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May 31, 2009

The F-Double-Prime Equation Of Love

Mathematician Steven Strogatz, guest-blogging for Olivia Judson:

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.)

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Posted May 31, 2009 at 9:54 | Comments (0) | Permasnark
File under: Science, Society/Culture
Dan's thoughts: For a moment there I thought the title referred to "Ira Flatow," who would not fit nearly so well... >>

Ira, Jad, and Robert

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.)

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Posted May 31, 2009 at 7:29 | Comments (1) | Permasnark
File under: Media Galaxy, Radio, Television

Dating the Past

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.

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Posted May 31, 2009 at 7:15 | Comments (0) | Permasnark
File under: Learnin', Object Culture, Science, Worldsnark

May 30, 2009

Dan's thoughts: Greenspun says: "How much ancient wisdom was lost because the common Roman citizen lacked TCP/IP?... >>

Finally, You Too Can Be Marcus Aurelius

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.

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Posted May 30, 2009 at 6:40 | Comments (3) | Permasnark
File under: Books, Writing & Such, Learnin', Object Culture, Technosnark

The Earth Is Hiring

Robin says,

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