Vitanuova for 2003 January
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I've been finding a lot of popular press coverage distressing. Maybe I should keep some sort of journal of my specific objections.

Here are a couple of bad habits which come to mind:

I got to celebrate the new year in Massachusetts with Eric and Kate, for what I think was my eighth straight year celebrating with Eric. I also saw a bunch of cool people whom I rarely see except at Eric's new year's party, and got a visit from Rachel and Vasilios, who graciously drove for hours and hours.

I did a countdown program in Python, using Tkinter. It's normally done with HyperCard, but Eric couldn't get HyperCard running right away, so I tried out Tkinter. I have to admit that I don't know an enormous amount of Tkinter, but it's pretty straightforward to get started with it. The most difficult part is probably the geometry management and packing stuff.

We thought we might be able to get the countdown to start a fire (as we'd hoped in previous years) -- lighting a candle, for example. Unfortunately, I couldn't get my solid-state relay to trigger from my laptop's parallel port, and I didn't have a voltmeter or LEDs or anything else to use for debugging purposes. So the computer control was out this year. We did try an experiment later on to see about the possibility of igniting something with electricity. Our experimental result is this: if you connect eight 9-volt batteries in series (which is very easy to do because of how the connectors are designed), a fairly large spark is produced by the 72-volt potential across the resulting gap when battery leads are brought close together. This spark is sufficient to ignite a small piece of cardboard wetted with 91% isopropyl alcohol.

A much simpler technique would be to get a thin wire like those used in cigarette lighters in cars, and connect this to a relatively small DC voltage. The wire should become hot enough to ignite things (like cigarettes). There is some detail about matching the internal resistance of the power source in order to maximize the power dissipated through the wire.

The theory here is pretty simple. Suppose that we want to cause heat by connecting a wire in series with a battery. Assume that the battery's total voltage is V, and the internal resistance of this source is Rs, the resistance of the wire is Rw. Then the total series resistance is Rs+Rw, current I=V/(Rs+Rw), power in the wire Pw=I*Vw=V^2*Rw/(Rs+Rw)^2. I did take dPw/dRw by hand (I'm ashamed to say it's the first derivative I've taken in a year or two), and found it to be V^2[(Rs+Rw)^2-2Rw(Rs+Rw)]/(Rs+Rw)^2, which has a zero when Rs=Rw. This implies that the wire will become hot most quickly when its resistance is exactly equal to the internal resistance of the battery.

(In that case, of course, the battery will also dissipate power at the same rate as the wire, so the battery may become rather hot as well.)

There's a much more general result, or technique, known to electrical engineers, and it's called impedance matching. I never got far into alternating currents in my physics class, so I didn't learn too much detail about impedances.

I'm glad I got to be here for the new year. I'll be back in California soon.

Happy new year!

I'm headed back to San Francisco.

After celebrating the new year in Hopedale, I took the commuter rail back to Boston, accessed a wireless network near MIT, and had more tea at Tealuxe in Harvard Square.

I'm reading The Mother Tongue: English and How It Got That Way by Bill Bryson, which Riana gave me recently. It's hilarious! There's something incredibly amusing about historical linguistics, especially accounts of changes in usage.

Surprisingly often the meaning becomes its opposite or something very like it. Counterfeit once meant a legitimate copy. Brave once implied cowardice -- as indeed bravado still does. (Both come from the same source as depraved.) Crafty, now a disparaging term, originally was a word of praise, while enthusiasm which is now a word of praise, was once a term of mild abuse. Zeal has lost its original pejorative sense, but zealot curiously has not. Garble once meant to sort out, not to mix up. A harlot was once a boy, and a girl in Chaucer's day was any young person, whether male or female. Manufacture, from the Latin root for hand, once signified something made by hand; it now means virtually the opposite. Politician was originally a sinister word (perhaps it still is), while obsequious and notorious simply meant flexible and famous. Simeon Potter notes that when James II first saw St. Paul's Cathedral he called it amusing, awful, and artificial, and meant that it was pleasing to look at, deserving of awe, and full of skillful artifice.

(pp. 77-8)

There are lots of other funny parts. I liked the description of the Oxford English Dictionary (now discussed at great length in The Professor and the Madman). Bryson says that the famous dictionary insists oddly

that Shakespeare should be spelled Shakspere. After explaining at some length why this is the only correct spelling, it grudgingly acknowledge that the commonest spelling "is perh. Shakespeare." (To which we might add, it cert. is.)

When I read what Lessig wrote this morning about the Supreme Court's decision in Eldred v. Ashcroft today, I thought of what Rabbi Joshua says in Avot D'Rabbi Nathan when he sees the ruins of the Temple:

oi lanu al ze she-hu charev!

(Alas for us that it is ruined!)

Rabbi Nathan goes on to report that Rabbi Yochanan ben Zakkai (Rabbi Joshua's teacher) answers "b'ni, al yera l'cha" (my son, do not grieve). I hope Professor Lessig's teachers are even now writing to him: b'ni, al yera l'cha.

Yochanan ben Zakkai argues specifically that Rabbi Joshua need not grieve because there are alternatives to the Temple service ("yesh lanu capara acheret", "we have another atonement"). What is Eldred supporters' "capara acheret"?

Surely it starts with cultural struggle to show people that the public domain, and all the public's rights in copyright, are valuable; that, as the Eldred dissents recognized, the copyright law properly aims at a public rather than a private end; that no one is intrinsically entitled to property rights in creative work; that, as Professor Litman argues, legislation by private negotiation is not serving the public; and that copyright significantly burdens expression, and that the fair use doctrine may not always be adequate to remedy the harm.

The capara acheret is also to support all the people who are working on the accessibility of culture, from librarians in libraries through free software programmers through "vernacular archivists" (as Stewart Brand says) and the creators and operators of the "databases" so celebrated by Justice Breyer's dissent. And its includes supporting technologists who make creative work easier and cheaper.

It is odd that so many people should feel so comfortable with a tax -- the retroactive part of the extension -- solely to the benefit of heirs and assignees, where the creators of the famous works at issue are typically dead and buried.

Id cinerem aut manis credis curare sepultos?

(Aeneid IV, 34)

If you're feeling depressed about the Eldred decision, a little proofreading might cheer you up.

Having seen Larry Lessig argue this cause is one of the highlights of my life.

EFF has started publishing Cruelty to Analog, which will cover the activities of the ARDG.

If you use wavemon with an 802.11b wireless network, you'll notice that signal quality is measured on a scale from 0 to 92, and can be affected directly simply by bringing your hand near to your wireless card. The closer your hand gets to the card, the poorer the signal quality will become.

wavemon even has a mode in which a graph of signal quality over time is displayed. While many people use that graph (and similar graphs in similar software) to help find wireless networks, or physically locate base stations, or figure out the best orientation for a laptop using a particular network, you can also just move your hand up and down and watch the graph line go up and down as your hand moves.

This means that the 802.11 card can function as a rough proximity sensor for your hand. This evening I realized that that means you can make a wireless card into a sort of poor man's theremin -- you just need to map the signal strength to a tone, play the tone, and move your hand. You'll be able to play several discrete pitches or scales, although with much less precision than a real theremin.

I wrote a three-line shell script which implements this idea (using Linux setterm, all on a beta test version of the LNX-BBC, it so happens), and later improved it a little bit with a small C program which wraps the Linux KIOCSOUND ioctl. It works just fine -- you can easily bring the tone up and down by moving your hand back and forth. That's a lot of fun. The most obvious problem is the discreteness of the whole thing. A real theremin is plainly an analog device. (The analogy is between the pitch level and the position of your hand.) This system is very obviously quantized, at best like someone playing a poor piano scale (and it's distorted sine waves rather than piano strings with their nice harmonics).

We can't really do better with the standard 802.11 drivers, because they definitely won't give anything more precise than the 92 discerete levels. You could modify the hardware (and build a real theremin, which is far simpler electrically than an 802.11b card). Another approach is to modify the way the tones are generated. What I'm currently thinking is something like this: we need to define a function i(s) and a function n(g, p), where i(s) is the ideal pitch in Hz corresponding to a signal strength measurement s and where n is the next pitch after some small constant time step if the goal is to reach pitch g and we're currently playing pitch p. So we use the function n to change pitch smoothly and always move gradually from the pitch we're currently playing toward a goal. The goal, at any given moment, will be i(s) -- that is, we do a loop like 

p=i(signal_strength())
while 1:
	play(p)
	p = n(i(signal_strength()), p)
	sleep(time_step)

Now the pitch will always change continuously, and yet the pitch will be directly responsive to the (discrete) signal strength measurement. If the signal strength rises quickly, the pitch will rise quickly. If the signal strength rises slowly, the pitch will rise slowly. If the signal strength stays constant, the pitch will stay constant. If you move the position of your hand to a position x centimeters away from the card at one time, and later move it to the same position, the pitch should in each case approach roughly the same value -- which should be i(s) Hz for whatever value of s happens to correspond to holding your hand x cm away from the card.

(There might not be a unique such value, because it also depends on a lot of other factors like the angle at which you hold your hand. Obviously there is lots and lots of radio hardware which would give you much better results -- maybe even an ordinary AM or FM radio if you tweaked the demodulation circuit and gave it a suitable input signal. But there's not lots of radio hardware you can get so easily if you're not a radio expert and get a single digital value out of so readily and at such a high frequency. We can hope GNU Radio will change this situation quickly!)

My little theremin script is apparently even famous in Italy. It has been published by Linux Journal. Some minor changes are useful, so I'll try to pass them along to Don.

On the ferry on Thursday, I happened across a discarded copy of the New York Times which happened to be open to an article about my colleague Fred von Lohmann. This was totally co-incidental -- I wasn't looking for the article or anything.

On Friday, I had the honor of meeting Whitfield Diffie.

I'm sorry I'm still so far behind in posting news from the past month or so. I think I'll be able to catch up soon. I've read two novels I haven't even mentioned here yet! (Well, one novel and one "romance".)

Hey, did you know that "romance novel" and "Romance language" have the same etymology? (And it originally dates back to the Roman language, which is even more obvious to English speakers in the French word "roman".)

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Contact: Seth David Schoen