07T20:47:00.000-05:00

Remember when I linked ColorSchemer Online? Fun toy, huh? Well, forget about it. What you want is the ColorSchemer Gallery. Three thousand color schemes created by actual graphic designers or sampled from art and nature. How does a really good garbage collector compare to explicit memory management (malloc/free)? According to a 2005 paper (PDF) by Matthew Hertz and Emery D. Berger, the

Black-Eyed Pea Dip

2007-12-02T02:09:00.000-05:00

Heat and drain: 1 can Bush's black-eyed peas You can just zap them in the microwave for 2 minutes. Mash them, then mix in: 1 tsp. seasoned salt 2 tbsp. chopped onions 1 tbsp. jalapeños (or salsa or diced tomatoes) 1½ cup grated cheddar ¼ cup unsalted butter, softened 1 3-oz. can of deviled ham Pour the mixture into a 9-inch baking dish. Sprinkle on top: 3 oz. grated mozzarella cheese

This week I learned...

2007-11-21T17:20:00.000-05:00

Net-casting spiders spin small webs which they hold in their long, spindly legs and slap down on unsuspecting insects. Amazing. In OpenGL, textures are applied after lighting has already been applied to the colors of whatever material you're drawing. So once you get a material to look the way you want, if you then try to put a red spot on it, using a texture with some red parts and some

This week I learned... (Toronto edition)

2007-11-16T18:41:00.000-05:00

It was a good week, because I was stuck in a room with Benjamin Smedberg and Taras Glek for a couple days. Virtual method calls are branch-predicted these days. What is the world coming to? When you fly from Canada to the U.S., you go through customs in Canada. I learned a little about why Mozilla's security code is the way it is. I hate the wrapper model, but the model I prefer, which

This week I learned...

2007-11-09T12:26:00.000-05:00

Chicken cacciatore isn't at all what I thought it was. Sure is tasty though. The recipe in The Joy of Cooking is recommended; here's a similar recipe (video). Searching YouTube for recipes is an awfully delicious time sink. My mouth is watering. Color Schemer exists—and does a pretty darn good job. Very helpful for the color-impaired like me. Dot (PDF) is a very simple little language

This week I learned...

2007-11-02T22:09:00.000-04:00

To view the wiki-source of any MediaWiki page, add ?action=raw to the URL. (Good for scripting.) Unix has system calls like mlock, mincore, mprotect, and madvise that interact with the virtual memory manager. (Some are more standard than others.) I only knew about the venerable mmap. There's a fast, easy way to avoid the agonizing worst-case fragmentation you can get when you use a simple

This week I learned...

2007-10-26T12:23:00.000-04:00

How to find the median of n items in O(n) comparisons. The easiest algorithm is merely O(n) expected time. Can you figure out how it works? Hints in the comments. You can sort items with string keys in O(kn) time, where k is the average length of the strings. But it requires, say, 5n words of extra table space. This is amusing because in JavaScript, Array.prototype.sort() sorts objects by

This week I learned...

2007-10-19T18:32:00.000-04:00

bug.gd is a web site dedicated to finding explanations and workarounds for every cryptic error message your computer can generate (with a little help from you). The Canadian Standards Association charges Canadian citizens hundreds of dollars for (copy-protected) CD-ROMs containing the detailed regulations they're required to follow to do their work. Mississippi medical examiner Stephen Hayne

The principle of explosion

2007-09-16T22:50:00.000-04:00

Pop quiz: 1 - 1 + 1 - 1 + 1 - 1 + 1 - 1 + ... = ? It's obviously 0, right? Or maybe it's 1. In the 17th and 18th centuries, everyone apparently thought the correct answer was ½ (and it wasn't because they were stupid back then: this includes people like Leibniz and Euler). Eh, so math is inconsistent. So what? It is important to point out that it is not enough to consider at the same

Floating

2007-09-16T10:37:00.000-04:00

It's not until you study math a little bit that you realize just how awful floating-point arithmetic is. I mean, so it's a little inexact. So what? But the following are examples of statements that are absolutely true for integers, rationals, and reals, but not for floating-point numbers (even setting aside floating-point infinities and “not-a-number”s): a - (a - b) = b If b > 0, then a + b

Where to eat in Nashua, NH

2007-08-26T15:28:00.001-04:00

Every town has something just a little different to offer. Here are the places I would recommend if you had a day to spend in Nashua, New Hampshire, U.S.A. Breakfast: The City Room Cafe. Try the Cajun sirloin crepes. (They're not what I expected; they should be called "crepes curry" and they're a treat.) Check out the specials; they're usually inventive and scrumptious. Or have a

Too cool for screenshots?

2007-07-17T09:55:00.001-04:00

Mac OS X comes with a command-line utility, pbcopy, that copies its stdin to the clipboard. pbpaste dumps the clipboard to stdout.

Usability gripes

2007-07-13T11:24:00.001-04:00

I wonder if I'm the only one who finds it ironic that LDAP, of all the Internet protocols the one most directly aimed at fixing the problem of discoverability, is, itself, undiscoverable: I happen to know the hostname of my company's LDAP server, so I only need to figure out 7 more settings before I can, you know, find out my colleagues' email addresses. Uploading this screenshot was an

Overheard in a car

2007-07-11T08:38:00.000-04:00

Buzz (not his real name) is 3; Woody is 22 months. ... Buzz: Yes you are! Woody: I'm not a are! Buzz: Yes you are! Woody: I'm not a are! ...

C puzzle

2007-07-06T08:52:00.000-04:00

I was reading source code this morning and came across this curious line in a header file: JS_STATIC_ASSERT(sizeof(JSGCThing) >= sizeof(JSString)); The effect of this macro is to check at compile time that sizeof(JSGCThing) >= sizeof(JSString). If the condition is not met, compilation fails with an error. The puzzle is: how does this work? A hint is in the comments.

Things die

2007-07-04T02:17:00.000-04:00

Around seven thousand languages are spoken today. Many are spoken only by a few elderly people. Over 500 such languages are headed for extinction. Some linguists go much further, claiming that more than half of the languages spoken in 2000 will be extinct by 2100.

Math links

2007-06-24T09:58:00.000-04:00

A mathematician's apology (PDF). The early chapters are mostly grumbling about getting old. But then he starts talking about mathematics, with real poetry and love for the subject. Very nice. Eudoxus. This ancient Greek anticipated Dedekind cuts and calculus. He also mapped the heavens and the earth. Yet no work of his survives--only frequent citations in the works of Euclid, Aristotle,

To do

2007-06-24T09:37:00.000-04:00

Frivolous projects I would undertake, if I only had the time. Submit a patch to Monotone that makes "mtn log" display log entries in chronological order. Finish debugging the new, faster syntax-case implementation I have for Try Scheme. (sigh) It's so close! Write about continuations. A good tutorial would be helpful. I haven't read anything I really liked. (Squawk of the Parrot has

Rooftop lab

2007-06-21T12:34:00.000-04:00

I just started a new blog for my Mozilla work. It's called Rooftop Lab, and it'll be pretty technical.

On the Cape

2007-06-19T12:54:00.000-04:00

If you happen to be on Cape Cod sometime, visit Scargo Pottery, just off route 6A. That whole stretch of 6A is like a sprawling crafts fair, but Scargo is something special. The little pictures on their web site don't do it justice. We were on Cape Cod for my birthday. It's a few weeks yet before the tourist season, but the weather was cooperative. Breezy, cool, sunny. Buzz was on his best

Strawberry alert

2007-06-17T12:52:00.001-04:00

If you happen to live in Nashua, NH, there's a small farmer's market on the Main Street bridge over the Nashua River. It's there every Sunday, all summer. A booth there is selling strawberries that were picked this morning.

Woody goes to the park

2007-06-15T18:02:00.000-04:00

A. is 22 months old now and insists on being called “Woody”, except when she's “Steve”. Mommy: What did you do at the park? Did you slide down the slide? Woody: Yeah. Mommy: Did you run around? Woody: Yeah. Mommy: Did you meet some other kids? Woody: Yeah. Mommy: Did you eat some blueberries? Woody: Yeah. Mommy: Did you see a zebra? Woody: Yeah.

Productivity through eccentricity

2007-06-08T22:35:00.000-04:00

From The Pmarca Guide to Personal Productivity (click the link, it's interesting): [R]efuse to commit to meetings, appointments, or activities at any set time in any future day. As a result, you can always work on whatever is most important or most interesting, at any time. Want to spend all day writing a research report? Do it! Want to spend all day coding? Do it! Want to spend all day at

Danger!

2007-06-05T09:14:00.000-04:00

In Scheme and Ruby, procedures that modify variables or data structures are marked with a ! by convention: // Java static void arraySwap(T[] arr, int i0, int i1) { T tmp = arr[i0]; arr[i0] = arr[i1]; arr[i1] = tmp; } ;; equivalent Scheme (define (vector-swap! v i0 i1) (let ((tmp (vector-ref v i0))) (vector-set! v i0 (vector-ref v i1)) (

Types

2007-06-03T11:12:00.001-04:00

I've been working through Types and Programming Languages by Benjamin C. Pierce. It's filling in a lot of blanks for me. According to the drafts, ECMAScript 4 will have an ambitious new type system with optional type-annotation. So for example you could write: //code without types function sortLines(text) { let lines = text.split(/\r\n?|\n/g); lines.sort(); return lines.join("\n")

A new gig

2007-05-31T13:22:00.001-04:00

Last week I accepted a position at Mozilla Corporation, the tiny company behind the hugely popular Firefox web browser, now used by 80 million people around the world. I'll be working full-time on Mozilla's JavaScript engine, one of the core technologies that make Firefox tick. It's my dream job. I can't believe my good fortune. You can read the latest Mozilla news on Planet Mozilla. (

Concerning gifts (and other puzzles)

2007-05-13T17:46:00.001-04:00

What can you conclude from the following three premisses? If something is not gift-wrapped, it's not a gift. Nothing that's gift-wrapped is entirely unlike a box of chocolates. Life is a gift. Lewis Carroll published a book of about a hundred puzzles like this one. Read it online: introduction; puzzles. My nephew IM and I stumbled upon them in Memphis last week. He pretty much knocked them