* I am something of a complete idiot; until Tom's recent post on De Morgan's spicular notation, I had never noticed the connection between the spicular notation and Euler diagrams. That makes so much sense, and I don't see how I could have missed it; and given that one can use different conventions in drawing Euler diagrams, it shows that spicular notations actually form a family, rather than a single arbitrary notation, of which De Morgan's version is only one. This opens up the possibility that there may be possible spicular notations that are better than De Morgan's. And as Tom notes in another post, recognizing the link between spicular notation and Euler diagrams makes clear the value of the former as a quasi-diagrammatic notation.
* Enbrethiliel has a post that, in its general points, pretty much sums up my view of the recent furor over Anne Rice's conversion to noninstitutional Christianity.
* Kim Sterelny on apprenticeship as a learning model for cultural learning. (ht)
* Steve Matheson on randomness in embryo growth, i.e., organized processes involving stochastic processes as subprocesses.
* Stanley Fish argues that plagiarism is not a big moral deal. I think he's right; the analogy between stealing and plagiarism has never actually been very strong. But it still can get you an F in my class. Plagiarism is a problem not because it is immoral in general but because it obscures evaluation on the actual merits of one's work in fields where reputation or money are important. And he's right about something more important, namely, that we should stop pretending the rules governing plagiarism are easy and obvious: students do not usually find them so. They have difficulty seeing the proper line between common knowledge and what must be cited; they have difficulty seeing the relevance of particular methods of citation; they don't have a clear conception for how paraphrase fits into the scheme of things; and so forth. Moreover, the conventions governing plagiarism are not uniform across all fields. If you want to be a lawyer dealing with contracts, for instance, you will succeed best if you have a large file of very different kinds of prior contracts that you can simply copy and adapt and mix-and-match whenever new occasions arise, rather than absurdly trying to start from scratch each time. Nobody will ever get bothered by the fact that the contract language is exactly the same as some other contract; reputation and money for lawyers simply doesn't depend on how much work they themselves put into the particular contract language used. And while that's an extreme case, there are lots of fields where common practices would count as plagiarism if they were done in some other field.
That said, Fish is simply wrong that if plagiarism is an artificial and conventional concept rather than a fundamental moral one that there is no point in looking at its philosophical underpinnings; philosophers have been looking at the philosophical underpinnings of purely conventional practices since Socrates. And, in fact, it's those philosophical underpinnings that show that, contrary to common belief, originality or literary property has nothing to do with it; plagiarism conventions exist not to protect originality or literary property but to limit rewards to people who actually and consistently do the work, to prevent people who let others do the work from being rewarded as if they had done it. This is why plagiarism conventions have to vary somewhat across fields -- what counts as 'the work' is itself something that varies across fields.
* For the first time in a long time it looks like there's a promising answer to the question of whether P is equal to NP. It's something of an esoteric question, but like many esoteric questions in mathematics, it has practical implications: if P is equal to NP, many codes and computer security systems are breakable that would be relatively unbreakable if P is not equal to NP. (If I haven't garbled that too badly; it's well outside my field.)
ADDED LATER: John Perry clarifies in the comments: "If P = NP, it's not quite true that many codes would become unbreakable: they would, rather, be unbreakable in a number of operations that is deterministically polynomial in the worst case. However, that worst case could have a quite high and impractical exponent, and could occur frequently enough in practice to render the method useless in many cases."
* The physics of the Beacon of Gondor. As some of the commenters notes, the system is based on the Malverns. A beacon of fires similarly conveys word back to Argos that Troy has fallen in Aeschylus's Agamemnon, but there are notorious problems with both time and geographical location in Aeschylus's description of it. Aeschylus is probably trying to give a plausible system for the Greeks that would do for them (i.e., give advanced notice) what the Persian rider-system (one of the things the Greeks admired about the Persian empire) did for the Persians. Tolkien is very clear, I think, that the beacon-system is actually combined with a rider-system, which would be the most reasonable way to do it: the beacon would provide an alert, details to follow by fast horse. So all the beacon ultimately has to do is outrun the horses, warning each station in advance to start getting riders ready because an emergency message is coming. This would massively cut down on wasted time, the biggest problem with a rider-system; and it would prevent the beacon-system from breaking down (even if station B doesn't pick up station A's signal, this will be fixed when the riders from A reach B and the beacon begins again). There still would be room for the system to break down, but the chances are that everyone would at least know that something was up. You want a fast alert system, but fast alert systems don't usually carry a lot of information (when the Horn of Buckland blows you know there's a big problem somewhere, but you don't know if it's bandits or floods or fires); and you want an adequate message system, but adequate message systems usually have a lot of inefficiencies. It makes sense to combine the two.
* The Library of Historical Apologetics (ht)
* Last week my sister took me to see Inception at the Alamo Draft House (for my birthday this past weekend); very good. One of the reasons it is good is that it is about the only movie that captures dreaming properly: conveying not only its surreal association but also the fact that these associations flesh out very logical correspondences and implications. If you see any big Hollywood movie this year, this is it. It's basically a caper movie, but I was impressed as to how well the characterization was done, given that by it's nature it's not a character-driven story but a plot-driven one.