by Hari Balasubramanian

The Shortest Path

How does Google Maps figure out the best route between two addresses? The exact algorithm is known only to Google, but probably some variation of what is called the shortest path problem has to be solved [1]. Here is the simplified version. Suppose we have a network of nodes (cities, towns, landmarks etc.) connected by links (roads), and we know the time it takes to travel a particular link. Then what is the shortest path from a starting node A to a destination node D?

In the instance above, there are 4 nodes. The rectangles provide the link travel times. The B-C link takes 2 time units to travel; the A-D link takes 5; the C-D link takes 1; and so on. The five possible routes from A to D are: A-D; A-B-D; A-C-D; A-B-C-D; and A-C-B-D. The easily spotted shortest path is A-C-D, with a total length of 3. But what if a network has hundreds of nodes and links? It would be impossible to visually identify the shortest path. We would need an efficient algorithm. By that I mean an algorithm whose execution time on a computer stays reasonable even when the problem size – the number of nodes or links in the network – gets bigger.

In 1959, Edsger Djikstra published just such an algorithm. Djikstra's Algorithm doesn't simply look for all possible routes between the start and destination nodes and then choose the shortest. That kind of brute-force approach wouldn't work, given how dramatically the number of possible routes increases even with a slight increase in network size. Instead, Djikstra's Algorithm progressively explores the network in a simple yet intelligent way. It begins with the start node A, looks at all its immediate neighbors, then moves on to the closest neighbor, and from there updates travel times to all as yet unvisited nodes if new and shorter routes are discovered. I am fudging important details here, but this basic procedure of moving from a node to its nearest neighbor and updating travel times is repeated deeper and deeper in the network until the shortest path to the destination is confirmed. Wikipedia has a good animation illustrating this.

How fast does the algorithm run? Let's say there are V nodes. Then, in the worst case, Djikstra's Algorithm will take in the order of V x V steps to compute the optimal path. An algorithm like this that grows polynomially with the problem size is something we will call efficient (of course lower order polynomials, such as the square function, are preferable; V raised to the power 50 wouldn't be helpful at all). So a 10-node problem might take around 100 steps; a 1000-node problem will take 1000000 steps. This increase is something a modern day computer can easily handle. The algorithm might do much better in most instances, but the worst case is commonly used as a conservative measure of efficiency. There are faster variations of Djikstra's Algorithm, but for simplicity we'll stick to the original.

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Early Autumn Surf

…… it’s still

the birds have gone
knowing it’s time

but today is an anomalous summer day
which, breaking protocol,
has oozed into early fall
with temperate trappings
lulling me with spacious softness
and late brilliance,
being the last echo of July,
the final peal of August’s bell
expanding as I surf
down the hump of its luxurious waveform
under the comfort of its breaking curl
.

by Jim Culleny
9/27/14, 2:45

Photo and poem, shot
and jotted together

by Brooks Riley

Go on, admit it. You’ve always wanted to come back as a capybara.

Why not? There are worst entities for a come-back kid when its mortal coil is taken up again. As a capybara you would live in a small community of peaceful vegans, free to join the party or to wander off on your own without being ostracized. You’d enjoy communal living with all the advantages, including a swimming hole in the vicinity. Your leader would be the biggest male, not a testosterone-driven despot intent on hoarding all the females for himself, but a gentle giant who shares. He might get first choice, but there’s plenty enough to go around. If the kids got on your nerves, allomothers would take over for a while.

The real question is, why would you want to come back at all?

Hope is like a birthmark no one can see: Everyone has one, and it doesn’t go away. It all starts with hoping to inhale your first breath, and progresses to hoping your mother will pick you up when you cry. It ends with hoping there’s something to look forward to when you die—call it heaven, call it oblivion. As the hopes in this life diminish, they get transferred to the other side, even if there’s no there there, as Gertrude Stein once said of Oakland, California.

The problem is that our notions of heaven are so pathetically limited. Why would I want to sit on a cloud playing a harp? If I wanted to play a harp, I’d have tried it in this life. And what if I see my loved ones in that light at the end of the tunnel? What then? Do I embrace them over and over again? For men who dream of an endless supply of virgins, is heaven just a coitus repetitus? Let’s face it, nothing we can possibly imagine or wish about heaven can allay the inevitable tedium that would arise from a satisfaction repeated many times over. Our visions of heaven quickly expose themselves as visions of hell, adulterated by endless repetitions and endless time. Even Pope Benedict suggested as much.

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by Emrys Westacott

Like millions of other people, I found the recent Israel-Gaza conflict sickening and depressing. After fifty days of military exchanges from July 8 to August 26, over 2,000 Gazans had been killed of which, even according to Israeli government estimates, over half were civilians. Around 11,000 Gazans had been injured, and several hundred thousand had been displaced from their homes and needed emergency assistance. On the Israeli side, 62 soldiers and 6 civilians were killed, and around 1,300 were injured. To what end?

While it went on I read, watched and listened to dozens of interviews and debates about the conflict. These involved Israeli government ministers, leaders of Hamas (the governing party in Gaza), journalists, scholars and political analysts, some highly critical of the Israeli government, others defending its actions. Two things struck me about what I heard.

First, there was a great deal of repetition: “Israel has the same right as any other country to defend itself against attacks.” –”The people of Gaza have the right to resist occupation.” – “Israel is ultimately responsible for the conflict because they continue to impose intolerable living conditions on the Palestinians.” –”Hamas is responsible because they committed the first acts of violence.” –”Israel targets civilians in breach of basic moral principles and international law.” ­–”So does Hamas.” –”Hamas still won't recognize the right of Israel to exist.” –”Israel continues to undermine the possibility of a viable Palestinian state by constructing new settlements.” Listening to these debates is like being on a merry go round, going round in circles, seeing the same sights come and go; you hear the same points being made again and again in more or less the same order.

Second, the points made by the parties to the debates typically pass each other like skew lines, not quite engaging. Question: “Isn't the Israeli governments showing a callous disregard for the lives of Palestinian civilians?” Answer: “It's Hamas with their rockets that is targeting civilians. And why is Israel being singled out for special criticism when other countries also kill civilians when they're fighting a war?” Question: “Does Hamas accept the right of Israel to exist?” Answer: “The Israeli occupation of Palestine is illegal under international law.” So often, the answers don't engage with the questions. This aspect of the debates is most frustrating.

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by Mathangi Krishnamurthy

On July 15, 2013, after a hundred and sixty-three years of witnessing birth, death, revolution and marriage, the Indian telegraphic service sent out its last telegram. I felt a small sense of loss, but truth be told, the telegram was already a thing of the past to my communicative repertoire. In all my life, I had neither sent nor received a telegram. Also, with all my Hindi film infused understanding of the world, I assumed that all they ever brought was bad news. I would however be more than heartbroken if some day the postal service stopped sending letters.

The first letter I ever received was from my father. Truth be told, it was a postcard. He was away in faraway lands and had sent me a one-line missive with a picture of some Disneyland minion in Mickey Mouse costume, looking both avuncular and eerie. I remember feeling a distinct happiness at the sight of his handwriting, all beautiful, cursive, and grand. People wrote me letters for a large part of my life. My father, my grandfather, two cousins, friends that moved away, and friends in foreign lands. I have letters bearing dates right up until the nineties. I wrote back letters and in the process, accumulated beautiful pens, inkpots, and thick, fancy letter-writing paper. Also, for those who remember, I owned blotting paper; inspite of that, my hands were permanently ink-streaked. I always owned what used to be called a China pen even though it bore the brand name “Hero”. The need for good handwriting was drummed early into my head. Pages of pages of cursive writing have rendered permanent the callus on my middle finger.

Two things show up regularly on my reading list these days; one, the daily habits of artists, scientists, thinkers, and writers, and two, their prolific and thoughtful correspondence. As others have argued so forcefully, letter writing was for writers, not merely a distraction but a way to find some breathing space from their craft while also allowing them the possibility of re-infusing it with vigor and vitality. Through letters they made manifest their orientation towards life and the world, but also communicated and cleansed new ways of thinking about their craft. Writing about writing to empathetic interlocutors seems to also been also about finding community, and laying the foundations for a new world.

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by Charlie Huenemann

How much of the world do we actually experience? Of course, I'm not bemoaning the shortness of human life, or the narrow range of the visual spectrum, or the insensitivities of our skins and tongues. There's no doubt we're missing out on a lot. But within the world of our experience – how much of it do we in fact experience?

This is a big question always, but it was particularly big over the course of the 17th and 18th centuries. Some thinkers abided by the scholastic dictum – “there's nothing in the mind that isn't first presented by the senses” – which means that all of the content in our model of the world is gained through sensory experience. There is something very neat and tidy about this – nothing comes from nothing, and everything is accounted for.

Other philosophers found, as they carefully parsed their own sensory experience, that there was a lot less in it than they thought. We see patches of colors, not objects; we see sudden bright changes, and hear loud booms, and it is only with some mental effort that we combine them into a single event; we observe one change, and another, and we only come to think of the changes as causally related. The senses surely give us some data, these philosophers believed, but the mind is required to structure these data into a world. There is order in our experience that does not come from the senses.

The general debate became focused on a thought experiment raised by William Molyneux in a letter to John Locke (1693):

Suppose a Man born blind, and now adult, and taught by his touch to distinguish between a Cube, and a Sphere of the same metal, and nighly of the same bigness, so as to tell, when he felt one and t'other; which is the Cube, which the Sphere. Suppose then the Cube and Sphere placed on a Table, and the Blind Man to be made to see. Quaere, Whether by his sight, before he touch'd them, he could now distinguish, and tell, which is the Globe, which the Cube.

Those of us used to coordinating sight and touch must make some effort to imagine what it would be like to see a sphere and a cube for the first time, without already knowing from experience what each would feel like, were we to reach out and touch it. Without having had that experience, would it be obvious that one shape would feel sphere-y, and obvious that the other would feel cube-y?

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by Carl Pierer

Hard-working, dedicated snow plough driver, Nils Dickman (Stellan Skarsgård), is living a peaceful life with his wife Gudrun in a small, rural town in Norway. Just after being named Citizen of the Year, their son is found dead, apparently due to an overdose. The beautiful shots of wintery Norwegian landscapes, Nils' doubts that his son could ever have been an addict and Gudrun's acceptance of this fact seem to set the scene for a sombre Nordic drama. The film shifts gears, however, as Nils starts to investigate his son's death. The rest of the film, reminiscent of the blockbuster “Taken”, sees Nils meticulously eliminating gangsters one after another, thereby incidentally causing a drug war between the Norwegian-Swedish gang, headed by “the Count” (Pål Sverre Valheim Hagen), and the Serbian gang under “Papa” (Bruno Ganz). Rather predictably, it all ends in a final showdown between all the major actors involved. While the plot suggests an action film à la Hollywood, the film playfully escapes confinement to this category.

It is not quite clear to whom the Norwegian title of Hans Petter Moland's new film, “Kraftidioten” (roughly: ‘really dumb person'), is meant to refer. Any of the characters seem to be a suitable candidates. The English title, on the other hand, “In Order of Disappearance” points toward the first central element in the film's comedy: it lets the audience expect, but meets those very expectations only through inversion. For instance, the film flips the standard cast-list in the closing titles. Instead of their order of appearance, a brief obituary is shown as the characters disappear throughout the film. This motif is varied on different levels: the evil boss of the Norwegian drug gang, “the Count”, is indeed a very progressive and forward thinking individual. He is a vegan, gets coffee for his men while they are busy torturing one of their victims, and does not readily give in to his ex-wife's custody battle over their son. In short, a modern business leader. Nils, in contrast, is a calculating, cold-blooded serial killer. He shows no signs of pain nor remorse. Yet, the film challenges the viewer subtly: while “the Count” should be appreciated (and Nils condemned) because of their respective deeds, the audience sympathises with Nils' Nordic Stoicism. Fortunately, this moral dilemma is resolved for the spectator in the second half of the film as “the Count” acts more and more as an evil overlord is supposed to do: shooting his own men, hitting his ex-wife, killing his informants after they delivered their information.

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by Maniza Naqvi

Offspring of wanton wants, they arrive, together, these gods of war and weather, to the beating drums, and sound of thunder, crying out crisis, each September. This century's, Septembers, all arrive back to school, as it were, refreshed from resorts and beaches, in need of replenishing, their depleted coffers, of personal savings, and future job offers.This century's September, as if afraid of endings, arrives as though, unrepentant, its own immortal endless season, of unceasing sameness, an eerie stillness of repeated scripts and finite possibility: War as weather and weather as war. Each September, reminds us, of an, unchanging, unreformed industry, of needs, that guarantees, more spectacular bombs and thunderous storms. Bombs and storms. Lovingly named for eradicated tribes, victims of genocide, and of course women. Apache Helicopters, and Tomahawk missiles, Rita, Katrina, and Ophelia. Do you even remember, come September, as we lurch from one year to the next, all the threats and crisis, these Septembers past have presented as pretexts? And we, the video generation, watching and watched, posting selfies, we need only a video to suspend belief, acquiesce and agree. War is peace! This is a crisis, indeed. These past, two half dozens, and change, Septembers,this same cry of crisis? And we, resolutely unquestioning, of how rules were changed, to protect us, from ourselves. The Patriots Act? Remember? In September 2005 came Katrina, after Rita,and Ophelia: and army boots and troops came out, to act and protect the land, while patriots drowned? Boots on the ground? This ground. Remember Septembers past, and to come. Then, came FISA ‘Protect America Act', in September 2007. Do you remember? (here.) Do you remember the rules, that changed? Rules on how you were to be protected, by being watched and listened to, and put in your place, if needed, by guns and batons, and military courts, and tear gas and bullets and fantastical costumes of robot cops and juggernauts. Do you remember that September? For your own protection, for your own, good, of course. Who elses'? Do you remember, the Financial Crisis, come September in 2008? The rules that changed? And Wall Street won and you lost your gains—and your roof, in its name, and, of course, your good name? And then, came the Gulf spill and by September 2009 British Petroleum, how it threatened, do you remember, the war on life? Or the threat for burning of the Quran, again godsent, then, in September 2010 that almost ushered in the chance on changing the rules on freedom of speech? And in September 2011, the Occupy Movement, which revealed, to us, the extent of our powers, against power, which as it turned out, were: None. That revealed to us, that the police, primarily protects property. That even a movement for rights and freedom, uses the term, Occupy. Are we mystified? And then the storm of Sandy which by September 2012 had made it clear, as it battered and washed away, our water front properties and flooded, Wall Street how powerless the batons, bullets, the tear gas, the shells, the bombs were against, the real threat. That year, they bombed Libya straight to hell. Then, a video of insanity, and that September, the attack at the embassy, in Bengazi? Yes, that was September 2012. Come September 2013, the drums of war turned to a deafening roar—that bloodlust's design, to go bomb Syria, all the way back to Afghanistan and more, Iraq and Libya and even Iran! A video, several, tried to help. Always a video, to make the case, to go bomb and invade, yet another place.That juggernaut denied its chance, by another hegemon, rose again, metamorphosed to fight another day. And come September now today, bombing of Syria, anyway—just the same, for now, lo and behold, there it is, ISIS, proof in hideous videos, for our eyes to suspend disbelief, that lets them there drop their bombs, which they had baked, and ached to drop for years, and almost did, last year. Iraq, has been bombed, for twenty five years! A gift from God, for endless war. Who created this new Goddess? This new crisis, of this ISIS? (here,here,here and here). So here we are, this September, with the headlines developed so far, which we won't remember, this time, next year, which gives us, our latest bed time story, and the newest season of hideous videos galore. No way, not today, will we slash defense spending, cut down weapons, roll back armies as was proposed. Hurray, we are on our way, again to war and endless hay. Hurray, for this new goose, this ISIS, and to the golden eggs, that it lays! And yet another resolution, a rule that claims, the right to kill belongs to only one hegemon, one Military. This, we will have forgotten by next September? Remember? War and weather. Bombs and storms. Rita, Ophelia, Katrina, Gustave, Ike and Sandy. Afghanistan, Iraq, Sudan, Libya, now Syria. And what can we do except this time, too, accept, and: Cry, it is a crisis, store canned food, upgrade the flat screen, consume the news, buy rubber boots and torches and: Cry Isis.

More Writing by Maniza Naqvi here.

by Thomas Rodham Wells

‘Libertarian paternalism' is how Richard Thaler and Cass Sunstein characterise their big idea, redesigning how choices look so that we will be nudged to choose the option in our own best interests. Their proposal has come in for fierce and sustained academic criticism, from both left and right, and from both philosophers and economists. But all the critiques I've read seem misguided in important ways.

Thaler and Sunstein argue that the behavioral economics evidence is quite clear that people do not choose as rationally as standard economic theory (or our folk psychology) suggest. In particular, people's choices are often strongly influenced by what should be irrelevant features of how their choices are framed. People tend to put more food on their plate if the plate they are handed is bigger; most of us go along with whatever the default option is for choices about pension contributions and organ donation; and so on. In many cases it seems that we don't have an existing specific preference over outcomes and are therefore open to having our subjective valuations shaped or induced by how the options are presented.

Libertarian paternalism is the ethical thesis that, since how people make many choices is so influenced by their framing, it is right and proper for governments to try to design the choices people face in a helpful way (paternalism). Yet nothing about designing the presentation of choices forces people to choose what the designers had in mind. People are still as free as ever to choose what they want, if they know what they want (libertarian). (Sunstein went on to try to put some of his ideas into practice as Administrator of the Office of Information and Regulatory Affairs from 2009-12.)

Now, the critics of this approach have landed a couple of good blows.

First, how do we know what the 'rational' choice is that people should be making? In order to design choice architectures that nudge people to make the 'correct' choice – e.g. about signing up as an organ donor – policymakers must believe that they know the correct answers to these. In other words, government civil servants (no doubt with the assistance of behavioural economics consultants) are supposed to be able to work out what is in the best interests of 'ordinary' people more accurately and reliably than we can.

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