Sean McGrath gave the closing presentation at XTech 2008 last week in Dublin. He quoted from Jorge Luis Borges's The Analytical Language of John Wilkins. Wilkins was an 17th Century English scientist. (He is also one of the characters in Neal Stephenson's Quicksilver.) Wilkins designed a Philosophical Language in which the letters of each word give not just the sound but also the specific meaning of the word. It would have been an amazing accomplishment had it worked. Borges suggests why it didn't.

Wilkins's Real Character depended on his exhaustive taxonomy of all knowledge and topics of conversation. This must be done perfectly, and a perfect taxonomy is impossible to produce from our mortal vantage point. Borges points out that

The whale belongs to the sixteenth category; it is a viviparous oblong fish.

That may have been a reasonable classification in Wilkins's time, but in our time it looks wrong. But it could look much worse.

Borges's wrote in Spanish. There are translations on the net that render that statement differently.

Beauty belongs to the sixteenth category; it is a living brood fish, an oblong one.

Beauty is a fish? What does this mean? Is it a metaphor? No, it is a typo. In Spanish, beauty is belleza, and whale is ballena.

Gray code is a binary sequence encoding in which any state differs from the next or previous state by only one bit. This is an example of a four bit Gray code:

BITS
 4321
 0000
 0001
 0011
 0010
 0110
 0111
 0101
 0100
 1100
 1101
 1111
 1110
 1010
 1011
 1001
 1000

Gray code is useful in shaft encoders, where you want to sense the state of rotation. An optical encoder could have each state represented by a pie wedge, where the 0 bits are white and the 1 bits are black.

The Towers of Hanoi is a puzzle in which there are three posts and several discs of various sizes. This is a JavaScript program that solves the problem of moving the discs from one post to another:

hanoi = function (n, src, aux, dst) {
    if (n > 0) {
        hanoi(n - 1, src, dst, aux);
        document.writeln('Move disc ' + n + ' from ' +
                src + ' to ' + dst);
        hanoi(n - 1, aux, src, dst);
    }
};

The solution to a tower of 4 discs is obtained by hanoi(4, 'Src', 'Aux', 'Dst'):

Move disc 1 from Src to Aux
Move disc 2 from Src to Dst
Move disc 1 from Aux to Dst
Move disc 3 from Src to Aux
Move disc 1 from Dst to Src
Move disc 2 from Dst to Aux
Move disc 1 from Src to Aux
Move disc 4 from Src to Dst
Move disc 1 from Aux to Dst
Move disc 2 from Aux to Src
Move disc 1 from Dst to Src
Move disc 3 from Aux to Dst
Move disc 1 from Src to Aux
Move disc 2 from Src to Dst
Move disc 1 from Aux to Dst

The number of the disc to move corresponds exactly with the next bit to toggle in the Gray code.

I relied on two models when I wrote JavaScript: The Good Parts. The first was Kernighan and Richie's The C Programming Language. It is a brilliant little book. I thought there should be a K&R for JavaScript. When it seems that most tech books are sold by the pound, it is nice to read a little book that cleanly lays out what you need to know.

The other was William Goldman's The Princess Bride. Goldman remembers his grandfather reading him a wonderful book by S. Morgenstern. When he's grown he searches for the book and is very excited when he finally finds a copy, but discovers to his horror and confusion that it really isn't very good. Why did he remember it as being so wonderful? Because his grandfather only read him the good parts.

Blu-ray won. Sony ultimately paid off enough of the other studios to tip the contest in their favor. Toshiba has withdrawn HD-DVD. But Sony's victory may have come too late.

The expectation was that when the format war ends, that sales of Blu-ray players would immediately exceed the sales of HDTV sets. That didn't happen. Sales of Blu-ray players have stayed pretty flat.

Blu-ray can deliver much higher quality than DVD, but the difference is not significant in most homes, so Blu-Ray is going to have a much harder time getting mass acceptance. Sony may be forced into price reductions. They don't have much time because the window is closing. To survive, Blu-ray must become dominant before is made obsolete by network delivery.

My recommendation is still to stick with DVD at least until Sony announces that they are going to remove the DRM components from Blu-ray. DRM makes the gear and discs more expensive and harder to use, so clearly it is something you don't want.