Linux "just works"!

We just got two new toys: a Mac Mini (the basic model), and a printer/scanner (HP Deskjet). The Mac -- both the tiny little machine and the OS that it runs -- looks spectacular, even though the peripherals are all non-Apple (Dell monitor, Logitech keyboard and mouse).

The printer came with a Mac OS driver CD; we inserted, installed, and... it didn't work. The scanner program quit with an "unknown error", and offered to send a bug report to Apple. We suspect that a newer driver is required: the CD says it is for Mac OS X 10.3, 10.4 and 10.5, but the Mini has 10.6 (Snow Leopard).

So I tried plugging the printer into my Linux laptop. No driver downloads, because the HP-supported linux printer drivers were already installed. I then tried scanning an image: the scanning program (xsane) detected the scanner, and it Just Worked.

I expect the updated Mac drivers will work too. If not, it's over to consumer support. But the interesting thing to me is this: unlike many Linux drivers, which are developed by third parties, the HP drivers are from HP -- as "official" as things ever get on Linux. But the way it is done is very different. HP's Mac (and Windows) drivers are binary "blobs" that are designed for a particular OS and its particular driver model; when the OS is updated, the driver can break. Windows Vista was notorious for malfunctioning peripherals, for this reason; apparently Snow Leopard is not immune. Linux drivers are provided (mostly) as source code, and compiled against the kernel source, which is a constantly evolving object (essentially no two Linux distributions use exactly the same Linux kernel, and the kernels they use are not the "official" kernels released by Linus Torvalds). So the user does not get the HP drivers from HP's website or installation media, but bundled with the OS itself -- and it works.

Linux is sometimes criticised for evolving too rapidly, making it extremely difficult for device manufacturers to supply binary "drivers". The linux developers respond that it is better for the companies to work with the kernel community, open-source their drivers, and, if possible, include them in the "mainline kernel". That way, first, users will not need to download drivers or run "installation CDs" to get their hardware to work; second, the drivers will generally stay working. (Here's a position statement from Linux developers.)

Based on my one data point (I don't use Windows and this is my first experience with a Mac), I'd say the Linux developers have a point.

"The pilot is the weak link"

According to a new book by William Langewiesche, reviewed here by the NYT, the true hero of the incident earlier this year when a US Airways plane was landed safely on the Hudson river after losing both its engines was not the pilot, Chesley "Sully" Sullenberger. It was Bernard Ziegler, a Frenchman who perfected the "fly-by-wire" technology used by Airbus. Langewiesche asserts that the Airbus was nearly capable of landing itself, even after losing its engines, and while Sullenberger made the right choice to land in the river, the landing itself required only moderate skill and any decent pilot could have done it.

It is an interesting claim, because the other headline-making air accident this year was the loss of Air France flight 447 on June 1, en route from Rio de Janeiro to Paris. On that occasion, there were several suggestions that fly-by-wire, and the lack of manual pilot overrides on Airbus aircraft (in contrast to Boeing), were responsible.

Langewiesche further claims, credibly, that being an airline pilot is such an incredibly monotonous job that the best and brightest do not want to do it today. (Some pilots may find unusual ways to alleviate that boredom.) Michael Moore says that pilots in the US are so poorly paid today that many of them work second jobs. No wonder so many foreign pilots are now working for Indian carriers, who not only continue to pay well, but Air India pays expat pilots more than Indians. In fact, their annual bonuses (up to $15,000) are comparable to the total annual pay ($17,000) of some pilots for major US airlines, if Moore is correct.

Air India, of course, is in a financial crisis, as -- to a lesser extent -- are all Indian carriers; so such generous pay may not last long. But good pilots are still required, even if Airbus planes require little skill to fly.

Unless Airbus invents a pilotless aircraft (Boeing doesn't seem very impressed with fly-by-wire), I think interesting times are ahead for the airline industry, and for passengers.

CSIR, bitten by the one it fed

Suppose you are heading the country's largest and most important scientific organisation. You know that, despite some very bright spots, it has been getting creaky and bureaucratic over several decades. Being a dynamic and go-getting scientist, you have several ideas on what is to be done. One of the things you want to do is to set up a new department aimed at streamlining the process of commercialising new technologies, and establishing better links with industry. Would you hire this guy? Would you offer him a job the very first time you met him?

The current director-general of the CSIR apparently did. And there, in my opinion, started the trouble that has since then accounted for much column-space and blog-energy. Good reviews, and links, are on Abi's blog: here and here (some of the comments are interesting too).

V A Shiva, also called Shiva Ayyadurai, seems to have had an interesting career. He is not a career scientist, but has bachelor's and master's degrees in electrical engineering and computer science, visual studies and theoretical mechanics from MIT; and recently, apparently, he earned a Ph.D. in systems biology from the same institution. In between, he has mainly been in what we like to call the IT sector, primarily running an e-mail provider, EchoMail. Read his biography for more.

The DG of CSIR, Prof S K Brahmachari, is a smarter man than me, and no doubt a better and more experienced judge of others' CVs and abilities. It appeared to me that Shiva Ayyadurai has few notable academic achievements, and his primary commercial undertaking, EchoMail, is not exactly a household name. He seems prone to bombast: for example, he claims to have created "one of the world's first e-mail systems" in 1979, but e-mail has been around since the 1960s. Nevertheless, a thorough interview and review of the man's abilities and accomplishments may have led Prof Brahmachari to conclude that he was the right person to head his pet project, CSIR-Tech. But was that done, or was it an instantaneous decision, as Shiva suggests?

Having been hired, at a generous salary, he was apparently asked to produce a report on the functioning of the CSIR and future improvements. This he did, and that is when all hell broke loose, and the CSIR terminated his appointment (the CSIR claims that he was not employed in a permanent position, only hired on contract, and there are also claims that he was asking for too much money). Shiva went ballistic, complaining to everyone in the media who would listen that he was being victimised for his genuine and well-meaning criticisms of the organisation. He claims also to have written to the Prime Minister. What the PM thinks of it, we don't know.

So what did he say? The Deccan Herald excerpts the report here. I have seen the full report but do not think it is worth "leaking": it seems hastily put together, is unprofessional and often personal in tone, identifies obvious problems that I'm sure are well known to all CSIR scientists, and prescribes remedies that would be within the province of a first-year MBA student. Nevertheless, do read the DH link for its entertainment value, if you like. As Abi asks, if this is Shiva's opinion of the man who hired him, why does he want to keep the job, and having aired such an opinion, why should he expect to keep the job?

As some commenters on Abi's blog suggest, maybe he was already told not to expect to be hired in a permanent position, and his report was his way of venting his grievance at the CSIR DG. Which makes it even more unprofessional. Regardless of the truth or otherwise in his observations, I don't think the report will now be taken seriously, nor should it be.

But that shouldn't detract from two key issues. First, exactly what sort of position was Shiva hired under in the first place, why, and what was his mandate? Second, the need to reform and streamline CSIR remains: what does the DG plan to do in this regard? I suspect the CSIR DG made a mistake (caused by over-eagerness to "get things done") in hiring V A Shiva, and knows it; he should now make amends -- first, by coming clean on exactly what happened; and second, by making sure the need for reforming and modernising CSIR is not sidetracked.

This is it: review from a non-fan

Two days ago we saw "This is it", the film of the rehearsals for Michael Jackson's planned last concert series that never took place.

I was never much of a MJ fan -- "Thriller" happened when I was under 10, and by the time "Bad" happened he was already being viewed as a bit of a joke, with his skin-bleaching and plastic surgery and oxygen tents and whatnot. By the time I started listening to rock and blues (and, later, jazz), the Michael Jackson brand of pop seemed too tame.

After he died, my view was coloured by articles like this one. Supposedly the guy was skeletal, unable to sing let alone dance, and only being kept alive by insane quantities of medication; if he hadn't died before the scheduled 50-concert series, he would not have survived that ordeal.

So it was a surprise to see Jackson in the movie. Thin he certainly was -- skeletal, it was harder to say. But the rest?

He could sing, and did sing. He wasn't lip-syncing. His voice was a bit different from the old days, still high and child-like but somewhat thicker (an improvement, in my opinion). He talked frequently about needing to "preserve his voice", but it sounded more like hypochondria than a real problem -- no doubt it was a bigger problem than even he knew, but it did not show in the performances. "I just can't stop loving you", in particular, ended in an extraordinary extended bluesy call-and-response sequence between him and a female singer that would not have sounded out-of-place on a 1950s album from Chess Records, and showed some improvisational ability that I had never associated with him.

He could dance. Not like a 20-year-old, but better than most 50-year-olds, and certainly not like someone who only had weeks to live.

He was in control. Directing the choreography, the film-editing, and the musicians with authority -- telling the lighting and video people to "watch his cue", telling them that he would sense the video changes without needing to see them, telling his musicians to prolong a pause and "let it simmer"...

And the musicians were outstanding. If I had expected MJ to lip-sync his performances, I had also expected him to use recorded music, like most other pop singers these days. But no, he had a small, tight band -- two guitars, bass, keyboard, drums -- and while what they did wasn't too different from his recordings, it sounded much punchier and more intimate. The bass was funky -- I'd never noticed a bass in MJ before. The lead guitarist, a young woman called Orianthi Panagaris, ripped it up, not missing a step even when MJ was dancing in her face and all over her guitar. "Black and white" climaxed with a guitar duel between her and another guitarist. I found I could relate to the music: I could hear Motown and the blues in it, which I never did before, perhaps because I never listened to it very much, or perhaps because it was over-produced.

Kenny Ortega chose to put together a raw montage from the rehearsals, consisting of complete or nearly-complete songs, some shots of the team planning the performance, some interviews with the crew, and nothing else. It is obvious that an enormous effort must go into an MJ show -- let alone a 50-night run -- but the sheer scale of it all hadn't really come home to me. Nor had the level of commitment and enthusiasm of all the performers and crew, and their interaction with MJ, who was like a god to most of them. It must have been absolutely shattering for them when Jackson died a week before the concerts. But this movie has brought them to a wider audience than they would have planned for. I expect to hear more of Orianthi Panagaris, in particular.

A truck on a pedestrian bridge

Chennai has three waterways running through it, one of which is the Buckingham Canal -- once an elegant canal on which barges transported people and goods, now essentially an open sewer. But the canal divides the city, especially the southern parts of the city: there are very few motorable crossings south of the Adyar river. The first major one is at Sardar Patel road, the next at Tidel Park about 2km further south, and the next at Shozhinganallur nearly 10 km beyond that.

In between the first two above, there was a narrow pedestrian bridge, which served as the main route for residents of our institute's hostel and guest house -- and several others in the neighbourhood -- to access the commercial areas of Indira Nagar, Adyar and Besant Nagar on the other side. The bridge was designed for pedestrians and cyclists; motorbikes were always frequent users, but recently auto-rickshaws and even cars have been using it heavily. Whenever police tried to barricade it so that only pedestrians could access it, the barriers were removed.

Early on Sunday morning, a truck laden with bricks tried to use it. This was the result.

Thanks to one truck driver who had no idea what his vehicle weighed, and several inconsiderate souls who kept removing those barricades, residents of this mainly academic neighbourhood will no longer be able to walk across (or cycle across) to the commercial area on the other side. And when I cycle to work, which is fairly often, I will need to use the busy main road and not the quiet inner roads that I earlier favoured.

Business sense

Even in a land where money is valued and Lakshmi is worshipped, Dilip's experience with online tourism firm ExtendedStay is breathtaking. Go read.

If John Cleese had met Vishwas Tiwari and not Donald Sinclair, he'd have done something much funnier than Fawlty Towers.

(On the other hand, Dilip has nice things to say about Apple Inc and their customer service, as do many of my colleagues.

Magnetic monopoles from classical physics

Much recent media attention has been showered on a recent paper by Bramwell et al, that observes the motion of "particles" in a solid that behave like carriers of "magnetic charge", or magnetic monopoles. This is an experimental confirmation of a theoretical prediction made by Castelnovo, Moessner and Sondhi nearly two years ago, and other recent experiments have added corroboration. The solid in question is an exotic rare-earth compound called dysprosium titanate.

Magnetic monopoles don't, as far as we know, exist in nature. There is no such thing as a "magnetic charge". An ordinary "bar magnet" behaves much the same way as an "electric dipole", that is, two electric charges placed close together, but if you break an electric dipole you get two electric charges ("monopoles") while if you break a bar magnet you get two bar magnets. This is because magnetism is not produced by static "magnetic charges" but is produced by moving electric charges (that is, currents). In an electromagnet, the the movement is of conducting electrons along a coiled conducting wire; in a bar magnet, the movement is the quantum-mechanical "angular momentum" of electrons, which is not very similar to classical "rotation" but has the same effect. In particular, electrons have an "intrinsic angular momentum" or "spin" that cannot be explained as an analogue of any classical quantity; but this spin, too, contributes to a magnetic dipole moment for each electron. Nuclei, too, can have their own magnetic dipole moments.

The recent experiments have not discovered a new phenomenon of nature -- the laws of physics don't need to be rewritten. What they have found is something that would behave exactly as a collection of magnetic monopoles would behave, if observed at not too fine a scale. The explanation is really quite simple. I myself worked on this system long ago: we published the basic physics of this compound in 1999 and, between then and 2008 (when Castelnovo and colleagues published their prediction), hundreds of papers on the subject have been published. I'm sure lots of those authors are kicking themselves for not having thought of it first.

These systems have a rather exotic geometry that has become widely known as the pyrochlore lattice, after an otherwise unrelated mineral. This is a lattice of tetrahedra (solids with four triangular faces) joined at their corners, such that two tetrahedra share a corner. Here is a picture (click on it for source page).

The dysprosium atoms (which are the main players here) sit at the red dots. Each carries a large magnetic moment arising mainly from electrons in the f shell. In free space, this magnetic moment could point everywhere, but in the presence of electrostatic fields of neighbouring atoms (in particular, the oxygen ions), it turns out that the preferred direction is along the lines joining the centres of the adjoining tetrahedra. Quantum-mechanically, the possible components of the angular momentum along this direction are discrete, and it turns out that the state where the angular momentum is entirely in this direction is about 200 kelvin lower in energy than other states. So at low temperatures (these experiments are performed at temperatures close to liquid helium, that is, less than ten kelvin), the atoms behave like magnets that point along the lines joining adjoining tetrahedral centres, in either direction. And because the angular momenta are relatively large, they can be treated as classical magnets. They interact primarily via the long-ranged "magnetostatic" interaction of two classical dipoles, but their nearest-neighbour interaction is somewhat reduced by a quantum-mechanical "superexchange" effect (but is still the dominant interaction).

And that is the only entry of quantum mechanics into this discussion. The physics henceforth is entirely classical and would have been understood in the 19th century, which is part of what makes it all so remarkable.

If the nearest-neighbour interaction were all, the "ground state" of these systems -- the lowest-energy state -- would be any state where each tetrahedron had two "magnets" (which we will call spins) pointing in and two pointing out. There is a macroscopic number of such states, leading to a non-zero entropy in the ground state (which is what we observed in 1999, and there is a remarkable analogy with the entropy of ice, which led to these systems being called "spin ice" -- but that is another story). Remarkably, the addition of long-ranged interactions does not seem to affect this picture much. Strictly speaking, the true ground state in the presence of long-ranged interactions is a fully-ordered state, unique apart from rotations. But experimental probes have only shown small signs of this form of ordering.

Since the three-dimensional lattice is hard to visualise, at this point let us consider instead a two-dimensional "square lattice", as shown below.

The constraint is that each shaded square must have two spins pointing in and two pointing out. This leads to results very much analogous to the pyrochlore case (in fact, this lattice, with all pairwise interactions within the shaded squares being of equal strength, is often called the "square pyrochlore" lattice). An example ground state satisfying this constraint is shown. Again, there is a large (macroscopic) number of such states.

Now how do we visualise excitations? The simplest excitation is a "spin flip" -- reversing the direction of a single arrow. This upsets the balance of arrows: one square has three arrows pointing in (with a net "north charge") and another has three arrows pointing out (with a net "south charge"). It is like placing a little magnet locally in an otherwise magnetically-neutral material.

But the key point is that the "north charge" and "south charge" can now migrate and separate, via a series of spin flips. Click on the above figure for an animation.

Viewed on a coarse scale, what this looks like is two magnetic "monopoles" that can move around freely. Castelnovo et al. examined the dynamics of this process theoretically, and now Bramwell et al. have measured it in the laboratory.

It is a simple idea, and a remarkable experimental observation. Whether it is just a curiosity or has further scientific or technological importance, only time will tell.

It should once again be emphasised that these "monopoles" are not elementary particles. People familiar with semiconductors will think of an analogy with "particle-hole excitations", where a electron gets excited and leaves behind a positively-charged "hole" that behaves like a particle in its own right. But that is a quantum-mechanical phenomenon which cannot be understood classically. The magnetic "monopoles" here, however, are purely a phenomenon of classical physics. If you could build a model with wires, springs and magnets, designed to mimic the geometry of the system and enforce the constraints of the allowed magnet directions, it should behave in exactly the same way. That in itself is of interest: I'm not aware of any other examples of "quasiparticles" or "particle-hole excitations" that can be described purely classically.

Happy birthday, Martin Gardner

Martin Gardner is 95, and the New York Times has a great article about the man and his new book.

For those who don't know the name, Gardner wrote the column "Mathematical Games" in Scientific American for a quarter of a century. The following quote from the NYT article summarises the impact of those columns perfectly: "Martin has turned thousands of children into mathematicians, and thousands of mathematicians into children."

I am not a mathematician, but perhaps close enough to be counted. I first read him as a child -- it was my mother's yellowing copy of Mathematical Puzzles and Diversions, a collection of Scientific American columns that began with the "Hexaflexagons" column mentioned in the NYT article above -- and was hooked. I collected several more of those volumes over the years.

Almost equally delightful has been his debunking, over the years, of various forms of pseudoscience. I say "almost" because I think he sometimes went a bit overboard, to the detriment of his argument. But perhaps I will leave that to another blog post.

And then there are gems like "The Annotated Alice" and "The Annotated Snark", which will teach you more about the hidden layers in the Lewis Carroll books than you ever believed existed...

Fouad al-Rabiah, Obama and peace

I linked the case of Fouad al-Rabiah in my last post, but didn't provide any details. I think it is worth talking about more. First, here is Andy Worthington's original article on the subject. It is a long and disturbing read. If you want a shorter and equally disturbing one, here is a new article by Andrew Sullivan in The Times.

From Sullivan's article:

We know that an American interrogator, operating under the authority of the US government, said the following words to a detainee: “There is nothing against you. But there is no innocent person here. So, you should confess to something so you can be charged and sentenced and serve your sentence and then go back to your family and country, because you will not leave this place innocent."

This man had worked at Kuwait Airways for 20 years; he was also a humanitarian volunteer in Afghanistan, who got caught up in the war and found his entry route (via Iran) blocked for exit. Trying to leave via Pakistan, he was caught by US troops and sent to Guantanamo. But even after initial interrogators concluded he was innocent, he was kept there and tortured -- because he couldn't be allowed to leave Guantanamo.

This happened mostly under the Bush administration, but the Obama administration continued to pursue the case despite knowing he was innocent. Says Sullivan (who was, and in some ways still is, one of Obama's strongest supporters):

Shockingly, although Barack Obama’s justice department knew the details of this case, it persisted with the Bush administration’s attempt to prosecute him. Last week, the Obama administration also backed a legal provision to withhold permanently all unreleased photographic evidence of torture in sites and prisons far away from Guantanamo and Abu Ghraib. And some of us believed we were voting for change.

And a President who defends the torture of a man known to be innocent is rewarded with the Nobel Peace Prize. Tom Lehrer once said that satire died when Henry Kissinger won the peace prize. But was it necessary to stab the dead body again?

Nobel thoughts

As I type this, the winners of the five original Nobel prizes have been named for this year; only the winner of the Bank of Sweden (Nobel memorial) prize in economics remains to be announced. It is usually the case that the science awards are noncontroversial, while the literature, peace and economics awards attract much discussion.

The Physiology and Medicine and the Chemistry awards are richly deserved this year. The Chemistry award has of course attracted lots of interest in India because of the origins of one of its recipients. But I found another point interesting: while there was originally no Nobel prize in "biology", these days there are, in practice, two in molecular biology: the Physiology and Medicine prize, and the Chemistry prize. This year's chemistry prize was awarded for improved understanding of the structure and functioning of the ribosome. Last year, it was awarded for discovering the green fluorescent protein and developing it as an important tool. In 2006, it was awarded for a better understanding of the transcription process; in 2004, for ubiquitin-mediated protein degradation; in 2003, for determining the structure of ion channels.

The Physics prize this year went not to fundamental discoveries, but to inventions: fibre optics and CCDs. But there is a spot of controversy in the award for Charles Kao: the "father of fibre optics" is widely held to be Narinder Singh Kapany, whose work preceded Kao's by over a decade. Kapany's work focussed on imaging, while Kao's Nobel award was specifically for developing fibres that could carry signals over 100 kilometres; both innovations were extremely significant, and both were technological rather than fundamental.

The literature prize went to Herta Mueller, whom I hadn't heard of. But this must be the hardest prize to give: there are more deserving candidates than prizes available, and unlike in the sciences, it doesn't make sense to share it among multiple candidates. I had never heard of Wisława Szymborska, the 1996 winner, until two weeks ago (well, I suppose I'd heard her name in 1996, but it did not stick in my memory); having been introduced to her poetry, I find it extremely interesting.

That leaves the peace prize, announced today. I personally think it is a laughable idea giving it to Barack Obama at this stage of his career, when he has absolutely no concrete achievements, has backtracked from many of his earlier promises, has had his Justice Department defend the torture of innocent people by the previous administration, is prolonging the war in Afghanistan, and is achieving little success in his domestic agenda.

Perhaps the future will vindicate this prize; but giving a prize for future achievements requires extraordinary clairvoyance.

It remains to be seen what surprises are sprung by the award committee for the Economics prize. We will know soon.