21 November 2006

That's rather odd

According to Reason magazine, some guy was convicted of smuggling French silicone gel breast implants into the U.S. He was sentenced to two years and a $10,000 fine.

The article says, “According to the government, Martin illegally imported 47 implants in 1995 and has distributed close to 600 implants to doctors throughout the country.” Does anything about that sentence strike anyone else as ...odd?

20 November 2006

Constitutional law fact of the day

I didn't know this: apparently a nursing mother has a Constitutionally protected right to breastfeed her child. The following block quote describes Dike v. Orange County School Board, 650 F.2d 783 (5th Cir., 1981).

[A] teacher wanted to nurse her baby on her duty free lunch break. The school claimed that insurance provisions prohibited teachers from bringing their children onto school property, and also prohibited teachers from leaving the school grounds during the day. The trial court ruled that the mother had no right to breastfeed. In Dike, the appeals court reversed the case and remanded it for a new trial, stating that breastfeeding is a protected constitutional right. “Breastfeeding is the most elemental form of parental care. It is a communion between mother and child that, like marriage, is ‘intimate to the degree of being sacred,’ Griswold v. Connecticut, 381 U.S. at 486, 85 S. Ct. at 1682, 14 L. Ed. 2d at 516. Nourishment is necessary to maintain the child's life, and the parent may choose to believe that breastfeeding will enhance the child's psychological as well as physical health. In light of the spectrum of interests that the Supreme Court has held specially protected we conclude that the Constitution protects from excessive state interference a woman's decision respecting breastfeeding her child.” 650 F.2d at 787

Constitutional rights are not absolute, and often collide with legitimate, recognized interests. Sometimes the courts must balance individual rights with state interests. In the Dike case, the trial court determined that the state had a legitimate interest in restricting the teacher's comings and goings because of certain school policies. Although the appellate court ruled that mothers have a constitutional right to breastfeed, Mrs. Dike did not have the right to leave school to go home and nurse her baby, or to bring her baby on to school grounds.

—Elizabeth N. Baldwin, “A Look at Enacting Breastfeeding Legislation”

It's really cool what happened here. The lower court said, in an offhand way, “There's nowhere in the Constitution it says you have a right to X.” And the higher court, showing truly inspiring wisdom, says, “Look again.” Over the years, I think the U.S. courts have been better than anyone could've reasonably expected about protecting “personal” rights, beyond the political rights that the Constitution addresses most directly. It's a sometimes thing, but on a good day, the government can't just go in and randomly muck about with your private life. It's nice to be an American.

19 November 2006

Rematches

Ohio State is #1. Michigan is #2. Ohio State beat Michigan yesterday in a pretty close game.

The college football championship game is January 8. Should Michigan be invited?

On the one hand, the whole point of a championship game is that #1 gets to play #2 for all the marbles. On the other hand, there are a dozen awesome teams that have not had a chance to unseat Ohio State this year. If USC, for example, doesn't get a chance, why should Michigan get two chances?

Listening to the commentators yesterday, I could tell they were carefully restraining themselves from re-re-re-stating the obvious: we wouldn't even have this problem, if... yeah, I can't bring myself to say it again. I'm officially blue in the face.

Did you know that it's possible in the NFL for the Super Bowl to be a rematch between two teams that already played during the regular season? It has happened eleven times. And it's the darnedest thing—no one ever complains about it. In the NFL, if you get to the Super Bowl, no one ever tries to say you didn't earn it. I have a theory. I think there is a reason for this. If you're in the Super Bowl, you've beaten two of the best teams in the league in consecutive weeks. All the other contenders had their shot, and they lost. It's that simple.

In college football, there's no playoff, so you get situations like this one with Michigan.

The BCS was a huge leap forward. We now have a controversy-free, undisputed national champion about 20% of the time. Let's take the logical next step. It ain't rocket science.

Postscript: For the record, I favor treating yesterday's game as a playoff game. Michigan lost. They should be out.

17 November 2006

Euclid redux

In 1882, Moritz Pasch published a book revealing unstated assumptions in Euclid's Elements and calling for a new examination of the foundations of geometry.

Here are three axiomatizations of plane geometry. I'm posting this because they're three surprisingly creative, different approaches.

  • Hilbert's axioms (1899) are simply a more rigorous version of Euclid's axioms. Whereas Euclid states five postulates and five “common notions”, Hilbert requires 20 axioms—plus set theory.

  • Birkhoff's axioms (1932) take a totally different approach. Birkhoff starts with the real numbers. The distance between points on a line is defined by analogy to the reals, and something similar defines angle measures. The astonishing result is a complete axiomatization of plane geometry in just four postulates.

  • Tarski's axioms (1983) are built directly on top of first-order logic, so they don't require set theory. As a result, Tarski was able to prove (posthumously, no less) that the system was consistent, complete, and decidable.

10 November 2006

Poorboy Legacy

My friend Reuben Torrey just released a CD! Check it out: Poorboy Legacy. The title track has a sort of folk-blues-meets-indie-rock thing going on—fantastic.

Oh my angel mother
help me up the hill
I'm goin' to meet the good Lord
and I didn't write no will
'cause all I got
is a poor boy's legacy
I'm gonna leave to my son
everything my daddy left for me

$8 for the CD, free shipping, free MP3 download once you buy.

03 November 2006

Election day

On Tuesday, I can vote for incumbent Republican Charlie Bass, Democrat Paul Hodes, or Libertarian Ken Blevens. ::sigh::

01 November 2006

Elements, part 2

RT asked me last weekend about programming. She just learned HTML. Now she's considering learning PHP.

It was this conversation that got me interested in Euclid's Elements. RT has a classical liberal education; she actually studied the Elements. (Sidetrack: Wikipedia says the Elements were “the basic text on geometry thoughout the Western world for about 2,000 years. For centuries, when the quadrivium was included in the curriculum of all university students, knowledge of at least part of Euclid's Elements was required of all students. Not until the 20th century did it cease to be considered something all educated people had read.” Now get this: the mathematical discoveries of the past hundred years are so mind-blowing, so revolutionary, that the relegation of the Elements to obscurity is arguably justified. The mathematician's view of geometry is forever changed; the Elements can never again be what it was. I mentioned this to SC at work. He says we're living in the golden age of mathematics.)

RT liked Euclid's approach of starting from a few axioms and deriving everything else from them. She wanted to know if it is possible to learn programming in the same way, from the ground up.

Here's my answer: Structure and Interpretation of Computer Programs. (You can read the full text for free online.) Elsewhere I've called this “the best programming book ever written”. As it turns out, Section 1.1 is actually titled “The Elements of Programming”. These first few sections still bear re-reading. Powerful stuff.

Is SICP a practical book? It walks a fine line. The programming language you'll learn, if you read it, is not Java or PHP or Ruby or C#. It's Scheme. Scheme has a simple design well suited to the Elements approach. You might find one of those others better suited to the program you're interested in writing, and if so, you might prefer some other book. On the other hand, page 1 of SICP starts by quoting an essay by John Locke; and then it tells you what a program really is, what the word means; and then by section 1.2.1 it's telling you things that I went through a whole CS degree program without learning. That kind of book.

A discovery

This happened last year. I never heard about it.

A reviewer on amazon.com writes:

With so many things going wrong in the world, it's nice to see one important thing going right—a certain Mr. Applebaum stumbles onto the recordings at the Library of Congress in January, a crack team spends the better part of the year restoring and remastering, and Blue Note and Thelonious Records put out the CD in September.

It's a true and lovely story. National Public Radio tells it here (ignore the text and click the “Listen” button near the top). The disc is Thelonious Monk Quartet with John Coltrane at Carnegie Hall.

29 October 2006

A speaks

A's first words are: book, apple (“ap”), bump (“bup!”), up, ball, drink (“guk”), hat (clear as a bell), and something that sounds like bite or eat.

Elements

“Euclid's text Elements was the first systematic discussion of geometry. It has been one of the most influential books in history[.]”

—Wikipedia, “Euclidean geometry”

I'm not sure this is an exaggeration.

Observation

J, who is three, enjoys A Light in the Attic. O says Shel Silverstein's best poems are the ones that are really about himself. This led me to a new appreciation of his stuff.

I've never dealt draw poker
In a rowdy lumber camp.
Or got up at the count of nine
To beat the worlds champ.
I've never had my picture on
A six-cent postage stamp.
I've never scored a touchdown
On a ninety-nine yard run.
I've never winged six Daltons
With my dying brother's gun...
Or kissed Miz Jane, and rode my hoss
Into the setting sun.
Sometimes I get so depressed
'Bout what I haven't done.
—Shel Silverstein, Never

26 October 2006

"We all have a common enemy..."

Marquette University censors the office doors of its Ph.D. students. A quote from a noted terrorist has been removed.

Sorry, did I say terrorist? I meant syndicated humor columnist. The censored quote is from Dave Barry. Click the link. The story defies belief (and the quote is actually kind of funny).

Why does no one seem to care about this? A little part of me dies every time I read a story like this. It takes me a while to get over it. "Free speech zones" on university campuses. God help us.

28 September 2006

It's turtles all the way down

I haven't yet grasped the relationship between proof and truth. And the ground is sufficiently tricky that I have a hard time trusting anything I read. I got something from the local public library called Fundamentals of Mathematics, which has an introductory chapter on model theory—but they go around proving things about models and logic using ordinary mathematical reasoning. This is like writing a Python compiler in Python: one feels that some bootstrapping must be involved somewhere. It's probably in a later chapter, but in the meantime my brain involuntarily rejects everything the book claims. Unproductive.

Metamath responds

Norm Megill, the man behind Metamath, responded to my recent post about Metamath and hygienic macros:

You are correct that substitution in Metamath is the simple replacement of a variable with a (well-formed) expression and thus isn't hygienic, in Scheme's terminology. In logic, the term used for “hygienic substitution” is “proper substitution,” which Metamath does not implement directly.

Instead, Metamath natively implements a simpler concept of “disjoint variables” as an optional proviso on an axiom (and inherited by theorems), that will forbid certain substitutions. In more standard terminology, this means, for example, that (if the axiom says so) a certain bound variable may not occur in a wff. In this case, the wff may have to be transformed, in the proof, to an equivalent wff with the bound variable renamed before we are allowed to substitute it for the wff variable of the axiom. In effect, the work of renaming bound variables, in order to make a sound (hygienic) substitution, is done by the proof itself rather than by the proof verifier. This simplifies the underlying primitive concepts needed by the Metamath language itself, with a consequence that the proof verifier can be very simple.

How simple is Metamath's verifier? About 300 lines of Python does the trick.

Simplicity is not the motivation in Lisp; in fact Lisp is generally more complicated than Scheme. Rather, Lisp programs actually take advantage of symbols getting crossed. (If you know Lisp macros, you know what I mean, and if you don't, I can't easily explain it.) I know Metamath does something similar in at least one place: its definition of proper substitution.

([y / x]φ ↔ ((x = y → φ) ∧ ∃x(x = y ∧ φ)))

I wonder if similar tricks are used elsewhere.

27 September 2006

Amazingly bad

It reads like a deliberate insult:

To distribute a .NET Framework application both to 32- and 64-bit platforms, build two MSI packages, one targeted at a 32-bit and the other a 64-bit computer.

I have to say, Microsoft's support for 64-bit architectures is a total nightmare. MSI can't compete with that, but it's pretty darned awful.

.NET supposedly supports XCOPY deployment. Even MSI can make a directory and put files in it, and as far as I know the MSI database contains nothing platform-specific. What's the problem here?

I know the answer. The problem is that XCOPY deployment doesn't really work. Not for everybody, certainly not for apps with legacy dependencies. What's a tech writer supposed to do? Document how things would work if the world were ideal, because they might work that way for your app? Or give everyone the ugly workaround that most real-world apps need to apply?

Blaaargh.