Sunday, February 27, 2011

What are colleges for? etc.

There's been a good deal of talk lately about increasing the educational "productivity" of universities, making college cheaper and more "scalable" in innovative ways, etc. I think this is a lost cause as it is hard to quantify outcomes, or expect the market to do so, partly because the monetary "value" of a college education usually has little to do with the skills one is supposed to have acquired. Most of the college wage premium accrues to people who take up jobs that are not related to material they learned at college. (This is increasingly inevitable as service-sector opportunities fluctuate more rapidly than manufacturing opportunities.) It is possible that the premium has to do with some vague notion that people learn "critical thinking" etc., but this doesn't seem likely. My impression at least is that the primary factors behind the wage premium are: (a) employers assume that people who got into good colleges are smart, (b) working through college and not dropping out demonstrates traits -- e.g., a willingness to do things because one has to, to meet deadlines, etc. -- that are useful, (c) most hirers have been to college, and there's a networking effect. (a) and (c) are difficult to industrialize but it seems unlikely that a college education without either would be sought after.

It seems easier to justify universities starting from the research end. As Sean Carroll has remarked, this is really the only way one (or, more precisely, an intelligent Martian) can make sense of the setup. To put it crudely, the core function of the university is to act as a patronage system for scientists, artists, and other scholars working on things that are arguably valuable but, for various reasons, do not offer a "market-based" livelihood. (In the simplest-to-justify cases, as with medical research, the reasons have to do with the problems of secrecy and/or free-riders in market-based alternatives.) In order to keep its patrons (rich -- and/or, for state schools, powerful -- alumni) loyal and happy the university admits their kids (which gives them "cultural" prestige markers, which include a possibly undeserved reputation for intelligence -- this is partly why elite universities need to admit smart kids!), arranges sports and alumni events, etc. The elite university serves two further purposes: (a) it perpetuates knowledge, and itself, by training academics as well as various people who are in the broad penumbra of the academic world -- editors, certain kinds of journalist, etc., (b) it provides a channel for a few people from disadvantaged backgrounds to leapfrog the various middle classes and land in the elite, or at least impress their existence on the elite. In political-economy terms (b) is important as most decisions are made by elites and the extent to which they are even aware of how the poor live determines the extent to which their policies hurt the poor.

One can also argue that a task like teaching, which -- as Robert Lowell remarked -- "you're always up to, or more or less up to," is a good thing for a creative artist. One doesn't have teacher's block. Cf. Lowell's contemporary Richard Feynman, famously, on the Institute for Advanced Study --
When I was at Princeton in the 1940s I could see what happened to those great minds at the Institute for Advanced Study, who had been specially selected for their tremendous brains and were now given this opportunity to sit in this lovely house by the woods there, with no classes to teach, with no obligations whatsoever. These poor bastards could now sit and think clearly all by themselves, OK? So they don’t get any ideas for a while: They have every opportunity to do something, and they’re not getting any ideas. I believe that in a situation like this a kind of guilt or depression worms inside of you, and you begin to worry about not getting any ideas. And nothing happens. Still no ideas come.
Nothing happens because there’s not enough real activity and challenge: You’re not in contact with the experimental guys. You don’t have to think how to answer questions from the students. Nothing!
[Along these lines there is a wonderfully snide remark in Auden's "Letter to Lord Byron" about the newly financially independent poet of Byron's generation: "he sang and painted and drew dividends / but lost responsibilities and friends." The flip side is that you've got to guard against the complacency that comes from being engrossed in unimportant tasks even as your real agenda languishes. I must admit that my choice of graduate school was not unaffected by a desire to avoid teaching, on the (all-too-plausible) grounds that it would be work and I'd be crap at it.]

I tend to think that these functions are important, and that the modern university is the minimal setup that performs all of them and locks in enough interests to form a sustainable ecosystem. It doesn't scale well because it is so heavily about access, which doesn't scale at all. One is left with two questions: (a) if access is to be rationed, who should get it? (b) what about everyone else? I think the "fairness" aspects of (a) are over-pondered; any conceivable admissions process would be unfair in some respects. (b) is an interesting issue but I don't think one could discuss it in detail without lapsing into futurism. There are motivated, clever, and unlucky people for whom (e.g.) the secondary campuses of state schools offer just about enough by way of resources to get a good education or sustain a decent research program; one supposes, however, that the majority of students are there as a way of getting ahead, which means that they are demonstrating their willingness to do arbitrary tasks to deadlines in a rather expensive way. There must be simpler arrangements... (Of course college is also about access to booze while under 21, which does scale, and this shouldn't be underrated.) Before one thinks of such rearrangements, though, it would be nice if graduate schools were more open to applicants with nontraditional backgrounds.


This is really in the spirit of "closing tabs," but re justifying research: last semester I was at a KITP talk on giving talks that was notable mostly for a spirited exchange near the end between Tony Zee and Bill Phillips on how to sell physics (say to the DoD/DoE/Congress). Zee took the line that one should assert that the sciences (and humanities) are what make a civilization worth defending; Phillips objected, reasonably enough, that this wouldn't work with any actual congressmen, and that one had to focus on concrete possibilities. I mostly agree with the destructive half of Phillips's point but I don't think that carving out little bits of academia as "obviously useful" is much of a solution. To some extent it plays into the hands of the large fraction of Congress that is explicitly anti-academic, by setting up their salami tactics for them. It isn't clear to me that we aren't doomed. (See Michael Berube on this.)

I remember Phillips and Zee disagreeing, too, about the utility of structuring talks to make them exciting (which was what the meta-talk was about). There is an ideal of complete spontaneity and informality in many corners of physics -- the ideal talk is a lucid extemporaneous (if blackboard-assisted) lecture delivered in one's bedclothes, and any too-obvious sign of preparation -- fancy slides or pictures, a prepared text (the horror!) -- is vaguely frowned upon, and marks you as possibly an experimentalist. Far worse, though, to come off as making your work sound more interesting than it is, even if that is obviously what everyone wants to do; the most admired talks are the kind described in this post (via Ross McKenzie's blog):
He showed up in the convention center wearing a brightly colored short-sleeved shirt, shorts, and, if I remember correctly, sandals. Not only had he forgotten to dress for Boston's weather, he'd also left his laptop in California. [...] Using hastily prepared, hand-written viewgraphs, he gave one of the best talks of the meeting. Indeed, it's conceivable that in creating his viewgraphs, Heath was forced to focus more on his message than on its presentation.

"Pure content" is a myth, of course, but a widely held one. There is an implied arrogance behind all of this that is pervasive in academia but is perhaps exacerbated by the overwhelming maleness of physics, and that hurts us when we have to deal with the possessors of real power. (This is related to Nozick's notion, in some typically obnoxious essay, that academics have a sense of entitlement that businessmen do not.) I remember saying once that I was a trust fund brat without a trust fund; this is true of all academics, to a degree (ineluctable pun).

Ice blink

 Photo by Sara Wheeler, Slate

There was a brief period, between the Russian visa debacle and the other horrors of 2006, when I meant to go to Spitsbergen on the Watson. This is presumably what it would have been like:
Puffins, pink-footed geese, long-tailed ducks, ivory gulls, dunlins, king eiders, sanderlings, and red-throated divers shrieked and squawked around lime-stained fissures. It was startling to see species familiar in dowdy British winter coats resplendent in summer plumage. Gray phalaropes in Arctic carmine, snow buntings transformed from dusty slate into dazzling black and white, golden plovers with refulgent breast feathers.
I'd never heard of "ice blink":
Big wind-sock-shaped clouds hung in the sky below a layer of cirrostratus. Richard lay down to photograph ribs of driftwood. I picked among beluga tusks and rusted barrel hoops in the yard-high ice foot, a weak and unstable wall of ice and snow left on the shore when the winter sea ice broke up. We looked out for bears and listened to small waves slap the pebbles. Out in the open sea at the end of the fjord, a dazzling stripe on the underside of distant clouds mapped the sea ice. In a polar phenomenon called ice blink, clouds are lit from underneath by sunlight reflected up from a patch of pack ice in a contrasting dark area of water. When Nansen first came upon ice blink, he wrote, "I felt instinctively that I stood on the threshold of a new world."

The article also mentions the wild fluctuations in the numbers of barnacle geese in Spitsbergen; perhaps because the ecosystems are both younger and more sensitive, this appears to be a recurring theme. I remember hearing in Shetland five years ago that the population of fulmars had grown to almost dangerous levels.

Saturday, February 26, 2011

Yeats and the sea-horse

I was looking for a Yeats concordance online to see if he had done much with sea-horses (of which more below), but found Peter Ure's old review of a Yeats concordance [Rev. Eng. Stud. XVI, 221 (1965)] :
The golden smithies of the Emperor, Yeats might disapprovingly have noted, could not have contrived anything remotely resembling this volume, from which we can learn that he used Emperor twice, smithy five, and golden sixty-four times. Yeats has been chosen as the second poet (the first was Arnold) to submit his vocabulary to the IBM 704 Electronic Data Processing Machine at Cornell. An impressive compilation is the result: a total of 10,666 words (the text used being the Variorum edition), recorded with an accuracy utterly out of reach of the nonelectronic scholar. One can ramble about in it discovering all sorts of facts, such as the numbers of 'savage or noxious animals', as Mr. Parrish puts it, of birds of prey, of 'circus animals', of goats and monkeys (four of the former, only one of the latter). Perhaps the first temptation that it offers to its user is of a rather simple-minded kind: there are no demons in Yeats's verse after 1892 (14 of the 16 are in The Wanderings of Oisin), nor does dim occur after 1913; moon is nearly twice as frequent as sun, and king as queen; dream and its derivatives occupies three pages; there are six and a half pages of old and only two of young; shame occurs five times and glory twenty-eight; Coole and die have twice as many entries as, respectively, Sligo and live; England has two entries, Greece five, and Ireland thirty-nine; Oxford and Cambridge do not occur at all, but Liverpool gains a toe-hold.

How far we've come -- I ended up running Ctrl-F on the Project Gutenberg text (one has always to remember that this is case-sensitive) and finding out that sea-horses only occur in the poem that I was originally thinking of, "High Talk":

PROCESSIONS that lack high stilts have nothing that catches the eye.
What if my great-granddad had a pair that were twenty foot high,
And mine were but fifteen foot, no modern stalks upon higher,
Some rogue of the world stole them to patch up a fence or a fire.

Because piebald ponies, led bears, caged lions, make but poor shows,
Because children demand Daddy-long-legs upon his timber toes,
Because women in the upper storeys demand a face at the pane,
That patching old heels they may shriek, I take to chisel and plane.

Malachi Stilt-Jack am I, whatever I learned has run wild,
From collar to collar, from stilt to stilt, from father to child.

All metaphor, Malachi, stilts and all.  A barnacle goose
Far up in the stretches of night; night splits and the dawn breaks loose;
I, through the terrible novelty of light, stalk on, stalk on;
Those great sea-horses bare their teeth and laugh at the dawn. 

This is a very late poem that was written at about the same time as the "Circus animals' desertion," which also mentions "stilted boys." The narrator here is one of the deserting circus animals I suppose. The poem has stuck with me because of the sestet (it is a sonnet of sorts); the stilts bit is fine but the sea-horse image really comes out of nowhere as far as I can tell -- presumably the point is that sea-horses, qua photosensitive force of nature, can go back out of the light unlike Malachi; that life in the modern era is hard and mostly inglorious work, and that this is so partly because of the "broken hierarchies" (of which more in a later post) that connected life with art with death; there must also an underworld aspect to all of this (the primary sea-creatures in Yeats being dolphins, but of course Neptune was both a sea-god and a horse-god), which was what I was trying to get at from the concordance. But in the event the sea-horses seem to be a one-off and probably have to be taken on their own terms.

Friday, February 25, 2011

Dogs, not quacking

It seems that polls are only talked about to the extent that they agree with the prejudices or agendas of some large group of people. (This is also true of popular psychology.) While it is inevitable and perhaps healthy that most people interested in politics in one sense should also be interested in the other, and that most "analysts" should be propagandists, one sometimes finds that genuine puzzles are widely ignored. For instance, Nate Silver has two state-by-state maps of Obama's approval rating now vs. his vote share in 2008. Here is the absolute change:

And here is the swing-relative-to-national-average:

Blue is better for Obama, red is worse. The zero has no obvious significance: approval ratings track votes but there might well be an overall offset of a couple of points. (For instance, one knows people in New England who disapprove of Obama but would be unlikely to vote for a Republican.) To the extent that this offset is different for every state one should be skeptical of treating this as an apples-to-apples comparison; but some of the effects are large and presumably real.

I find this data puzzling.

1. Re the south, one's default hypothesis is that support for Obama is inelastic -- being determined almost exclusively by demographics -- so the first graph is the relevant picture. Most states where Obama hasn't lost ground are states where he didn't have ground to lose.

1'. Silver suggests that Obama might be gaining ground among racists as they become used to having a black president. (The diminishing-salience-of-race theory.) I don't buy this theory as the pattern is evidently about deeply Republican states (NE/AK/UT), rather than southern ones in particular.

2. I don't know what's going on in upper New England. At all. Nor does anyone else seem to, at least that I've read... is there a story here that I missed? "Libertarianism" does NOT work as the Dakotas, Montana etc. do not look like NH/VT/ME.

3. Silver suggests a "swing state effect" -- states where Obama campaigned heavily in 2008 were artificially pro-Obama because he outspent McCain. I don't see it; NH looks more like VT than like Ohio or Florida.

4. If there is a pattern here -- and I'm not sure there is -- it raises exactly the opposite worry from the usual one about "working-class whites" (see Galston for another formulaic implementation of this meme, and Clive Crook for a robotic blurb). Obama has lost more ground in Colorado than in Ohio. If I had to draw a general inference from the second map it would be that (barring W. Va.) the states in red have disproportionately many cultural progressives, many of them well-off. Three obvious narratives come to mind. The first is that these people were unusually starry-eyed and are now unreasonably disillusioned. (But what about New York and Massachusetts?) The second is that, having had more to begin with, they lost more in the crisis, and are therefore unusually sour. (But Vermont and New Hampshire have low unemployment.) The third is that, having more leisure, they have been paying more attention -- this is the notion of the "high-information" voter -- and that when others really begin to tune in they will come to similar conclusions.

Though who knows what things will look like on the other side of the government shutdown.

Thursday, February 24, 2011


In a recent IM conversation I brought up the possibility of lowellcats, i.e., lolcats with captions from Robert Lowell poems. (If absolutely necessary one is allowed to use James Russell Lowell or Amy Lowell.) Matt P. immediately generated this one (quote is from "Skunk Hour"):

The theme is one for the tumblr, where no doubt they will all get text captions involving Alan.

Addendum. cf. Lowell Katz.

Addendum 2. via Kit, Lowell Cats. I guess the name was too obvious to be original... I quite like the Lowell Cats site though.

Wednesday, February 23, 2011

Dear John, wright and wrong, the aggression of "about"

1. C.K. Stead, in an interesting LRB article [gated] about T.S. Eliot and Katherine Mansfield, quotes this letter from TSE to Mansfield's then-widower John Middleton Murry:
My dear John,
You know it is impossible for me to come to your wedding, as I am in a bank and cannot get away at such an hour. I am sure that you have done the best thing for yourself in marrying again, but you know that it has always been impossible for me to understand any of your actions.
Ever yours
2. A series of puns on W/right in a Google reader thread led me to look up the etymologies of right and wrong to find out why there's a w in wrong. The "original" meanings were straight/crooked; "right" is from the rect- root and "wrong" seems to have begun life as part of the conjugation of "wring" in the wrung-out-of-shape sense. [The first Mid. E. uses of "wrong" are in place names like "Wrangebroc" and "Wrongedichhundred" (a hundred is an administrative unit).] There seems to be no principle behind the w in wring/wrong; the Old Norse and High German forms are w-less. On the other hand the w in wright is there for a reason,"wright" having come from forms that had the form "worked" via the interchange of front vowels and r that is so common in Middle E. (cf. "bryd" for "bird" etc.)

Interestingly "wrong" once meant "oblong" -- a rectangle being, one supposes, a wrecked tangle.

3. David Orr encounters the law and literature movement in the form of an anthology on the Poetry of Law; re the preposition, he says:
And it’s comforting, isn’t it, to suppose that pursuits like law and poetry aren’t really “about” each other in the almost aggressive way that instruction manuals are about food processors, but rather are as delicately interrelated as sea and shore, or bees and roses.

4. Gaddafi's flamboyantly Elizabethan approach to spelling (Language Log; see also Johnson) and Elizabethanly flamboyant approach to dress (Vanity Fair). Discuss: is he the Christopher Marlowe of our age?

Tuesday, February 22, 2011

Auctoresse speketh funnyliche, defyneth manye termes

Y-wis, it semeth me that Margery Attewode doth damage to myn opinioun of hire werkes of the ymaginacyoun, whenever that she doth speke, tweete, blogge, etc. Natheles, hire interviewynge by the greete Galfridus Chaucer -- in his native tongue, hire comaunde of the whiche me liketh, althogh Stickleres mighten saye it wanteth somdeel -- meriteth ful wel yower attencioun, an ye have it nat yet y-seene.
GC: Oftymes my freendes do mocke me for the studye of oolde bookes, for that Ich am alwey poringe over Macrobius or the tales of Ovide or sum swich thynge. What thinke ye of oold bookes? What good have they yn this tikel worlde, the which chaungeth into newe and shinye thinges with each passinge daye?

MA: The oold storyes are the keyes to Dreame-land. Scratch a newe and shinye thing, and ye will fynde an oold and shinye thing lurking beneath.

GC: Ye maye wisshe to telle the rederes of thys blog of the magical beastes of the far lande of Canade. Ich have reade of swich thinges in the Travels of John Mandeville. Are the legendes trewelye to be believed?

MA: Yes, Mayster Chaucer, the tales ye heare are trewe (thogh I feare nat to be found in Mandeville). To wit, the Beaver, much hunted for his scent, which biteth off its owne Stones and casteth them behind yt to distract its pursuers — and in such maner often do ower owne Politicians behave. Yet other straunge beastes abound: the Ice-wormes, that heate themselves up to drill holes; and the Wendigos, that flyen hungrily and with sharp teeth and claws over the snowe with feet a-flayme, and devoure men, which some do name as Tax Collectors. And many more straunge and curious creatures abounde.

Mistris Attewoode expoundeth wel and uptodatelyche the menynge of certayne oolde termes:
GC: Nowe Ich am goynge to seye a fewe wordes, and yf it plese ye, ye maye responde wyth the firste thynge that cometh yn to yower hede whanne ye heare the worde that Ich saye. (Thogh thys did nat go too welle wyth Ms. Launcecrona in an earlier interviewe, peraventure yower grete wisdam and gentilesse shal make for bettir resultes.)

GC:The Black Deeth?

MA: 1) Inspiracioun for The VIIth Seal. 2) And for Boccaccio. As Alice Munro hath seyde, no mattir how awful a thynge may be, “It’s all material.” 3) That which raised wages for (the remayninge) labourers. Hey, there’s always a bryghte syde! 4)Goinge to the dentist in the 1940s. 5) And, as luck wolde have it, the Great Mortalytye -- as it was trewly spoken of in yower tyme -- is one of my litel hobbyes. See Payeback, Chapter V.

GC: Chivalrie?

MA: Code of honour seldom followed, except in literature, and by parfit gentil Knyghtes; OR rescuing chained-up maidens, with soft-porne illustracciouns; OR sayinge thank you when someone openeth the door for you.

GC: Alchemie?

MA: 1) My recipe for Calla Lilies, a swetemete of great delicacye. 2) What geekes did in late mediaeval tymes.

Monday, February 21, 2011


[today being the 104th anniversary of Auden's birth -- this is not an anthology piece but is, I think, one of the better examples of Auden's late style when it comes off. Proximate source here.]

W.H. Auden

There is a time to admit how much the sword decides,
with flourishing horns to salute the conqueror,
_____impassive, cloaked and great on
__horseback under his faffling flag.

Changes of heart should also occasion song, like his
who, turning back from the crusaders’ harbour, broke
_____with our aggressive habit
__once and for all and was the first

to see all penniless creatures as our siblings. Then
at all times it is good to praise the shining earth,
_____dear to us whether we choose our
__duty or do something horrible.

Dearest to each his birthplace; but to recall a green
valley where mushrooms fatten in the summer nights
_____and silvered willows copy
__the circumflexions of the stream

is not my gladness today: I am presently moved
by sun-drenched Parthenopea, my thanks are for you,
_____Ischia, to whom a fair wind has
__brought me rejoicing with dear friends

from soiled productive cities. How well you correct
our injured eyes, how gently you train us to see
_____things and men in perspective
__underneath your uniform light.

Noble are the plans of the shirt-sleeved engineer,
but luck, you say, does more. What design could have washed
_____with such delicate yellows
__and pinks and greens your fishing ports

that lean against ample Epomeo, holding on
to the rigid folds of her skirts? The boiling springs
_____which betray her secret fever,
__make limber the gout-stiffened joint

and improve the venereal act; your ambient peace
in any case is a cure for, ceasing to think
_____of a way to get on, we
__learn to simply wander about

by twisting paths which at any moment reveal
some vista as an absolute goal; eastward, perhaps,
_____suddenly there, Vesuvius,
__looming across the bright bland bay

like a massive family pudding, or, around
a southern point, sheer-sided Capri who by herself
_____defends the cult of Pleasure,
__a jealous, sometimes a cruel, god.

Always with some cool space or shaded surface, too,
you offer a reason to sit down; tasting what bees
_____from the blossoming chestnut
__or short but shapely dark-haired men

from the aragonian grape distil, your amber wine,
your coffee-coloured honey, we believe that our
_____lives are as welcome to us as
__loud explosions are to your saints.

Not that you lie about pain or pretend that a time
of darkness and outcry will not come back; upon
_____your quays, reminding the happy
__stranger that all is never well,

sometimes a donkey breaks out into a choking wail
of utter protest of what is the case or his
_____master sighs for a Brooklyn
__where shirts are silk and pants are new,

far from tall Restituta’s all-too-watchful eye,
whose annual patronage, they say, is bought with blood.
_____That, blessed and formidable
__Lady, we hope is not true; but since

nothing is free, whatever you charge shall be paid,
that these days of exotic splendour may stand out
_____in each lifetime like marble
__mileposts in an alluvial land.

Sunday, February 20, 2011

Leidenfrost ratchets

This week's flood of recreational physics continues... Nature Physics has a new paper online (gated version here, no arxiv that I could find) on self-propelling Leidenfrost droplets. The Leidenfrost effect is the fact that a droplet [1] of water floats above a really hot skillet on a cushion of steam (generated, say, by the bottom of the droplet boiling -- see this youtube video). As steam is a bad conductor of heat, the floating droplet takes a long time to heat up and boil. It was discovered a few years ago [Linke et al., PRL 96, 154502 (2006), gated supplementary material has video] that droplets placed on "ratchets" -- i.e., surfaces with sawtooth-shaped serrations -- moved at about 10 cm/s "against the grain" of the serrations.

As the new Nature Physics paper says, various explanations are possible:
First, the base of the drop is deformed by the presence of the ratchet below, which induces a modulation of its curvature and consequent Laplace pressure gradients4. Second, a wave propagates from the trailing edge to the leading edge of the drop, making the transport of matter possible in the direction of its motion. Third, a Leidenfrost drop is likely to oscillate spontaneously20; for each elementary rebound, part of the kinetic energy can be transferred from the vertical to the horizontal direction because of the slope of the teeth. Fourth, the Marangoni effect related to temperature differences might cause a displacement, as seen in Marangoni-levitating drops heated asymmetrically using a light source21. Fifth, as the drop loses material, this gas flow might provoke a motion provided it is made directional (or rectified) by the presence of the teeth.

The fifth explanation differs from the other four in that it doesn't rely on the droplet being fluid -- all the others depend on the deformability of the droplet. So the authors tested this by repeating the experiment with dry ice. Since dry ice sublimates, it too should levitate on a cushion of gas when dropped onto a "skillet" with a sufficient temperature gradient. But it isn't liquid, so it can't, e.g., "modulate its curvature."

In the event, a piece of dry ice propels itself exactly like a droplet of water; this establishes that gas flow is behind the self-propelling. How does this work?
As the gas moves towards the step, that is towards a sudden contraction in the fluid channel, the flow resistance is higher than in the reverse direction23. As a consequence, the vapour will mainly escape along the smallest slopes of the texture, which propels the Leidenfrost body in the direction shown in Figs 1 and 2 (jet thrust). This interpretation was confirmed by forcing contact between the hot ratchet and a disk of dry ice, thus printing the tooth pattern on the bottom of the disk, and observing a similar motion with this textured disk on a hot flat solid.

In other words most of the evaporated carbon dioxide moves up the gradual ramps, i.e., "with the grain" of the ratchet, so (by Newton's third law) the levitating solid is pushed in the opposite direction.

In addition to the appeal of all simple phenomena that could have been discovered centuries ago, this work is a neat example of the scientific method in action, and esp. of the value of clever controls. This is an aspect of good scientific practice that doesn't get the attention it deserves; the original Freakonomics book is actually the only piece of popular writing about anything where I've seen it covered in any detail.

[1] I don't know what the technical difference is between a droplet and a drop. No one ever seems to talk about drops of water in physics.

A plug, a blague, and a bleg

Colin Burrow's new LRB piece on Samuel Johnson's Lives of the Poets -- unfortunately gated -- is very good; it says many clever things and a lot of it is written in an enjoyable pastiche of Johnson's style. I particularly liked Burrow's remarks on Johnson's "not unpriggish" moral psychology [attn. ADL]:
Johnson believed that the intellect without sociable interchange or occasional enforced periods of reflection will rust into melancholy. Experience has a general tendency to become a chaotic and unregulated sequence of ideas, and ideas received in the past tend to fade unless regularly refreshed. Each person is subject to these general laws of the mind, and each person also has a disposition to decline into his particular set of vices. Each of us, however, has a sluggish but voluntary power to arouse ourselves from both our collective and our individual weakness.

And the application to Pope and Swift:
Pope was ‘fretful, and easily displeased, and allowed himself to be capriciously resentful’. That phrase ‘allowed himself’ is absolute Johnson: Pope’s failure to correct his own inclination to be fretful turns his natural disposition into a moral failing. In a similar way Swift, towards whom Johnson is generally hostile, condemned himself to eventual madness by his refusal to participate in society: ‘His asperity continually increasing, condemned him to solitude; and his resentment of solitude sharpened his asperity.’ The sentence is so damning because it makes no reference to Swift’s own agency. He failed to prevent himself from becoming an isolated curmudgeon because he allowed his passions to drive his behaviour into a loop of decline, and that way madness lay: ‘His ideas, therefore, being neither renovated by discourse, nor increased by reading, wore gradually away, and left his mind vacant to the vexations of the hour, till at last his anger was heightened into madness.’ 

On Johnson's criticisms of the metaphysical poets, Burrow has this to say:
He believed that a heterogeneity of elements – the method of metaphysical poetry according to Johnson – was intrinsically prone to cause corruption and impermanence in poems as it was thought to do in physical bodies. Hence modes which bring together contrasting registers – notably burlesque and mock epic – are not of permanent value: ‘Burlesque consists in a disproportion between the style and the sentiments … It, therefore, like all bodies compounded of heterogeneous parts, contains in it a principle of corruption.’ 

I am not so sure about this. After all, Johnson explicitly praises heterogeneity of a kind in the Preface to Shakespeare:
The end of writing is to instruct; the end of poetry is to instruct by pleasing. That the mingled drama may convey all the instruction of tragedy or comedy cannot be denied, because it includes both in its alterations of exhibition, and approaches nearer than either to the appearance of life, by shewing how great machinations and slender designs may promote or obviate one another, and the high and the low co-operate in the general system by unavoidable concatenation. [...] let it be considered likewise, that melancholy is often not pleasing, and that the disturbance of one man may be the relief of another; that different auditors have different habitudes; and that, upon the whole, all pleasure consists in variety.

A play isn't a poem but this cannot be the relevant distinction. I think the principle of corruption is a red herring; Johnson's objection to the metaphysical poets is that their metaphors do not approach "the appearance of life" and are frigidly artificial, the metaphor is one of desiccation rather than rot. And Johnson's praise of the mock-epic Rape of the Lock is, as far as I remember, unreserved. As Johnson remarks about the Metaphysicals, "if their conceits were far-fetched, they are often worth the carriage"; it is better to understand his objections to Cowley and Donne were as being of a piece with his objections to "academic" poetry more generally, for being (in Burrow's phrase) "mean, donnish and unnatural."


While looking up the Rape in the life of Pope I came upon this delightful paragraph that I had unaccountably never noticed before:

[340] The purpose of the Poet is, as he tells us, to laugh at "the little unguarded follies of the female sex." It is therefore without justice that Dennis charges The Rape of the Lock with the want of a moral, and for that reason sets it below The Lutrin, which exposes the pride and discord of the clergy. Perhaps neither Pope nor Boileau has made the world much better than he found it; but if they had both succeeded, it were easy to tell who would have deserved most from publick gratitude. The freaks, and humours, and spleen, and vanity of women, as they embroil families in discord and fill houses with disquiet, do more to obstruct the happiness of life in a year than the ambition of the clergy in many centuries. It has been well observed that the misery of man proceeds not from any single crush of overwhelming evil, but from small vexations continually repeated.

And I think that one aspect of Johnson's lives that Burrow doesn't stress enough is that they are full of good technical criticism. The now-well-known observation that Pope's poems have too many adjacent couplets with similar rhymes, for instance, or this remark about Dryden's use of rhyme:
The rhymes of Dryden are commonly just, and he valued himself for his readiness in finding them; but he is sometimes open to objection.
It is the common practice of our poets to end the second line with a weak or grave syllable:
Together o'er the Alps methinks we fly,
  Fill'd with ideas of fair Italy.
Dryden sometimes puts the weak rhyme in the first:
Laugh all the powers that favour tyranny,
  And all the standing army of the sky.

It is absolutely true that there is a difference between the two patterns, but I have never seen anybody else point this out.


I'd like to conclude this overlong post with a bleg. My friend Calista is looking for passages in novels, poems, etc. that involve grease-smeared or food-encrusted books. The purpose, as I understand it, is to endow her frequent book-besmirchings with literary associations. I can barely think of anything; examples would be welcome.

Saturday, February 19, 2011

Juggling in noisy channels

Claude Shannon, the father of error correction and partial subject of Freeman Dyson's entertaining new NYRB piece (they always start beautifully and end in banal technophilia -- this one is at least silent re carbon-eating trees, though it has some puzzling things to say about Wikipedia), was an interesting character:

Professor Shannon had a whimsical side and developed a juggling machine, rocket-powered Frisbees, motorized Pogo sticks, a mind-reading machine, a mechanical mouse that could navigate a maze and a device that could solve the Rubik's Cube puzzle. At Bell, he was remembered for riding the halls on a unicycle while juggling three balls.

Shannon's interest in juggling was not purely practical; there is apparently a seminal article on the theory of juggling in his collected works (something else I learned from a Dyson article, see here). I have tried and failed to find this online. And Shannon is also reputed to have built an Ultimate Machine that he kept on his desk:

Friday, February 18, 2011

Recreational physics roundup

I have always enjoyed work on pattern formation on the everyday scale; it is heartening (a word I overuse, perhaps revealingly) to see that there is still so much in front of one's nose that bears closer inspection. (See here and here for previous local coverage.) The past few days have been abnormally rich on this front -- three worthwhile stories! -- and I wanted to blog about them, partly for ease of future reference.

Bubbles and memory

There's a new story in Phys. Rev. Focus about hysteresis in soap bubbles. (Like most Focus articles it seems to have been written by a journalist. I also find it irritating that they publish Focus articles a while before the paper comes out, because you've typically forgotten all about the work by the time it's published.) Soap bubbles grown on a triangular-prism-shaped frame form dipyramids that either intersect at a triangle -- for a squat prism -- or are joined by a thin vertical strand of soapy water -- for a skinny prism. For a certain range of aspect ratios both solutions are possible, so as you stretch or contract the sides of the prism, the bubble can take either form depending on which way you were tuning the length (i.e., on the bubble's "past"). This is interesting primarily -- from a physics point of view -- as the most purely geometrical example of hysteresis that I know of: the films try to minimize their area, and in this range the two lowest-area configurations look substantially different.

It is also an excuse to replug a beautiful old paper by the Chicago group on a much more nontrivial example of memory in bubbles -- viz. how air bubbles blown through a nozzle "remember" irregularities in the shape of the nozzle.

"Nonideal icicles"

Stephen Morris at the University of Toronto does a lot of beautiful work on pattern formation in systems that are "fluid" in some sense. (My favorite thing on his website is the fluid mechanical sewing machine, but irritatingly that link is broken.) Morris's group has a new paper out in Phys. Rev. E, featured in Physics, on the growth of icicles. They grew large numbers of icicles in their lab and studied how the quality of water, the wind speed, etc. affect the growth of icicles. A result that jumped out at me: lab-grown icicles often have bifurcated tips as in (c) and (d) of the figure, but this seems to happen most often when the fan in the experiment is turned off. The implication is that wind somehow straightens out icicles.

Huddles of tetrahedra

This is somewhat older work that Ross McKenzie recently linked to. Here's an NYT piece on the race to find ever-closer packings of regular tetrahedra. I recommend reading the linked Nature article (journal link here, ungated arxiv here), which is pretty accessible. There is some back-story to this: Stanislaw Ulam conjectured a long time ago that it should be possible to pack any kind of convex shape more closely than hard spheres. As far as I know there is no proof of this, but it's plausible and known to be true for lots of shapes including M&M's (another NYT story) and more recently tetrahedra. How tetrahedra pack is of particular interest as there is a theory of glassiness (see an old post here) that depends rather crucially on the fact that you cannot tile three-dimensional space with tetrahedra. The theory is basically that particles in an incipient solid like to clump into tetrahedra (each particle is exactly as far away as it wants to be from every other) but the tetrahedra can't line up, so that on large scales you have a jammed amorphous mess: here is a PRB paper by David Nelson related to this theory. The Nature paper is prima facie a beautiful application of ideas from physics to solve a purely mathematical problem -- a project that's close to the formalist, interdisciplinary lump of matter I sometimes refer to as my heart -- but its really surprising finding is that one of the best ways to put the tetrahedra together is to have them form a quasicrystal. This actually makes it a little surprising that 3D quasicrystals aren't common in nature, unless tetrahedra are a much less central motif than the Kleman-Sadoc-Nelson line of thinking about glasses would suggest.

Thursday, February 17, 2011

"A bawd, my lord, one that sets bones together"

From The Revenger's Tragedy:

L. What hast been, of what profession?
V. A bone-setter.
L. A bone-setter?
V. A bawd, my lord, one that sets bones together.

Nature News backs up the pun with studies on rat femurs.

Decreases in sex steroid hormones can lead to loss of bone mass in humans. Karsenty and his colleagues hypothesize that, conversely, a decrease of hormones derived from bone might prompt a decline in sex hormones and fertility. They also speculated that this would be more pronounced in females. "We were betting at the beginning that it would regulate female fertility more than male fertility," Karsenty says.

In a series of experiments on mice engineered to have low levels of osteocalcin, however, the researchers consistently found that the male mice had lowered fertility, whereas osteocalcin levels had no impact on the fertility of female mice. "We were slightly wrong," Karsenty admits.

While on the topic of bones, here's a story about skull cups in prehistoric England (via Matt P. via the Awl, which makes the inevitable joke about "skulling").
Cut marks and dents on the bones suggest they were scalped and scrupulously scraped clean of skin and flesh with flint tools shortly after death. The crafters then removed the face bones and bases of the skulls from the adults and the 3-year-old, meticulously chipping at the broken edges of the resulting cups, possibly to straighten their rims.
Cf. skull-bongs. The skull cups story mentions that the skulls might have been used to store blood; cf. Marianne Moore's jerboa poem:
Lords and ladies put goose-grease
paint in round boxes with pivoting
lid incised with the duck-wing

or reverted duck-
head, kept in a buck
or rhinoceros horn,
the ground horn, and locust oil in stone locusts...

Also a time-lapse video of the afterlife of an elephant, at New Scientist TV (via Mary Roach on twitter). And the afterlife, in a brighter sense, of Elisabeth Fritzl (via Light reading).

I'm back in Urbana with a cold. The spacebar has more-or-less come back to life. The Georgia Tech talk was OK but a little blah; fortunately nothing depends on it. I got yet another invitation to give a talk "if you're ever in Europe"; European scientists are glib with invitations as the condition is rarely satisfied. Grad students are of course never worth the transatlantic airfare.

Tuesday, February 15, 2011

Confusion over crash blossoms linked to verblessness

This NYT headline is a bit of a crash blossom, I think:
British Anger Over Release of Man Linked to Bombs

This seems to be an instance of the principle that if one has a lone verb in a headline it ought to be the main verb: the psychology of crash blossoms has to do with one's natural tendency to parse sentences by identifying a verb to drape them around. (A nose, I feel, is an analogous organizing principle for a face.) It doesn't help that the "bad" reading, in which the (inexplicable) British anger over release of man is (ingeniously) linked (how?) to bombs, conforms exactly to one's expectations of public psychology. No one would give ex-cons a break during the Blitz.

PS "Linked" features in anomalously many crash blossoms, including the defining example of the genre, "Violinist linked to JAL crash blossoms."

PPS The rain in Spain -- you can't explain that!

Monday, February 14, 2011

Claustrophilic keyboards

Blogging's been light, partly because I've been traveling -- I'm in Atlanta now -- but more because the spacebar on my keyboard has turned unresponsive, which makes typing pretty unpleasant. (Keyboard woes are a bit of a leitmotif; some still remember the time, almost a decade ago, that my O key got stuck and I had to invent a fake Scots dialect in which O always had to be ai/ae/a/ui, as appropriate -- except every nu and then I'd break into relentless bouts of O's.) I'm in Atlanta; the adviser's putting me up in his spare bedroom, which is just outside the GA tech campus but quite far from other visible signs of civilization. Back in Urbana Wed.

One can quote without typing so, "topically," here's Chekhov:
Something strange was happening to him. His neck, round which soft, fragrant arms had so lately been clasped, seemed to him to be anointed with oil; on his left cheek near his moustache where the unknown had kissed him there was a faint chilly tingling sensation as from peppermint drops, and the more he rubbed the place the more distinct was the chilly sensation…. He wanted to dance, to talk, to run into the garden, to laugh aloud. He quite forgot that he was round-shouldered and uninteresting, that he had lynx-like whiskers and an “undistinguished appearance.”

And here's Shakespeare (one assumes), from his late play Two Noble Kinsmen (written with John Fletcher):
Hail, sovereign queen of secrets, who hast power
To call the fiercest tyrant from his rage,
And weep unto a girl; that hast the might,
Even with an eye-glance, to choke Mars’s drum
And turn th’ alarm to whispers; that canst make
A cripple flourish with his crutch, and cure him
Before Apollo; that mayst force the king
To be his subject’s vassal, and induce
Stale gravity to dance; the poll’d bachelor,
Whose youth, like wanton boys through bonfires,
Have skipp’d thy flame, at seventy thou canst catch,
And make him, to the scorn of his hoarse throat,
Abuse young lays of love. What godlike power
Hast thou not power upon?
I knew a man
Of eighty winters—this I told them—who
A lass of fourteen brided. ’twas thy power
To put life into dust: the aged cramp
Had screw’d his square foot round,
The gout had knit his fingers into knots,
Torturing convulsions from his globy eyes
Had almost drawn their spheres, that what was life
In him seem’d torture. This anatomy
Had by his young fair fere a boy, and I
Believ’d it was his, for she swore it was,
And who would not believe her? Brief, I am
To those that prate and have done, no companion;
To those that boast and have not, a defier;
To those that would and cannot, a rejoicer.

Thursday, February 10, 2011


Anne Enright writes about Angela Carter in the LRB:
I can’t describe the book I worked on that year. It was about Cressida. It was about Colley Cibber’s daughter Charlotte Charke, an actress who, according to me, played Cressida, not in Shakespeare’s but – for reasons that must have seemed urgent at the time – in Dryden’s bastardised version of the play. This section of the book was written in makey-uppey 18th-century stage dialogue. Everything kept splitting into threes. I may have set part of the book during the siege of Troy, but I am not going to admit to this. There was a modern section told by an actress, who opens the book with a description of Juta Mai – a 19th-century geisha dance I had come across at a theatre festival in France. The narrator describes the dancer’s costume, her tiny movements: she tells how the actress holds in her eye which is always brimful a tear that never falls.
We were all very tense. The student ahead of me came out of her office, made a big face and hurried away. I went in. Carter sat beside, rather than behind a desk. On the edge of it, facing me, were the pages I had submitted, with a handwritten note from her on the top sheet. She indicated the pages with a graceful hand. She said: ‘Well this is all fine.’
And then we talked of other things.
If the question was in the mirror, then the answer was in the eye. This was the problem that obsessed me in the spring of 1987. ‘The eye, is it the mirror to the soul?’ says one of my 18th-century thespians. ‘It is an orifice, rather,’ Charlotte Charke says. ‘In brief, sir, it is a hole.’

And here is Enright using Lacan to surprisingly good effect:
The shift from feeling into fiction was a shift from being into an image of being, from inside to outside. ‘To break out of the circle of the Innenwelt into the Umwelt,’ Lacan wrote – and at the time I understood this completely – ‘generates the inexhaustible quadrature of the ego’s verifications.’ I think he meant you fall apart a bit, when, as an infant, you see or construct your image in the mirror. It is also possible that you have to fall apart a bit in order to make fiction; that making an image from yourself is a kind of falling apart. And that the image is always too coherent and rigid – what Lacan termed ‘orthopaedic’.

It's a pity that Alan Sokal was so deaf to the poetic aspects of technical language. I suspect Lacan is using "quadratures" purely as a register-marking device here, but it's still quite appealing. Perhaps it's the sort of thing one comes up with in work-addled dreams.

Roundabout dogs, southern discomforts, etc.


[Flickr, Creative Commons, etc.]

Wikipedia has this to say (re roundabout dogs):
The phenomenon consists of anonymous people placing homemade dog sculptures, typically made of wood (or sometimes plastic, metal or textile) in roundabouts (traffic circles). Occurrences were reported all over Sweden, and the phenomenon also spread to other countries, such as Spain after it was mentioned on Spanish television (PuntoDos).[1] Swedish tabloid paper Expressen even placed one at Piccadilly Circus.

The prophet Muhammad was drawn as a roundabout dog but apparently not installed as one. (The installation would have been ephemeral in any case I suppose.)


I'm in Charlottesville, VA. The trip was smooth, except for a distressing encounter with a manic autoflush at O'Hare; I'm being put up at the Marriott, which is nice except that my room is next to the ice machine. Garrulous taxi drivers are a recurring theme in my existence. Last night I did trivia -- which I'm crap at -- with Joe Caissie, an Amherst non-acquaintance and twitter friend, who replied to my tweet saying I was in C'ville and debating whether to explore it before snarking about it. I gave a talk this afternoon; the slides are here, though I'm afraid they pdf'ed the hidden slides as well as the real ones, so the talk seems even less coherent than it was. Heard a horrifying story at lunch about some climate scientist who is being persecuted by Ken Cuccinelli for "fraudulence" because he "cited" a later-shown-to-be-flawed paper of his in his publication list. (I love that if he hadn't cited the paper he would have been fraudulently hiding something.) I am also sad to hear that Jim Webb doesn't intend to run again; his politics and mine aren't identical, but he is one of the few politicians that care about convicts'/prisoners' rights, the one political cause I'm passionate about.

Dinner at Boylan Heights; being an experimental feeder I tried the "green eggs and ham" -- i.e. hamburger on English muffin with ham, a fried egg, and pesto on it -- the pesto was definitely a mistake. On the other hand tater tots are superior to fries as a side. I had just reread The Debt to Pleasure on the flight (having switched it in at the last minute for Seamus Deane's creditable but tedious memoir), and could imagine Tarquin Winot inveighing against the combination. Next to me at the bar was some guy who was talking to some chick, not his girlfriend, about abortions and messed-up mutual friends and the like. At some point he (distinctly) said, "she just sprinkles her pussy-dust all over the situation," a felicitous phrase if only because it reminds me of this appalling old story in The Economist that I've never been able to forget. (You've been warned.) And they agreed that the woman in question was "close-chested," another new expression to me, though apparently not to Google. I'll be here tomorrow, then in Atlanta until Wed., then back in Urbana until March meeting.

Tuesday, February 8, 2011

"Thy staffe & thy shepehoke"

I have always had a mild preference for Tyndale's Bible over the King James version; it has most of the same virtues, as well as that of relative unfamiliarity, which leads to an increase in felt vividness. Carol Rumens has a nice post at the Guardian books blog on Psalm 23 that quotes both the Tyndale and the KJ versions of the psalm; here's Tyndale:
The LORDE is my shepherde, I can wante nothinge. 2 He fedeth me in a grene pasture, and ledeth me to a fresh water. 3 He quickeneth my soule, & bringeth me forth in the waye of rightuousnes for his names sake. 4 Though I shulde walke now in the valley of the shadowe of death, yet I feare no euell, for thou art with me: thy staffe & thy shepehoke comforte me. 5 Thou preparest a table before me agaynst mine enemies: thou anoyntest my heade with oyle, & fyllest my cuppe full. 6 Oh let thy louynge kyndnes & mercy folowe me all the dayes off my life, that I maye dwell in the house off the LORDE for euer.
"Shepehoke" does a much better job than "rod" of getting the right pastoral tone. The big countervailing loss, of course, is "my cup runneth over." By the way I hadn't quite realized how similar the feeling of Heaney's "Harvest Bow" is to verse 4 of the psalm:
Me with the fishing rod, already homesick
For the big lift of these evenings, as your stick
Whacking the tips off weeds and bushes
Beats out of time, and beats, but flushes
Nothing: that original townland
Still tongue-tied in the straw tied by your hand.

Monday, February 7, 2011

Moving snouts

One of my favorite Bishop poems:

The Prodigal
Elizabeth Bishop

The brown enormous odor he lived by
was too close, with its breathing and thick hair,
for him to judge. The floor was rotten, the sty
was plastered halfway up with glass-smooth dung.
Light-lashed, self-righteous, above moving snouts,
the pigs' eyes followed him, a cheerful stare--
even to the sow that always ate her young--
till, sickening, he leaned to scratch her head.
But sometimes mornings after drinking bouts
(he hid his pints behind a two-by-four),
the sunrise glazed the barnyard mud with red;
the burning puddles seemed to reassure.
And then he thought he almost might endure
his exile yet another year or more.

But evenings the first star came to warn.
The farmer whom he worked for came at dark
to shut the cows and horses in the barn
beneath their overhanging clouds of hay,
with pitchforks, faint forked lightnings, catching light,
safe and companionable as in the Ark.
The pigs stuck out their little feet and snored.
The lantern -- like the sun, going away --
laid on the mud a pacing aureole.
Carrying a bucket along a slimy board,
he felt the bats' uncertain staggering flight,
his shuddering insights, beyond his control,
touching him. But it took him a long time
finally to make his mind up to go home.


Misc. other. 1. While looking for moving snouts, I came upon this Youtube video. Potentially NSFW. 2. Also pig-related is this amazing correction in Australia's Morning Bulletin (The Media Blog via Language Log):

Sunday, February 6, 2011

Bishop centenary linkage

The Elizabeth Bishop centenary is on Tuesday, and twitter has been abuzz with Bishop linkage. So here are two of Bishop's translations of stories by Clarice Lispector (via Jenny McPhee via the indispensable seventydys on twitter). Here, via Bookslut, is a Bishop short story at the Library of America. (I wish she'd written more!) And, at the same place, a post by Lloyd Schwartz that quotes that beautiful late unpublished aubade of hers:
Breakfast Song
My love, my saving grace,
your eyes are awfully blue.
I kiss your funny face,
your coffee-flavored mouth.
Last night I slept with you.
Today I love you so
how can I bear to go
(as soon I must, I know)
to bed with ugly death
in that cold, filthy place,
to sleep there without you,
without the easy breath
and nightlong, limblong warmth
I've grown accustomed to?
—Nobody wants to die;
tell me it is a lie!
But no, I know it's true.
It's just the common case;
there's nothing one can do.
My love, my saving grace,
your eyes are awfully blue
early and instant blue.


Despite my fondness for her work I remain puzzled by Bishop's popularity and, as Schwartz says, centrality in American literary culture. Her direct influence seems to me limited to two types of poet -- the maximalist New York school descendants who picked up her habit of writing superficially inconsequential poems, and formalists of all kinds. Perhaps both schools are over-represented in academia/mags? The poems themselves, I think, are more uneven than is generally admitted; even the very best ones, like "At the Fishhouses" and the "Concordance" poem, have some clunky transitions, and far too many have an annoying habit of going transcendental on you at the end. ("The Fish" is the canonical example here.) This is one of many traits Bishop shares with Philip Larkin, another anti-confessional perfectionist. Perhaps what is most interesting about Bishop is the peculiar relation of her poems to speech: she is like an amorphous George Herbert at times, a voice almost defined by quietness and reticence; there is never much rhetorical drive, the climaxes have to be processed higher up in the brain than in most other writers. The only remotely similar writer in this sense is Stevens, but his reticence comes off differently because of the Christmas-tree plenitude of the language... None of this seems likely to help someone become popular, though.

Addenda. 1. Cynthia Haven has a centenary post. 2. Someone pointed out on twitter that superbowl can be parsed as superb owl.

Adiabatic quantum computation in Egypt

I am amused by the recent proliferation of things Egypt-related but not Egypt-specific essentially related to the current mess. This is the case, e.g., with Hernando de Soto's [1] WSJ op-ed on property rights in Egypt, and, more benignly, with this old NASA photograph of Cairo and Alexandria that has been circulating about the internet. (Alexandria turns out to be one of those long skinny coastal cities like Santa Barbara.) I suppose there's no harm in using topical excuses to force one's longstanding obsessions down the casual reader's throat, though it's hard to do this in a way that's not misleading. So instead of parodying de Soto with "How Egyptian protesters used the laws of gravity to bring down the regime," I'll just write a physics-y post that I was meaning to anyway and add "in Egypt" the way one adds "in bed" at the end of a fortune cookie.

[NASA photo, Flickr, creative commons, etc.]

What follows really belongs on the defunct physics blog, being a little technical. But it isn't really physics, and has to do, besides, with the work of Dorit Aharonov, another of the squalid scholars.


1. Conventional quantum computers are structured like Turing machines. They consist of a (finite) set of internal states (logic gates, etc.) and a "tape" which (at the beginning of the computation) has the input string written on it, say in Arabic numerals. The tape is connected to the machine by a read-write head. At each step of the algorithm one can move the tape back and forth, change the internal state, and/or write on the bit of tape that's under the head. At some point the algorithm stops (assuming the problem is decidable); this happens when the internal state of the machine is the designated "end" state and the answer to the original problem is on the tape. Quantum computers differ from classical computers in that the number of allowed tape configurations is (in principle) much larger, as superpositions are allowed in intermediate steps. The complexity of an algorithm is related to how many steps it takes to process an input string of length N, and in particular how this grows with N (e.g., polynomially/exponentially). The complexity of a problem is the complexity of the asymptotically slowest-growing (at large N) algorithm that can solve it.

The problem with this construction is that, while it is easy to find upper bounds for complexity (just write down an algorithm), it is generally hard to establish lower bounds, because it is hard to make useful statements about all conceivable algorithms, or to rule out the possibility that one is just not being clever enough. Generally in this sort of situation one's instinct is to look for a way of talking about the "space of all problems," which (if one is lucky) has some degree of geometric structure -- so that, e.g., two problems are "near" or "far" in problem space.

2. Adiabatic quantum computation begins with the observation that "satisfiability" problems in computer science [2] can be recast in terms of the physics of magnets. Magnets consist of spins that can either point up or down (i.e., true or false); depending on the details, spins might want either to line up or to point in opposite directions [3]. Depending on the interactions there might be a "good" configuration for the spins (i.e., one in which all pairs of spins that want to line up do so and all pairs that want to point in opposite directions do so) or not. (In the latter case the system is called "frustrated." A simple example of a frustrated system: three spins on a triangle that all want to point in opposite directions. If 1 is up, then 2 and 3 want to point down, but this doesn't work because 2 and 3 want to point in opposite directions. No configuration satisfies all the bonds in Egypt.) The lowest possible energy of a frustrated system is higher than that of an unfrustrated system, so the question of whether a spin system is frustrated reduces to that of what its lowest possible energy ("ground state energy") is. Obviously the question of whether a spin system is frustrated is closely related that of whether a set of statements can be satisfied, if you map the clauses onto spins (T/F = up/down). There are some explicit examples of this mapping in the original paper of Farhi et al.

3. This mapping isn't immediately useful as it just recasts the satisfiability problem in the language of magnetism. This is where the physics comes in. Farhi et al. observed that the quantum mechanical "adiabatic theorem" tells you that, if you change your Hamiltonian (the Hamiltonian of a system is an assignment of an energy to every possible configuration of the system) sufficiently slowly, the ground (lowest-energy) state of the original Hamiltonian goes into the ground state of the final Hamiltonian. How slowly you have to go depends on the energy gap between the ground and the next-lowest-energy (first excited) state all along the path in "Hamiltonian space" that leads from the initial to the final Hamiltonian. The bigger the minimum gap, the faster you can afford to go. Often the minimum gap vanishes in the large-system limit (this is called a quantum phase transition); in this case you have to go arbitrarily slowly as the number of spins increases. The minimum allowed speed might either vanish as a power-law or exponentially with the system size. Alternatively there might be exact "degeneracies" for finite systems in which case the algorithm is doomed.

4. The adiabatic algorithm works like this. You start the system off in some reference "trivial" state, let's say with a Hamiltonian that wants all the spins to point up. (E.g. spins in a strong external field.) Call this H_0. The problem Hamiltonian, which encodes the input -- the logical expression you want to check the satisfiability of -- is called H_1. You turn a hypothetical knob so that at time t, the Hamiltonian is H(t) = t/T H_1 + (1 - t/T) H_0. Or you use a curvier path. Assuming T is large enough, the ground state of H(T) is the answer to your problem. The complexity question becomes one of finding the path with the slowest-growing T(N); in general the slowness comes from segments of the path that are near the phase transitions between the initial and final states; the gaps here are given by the theory of critical slowing down; therefore you have mapped the complexity problem into a problem about phase transitions. To rephrase, what this approach does for you is it maps the space of problems onto the space of quantum Hamiltonians, the structure of which can be understood in terms of renormalization group flows.

5. Satisfiability problems aren't everything. The Aharonov et al. paper establishes that adiabatic quantum computation is equivalent to standard quantum computation. (I haven't read the proof.)

6. Of course, the Hamiltonians of conventional magnetic systems are what they are; you can't implement the adiabatic algorithm as stated, and it isn't likely to be terribly useful as a means of quantum computation. However, one does have a fair amount of control over the Hamiltonians describing cold atomic gases, and there's been a fair amount of work on actually implementing the algorithm. A variant that's been proposed is computation-through-dissipation, which is a clever mashup of the adiabatic algorithm and optical pumping. I'm a little skeptical about the practical prospects for this approach, but it is theoretically interesting because dissipative systems are hard to analyze and it would be nice if one were able to use the mapping in reverse and use computer science results to say something about them.

[1] Yes, I considered calling him Hernando de Stoato and posting this on STOATUSblog.
[2] Viz. questions about whether a very long logical string is true on any assignment of truth-values to its constituent particles, which, e.g., A or B is but A and not-A isn't
[3] In a physical system this depends on why the spins are interacting at all; there are various possible mechanisms. In the model one puts this in by hand by assigning an energy penalty to undesired configurations.

Friday, February 4, 2011

Addendum on gaggles

OED says about gaggles:
One of the many artificial terms invented in the 15th c. as distinctive collectives referring to particular animals or classes of persons; but unlike most of the others, it seems to have been actually adopted in use.

An early example:
(1584) A shoale of goslings, or (as they saie) a gaggle of geese.

Google provides this list of 15th century collective nouns. Here are some more at the Baltimore bird club. There is also a book, An Exaltation of Larks, by James Lipton, that I sort of want to buy... ("Exaltation of larks" makes an appearance in one of the odes in Auden's Orators.) Perhaps one can attribute the failure and general unviability of many of these terms to the fact that they were coined by John Lydgate, the "voluminous, prosaic and drivelling monk" of Bury.

Stories of Alan's life, part XLII

Inspired by this Language Log post ("a little light draggle"):

There once was a man in the draggle
Who continued to strive and to straggle:
In the end he congealed
In a desolate field
And was gobbled up whole by a gaggle.

Thursday, February 3, 2011

"Arseholes, considered as a strategic entity"

The TLS's slang dictionary review sent me back to an old essay in Thumbscrew by Craig Raine, on swearing and translation, which doesn't live up at all to my memory of it. However this bit has always stuck with me:
I recall Thom Gunn asking me in San Francisco if I had really published a poem entitled ‘Arsehole’. I had. […] Gunn’s comment was a poet’s comment on two languages. “Gee, ‘arsehole’ is so much dirtier than ‘asshole’.” […] “Asshole” is a possible translation of “arsehole” but it isn’t the right translation - not only for the reason given by Thom Gunn. To call someone an “arsehole” is quite different from saying someone is an “asshole”. The former is malignant where the latter is harmless. To be on a desert island with an asshole would be irritating perhaps. To be on the same desert island with an arsehole might even be dangerous.

And, as if on cue, here's Daniel Davies on Egypt:
Basically, what you need is a large population who are a few rungs up from the bottom of society, who aren't interested in freedom and who hate young people. In other words, arseholes. Arseholes, considered as a strategic entity, have the one useful characteristic that is the only useful characteristic in the context of an Egyptian-style popular uprising - there are fucking millions of them.

(Via Yglesias, who has the linguistic tact not to translate the word.) One is inevitably reminded of the "I'm surrounded by assholes" set-piece in Spaceballs, a precisely converse situation where "arsehole" would be a mistranslation.

I wonder if anyone's bothered to study the difference between "arsehole" usage in rhotic and non-rhotic dialects -- Green's dictionary, maybe? -- there must be something, I feel, but it's hard to isolate immediately from all the other differences between Scottish and southern English speech.

Any time Thom Gunn comes up is a good time to reread "The Gas-poker."

As if airports weren't disorienting enough

From the BBC via Dainty Ballerina, Luton airport has introduced holographic announcers Holly and Graham. Rationale: 1. "They're absolutely compelling" 2. "They'll be really consistent in the message they give":

Tuesday, February 1, 2011

Hanseatische Gummiwerke

As all possible flights out of O'Hare are canceled, I've had to put off the UVA seminar until next week. I must say I'm not entirely displeased at this outcome, seeing as the weather in the midwest is pretty dire right now. We have been subjected to a considerable amount of "wintry mix" -- the sidewalks are all covered in inches of ice-encrusted snow of a strange plasticky consistency -- and I believe it is supposed to get worse tonight.

Meanwhile, an article about German condom manufacturer Julius Fromm, whose enterprise was taken over by the Nazis. (I like that the Berlin Review of Books abbreviates as brb.)
Fromm improved on the manufacturing technique. He used glass moulds, which were mounted on carrier frames and dipped into a vat of rubber solution liquefied with gasoline, benzene and tetrachloromethane. After two dippings, a thin rubber skin formed around the glass moulds and this was then vulcanised in special ovens with sulphur vapours. The condoms were dusted with a lubricant, rolled off the glass moulds and tested by inflation with compressed air, inverted and packaged. Fromms’ condoms were sturdy yet elastic, durable enough to be warehoused and transported for long distances. In fact this technical process of condom manufacturing has remained largely unchanged, with the exception of automation and the replacement of the benzene treatment with a latex process in the 1960s. Using a similar setup, Fromm also made surgical finger cots, rubber gloves, pacifiers and teats for baby bottles – another sound business move given the rising birth rate in Germany.

After the war, Fromm's trademark, at least in West Germany, devolved to the Bremen-based company Hanseatische Gummiwerke, which is a pretty great name.

Alas, the book is unlikely to be of wide interest; the reviewer ruefully notes that "Aly and Sontheimer do not seem to be that interested in condoms."