Vitanuova for 2002 February 12

TV

Andrea saw me on TV -- the Bamford lecture was covered by local TV news, and they had shots of the audience.

BayFF

I had a nice time at BayFF and saw many old friends and unindicted co-conspirators. (I haven't been indicted either, so that's nice.)

There were lots of Linux people there, and people from other connections. The audience asked nice questions and the EFF lawyers gave good answers.

I didn't get to give my "In 1995, I read a virus" commentary on the expressive content of code. I'm hoping that, if I tell enough lawyers about it, the phrase "In 1995, I read a virus" may make it into some law review article.

I met Eric Blossom of GNU Radio fame, and went to dinner for the second night in a row with a bunch of freedom-loving geeks in Berkeley, although it was a completely different crowd with no overlap at all. The people who went to Bamford's talk were just not the same people who went to EFF's talk, which doesn't quite make sense to me.

"Will you read me a story?"

"Read you a story? What fun would that be? I've got a better idea: let's tell a story together."

(Photopia)

Compression paper

I saw Nathaniel at BayFF, and he told me about the paper "Language Trees and Zipping", by Dario Benedetto, Emanuele Caglioti, Vittorio Loreto. I wrote about this a few days ago, and it turns out that I got it wrong. I thought it was just about compression ratios; it's actually about something much more subtle. So I'll have to try to experiment with that a little more.

Universal gates

Given a universal n-input gate, adding an ignored input yields a universal (n+1)-input gate. That is, if U(a,b,c,...) is universal, then U_new(a,b,c,...,N)=U(a,b,c,...) is also universal.

So, I've been studying what happens if you compose a new 2-input gate with a universal gate (not vice versa, yet). I found some straightforward results. Let U(a,b,c,...) be a universal n-input gate from which we will produce a new (n+1)-input gate which takes the inputs a,b,c,... and the new input N by using some 2-input gate with inputs U(a,b,c,...) and N. Then

• U XOR N can be used to produce U XOR U, which is 0; then with N=0, U XOR 0=U, which is universal.
• U XNOR N can be used to produce U XNOR U, which is 1; then with N=1, U XNOR 1=U, which is universal.
• U OR N can be used to produce U OR U, which U, which is universal.
• U AND N can be used to produce U AND U, which is U, which is universal.
• U AND NOT N produces U AND NOT U, which is 0, and so U AND NOT 0, which is U.
• However, (NOT U) AND N is not necessarily universal. For example, let U be an n-input NAND. Then (NOT U) AND N is (NOT NAND(a,b,c,...)) AND N, which is AND(a,b,c,...,N), which is not universal.
• U OR NOT N produces U OR NOT U, which is 1, and so U OR NOT 1, which is U.
• However, (NOT U) OR N is not necessarily universal; for example, let U be NOR; then (NOT U) OR N is (NOT NOR(a,b,c,...)) OR N, which is OR(a,b,c,...,N), which is not universal.
• U XOR NOT N gives U XOR NOT U, which is 1, and then U XOR NOT 1, which is U.
• (NOT U) XOR N gives (NOT U) XOR U, which is 1, and then (NOT U) XOR 1, which is U.
• U XNOR NOT N gives U XNOR NOT U, which is 0, and then U XNOR NOT 0, which is U.
• (NOT U) XNOR N gives (NOT U) XNOR U, which is 0, and then (NOT U) XNOR 0, which is U.

There are probably only sixteen ways to combine U and N this way, although some of those I've given are actually trivially equivalent, like (NOT U) XOR N and U XOR NOT N, which I examined as separate cases but which always yield exactly the same value.

The problem is that there are sixteen ways to combine U and N by composing 2-input gates with U. (Perhaps there are more and I've miscounted.) But there are many other possibilities for what a new input could "do" to a universal gate, aside from just being an input to a gate composed with it. I don't have a convenient notation for many of these.

Wow

PRO-ANOREXIA SITES RAISE CONCERNS
A growing number of sites devoted to promoting anorexia is
raising concern among health officials.  Groups have begun
to take their concerns to ISPs and content providers with
sites such as Yahoo! removing such content citing them as
harmful or threatening.
<http://www.latimes.com/technology/la-000010755feb12.story>

One of the amazing things about free speech and maybe about the large world of the Internet is that it sometimes seems to be only a matter of time before a seemingly universal consensus is broken by somebody who advocates what had seemed like a problem to everyone else. (Compare Artists for Earthquakes, the Bay Area's leading seismicity advocacy group. SF Weekly coverage, Pigdog Journal coverage. Fortunately, Artists for Earthquakes is a joke. The pro-ana sites aren't, as far as I can tell. Somehow I am reminded of the disclaimer I saw in one edition of Scot's Discoverie of Witchcraft where Scot talks about how to kill birds and bring them to life again. One editor felt compelled to tell people that Scot's method wasn't reliable and, in any case, was cruel to animals. This is true; the editor seemed to feel that such was the power of Scot's narrative that it might actually seduce some would-be present-day charlatans into attempting to kill and revive birds using King James-era magicians' methods. Or again when people describe pyrotechnics recipes and some of them are reprinted -- we are always tempted to say "Do not try this at home; anorexia may be hazardous to your health (and is cruel to animals)".)

Horace

(Sumana wants to create abiding works. Don't you?)

There is a high school ritual of writing essays about the unintended truth of the poem "Exegi monumentum aere perennius". Everyone gets to make the observation that Horace spoke truer than he knew, because even the things he held up as metaphors for permanence ("cum tacita virgine pontifex") did not last as long as his own poetry. It's not a very original observation, since it seems to appear in every discussion of "Exegi monumentum aere perennius". So a different lesson from this poem -- outside the "Horace did achieve what he claimed to have achieved" -- might be the difficulty in getting a sense of eternity.

Stewart Brand talks a lot about this in The Clock of the Long Now (I've just ordered Time and Bits, which will be very interesting). We tend to think of long time spans in terms of the accumulated small changes in things we know, but it seems that those things may not even exist in a few hundred years. (We expect to be able to watch the progress of state changes on an object to which we hold a reference, only to find that the object has passed out of scope and been garbage collected. Insert "scrap heap of history" joke here.) I was told yesterday by a Russian I encountered in Soda Hall that it was funny that we spend so much time studying U.S. history, because "U.S. history is so short! My city is older than your country".

Rome was already getting up toward Moscow's present age when Horace wrote, yet Rome fell, too, and the current "city of Rome" has very little cultural, civilizational, political continuity with the ancient Rome.

NOUVEAU venu, qui cherches Rome en Rome
Et rien de Rome en Rome n'aperçois,
Ces vieux palais, ces vieux arcs que tu vois,
Et ces vieux murs, c'est ce que Rome on nomme.
Vois quel orgueil, quelle ruine: et comme
Celle qui mit le monde sous ses lois,
Pour dompter tout, se dompta quelquefois,
Et devint proie au temps, qui tout consomme.
Rome de Rome est le seul monument,
Et Rome Rome a vaincu seulement.
Le Tibre seul, qui vers la mer s'enfuit,
Reste de Rome. O mondaine inconstance!
Ce qui est ferme, est par le temps détruit,
Et ce qui fuit, au temps fait résistance.

THOU STRANGER, which for Rome in Rome here seekest,
And nought of Rome in Rome perceiu'st at all,
These same olde walls, olde arches, which thou seest,
Olde Palaces, is that which Rome men call.
Behold what wreake, what ruine, and what wast,
And how that she, which with her mightie powre
Tam'd all the world, hath tam'd herselfe at last,
The pray of time, which all things doth deuowre.
Rome now of Rome is th' onely funerall,
And onely Rome of Rome hath victorie;
Ne ought saue Tyber hastning to his fall
Remaines of all: O worlds inconstancie.
That which is firme doth flit and fall away,
And that is flitting, doth abide and stay.

(Bellay/Spenser; the translation is remarkably literal!)