Archive for May, 2009
In all cases, the business of theoretical physics boils down to finding the right differential equations and solving them. When Newton discovered this key to the secrets of the universe, he felt it was so precious that he published it only as an anagram in Latin. Loosely translated, it reads: “it is useful to solve differential equations.”
The silly idea that love affairs might progress in a similar way occurred to me when I was in love for the first time, trying to understand my girlfriend’s baffling behavior. It was a summer romance at the end of my sophomore year in college. I was a lot like the first Romeo above, and she was even more like the first Juliet. The cycling of our relationship was driving me crazy until I realized that we were both acting mechanically, following simple rules of push and pull. But by the end of the summer my equations started to break down, and I was even more mystified than ever. As it turned out, the explanation was simple. There was an important variable that I’d left out of the equations — her old boyfriend wanted her back.
In mathematics we call this a three-body problem. It’s notoriously intractable, especially in the astronomical context where it first arose. After Newton solved the differential equations for the two-body problem (thus explaining why the planets move in elliptical orbits around the sun), he turned his attention to the three-body problem for the sun, earth and moon. He couldn’t solve it, and neither could anyone else. It later turned out that the three-body problem contains the seeds of chaos, rendering its behavior unpredictable in the long run.
Guess we shouldn’t toss DiffEq just yet.
(Via the Radiolab blog.)
Must listen: Ira Glass, Jad Abumrad, and Robert Krulwich on the differences between radio and television. Includes such gems as how radio amplifies intimacy and television turns gesture into parody, Jad’s observation that This American Life made real people’s true stories sound like fairytales, and how Stephen Colbert is more like a radio personality (his show more like a radio show, his audience more like a radio audience) than a television one.
(My own thesis about Colbert: it’s his perfect miming of big-personality talk show hosts like Limbaugh, O’Reilly, Scarborough, Hannity, Olbermann, usw., most of whom started on radio, continue to host radio shows, and whose TV shows and audiences are still a whole lot like radio.)
Historiscientific nerd alert: There’s a hot new method of dating historical artifacts, specifically ceramic artifacts, based on their moisture uptake. But there’s at least one big problem — it assumes that mean temperatures are constant. HNN’s Jonathan Jarrett has the goods, in a paragraph so well-linked that I’ve cut-and-pasted them all. (I also changed some of the punctuation and split Jarrett’s long paragraph into a few short ones.)
Now, you may have heard mention of a thing called “the medieval warm period.” This is a historical amelioration of temperature in Europe between, roughly, the tenth and twelfth centuries. This probably decreased rainfall and other sorts of weather bad for crops, therefore boosted agricultural yield, pumped more surplus into the economy, fuelled demographic growth and arguably deliquesced most European societies to the point where they changed in considerable degree.
However, because of the current debate on climate change, it has become a ball to kick around for climate “scientists,” those who wish to argue that we’re not changing the climate pointing to it and ice coverage in Norse-period Greenland (which was less than there is currently despite less carbon dioxide in the atmosphere then), while those who wish to argue that we are changing the climate (and, almost always, that this relates to CO2 output, which does seem like a weak link in the argument) dismiss it as legend or scorn the very few and unscientific datapoints, not really caring that the historical development of European society in the ninth to eleventh centuries just doesn’t make sense without this system change from the ground. None of these people are medievalists and they’re not trying to prove anything about the Middle Ages, so it gets messy, but there is a case about this temperature change that has to be dealt with.
This obviously has an impact on this research. If the sample were old enough, the errors and change probably ought to balance out. But if it were, from, say, the eighth century, then the moisture uptake in the four or five subsequent centuries would be higher than expected from the constant that this research used and the figure would be out, by, well, how much? The team didn’t know: “The choice of mean lifetime temperature provides the main other source of uncertainty, but we are unable to quantify the uncertainty in this temperature at present.”
We, however, need to know how far that could knock out the figures. Twenty years? More? It begins to push the potential error from a single sample to something closer to a century than a year. That is, the margin of historical error (as opposed to mathematical error) on this method could be worse than that of carbon-dating, and we don’t actually know what it is.
Lots of good stuff in the whole, long post, including an annotated run-down of ALL of the ways we know how to date old things.
I am a sucker for long histories, especially when they’re summarized with simple schema. Phillip Greenspun wrote this for a talk on how the internet has changed writing, under the subhead “Publishing from Gutenberg (1455) through 1990″:
The pre-1990 commercial publishing world supported two lengths of manuscript:
- the five-page magazine article, serving as filler among the ads
- the book, with a minimum of 200 pages
Suppose that an idea merited 20 pages, no more and no less? A handful of long-copy magazines, such as the old New Yorker would print 20-page essays, but an author who wished his or her work to be distributed would generally be forced to cut it down to a meaningless 5-page magazine piece or add 180 pages of filler until it reached the minimum size to fit into the book distribution system.
In the same essaylet, Greenspun has a subhead, “Marcus Aurelius: The first blogger?”:
Marcus Aurelius, Roman Emperor from 160 AD to 180 AD, kept a journal during a military campaign in central Europe (171–175). It was not available until after his death and not widely available until printed in 1558 as the Meditations…
This was preserved because the author had been Emperor. How much ancient wisdom was lost because the common Roman citizen lacked TCP/IP? [By 1700 BC, the Minoans were trading with Spain, had big cities with flush toilets, a written language, and moderately sophisticated metalworking technology. Had it not been for the eruption of Thera (on Santorini), it is quite possible that Romans would have watched the assassination of Julius Caesar on television.]
It’s not all since-the-dawn-of-civilization stuff — there are lots of examples of writing that really only works on the internet and more pedestrian things like the virtues of blogs over Geocities. “Webloggers generally use a standard style and don’t play with colors and formatting the way that GeoCities authors used to.” This shows how in the weblog, content becomes more important than form. (Psst– It also suggests that if Minoan civilization had survived and spread, Augustine’s Confessions might have been excerpted on a lot of home pages with lots of crappy animated GIFs.)
Via Daring Fireball.
Commencement season continues! Nice one from Paul Hawken:
There is invisible writing on the back of the diploma you will receive, and in case you didn
Music critic Simon Reynolds praises music’s moments of in-between:
It rankles a bit that the late ‘80s are now treated as a mere prequel to grunge. The recently aired Seven Ages of Rock on VH1 Classic was a marked improvement on earlier TV histories of rock, which tended to jump straight from Sex Pistols to Nirvana. But its episode on U.S. alternative rock nonetheless presented groups like the Pixies, Dinosaur Jr., and Sonic Youth as preparing the ground for Nirvana. That’s not how it felt at the time: Sonic Youth and the rest seemed fully formed significances in their own right, creative forces of monstrous power, time-defining in their own way (albeit through their refusal of the mainstream). My Melody Maker comrade David Stubbs wrote an end-of-year oration proclaiming 1988
The role of mathematics in the language sciences is made more complex by the variety of different sorts of mathematics that are relevant. In particular, some areas of language-related mathematics are traditionally approached in ways that may make counting (and other sorts of quantification) seem at least superficially irrelevant
Paul Krugman reminds us of the awesome fact that he got into economics because he read the Foundation series as a kid. In the series, there’s a character named Hari Seldon who studies psychohistory — the imaginary super-socio-economics that allows you to predict mass-scale human behavior using quantitative models. He shows up as a hologram at various point in the series’ long chronology, long after he’s dead, saying: “I pretty much predicted what you will be doing right now.” And he’s always right!
Anyway, it made me remember seeing, in the new issue of Wired, that Google’s chief economist Hal Varian admitted the same thing!
“In Isaac Asimov’s first Foundation Trilogy, there was a character who basically constructed mathematical models of society, and I thought this was a really exciting idea. When I went to college, I looked around for that subject. It turned out to be economics.”
This makes me want to come up with some new, imaginary discipline and write a series of books around it, expressly in order to inspire a generation of smart young people to find ways to do it in real life. They will fail, but they will do such cool things along the way!
The idea is that Latinos have a dual experience that whites don’t have and that, all things being equal, they’ll be able to pull from that experience and see things that whites don’t. The problem with this reasoning is it implicitly accepts the logic (made for years by white racists) that there is something essential and unifying running through all white people, everywhere. But White–as we know it–is a word so big that, as a descriptor of experience, it almost doesn’t exist.
Indeed, it’s claims are preposterous. It seeks to lump the miner in Eastern Kentucky, the Upper West Side Jew, the yuppie in Seattle, the Irish Catholic in South Boston, the hipster in Brooklyn, the Cuban-American in Florida, or even the Mexican-American in California all together, and erase the richness of their experience, by marking the bag “White.” This is a lie–and another example of how a frame invented (and for decades endorsed) by whites is, at the end of the day, bad for whites. White racism, in this country, was invented to erase the humanity and individuality of blacks. But for it to work it must, necessarily, erase the humanity of whites, too.
TNC of course makes the further (and necessary point) point that these are all fictions that become socially real.
P.S.: I realize the “negative dialectics” reference is probably too insidery for 98% of readers. It’s a term that Theodor Adorno used for a title of his book. Hegel defined identity as “the identity of identity and nonidentity” — the idea being that any concept or act of identification glosses over differences and unifies things that are like in some ways but unlike in others. For Adorno, negative dialectics explores “the nonidentity of identity and nonidentity,” i.e., disintegrating all of that.
Cf. the kind of weird quasi-discourse on whether Judge Sotomayor will or will not be the first “Hispanic” judge on the Supreme Court — the idea being that Justice Cardoza (whose ancestors, Portuguese Jews, emigrated to New York state in the eighteenth century) would qualify. If you try to pursue a purist/universalist idea of racial identity to the end, you start to focus on definitional descriptors (biological and/or cultural ancestry on the Iberian peninsula) that just wipe out all differences. “Hispanic” in this context may be as much of a lie-word — that is to say, as powerful a concept — as “white.”