Archive for April, 2006

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Starlings and nested songs

April 30, 2006


Noam Chomsky pegged “recursive grammar” as the unique feature of human speech. We can recognize speech patterns that are defined by nested structures (“The cat that the sitter that the service that I called hired fed died,” or “What did you bring a book I didn’t even want to be read out of to up for?”), in which the final piece of the pattern may be arbitrarily far from the initial piece.

Now it seems we aren’t alone. Starlings can be trained to recognize and produce recursive song patterns. They get it, when they are rewarded for an arbitrarily long string of rattle calls followed by an equal number of warble calls. It’s a skill that’s been tested and found lacking in tamarin monkeys, but starlings are up to it.

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A long long trail to Iranian A-bombs

April 29, 2006

When they tell you Iran could have nukes any minute now, reply that they can’t get ’em for years, probably not until “into the next decade”. Who says? Bush’s own Director of National Intelligence, John Negroponte, that’s who. The transcript of his National Press Club briefing is also, at least for now, on Negroponte’sDNI site.

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Bush is listening. Use big words.

April 29, 2006

[On edit: The title phrase did not originate with me. If you’re looking for bumper stickers and other paraphernalia, try this site. But y’all come back, hear?]

You may have heard about the suit Electronic Frontier Foundation brought against AT&T, claiming that they’re running all their Internet traffic in selected cities through the NSA.

The class-action suit, which seeks an end to the collaboration it alleges, is based in part on the testimony of Mark Klein, a retired technician for the company who says Internet data passing through an AT&T switching center in San Francisco is being diverted to a secret room. There, Mr. Klein says, the security agency has installed powerful computers to eavesdrop without warrants on the digital data and forward the information to an undisclosed place.

Now the Feds are trying to quash the suit (U.S. Steps Into Wiretap Suit Against AT&T), by invoking the State Secrets Privilege. They’re saying EFF mustn’t be allowed to introduce its evidence that the NSA is in gross violation of the law, because then the gummint would have to deny it, and saying out loud whether or not the NSA stands in massive breach of the fourth amendment would be giving Osama TMI.

Glenn Greenwald provides his usual astute analysis of the State Secrets Privilege, its history and its abuse potential, in “Building the Secrecy Wall Higher and Higher“. (Fair warning: it’s long.)

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A mathematical farmer’s market

April 29, 2006

Every few weeks since ’92 or so, first on Usenet, now on the Web, John Baez of U Cal Riverside has published This Week’s Finds in Mathematical Physics. He slogs through the original research papers so you don’t have to, and then he explains the good parts. I’ve just added it to my link list.

Why do I call it a “farmer’s market”? Because it’s always fresh and tasty, it comes from many fields and vineyards, and he gives it his own local flavor. The intended audience is fools like me: with an undergrad degree in math or physics, and a desire to deceive ourselves into thinking that we’re keeping up. If it’s to do with string theory or quantum gravity, he’s on it.His gifts for exposition, and for fun, are enormous.

This week he takes up the quincuncial mapping of the sphere (see figure) and its connection to rational tangles. His homepage has links to other good stuff.

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A problem from hell

April 28, 2006

(With not very abject apologies to Samantha Power.) There’s a march in DC this Sunday, to press the government to get international troops in to stop the genocide in Darfur.

This shouldn’t be, and I think is not, a partisan issue at all. When Clinton failed to step into Rwanda, it was not just a shame for the Democratic party, but for America. And as near as I can tell, the Bush administration is in the throes of the same kind of non-partisan lassitude, born not of ideology but of inertia.

If you can be there, great. If not, MoveOn is sponsoring a virtual march. You can click on through and sign their petition.

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Britannica helps you rate your democracy

April 28, 2006

The King of Zembla blog pointed the way to this 9 minute Encyclopedia Britannica classroom film from the 50s. (Video and sound, DSL highly recommended.) Not appearing today in any civics classroom near you, but you can try out this simple democracy / despotism scale at home on the country of your choice, say countries with initials like U.S.A. or I.r.a.q.

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Black holes are green

April 28, 2006

The idea’s been around for a long time. Misner Thorne and Wheeler’s classic 1973 text Gravitation explained in Chapter 33 how to use a black hole to convert your garbage into electricity with astounding efficiency. They had a neato diagram of the ringworld civilization, the BH, and the trajectory of the garbage rocket.

A NASA press release Monday tells us we’ve proved it’s happening out there. The X-ray observatory Chandra was able to measure the efficiency of a black hole engine, which uses infalling gas as fuel to power a process that scoops out humongous cavities in the black hole’s surrounding material. (Here’s a larger photo.) Equivalent efficiency in a car engine would give you an EPA rating of a billion miles per gallon.