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Eric Umansky: Arabic and the NBA: Being a basketball fan has brought me much pleasure in life. But who knew it would help with my Arabic. "Generous" is kareem, as in... and... "wise" is hakeem, as in.... If you want to learn Arabic, you too should follow the NBA. It’s fan-tastic!
Last Words on Saletan: Saletan has written an epilogue, titled "Regrets", to his series, which is a very curious piece of work indeed. Here's the end of it in its entirety (except for the links):
In researching this subject, I focused on published data and relied on peer review and rebuttals to expose any relevant issue. As a result, I missed something I could have picked up from a simple glance at Wikipedia.
For the past five years, J. Philippe Rushton has been president of the Pioneer Fund, an organization dedicated to "the scientific study of heredity and human differences." During this time, the fund has awarded at least $70,000 to the New Century Foundation. To get a flavor of what New Century stands for, check out its publications on crime ("Everyone knows that blacks are dangerous") and heresy ("Unless whites shake off the teachings of racial orthodoxy they will cease to be a distinct people"). New Century publishes a magazine called American Renaissance, which preaches segregation. Rushton routinely speaks at its conferences. I was negligent in failing to research and report this. I'm sorry. I owe you better than that.
In my first post about this, I said that there were two possible interpretations of Saletan's actions: that he didn't know that the ideas he was spread were crap, or that he did, but spread them anyway to advance an agenda. Saying that the second interpretation was more charitable wasn't just a joke. Sadly, this partial mea culpa supports the first interpretation, that of incompetence. To put it in "shorter William Saletan" form, what he is saying is: I am shocked — shocked! — to discover that the people who devote their careers to providing supposedly-scientific backing for racist ideas are, in fact, flaming racists. And he does seem to be shocked, though it is hard (as Yglesias says) to see why, logically, he should strain out those gnats he displays for our horrified inspection while swallowing the camel of group inferiority (and telling his readers that camel is really great and the coming thing). This indicates a level of incompetence as a reporter and researcher that is really quite stunning — as Brad DeLong says, this seems like a trained incapacity.
But let me back up a minute to the bit about relying on "peer review and rebuttals to expose any relevant issue". There are two problems here.
One has to do with the fact that, as I said, it is really very easy to find the rebuttals showing that Rushton's papers, in particular, are a tragic waste of precious trees and disk-space. For example, in the very same issue of the very same journal as the paper by Rushton and Jensen which was one of Saletan's main sources, Richard Nisbett, one of the more important psychologists of our time, takes his turn banging his head against this particular wall. Or, again, if Saletan had been at all curious about the issue of head sizes, which seems to have impressed him so much, it would have taken about five minutes with Google Scholar to find a demonstration that this is crap. So I really have no idea what Saletan means when he claimed he relied on published rebuttals — did he think they would just crawl into his lap and sit there, meowing to be read? If I had to guess, I'd say that the most likely explanation of Saletan's writings is that he spent a few minutes with a search engine looking for hits on racial differences in intelligence, took the first few blogs and papers he found that way as The Emerging Scientific Consensus, and then stopped. But detailed inquiry into just how he managed to screw up so badly seems unprofitable.
The other problem with his supposed reliance on peer review is that he seems confused about how that institution works. I won't rehash what I've already said about it, but only remark that passing peer review is better understood as saying a paper is not obviously wrong, not obviously redundant and not obviously boring, rather than as saying it's correct, innovative and important. Even this misses a deeper problem, a possible failure mode of the scientific community. A journal's peer review is only as good as the peers it uses as reviewers. If everyone, or almost everyone, who referees for some journal is in the grip of the same mistake, then they will not catch it in papers they review, and the journal will propagate it. In fact, since journals usually recruit new referees from their published authors or people recommended by old referees, mistakes and delusions can become endemic and self-confirming in epistemic communities associated with particular journals. To give a concrete example, the community using Physica A is pretty uniformly (and demonstrably) mistaken about how to tell when something is a power-law distribution, so what that journal publishes about power laws is unreliable, and those who derive their training and information from that journal go on to propagate the errors. It would be easy to find even more extreme examples from the physical and mathematical sciences (especially, I must say, among journals published by Elsevier), but it would take too long to explain why they are wrong.
Put simply, the problem is that any group of quack scholars with a shared delusion can put together a journal, dub each other peer reviewers, and go on their cheerful way by endorsing each others' work for their journal. (One of the ways you can tell that intelligent design creationism is a propaganda front and not a real, if stupid, scholarly movement is that their effort to put together just such a journal was never more than half-assed, and it's moribund for some time now.) This isn't even always a bad thing, since sometimes people who seem like quacks are in fact right, and doing things like starting their own journals gives them a chance to get their act together and assemble a convincing case. But all of this does mean that the peer-review filter is a very weak and accepting one, especially on controversial topics. It does not seem unreasonable of me to ask that those who set themselves up as science reporters grasp this.
(I hope no one will mis-interpret me as saying that peer review is worthless — I think some form of it is essential, it's just not enough — or that I'm endorsing some silly social-constructionist view that science is just the views of the winners of the scientific community's internal political squabbles. If I thought that, I'd not be pursuing a scientific career, but rather making much more money, and reading many fewer boring papers and writing many fewer boring grant applications, on a sub-tropical island. Science is systematic and cumulative inquiry into what the world is like and how it works, and by and large one that succeeds in producing increasingly reliable and refined knowledge about the world. This is marvelous and inspiring, but it's still a social process implemented by East African Plains Apes [and some of their tools], and it's wise to be realistic about the implications of this fact.)
Let me close with a quotation (via Jessa Crispin) from William Langewiesche, which conveys, better than I could, something of what I was trying to say about the responsibilities of journalists:
"You have this precious, incredibly privileged thing," he said, "which is the reader's attention for a little while. And you can make the slightest misstep and the reader will put you down. People will say that the reader lives in a busy world. But that's not the reason why. The reason is that the writer blows it, and loses the reader's trust." Saletan has blown it very badly indeed.
Matthew Yglesias: Yes indeed if you oppose building a bigger building on the SW corner of 14th and U (right now there's a rinky-dink one story development there) you're a bad person and desperately need to stop being ridiculous. One of the great things about Washington, DC is that our Metro system is pretty good. And part of the very essence of making a pretty good Metro system viable over the long run is that in the immediate vicinity of Metro stations you're going to want to have big buildings and dense developments. That's just how it works. If you don't have dense development near transit, you can't have viable transit systems.
It's so incredibly frustrating to see time-and-again proposals to hear talk about how Americans "don't want" to live in cities or use mass transit or whatever else and then turn around and see tons of examples of situations where people certainly seem to want to build high-density structures and are confident that others would rent or buy space in the structures. Obviously, not everyone is going to want to live that way, but evidently many more people would like to than are currently allowed to.
Dennis Perrin: Teasing The Mesomorph: Driving around this morning, looking at the long faces of Michigan fans coping with their team's pitiful performance against Ohio State, I found myself behind a dented, faded black pick-up at a stop light. Stuck to its tailgate was a very long bumper sticker, two lines deep, that read in large letters: "As Hillary, Jennifer, and Nancy Rise In Stature, They Give New Meaning To The Phrase Ho Ho Ho!" As the truck turned, I saw the driver, a grizzled chubby redneck with a goatee and ball cap. Direct from central casting. Too perfect to be real.
But he was. You see plenty of these types in these parts, tooling around in large 4-wheel, sometimes 6-wheel, gas guzzlers, sporting various nativist and paranoid bumper stickers about how the Democrats are commies, their women a bunch of overspending, castrating, ugly ass sluts. Not for them any serious class-based political thinking or expression. To the guy above and numerous others like him, Clinton, Granholm, and Pelosi aren't corporate-militarist whores, a gender-neutral if indelicate description, but simply hos. Should Hillary win the White House, look out for an explosion of similar white male fear products. Ain't no commie dyke gonna tell them what t'do!
Meanwhile, the global wars rage on, geopolitical corporate positioning to control the Earth's dwindling resources, oil and water chief among them. The water wars will eventually speed up, as there'll be less and less drinkable H2O to go around, and those with the power to grab what clean water remains will do so with little ceremony. The Israelis have shown the way for years, diverting water from Palestinian lands to their drinking fountains, swimming pools and water slides. A rational move. After all, what good is a water park in Gaza?
Things are very bad in this part of the country, and it will get worse before it gets better, assuming that "better" has any contemporary meaning. I suppose it's easier to pretend that our economic problems are primarily due to liberal commie fags than to a global economic arrangement that squeezes the powerless until they're tossed on the garbage heap. Besides, painting corporations and their political servants as pussies doesn't make for snappy bumper stickers.
FT.com / Home UK / UK - An insider's tale of Brussels bureaucracy: Derk-Jan Eppink, a Dutch civil servant, has done something unique. He has written a genuinely entertaining book about the European Commission.
Of course, there is no shortage of books about the commission and the workings of the Brussels bureaucracy. But most of them are horribly dull. They are written by academics and aimed at other academics, or students or would-be eurocrats. Nobody would consider reading them for pleasure.
Eppink's work is different for three reasons. First, he was a journalist before he was a civil servant: he can tell a story and has an eye for anecdotes. Second, although he thinks that the European Union is definitely a force for good, he does not have a religious belief in "the project". As a result, he is able to ask awkward - and important - questions about the future of the EU. Last but not least, he has a sense of humour.
Eppink can take something that sounds very dull - a discussion with a French trade unionist about the EU's postal-services directive, for example - and turn it into an amusing story that tells you something important about how the EU operates. (In this case, that French trade unionists are a powerful and stubborn force working against economic liberalisation.)
The author also has a refreshing interest in the macabre and the tawdry that enlivens his account of working as a civil servant, charged with improving the functioning of the EU's internal market. He claims that Britain was forced to make important concessions on the free movement of goods after a case involving German importers of inflatable rubber women. He gives an account of a bizarre debate over whether the cross-border movement of corpses was the responsibility of the EU's internal-market directorate or the health department.
Not all Eppink's anecdotes are hilarious. And some of his literary devices can irritate. His habit of referring to the commission as "the Princess" begins to grate after a while. But, in general, he is successful in jollying along the reader with anecdotes, as he carefully builds up a picture of how the European institutions work. There are separate chapters on the commission, the European parliament, the Council of Ministers and the role of the commission's president.
Gratifyingly, Eppink seems to believe that one of the most important Brussels institutions is the Financial Times. He writes that: "The most prestigious newspaper for the mandarins is the Financial Times. An issue isn't an issue until it has appeared in the pink pages of Britain's premier daily." Less gratifyingly, he devotes quite a lot of space to what he regards as his successful efforts to manipulate FT coverage of his boss, Frits Bolkestein, the EU's commissioner for the internal market. The picture that Eppink paints of the European bureaucracy is - perhaps unintentionally - rather horrifying. The commission is ultra-hierarchical and full of back-stabbing time-servers. The president is treated as a sort of god - even if, like Romano Prodi, he has a habit of falling asleep in meetings. Individual commissioners are treated as minor deities, and civil servants compete fiercely for their ear. If a commissioner wants an informal chat with a junior official, civil servants higher up the pecking-order will do their utmost to prevent it happening.
Commission officials believe that, collectively, they are doing great work. But this doesn't stop them from devoting a lot of energy to frustrating each other's initiatives.
Perhaps all large bureaucracies behave like this. But reading Eppink's book made me profoundly grateful that I am never likely to work for the Brussels bureaucracy.
Most of the book is an insider's account of the workings of the commission. But Eppink has thought hard about the future of the EU. Unlike most Brussels insiders, he is prepared to acknowledge the fundamental difficulty with the European project. "She [the commission] assumes that the public admires her unreservedly, but in this she is gravely mistaken. Her aim is the unification of Europe, whether the public wants it or not."
Eppink is also sceptical about the EU's efforts to force through a set of institutional reforms - initially as a constitution and now as a "reform treaty". He notes - accurately enough - that "Europe's main problem is not the fact that it does not yet have a president, but rather that it is saddled with a political agenda that belongs to the past."
Comments such as these have endeared Eppink to some British eurosceptics. But the sceptics are wrong if they think that Eppink is one of them. His views on the commission - and the European project - are more interesting, nuanced and tolerant than that.
FT.com / Columnists / Martin Wolf - Judicial torture and the NatWest 3: The case of the “NatWest three” has stirred up huge concern among business people in the UK. This week, however, we learn that the three former NatWest bankers have pleaded guilty to wire fraud. So was this just much British ado about nothing? My answer is: “no”. The fact that these three men pleaded guilty does not prove they were. It demonstrates that the offers made by US prosecutors are of a kind sensible people cannot refuse. The pressures the former can exert make it rational, even for the innocent, to plead guilty. I do not know whether that happened here. But it would not be very surprising.
This case had yet another disturbing feature: the fact that the three men were extradited under a treaty agreed with the US in 2003 that allows US courts to extradite people without establishing a prima facie (preliminary) case in a British one. Many believe the good reason for this change was the need to co-operate over terrorism. Yet it has, in practice, been used extensively against British business people by US prosecutors who are targeting white-collar crime.
Because so many British businesses have some US involvement, their vulnerability to this judicial activism is self-evident. What made the case of the NatWest three more remarkable is that the bank, alleged victim of the fraud, never pressed for a British investigation of the events.
Yet why should anybody object to the extradition of suspects to face US justice? Is America not, after all, a bastion of the rule of law? The answer, I fear, is: “alas, no”. The urge to find guilt has overwhelmed the presumption of innocence on which Anglo-Saxon justice is based. It is easy to understand the frustration that ambitious prosecutors and populist politicians feel over the difficulty in sending criminals to prison. But hard cases make bad law. This is a good example of that axiom.
Plea-bargaining is effective because of four salient features of American justice: the exceptional severity of punishment; the justified terror of what might happen in prison; the uncertain outcome of fighting cases before juries; and the possibility of obtaining a far lighter sentence by agreeing to pleas of guilty.
In the case of the NatWest three, the accused faced the possibility of up to 35 years in prison for their alleged offences. It is a reflection of the gulf in culture that has grown up between the US and the UK that what are in effect life sentences might be imposed for their alleged involvement in helping Andrew Fastow, then Enron’s chief financial officer, defraud Enron.
Such a sentence would be far longer than all but the tiniest proportion of murderers could expect to serve in the UK. Yet, apparently, it is regarded as perfectly reasonable in the US. Nor is this all. A sentence in a US prison, particularly for middle-class men, is likely to be entry into a lifetime of torment. Indeed, a few cynical Americans responded to complaints about what happened to Iraqi inmates in Abu Ghraib by arguing that it could not truly be torture since it was no worse than what might happen to inmates of a US prison.
Now imagine that you might face such a sentence if found guilty. Imagine, too, that you believed yourself innocent of all charges, but recognised the great complexity of the case and the ease with which a prosecutor might twist evidence against you before an uninformed (perhaps prejudiced) jury. You might suppose you had a one-in-five chance of being found guilty. That would be particularly plausible if you had run out of financial resources and so were unable to retain a first-rate legal team. What would you do if the prosecutors offered a plea bargain, under which you would serve just 37 months in prison in your home country (and pay $7.3m in restitution to the Royal Bank of Scotland, now the owner of NatWest)?
The answer is that most people would plead guilty, not because it was true but because it is what any risk-averse human being would do.
To my mind, this system is tantamount to extracting confessions of guilt under a form of psychological torture. That torture consists of the reasonable fear of being found guilty and fear of the length of time one might then serve in prison and of what might happen while one was there. All but exceptionally brave people will confess to almost anything to escape even the possibility of torture. In the same way, the majority of people would surely confess to almost anything to avoid the possibility of spending the rest of their lives in prison. Recognition of the meaninglessness of confessions extracted under threat of torture was the main reason civilised jurisdictions abandoned its use. The same objection applies to pleas of guilty made under the kind of plea bargaining employed in the case of the NatWest three.
Let me be clear: I am not asserting that the men are innocent. But the fact that they have made a plea of guilty does not prove their guilt. It could just as well show that the US judicial system has a potent machine for extracting pleas of guilty to lesser charges. In this way, it has also effectively eliminated a presumption of innocence. It is, for this reason, not a system with which the UK should retain its current extradition arrangements. At the least, the US must be asked to make a prima facie case. The conclusion is that simple.
D-squared Digest -- FOR bigger pies and shorter hours and AGAINST more or less everything else: The tribute that vice pays to virtue
What with my acid remarks about "leftist hypocrisy" below and my occasional expressions of sympathy for social libertarians, some people in comments (and, as ever, in vast volumes of fictitious email correspondence all of which agrees with me, except some terrible, abusive fictitious letter-writers who everyone who disagrees with me should be ashamed of) have started suspecting me of harbouring Conservative tendencies. Oh yeh, and I said I was going to vote Tory at the next election. That also might have set people thinking.
To an extent, they're right. I've just received my P60 and an itemised bill telling me precisely how much Camden Council proposes to charge me for 2003. Added to that I increasingly dispair of the likelihood of the ECB ever democratising, I'm having trouble distinguishing one pudding-faced Geordie fixer on the Labour frontbench from another and the Home Office still haven't done anything about that bastard running a pirate radio station on the LBC frequency and ruining the Charlie Gregory show for me, and it's perhaps not surprising that I feel nostalgic for a government that would combine xenophobic authoritarianism with a slightly lower higher rate of income tax. Feh.
Anyway, the Tory vote is non-negotiable. Blair lied to me about Iraq, I wanna lash out at him, Iit's stupid and irrational but I'm going to do it anyway. But the question of "hypocrisy" bears a bit more explanation because it does appear to go to the heart of a lot of people's emotional politics.
Think about it this way. In my post below, I suggested that the difference between the progressivity of the tax systems students suggested for income versus for their own grades "might serve as a useful index of the hypocrisy of leftist students". When I use the word "hypocrisy" here, what do we actually mean? Well, the combination of the following two qualities:
The first is simply a baseline definition of what it means to have left wing politics. The second ... well put it this way, Buddhist monks spend twenty years living ascetically and meditating for hours at a time before they presume to believe that they have conquered all selfish desires. If you're talking about "leftist hypocrisy", you're just talking about "leftists who have not been able to transcend history, biology and socialisation in order to develop an unparticularised love for all sentient things". In other words, you're just talking about "leftists who happen to be humans".
Contrast with rightwing politics. As I've posted earlier, the single most sensible thing said in political philosophy in the twentieth century was JK Galbraith's aphorism that the quest of conservative thought throughout the ages has been "the search for a higher moral justification for selfishness". Some rightwingers are not hypocrites because they admit that their basic moral principle is "what I have, I keep". Some rightwingers are hypocrites because they pretend that "what I have, I keep" is always and everywhere the best way to express a general unparticularised love for all sentient things. Then there are the tricky cases where the rightwingers happen to be on the right side because we haven't yet discovered a better form of social organisation than private property for solving several important classes of optimisation problem. But at base, the test of someone's politics is simple; if their political aim is to advance all of humanity, they're on our side, while if they have an overriding constraint that the current owners of property must always be satisfied first, they're playing for the opposition. Hypocrisy doesn't really enter into the equation with rightwing politics; you don't (or shouldn't) get any extra points for being sincere about being selfish.
So where does that leave our students? Well, they're young. They're most likely insecure. They don't actually have a lot, and it's hardly surprising that they're a bit precious about what they have (a close runner for the most sensible thing said in political philosophy in the twentieth century was Michael Oakeshott's remark that "a conservative is a man with something to lose", and the genius of this remark is its ambiguity). One shouldn't blame them for not being Boddhisattvas.
In general, one of the biggest problems with the psychological politics of left and right is the need that people feel to think of themselves as not just having made what looks like on balance the best decision given the things they regard as important, but as morally good people themselves. People in general seem to be horribly uncomfortable with the idea that, by the standards they use to judge political situations, they themselves don't come out as moral heroes. At base, this is a fairly childish and decidedly illiberal attitude; childish because it demands a sort of moral perfection which everyone intellectually knows can't exist outside fairy stories (unless you count the way that parents appear to their children) and illiberal because it suggests that you're only prepared to have normal social interactions with people who pass your own personal moral examination (a rather prominent political philosopher has told me to my face on a couple of occasions that he regards me as morally beyond the pale because of the job I do; I've nonetheless been made to feel very welcome at his house).
So anyway, hypocrisy in people is not a vice, particularly when the alternative is to be sincerely horrible. In political parties, it's much worse; people who presume to take control of the state's monopoly on the use of ppowerhave to be held to a much higher standard of honesty, because they are explicitly asking for us to trust them on matters important to our lives. A double standard? Perhaps. But I just told you that I don't care about hypocrisy. Perhaps I should have termed my imaginary measure above an "index of political self-righteousness". On which score, it seems fairly clear, the political science professor himself would outscore most of his students.
D-squared Digest -- FOR bigger pies and shorter hours and AGAINST more or less everything else: OK, when I started this weblog, I promised myself that the two things I would never do because they're corny and cliched were:
Time for the other shoe to drop ....
Brad DeLong has a thing going on at the moment about the main trope of Martin Amis' "Koba the Dread" (capsule review: don't bother) and about Eric Hobsbawm. Basically, the question is:
Q: Why is it that there are so many people who are generally liked and respected who are ex-Stalinists, while we hate and revile people with a Fascist background?
The usual answers to this question tend to involve tendentious corpse-counting, or slightly less tendentious assertions about the utopian ambitions and/or historical conditions pertaining to various political parties active in Europe in the 20th century. I think the answer is much simpler:
A: Because there are lots of ex-Stalinists around who are likeable, intelligent people worthy of our respect despite their political history, whereas ex-Fascists are in general a horrible bunch of people
People who like Eric Hobsbawm despite his Stalinist past do so because "well, you can forgive Eric Hobsbawm", not because "well, you can forgive Stalinism". If he'd been the same intelligent, generous, personable bloke, but had been a Nazi, he'd still have been forgiven. In actual fact, Nazi geniuses like Heidegger and Furtwangler were given the most incredible free pass while they were alive. It just happens to be the case that there were a lot of decent and intelligent British and American people who supported left-wing totalitarianism in the 20th century, while there were almost no decent and intelligent British and American people who supported Nazism. Or rather, it doesn't "just happen" to be the case; I'm personally of the opinion that a Nazi Hobsbawm would have been a psychological and sociological impossibility.
Look at it this way; the question is well-posed, but most of the attempts to answer it (including Niall Ferguson's and Brad's) are not. Eric Hobsbawm and all the other Stalinist comrades are, in general, forgiven. Old Nazis, in general, aren't. That's a sociological fact, and the question invites an explanation of why that sociological fact should be the case. My explanation is that it's a particular example of a lawlike generalisation; that Communists are in general nicer people than Fascists, so they get given more leeway. What most of the attempts to answer it seem to boil down to, is an attempt to deny the fact that they ought to explain; to attempt to reopen a judgement which has clearly already been made by society in general. If you start fulminating at Eric Hobsbawm and trying to claim that he's on the same level as David Irving, then all you're doing is making a short polemic of your own; you're not coming any closer to explaining the fact that Hobsbawm is a nice old man who likes jazz and Irving is a bitter and occasionally dangerous old bastard. Furthermore, you tend to come across as a bit of a loony, or worse, as Martin Amis, and the market for that sort of writing (basically, the Daily Telegraph) is already saturated.
That's basically what attracted me personally to left wing politics in the first place; there isn't so much downright nastiness to left wing political writing. You can usually forgive most lefty commentators the parts of their ideas which are insanely dangerous, illiberal or impractical, because you know that their heart's in the right place; for the most part, they're trying to help someone less fortunate than themself, albeit usually in a monumentally counter-productive way and without thought of the side-effects. With their equivalents on the right (and it gets worse, the further right you go), the subtext is always there "me me me". Galbraith said it, and these few words are to my mind worth every word John Rawls ever wrote, that "the project of conversative political thought throughout the ages has been that of finding a higher moral justification for selfishness". Since I'm strongly of the belief that it matters not just what we do, but what kind of people we are, that matters to me.
While we're on the subject, here's a question of the same kind that I regard as much more interesting (because more personal and less subject to political grandstanding) than the one about "who was worse?":
Q: Why is it regarded as vastly more acceptable for an adult male to attack a small child with the intention of causing pain in certain circumstances, than is for him to attack an adult female (presumably vastly more capable of defending herself) in exactly the same circumstances?
We've got MPs and prominent politicians (I believe the USA has too) who think it's OK to beat their children in order to punish them for insolence. How many of them would hang onto their jobs and status if they came out tomorrow and said that they hadn't mentioned it before, but they also beat their wives in similar circumstances? Ought to get a few comments on this one...
PHYS771 Lecture 11: Decoherence and Hidden Variables: Scott Aaronson:
Why have so many great thinkers found quantum mechanics so hard to swallow? To hear some people tell it, the whole source of the trouble is that "God plays dice with the universe" -- that whereas classical mechanics could in principle predict the fall of every sparrow, quantum mechanics gives you only statistical predictions.
Well, you know what? Whup-de-f@#%ing-doo! If indeterminism were the only mystery about quantum mechanics, quantum mechanics wouldn't be mysterious at all. We could imagine, if we liked, that the universe did have a definite state at any time, but that some fundamental principle (besides the obvious practical difficulties) kept us from knowing the whole state. This wouldn't require any serious revision of our worldview. Sure, "God would be throwing dice," but in such a benign way that not even Einstein could have any real beef with it.
The real trouble in quantum mechanics is not that the future trajectory of a particle is indeterministic -- it's that the past trajectory is also indeterministic! Or more accurately, the very notion of a "trajectory" is undefined, since until you measure, there's just an evolving wavefunction. And crucially, because of the defining feature of quantum mechanics -- interference between positive and negative amplitudes -- this wavefunction can't be seen as merely a product of our ignorance, in the same way that a probability distribution can.
Today I want to tell you about decoherence and hidden-variable theories, which are two kinds of stories that people tell themselves to feel better about these difficulties.
The hardheaded physicist will of course ask: given that quantum mechanics works, why should we waste our time trying to feel better about it? Look, if you teach an introductory course on quantum mechanics, and the students don't have nightmares for weeks, tear their hair out, wander around with bloodshot eyes, etc., then you probably didn't get the point across. So rather than deny this aspect of quantum mechanics -- rather than cede the field to the hucksters and charlatans, the Deepak Chopras and Brian Josephsons -- shouldn't we map it out ourselves, even sell tickets to the tourists? I mean, if you're going to leap into the abyss, better you should go with an experienced guide who's already been there and back.
Into the Abyss
Alright, so consider the following thought experiment. Let |R⟩ be a state of all the particles in your brain, that corresponds to you looking at a red dot. Let |B⟩ be a state that corresponds to you looking at a blue dot. Now imagine that, in the far future, it's possible to place your brain into a coherent superposition of these two states:
At least to a believer in the Many-Worlds Interpretation, this experiment should be dull as dirt. We've got two parallel universes, one where you see a red dot and the other where you see a blue dot. According to quantum mechanics, you'll find yourself in the first universe with probability |3/5|2=9/25, and in the second universe with probability |4/5|2=16/25. What's the problem?
Well, now imagine that we apply some unitary operation to your brain, which changes its state to
Still a cakewalk! Now you see the red dot with probability 16/25 and the blue dot with probability 9/25.
Aha! But conditioned on seeing the red dot at the earlier time, what's the probability that you'll see the blue dot at the later time?
In ordinary quantum mechanics, this is a meaningless question! Quantum mechanics gives you the probability of getting a certain outcome if you make a measurement at a certain time, period. It doesn't give you multiple-time or transition probabilities -- that is, the probability of an electron being found at point y at time t+1, given that had you measured the electron at time t (which you didn't), it "would have" been at point x. In the usual view, if you didn't actually measure the electron at time t, then it wasn't anywhere at time t: it was just in superposition. And if you did measure it at time t, then of course that would be a completely different experiment!
But why should we care about multiple-time probabilities? For me, it has to do with the reliability of memory. The issue is this: does the "past" have any objective meaning? Even if we don't know all the details, is there necessarily some fact-of-the-matter about what happened in history, about which trajectory the world followed to reach its present state? Or does the past only "exist" insofar as it's reflected in memories and records in the present?
The latter view is certainly the more natural one in quantum mechanics. But as John Bell pointed out, if we take it seriously, then it would seem difficult to do science! For what could it mean to make a prediction if there's no logical connection between past and future states -- if by the time you finish reading this sentence, you might as well find yourself deep in the Amazon rainforest, with all the memories of your trip there conveniently inserted, and all the memories of sitting at a computer reading quantum computing lecture notes conveniently erased?
(Still here? Good!)
Look, we all have fun ridiculing the creationists who think the world sprang into existence on October 23, 4004 BC at 9AM (presumably Babylonian time), with the fossils already in the ground, light from distant stars heading toward us, etc. But if we accept the usual picture of quantum mechanics, then in a certain sense the situation is far worse: the world (as you experience it) might as well not have existed 10-43 seconds ago!
Story #1: Decoherence
The standard response to these difficulties appeals to a powerful idea called decoherence. Decoherence tries to explain why we don't notice "quantum weirdness" in everyday life -- why the world of our experience is a more-or-less classical world. From the standpoint of decoherence, sure there might not be any objective fact about which slit an electron went through, but there is an objective fact about what you ate for breakfast this morning: the two situations are not the same!
The basic idea is that, as soon as the information encoded in a quantum state "leaks out" into the external world, that state will look locally like a classical state. In other words, as far as a local observer is concerned, there's no difference between a classical bit and a qubit that's become hopelessly entangled with the rest of the universe.
So for example, suppose we have a qubit in the state
And suppose this qubit becomes entangled with a second qubit, to form the following joint state:
If we now ignore the second qubit and look only at the first qubit, the first qubit will be in what physicists call the maximally mixed state:
(Other people just call it a classical random bit.) In other words, no matter what measurement you make on the first qubit, you'll just get a random outcome. You're never going to see interference between the |00⟩ and |11⟩ "branches" of the wavefunction. Why? Because according to quantum mechanics, two branches will only interfere if they become identical in all respects. But there's simply no way, by changing the first qubit alone, to make |00⟩ identical to |11⟩. The second qubit will always give away our would-be lovers' differing origins.
To see an interference pattern, you'd have to perform a joint measurement on the two qubits together. But what if the second qubit was a stray photon, which happened to pass through your experiment on its way to the Andromeda galaxy? Indeed, when you consider all the junk that might be entangling itself with your delicate experiment -- air molecules, cosmic rays, geothermal radiation ... well, whatever, I'm not an experimentalist -- it's as if the entire rest of the universe is constantly trying to "measure" your quantum state, and thereby force it to become classical! Sure, even if your quantum state does collapse (i.e. become entangled with the rest of the world), in principle you can still get the state back -- by gathering together all the particles in the universe that your state has become entangled with, and then reversing everything that's happened since the moment of collapse. That would be sort of like Pamela Anderson trying to regain her privacy, by tracking down every computer on Earth that might contain photos of her!
If we accept this picture, then it explains two things: 5e29ecc3149047348c9aac30f18f2679
So, what about the thought experiment from before -- the one where we place your brain into coherent superpositions of seeing a blue dot and seeing a red dot, and then ask about the probability that you see the dot change color? From a decoherence perspective, the resolution is that the thought experiment is completely ridiculous, since brains are big, bulky things that constantly leak electrical signals, and therefore any quantum superposition of two neural firing patterns would collapse (i.e., become entangled with the rest of the universe) in a matter of nanoseconds.
Fine, a skeptic might retort. But what if in the far future, it were possible to upload your entire brain into a quantum computer, and then put the quantum computer into a superposition of seeing a blue dot and seeing a red dot? Huh? Then what's the probability that "you" (i.e. the quantum computer) would see the dot change color?
When I put this question to John Preskill years ago, he said that decoherence itself -- in other words, an approximately classical universe -- seemed to him like an important component of subjective experience as we understand it. And therefore, if you artificially removed decoherence, then it might no longer make sense to ask the same questions about subjective experience that we're used to asking. I'm guessing that this would be a relatively popular response, among those physicists who are philosophical enough to say anything at all.
Decoherence and the Second Law
We are going to get to hidden variables. But first, I want to say one more thing about decoherence.
When I was talking before about the fragility of quantum states -- how they're so easy to destroy, so hard to put back together -- you might have been struck by a parallel with the Second Law of Thermodynamics. Obviously that's just a coincidence, right? Duhhh, no. The way people think about it today, decoherence is just one more manifestation of the Second Law.
Let's see how this works. Given a probability distribution D=(p1,...,pN), recall that the entropy of D is
Then given a quantum mixed state ρ, the von Neumann entropy of ρ is defined to be the minimum, over all unitary transformations U, of the entropy of the probability distribution that results from measuring UρU-1 in the standard basis. To illustrate, every pure state has an entropy of 0, whereas the one-qubit maximally mixed state has an entropy of 1.
Now, if we assume that the universe is always in a pure state, then the "entropy of the universe" starts out 0, and remains 0 for all time! On the other hand, the entropy of the universe isn't really what we care about -- we care about the entropy of this or that region. And we saw before that, as previously-separate physical systems interact with each other, they tend to evolve from pure states into mixed states -- and therefore their entropy goes up. In the decoherence perspective, this is simply the Second Law at work.
Another way to understand the relationship between decoherence and the Second Law, is by taking a "God's-eye view" of the entire multiverse. Generically speaking, the different branches of the wavefunction could be constantly interfering with each other, splitting and merging in a tangled bush:
What decoherence theory says is that in the real world, the branches look more like a nicely pruned tree:
In principle, any two branches of this tree could collide with each other, thereby leading to "macroscopic interference effects," like in my story with the blue and red dots. But in practice, this is astronomically unlikely -- since to collide, two branches would have to become identical in every respect.
Notice that if we accept this tree picture of multiverse, then it immediately gives us a way to define the "arrow of time" -- that is, to state non-circularly what the difference is between the future and the past. Namely, we can say that the past is the direction toward the root of the "multiverse tree," and the future is the direction toward the leaves. According to the decoherence picture, this is actually equivalent to saying that the future is the direction where entropy increases, and it's also equivalent to saying that the past is the direction we remember while the future is the direction we don't.
The tree picture also lets us answer the conundrums from before about the reliability of memory. According to the tree picture, even though in principle we need not have a unique "past," in practice we usually do: namely, the unique path that leads from the root of the multiverse tree to our current state. Likewise, even though in principle quantum mechanics need not provide multiple-time probabilities -- that is, probabilities for what we're going to experience tomorrow, conditioned on what we're experiencing today -- in practice such probabilities usually make perfect sense, for the same reason they make sense in the classical world. That is, when it comes to transitions between subjective experiences, in practice we're dealing not with unitary matrices but with stochastic matrices.
At this point the sharp-eyed reader might notice a problem: won't the branches have to collide eventually, when the tree "runs out of room to expand"? The answer is yes. Firstly, if the Hilbert space is finite-dimensional, then obviously the parallel universes can only branch off a finite number times before they start bumping into each other. But even in an infinite-dimensional Hilbert space, we need to think of each universe as having some finite "width" (think of Gaussian wavepackets for example), so again we can only have a finite number of splittings.
The answer of decoherence theory is that yes, eventually the branches of the multiverse will start interfering with each other -- just like eventually the universe will reach thermal equilibrium. But by that time we'll presumably all be dead.
Incidentally, the fact that our universe is expanding exponentially -- that there's this vacuum energy pushing the galaxies apart -- seems like it might play an important role in "thinning out the multiverse tree," and thereby buying us more time until the branches start interfering with each other. This is something I'd like to understand better.
Oh, yes: I should also mention the "deep" question that I'm glossing over entirely here. Namely, why did the universe start out in such a low-entropy, unentangled state to begin with? Of course one can try to give an anthropic answer to that question, but is there another answer?
Story #2: Hidden Variables
Despite how tidy the decoherence story seems, there are some people for whom it remains unsatisfying. One reason is that the decoherence story had to bring in a lot of assumptions seemingly extraneous to quantum mechanics itself: about the behavior of typical physical systems, the classicality of the brain, and even the nature of subjective experience. A second reason is that the decoherence story never did answer our question about the probability you see the dot change color -- instead the story simply "pulled a Wittgenstein" (that is, tried to convince us the question was meaningless)!
So if the decoherence story doesn't make you sleep easier, then what else is on offer at the quantum bazaar? Well, now it's the hidden-variable theorists' turn to hawk their wares. (Most of the rest of this lecture will follow my paper Quantum Computing and Hidden Variables.)
The idea of hidden-variable theories is simple. If we think of quantum mechanics as describing this vast roiling ocean of parallel universes, constantly branching off, merging, and cancelling each other out, then we're now going to stick a little boat in that ocean. We'll think of the boat's position as representing the "real," "actual" state of the universe at a given point in time, and the ocean as just a "field of potentialities" whose role is to buffet the boat around. For historical reasons, the boat's position is called a hidden variable -- even though in some sense, it's the only part of this setup that's not hidden! Now, our goal will be to make up an evolution rule for the boat, such that at any time, the probability distribution over possible boat positions is exactly the |ψ|2 distribution predicted by standard quantum mechanics.
By construction, then, hidden-variable theories are experimentally indistinguishable from standard quantum mechanics. So presumably there can be no question of whether they're "true" or "false" -- the only question is whether they're good or bad stories.
You might say, why should we worry about these unfalsifiable goblins hiding in quantum mechanics' closet? Well, I'll give you four reasons. 3eed10d3c576bb30f6ee9f8957521109
From my perspective, a hidden-variable theory is simply a rule for converting a unitary transformation into a classical probabilistic transformation. In other words, it's a function that takes as input an N-by-N unitary matrix U=(uij) together with a quantum state
and that produces as output an N-by-N stochastic matrix S=(sij). (Recall that a stochastic matrix is just a nonnegative matrix where every column sums to 1.) Given as input the probability vector obtained from measuring |ψ⟩ in the standard basis, this S should produce as output the probability vector obtained from measuring U|ψ⟩ in the standard basis. In other words, if
then we must have
This is what it means for a hidden-variable theory to reproduce the predictions of quantum mechanics: it means that, whatever story we want to tell about correlations between boat positions at different times, certainly the marginal distribution over boat positions at any individual time had better be the usual quantum-mechanical one.
OK, obvious question: given a unitary matrix U and a state |ψ⟩, does a stochastic matrix satisfying the above condition necessarily exist?
Sure it does! For we can always take the product transformation
which just "picks the boat up and puts it back down at random," completely destroying any correlation between the initial and final positions.
No-Go Theorems Galore
So the question is not whether we can find a stochastic transformation S(|ψ⟩,U) that maps the initial distribution to the final one. Certainly we can! Rather, the question is whether we can find a stochastic transformation satisfying "nice" properties. But which "nice" properties might we want? I'm now going to suggest four possibilities -- and then show that, alas, not one of them can be satisfied. The point of going through this exercise is that, along the way, we're going to learn an enormous amount about how quantum mechanics differs from classical probability theory. In particular, we'll learn about Bell's Theorem, the Kochen-Specker Theorem, and two other no-go theorems that as far as I know don't have names.
1. Independence from the State
Alright, so recall the problem at hand: we're given a unitary matrix U and quantum state |ψ⟩, and want to cook up a stochastic matrix S = S(|ψ⟩,U) that maps the distribution obtained by measuring |ψ⟩ to the distribution obtained by measuring U|ψ⟩.
The first property we might want is that S should depend only on the unitary U, and not on the state |ψ⟩. However, this is easily seen to be impossible. For if we let
then
implies
whereas
implies
Therefore S must be a function of U and |ψ⟩ together.
2. Invariance under Time-Slicings
The second property we might want in our hidden-variable theory is invariance under time-slicings. This means that, if we perform two unitary transformations U and V in succession, we should get the same result if we apply the hidden-variable theory to VU, as if we apply the theory to U and V separately and then multiply the results. (Loosely speaking, the map from unitary to stochastic matrices should be "homomorphic.") Formally, what we want is that
But again one can show that this is impossible -- except in the "trivial" case that S is the product transformation Sprod, which destroys all correlations between the initial and final times.
To see this, observe that for all unitaries W and states |ψ⟩, we can write W as a product W = VU, in such a way that U|ψ⟩ equals a fixed basis state (|1⟩, for example). Then applying U "erases" all the information about the hidden variable's initial value -- so that if we later apply V, then the hidden variable's final value must be uncorrelated with its initial value. But this means that S(|ψ⟩,VU) equals Sprod(|ψ⟩,VU).
3. Independence from the Basis
When I defined hidden-variable theories, some of you were probably wondering: why should we only care about measurement results in some particular basis, when we could've just as well picked any other basis? So for example, if we're going to say that a particle has a "true, actual" location even before anyone measures that location, then shouldn't we say the same thing about the particle's momentum, and its spin, and its energy, and all the other observable properties of the particle? What singles out location as being more "real" than all the other properties?
Well, these are excellent questions! Alas, it turns out that we can't assign definite values to all possible properties of a particle in any "consistent" way. In other words, not only can we not define transition probabilities for all the particle's properties, we can't even handle all the properties simultaneously at any individual time!
This is the remarkable (if mathematically trivial) conclusion of the Kochen-Specker Theorem, which was proved by Simon Kochen and Ernst Specker in 1967. Formally, the theorem says the following: suppose that for every orthonormal basis B in ℜ3, the universe wants to "precompute" what the outcome would be of making a measurement in that basis. In other words, the universe wants to pick one of the three vectors in B, designate that one as the "marked" vector, and return that vector later should anyone happen to measure in B. Naturally, the marked vectors ought to be "consistent" across different bases. That is, if two bases share a common vector, like so:
then the common vector should be the marked vector of one basis if and only if it's also the marked vector of the other.
Kochen and Specker prove that this is impossible. Indeed, they construct an explicit set of 117 bases (!) in ℜ3, such that marked vectors can't be chosen for those bases in any consistent way.
NerdNote: The constant 117 has since been improved to 31; see here for example. Apparently it's still an open problem whether that's optimal; the best lower bound I've seen mentioned is 18.
The upshot is that any hidden-variable theory will have to be what those in the business call contextual. That is, it will sometimes have to give you an answer that depends on which basis you measured in, with no pretense that the answer would've been the same had you measured in a different basis that also contained the same answer.
Exercise: Prove that the Kochen-Specker Theorem is false in 2 dimensions.
4. Relativistic Causality
The final property we might want from a hidden-variable theory is adherence to the "spirit" of Einstein's special relativity. For our purposes, I'll define that to consist of two things: a541596b147810eeda4435b23d5d9608
Now, you might've heard of a little thing called Bell's Inequality. As it turns out, Bell's Inequality doesn't quite rule out hidden-variable theories satisfying the two axioms above, but a slight strengthening of what Bell proved does the trick.
So what is Bell's Inequality? Well, if you look for an answer in almost any popular book or website, you'll find page after page about entangled photon sources, Stern-Gerlach apparatuses, etc., all of it helpfully illustrated with detailed experimental diagrams. This is necessary, of course, since if you took all the complications away, people might actually grasp the conceptual point!
However, since I'm not a member of the Physics Popularizers' Guild, I'm now going to break that profession's time-honored bylaws, and just tell you the conceptual point directly.
We've got two players, Alice and Bob, and they're playing the following game. Alice flips a fair coin; then, based on the result, she can either raise her hand or not. Bob flips another fair coin; then, based on the result, he can either raise his hand or not. What both players want is that exactly one of them should raise their hand, if and only if both coins landed heads. If that condition is satisfied then they win the game; if it isn't then they lose. (This is a cooperative rather than competitive game.)
Now here's the catch: Alice and Bob are both in sealed rooms (possibly even on different planets), and can't communicate with each other at all while the game is in progress.
The question that interests us is: what is the maximum probability with which Alice and Bob can win the game?
Well, certainly they can win 75% of the time. Why?
Right: they can both just decide never to raise their hands, regardless of how the coins land! In that case, the only way they'll lose is if both of the coins land heads.
Exercise: Prove that this is optimal. In other words, any strategy of Alice and Bob will win at most 75% of the time.
Now for the punchline: suppose that Alice and Bob share the entangled state
with Alice holding one half and Bob holding the other half. In that case, there exists a strategy by which they can win the game with probability
To be clear, having the state |Φ⟩ does not let Alice and Bob send messages to each other faster than the speed of light -- nothing does! What it lets them do is to win this particular game more than 75% of the time. Naïvely, we might have thought that would require Alice and Bob to "cheat" by sending each other messages, but that simply isn't true -- they can also cheat by using entanglement!
So that was Bell's Inequality.
But what does this dumb little game have to do with hidden variables? Well, suppose we tried to model Alice's and Bob's measurements of the state |Φ⟩ using two hidden variables: one on Alice's side and the other on Bob's side. And, in keeping with relativistic causality, suppose we demanded that nothing that happened to Alice's hidden variable could affect Bob's hidden variable or vice versa. In that case, we'd predict that Alice and Bob could win the game at most 75% of the time. But this prediction would be wrong!
It follows that, if we want it to agree with quantum mechanics, then any hidden-variable theory has to allow "instantaneous communication" between any two points in the universe. Once again, this doesn't mean that quantum mechanics itself allows instantaneous communication (it doesn't), or that we can exploit hidden variables to send messages faster than light (we can't). It only means that, if we choose to describe quantum mechanics using hidden variables, then our description will have to involve instantaneous communication.
Exercise: Generalize Bell's argument to show that there's no hidden-variable theory satisfying the locality and commutativity axioms as given above.
So what we've learned, from Alice and Bob's coin-flipping game, is that any attempt to describe quantum mechanics with hidden variables will necessarily lead to tension with relativity. Again, none of this has any experimental consequences, since it's perfectly possible for hidden-variable theories to violate the "spirit" of relativity while still obeying the "letter." Indeed, hidden-variable fans like to argue that all we're doing is unearthing the repressed marital tensions between relativity and quantum mechanics themselves!
Examples of Hidden-Variable Theories
I know what you're thinking: after the pummeling we just gave them, the outlook for hidden-variable theories looks pretty bleak. But here's the amazing thing: even in the teeth of four different no-go theorems, one can still construct interesting and mathematically nontrivial hidden-variable theories. I'd like to end this lecture by giving you three examples.
The Flow Theory
Remember the goal of hidden-variable theories: we start out with a unitary matrix U and a state |ψ⟩; from them we want to produce a stochastic matrix S that maps the initial distribution to the final distribution. Ideally, S should be derived from U in a "natural," "organic" way. So for example, if the (i,j) entry of U is zero, then the (i,j) entry of S should also be zero. Likewise, making a small change to U or |ψ⟩ should produce only a small change in S.
Now, it's not clear a priori that there even exists a hidden-variable theory satisfying the two requirements above. So what I want to do first is give you a simple, elegant theory that does satisfy those requirements.
The basic idea is to treat probability mass flowing through the multiverse just like oil flowing through pipes! We're going to imagine that initially, we have |αi|2 units of "oil" at each basis state |i⟩, while by the end, we want |βi|2 units of oil at each basis state |i⟩. Here αi and βi are the initial and final amplitudes of |i⟩ respectively. And we're also going to think of |uij|, the absolute value of the (i,j)th entry of the unitary matrix, as the capacity of an "oil pipe" leading from |i⟩ to |j⟩.
The network G(U,|ψ⟩)
Then the first question is this: for any U and |ψ⟩, can all 1 units of oil be routed from s to t in the above network G(U,|ψ⟩), without exceeding the capacity of any of the pipes?
I proved that the answer is yes. My proof uses a fundamental result from the 1960's called the Max-Flow/Min-Cut Theorem. Those of you who were/are computer science majors will vaguely remember this from your undergrad classes. For the rest of you, well, it's really worth seeing at least once in your life. (It's useful not only for the interpretation of quantum mechanics, but also for stuff like Internet routing!)
So what does the Max-Flow/Min-Cut Theorem say? Well, suppose we have a network of oil pipes like in the figure above, with a designated "source" called s, and a designated "sink" called t. Each pipe has a known "capacity", which is a nonnegative real number measuring how much oil can be sent through that pipe each second. Then the max flow is just the maximum amount of oil that can be sent from s to t every second, if we route the oil through the pipes in as clever a way as possible. Conversely, the min cut is the smallest real number C such that, by blowing up oil pipes whose total capacity is C, a terrorist could prevent any oil from being sent from s to t.
As an example, what's the max flow and min cut for the network below?
Right: they're both 3.
As a trivial observation, I claim that for any network, the max flow can never be greater than the min cut. Why?
Right: because by definition, the min cut is the total capacity of some "choke point" that all the oil has to pass through eventually! In other words, if blowing up pipes of total capacity C is enough to cut the flow from s to t down to zero, then putting those same pipes back in can't increase the flow to more than C.
Now, the Max-Flow/Min-Cut Theorem says that the converse is also true: for any network, the max flow and min cut are actually equal.
Exercise (for those who've never seen it): Prove the Max-Flow/Min-Cut Theorem.
Exercise (hard): By using the Max-Flow/Min-Cut Theorem, prove that for any unitary U and any state |ψ⟩, there exists a way to route all the probability mass from s to t in the network G(U,|ψ⟩) shown before.
So, we've now got our candidate hidden-variable theory! Namely: given U and |ψ⟩, first find a "canonical" way to route all the probability mass from s to t in the network G(U,|ψ⟩). Then define the stochastic matrix S by sij := pij/|αi|2, where pij is the amount of probability mass routed from |i⟩ to |j⟩. (For simplicity, I'll ignore what happens when αi=0.)
By construction, this S maps the vector of |αi|2's to the vector of |βi|2's. It also has the nice the property that for all i,j, if uij=0 then sij=0 as well. 4530c457a39491dd1534aa2aaed561ba
Exercise (harder): Prove that making a small change to U or |ψ⟩ produces only a small change in the matrix (pij) of transition probabilities.
The Schrödinger Theory
So that was one cute example of a hidden-variable theory. I now want to show you an example that I think is even cuter. When I started thinking about hidden-variable theories, this was actually the first idea I came up with. Later I found out that Schrödinger had the same idea in a nearly-forgotten 1931 paper.
Specifically, Schrödinger's idea was to define transition probabilities in quantum mechanics by solving a system of coupled nonlinear equations. The trouble is that Schrödinger couldn't prove that his system had a solution (let alone a unique one); that had to wait for the work of Masao Nagasawa in the 1980's. Luckily for me, I only cared about finite-dimensional quantum systems, where everything was much simpler, and where I could give a reasonably elementary proof that the equation system was solvable.
So what's the idea? Well, recall that given a unitary matrix U, we want to "convert" it somehow into a stochastic matrix S that maps the initial distribution to the final one. This is basically equivalent to asking for a matrix P of transition probabilities: that is, a nonnegative matrix whose ith column sums to |αi|2 and whose jth row sums to |βj|2. (This is just the requirement that the marginal probabilities should be the usual quantum-mechanical ones.)
Since we want to end up with a nonnegative matrix, a reasonable first step would be to replace every entry of U by its absolute value:
What next? Well, we want the ith column to sum to |αi|2. So let's continue doing the crudest thing imaginable, and for every 1≤i≤N, just normalize the ith column to sum to |αi|2!
Now, we also want the jth row to sum to |βj|2. How do we get that? Well, for every 1≤j≤N, we just normalize the jth row to sum to |βj|2.
Of course, after we normalize the rows, in general the ith column will no longer sum to |αi|2. But that's no problem: we'll just normalize the columns again! Then we'll re-normalize the rows (which were messed up by normalizing the columns), then we'll re-normalize the columns (which were messed up by normalizing the rows), and so on ad infinitum.
Exercise (hard): Prove that this iterative process converges for any U and |ψ⟩, and that the limit is a matrix P=(pij) of transition probabilities -- that is, a nonnegative matrix whose ith column sums to |αi|2 and whose jth row sums to |βj|2.
Open Problem (if you get this, let me know): Prove that making a small change to U or |ψ⟩ produces only a small change in the matrix P=(pij) of transition probabilities.
Bohmian Mechanics
Some of you might be wondering why I haven't mentioned the most famous hidden-variable theory of all: Bohmian mechanics. The answer is that, to discuss Bohmian mechanics, I'd have to bring in infinite-dimensional Hilbert spaces (blech!), particles with positions and momenta (double blech!), and other ideas that go against everything I stand for as a computer scientist.
Still, I should tell you a little about what Bohmian mechanics is and why it doesn't fit into my framework. In 1952, David Bohm proposed a deterministic hidden-variable theory: that is, a theory where not only do you get transition probabilities, but the probabilities are all either 0 or 1! The way he did this was by taking as his hidden variable the positions of particles in ℜ3. He then stipulated that the probability mass for where the particles are should "flow" with the wavefunction, so that a region of configuration space with probability ε always gets mapped to another region with probability ε.
With one particle in one spatial dimension, it's easy to write down the (unique) differential equation for particle position that satisfies Bohm's probability constraint. Bohm showed how to generalize the equation to any number of particles in any number of dimensions.
To illustrate, here's what the Bohmian particle trajectories look like in the famous double-slit experiment:
Again, the amazing thing about this theory is that it's deterministic: specify the "actual" positions of all the particles in the universe at any one time, and you've specified their "actual" positions at all earlier and later times. So if you like, you can imagine that at the moment of the Big Bang, God sprinkled particles across the universe according to the usual |ψ|2 distribution; but after that He smashed His dice, and let the particles evolve deterministically forever after. And that assumption will lead you to exactly the same experimental predictions as the usual picture of quantum mechanics, the one where God's throwing dice up the wazoo.
The catch, from my point of view, is that this sort of determinism can only work in an infinite-dimensional Hilbert space, like the space of particle positions. I've almost never seen this observation discussed in print, but I can explain it in a couple sentences.
Suppose we want a hidden-variable theory that's deterministic like Bohm's, but that works for quantum states in a finite number of dimensions. Then what happens if we apply a unitary transformation U that maps the state |0⟩ to
In this case, initially the hidden variable is |0⟩ with certainty; afterwards it's |0⟩ with probability 1/2 and |1⟩ with probability 1/2. In other words, applying U increases the entropy of the hidden variable from 0 to 1. So to decide which way the hidden variable goes, clearly Nature needs to flip a coin!
A Bohmian would say that the reason determinism broke down here is that our wavefunction was "degenerate": that is, it didn't satisfy the continuity and differentiability requirements that are needed for Bohm's differential equation. But in a finite-dimensional Hilbert space, every wavefunction will be degenerate in that sense! And that's why, if our universe is discrete at the Planck scale, then it can't also be deterministic in the Bohmian sense.
Obsidian Wings: Tom Friedman Has Gone Insane: Every so often, I wonder whether Tom Friedman isn't some sort of peculiar performance artist, trying to show up the utter vacuity of the pundit class by demonstrating that someone can be respected as a Very Serious Person whose views on foreign policy are Very Much Worth Listening To, while nonetheless being completely and utterly insane. Today is one of those days:
I have no idea who is going to win the Democratic presidential nomination, but lately I’ve been wondering whether, if it is Barack Obama, he might want to consider keeping Dick Cheney on as his vice president.
Let's just stop for a moment and let that sink in, shall we? Dick Cheney is quite possibly the most disastrous Vice President in the history of the republic, and Tom Friedman thinks we should keep him on. Maybe next week we can expect him to recommend that the Democratic nominee make the disinterred corpse of Richard Nixon Attorney General, or Typhoid Mary the head of the Centers for Disease Control, or Pol Pot the Secretary of Housing and Urban Development.
So why, you ask, would Tom Friedman make such a bizarre suggestion? Is there some hitherto unappreciated corner of policy in which Cheney has actually managed to do some good? No:
After Iraq and Pakistan, the most vexing foreign policy issue that will face the next president will be how to handle Iran. There is a cold war in the Middle East today between America and Iran, and until and unless it gets resolved, I see Iran using its proxies, its chess pieces — Hamas, Hezbollah, Syria and the Shiite militias in Iraq — to stymie America and its allies across the region. And that brings me back to the Obama-Cheney ticket: When it comes to how best to deal with Iran, each has half a policy — but if you actually put them together, they’d add up to an ideal U.S. strategy for Iran. Dare I say, they complete each other. (...)
Mr. Obama’s stress on engaging Iran, while a useful antidote to the Bush boycott policy, is not sufficient. Mr. Obama evinces little feel for generating the leverage you’d need to make such diplomacy work. When negotiating with murderous regimes like Iran’s or Syria’s, you want Tony Soprano by your side, not Big Bird. Mr. Obama’s gift for outreach would be so much more effective with a Dick Cheney standing over his right shoulder, quietly pounding a baseball bat into his palm."
Excuse me for a second: I have to reattach my jaw and put my eyeballs back in their sockets.
The Bush administration has had its foreign policy completely hamstrung, in a number of areas, by an ongoing feud between its hawks, Cheney chief among them, and its more moderate figures, like Colin Powell and Condoleeza Rice. As far as I can tell, our MBA President, rather than acting to settle this feud and keep his subordinates in line, just let it fester, with disastrous results. (Think North Korea.) In the case of Iran, in particular, this has been a catastrophe. Iran cooperated with us after 9/11, but when we named them a member of the Axis of Evil, and even more when people like, oh, Dick Cheney started making noises about Iran being the next country on our list of targets, that cooperation, quite naturally, vanished. Then:
Just after the lightning takeover of Baghdad by U.S. forces three years ago, an unusual two-page document spewed out of a fax machine at the Near East bureau of the State Department. It was a proposal from Iran for a broad dialogue with the United States, and the fax suggested everything was on the table -- including full cooperation on nuclear programs, acceptance of Israel and the termination of Iranian support for Palestinian militant groups.
But top Bush administration officials, convinced the Iranian government was on the verge of collapse, belittled the initiative. Instead, they formally complained to the Swiss ambassador who had sent the fax with a cover letter certifying it as a genuine proposal supported by key power centers in Iran, former administration officials said.
Last month, the Bush administration abruptly shifted policy and agreed to join talks previously led by European countries over Iran's nuclear program. But several former administration officials say the United States missed an opportunity in 2003 at a time when American strength seemed at its height -- and Iran did not have a functioning nuclear program or a gusher of oil revenue from soaring energy demand."
And who was one of the main people responsible for torpedoing those negotiations? Dick "We don't negotiate with tyrants, we defeat them" Cheney, that's who. He has tried to block every diplomatic initiative we might have taken, just as he did with North Korea. He and the rest of the hawks in the White House are responsible for the fact that we now find ourselves confronted with an Iran seeking nuclear weapons, and virtually no leverage to use against them.
This is the guy Tom Friedman thinks Barack Obama needs on his team, to help him negotiate with Iran. And Tom Friedman is a person we're supposed to take seriously.
a href="http://matthewyglesias.theatlantic.com/archives/2007/11/originsofthesouthernstrate.php">Matthew Yglesias: Origins of the Southern Strategy: Under Franklin Roosevelt, the Democratic Party assembled a political coalition so vast and diffuse that it included the "solid south" voting bloc of white supremacists, but also included most African-American voters, who were attracted to the New Deal's economic program and who were beginning to be incorporated into some Northern political machines. This, in turn, helped spur the growth of a civil rights bloc inside the Democratic Party that saw its first meaningful stirrings during Harry Truman's administration. When Dwight Eisenhower came along to try to rebuild the Republican coalition, the GOP both pursued a strategy of trying to take advantage of Southern disgruntlement to win outer south states, and a strategy of trying to win black voters back over to the GOP. This latter strategy had some success in 1956 (driven in party by Ike's endorsement by Adam Clayton Powell, Jr.) but by the 1960 Kennedy-Nixon race those gains had all been re-erased. David Nichols recounts the post-election assessment discussion between Eisenhower, Richard Nixon, RNC chair Thruston Morton, and a few other White House aides (A Matter of Justice, page 262):
Ike turned the discussion to civil rights. He observed that Attorney General Rogers was "somewhat to the left" of himself on civil rights. Nixon groused that a statement during the campaign by his vice-presidential running mate, Henry Cabot Lodge, Jr., about possibly putting a Negro in the cabinet "just killed us in the South." Eisenhower bitterly complained: "We have made civil rights a main part of our effort these past eight years but have lost Negro support instead of increasing it." Negroes, the president said, "just do not give a damn." Nixon remarked that black loyalty to the Democrats was "a bought vote, and it isn't bought by civil rights." Morton agreed with the vice president and said, "the hell with them."
Eisenhower was tempted to agree with Morton, but he pulled the conversation back to a more civil tone. He would not say "the hell with them," although he could not comprehend why his efforts were not more appreciated. No one, he said, was "more sincere" than he was in "bettering opportunities" for African-Americans. He recalled reading about economic reprisals against Negroes in Tennesee and said that such reports still "infuriated him."
After a couple of years of dawdling, the Kennedy administration eventually got behind a strong civil rights program -- stronger than anything Ike had ever embraced -- and LBJ was able to get it passed through congress. With that done, the correct direction of the cynical calculation shifted decisively in favor of the Nixon/Morton "to hell with them" point of view and the rest, as they say, is history.
Obsidian Wings: Choose Your Own Adventure: by Katherine
(Note: In response to commenters' requests (thanks, guys) I'm promoting this response to Patterico's hypothetical about torture, which I posted last night. I've edited for grammar, & in one case--the bit about Abu Ghraib & its relationship to the CIA torture program--for factual precision.)
No, the waterboarding session was not worth it.
The CIA officers charged with waterboarding KSM, lacking the knowledge that everything would turn out so swimmingly, would demand assurances from their boss that they could not go to jail for this. Their boss, & his boss, would ask the Justice Department to assure them that they would not go to jail. In order to tell them that they wouldn't go to jail, the Justice Department would have to write a memo falsely concluding that: (1) terrorism suspects were not protected by any portion of the Geneva Conventions, & the war crimes act did not apply; (2) waterboarding (& such other "enhanced interrogation technqiues" as the CIA would deem necessary) was not torture.
As a result of those memos, CIA agents would torture many other prisoners, and kill several of them, including some who were not high level members of Al Qaeda & whose torture & death did not save a single life. In order to justify what they had done & avoid liability, they would cover up the evidence of this. They would also make false and exaggerated claims about how the program was necessary, how many lives had been saved by torture.
The techniques--not waterboarding, so much, but many of the others--would spread to the military. In some cases, it would be because the Secretary of Defense thought it would be convenient not to have the Geneva Conventions apply to terror suspects in military custody, & to have authorization to use "enhanced interrogation technqiues" to abuse prisoners. After all, were America's brave soldiers lives less valuable than civilians? In other cases it would be because members of the military stationed with the CIA saw what CIA agents could do to prisoners: a guard at Abu Ghraib prison in Iraq, say, might come into work one night & notice that a CIA agent had tortured a prisoner to death & left his body paced in ice in the shower while higher ups fought about what to do with the evidence. The guard might unzip the body bag, take some pictures with corpse. It might not be the first time the guard had seen a CIA interrogator torture a prisoner. It might assure him that if the CIA could get away with killing a guy, surely he & his friends on the night shift could continue to have some fun with the prisoners, & continue to take some pictures.
Soldiers would torture many, many, many prisoners--in Afghanistan, in Guantananmo, in Iraq. Some of them would be tortured to death. Some of those tortured would be innocent.
The people tortured would make false confessions, which whether they were guilty or not would lead to them being detained for years without charge or trial. Their false confessions would lead to other arrests, and more torture, and more false confessions. Intelligence would be led down God knows how many blind alleys, resulting in the torture of God knows how many, the imprisonment of God knows how many more.
The results would be downright bizarre sometimes. We'd not only imprison & torture innocents--we'd imprison & torture guys we captured in a Taliban prison bearing scars from torture by high level al Qaeda members; one of whom Osama Bin Laden had personally accused of trying to assassinate him in 1998. We'd keep one of them in prison in Guantanamo for the better part of 5 years; another for 6 and counting despite the fact that he kept trying to kill himself.
The administration wouldn't be able to admit that this happened; it would have to classify as much as the evidence as it could, for as long as it could. It would have to keep the courts from examining the legality of these techniques, & push laws through Congress immunizing itself from prosecution, & ensure that the Justice Department remained in the hands of lawyers who would continue to falsely claim that everything had been legal; who would never investigate; who would never prosecute. Members of the President's party would have to support "enhanced interrogation" & pretend it wasn't torture; otherwise they would be admitting that a President in their party had participated in a conspiracy to commit war crimes.
But they wouldn't be able to keep it all secret; the world would find out. It would destroy our reputation, & make it impossible for us to credibly pressure other countries not to torture people or detain them indefinitely based on a bare allegation that they were terrorists or national security threats. It would help drive recruiting for Al Qaeda. It would help seal the failure of our invasion of Iraq.
I suppose you could add a bunch of other stipulations to your hypothetical to prevent these things from happening: these techniques would be practiced only against the highest level suspects, in a few prisons. They would be restricted to trained, professional, carefully selected CIA agents. It would only be used to prevent attacks when there was no other possible way to stop them. We would never torture innocents. We would never torture anyone to death. You could stipulate that, but it just makes the hypothetical even more of an irrelevant fantasy. In real life, this happened. In real life, it always happens when a country experiments with torture: it always spreads, it always leads to innocents being tortured, it never saves more lives than it destroys. In real life, a government who promises that this time it will be different is either lying, or kidding itself.
You should trust a government claiming it needs to torture exactly as much as you should trust a terrorist leader explaining why it needs kill just a few civilians (or a few dozen, or a few hundred), in order to save hundreds of thousands of Muslim children from death and slavery. I could make up a hypothetical where a suicide bombing prevented more evil than it inflicted & saved more people than it killed; would that show that opponents of terrorism just don't understand the moral complexity of it all?
A few other things:
(1) I think this is obvious but just in case: I am not responding to an unrealistic hypothetical with another unrealistic hypothetical. The scenario I lay out here is, as they say in the movies, "based on a true story"-- very closely based on a whole bunch of true stories. I realize that a lot of people aren't going to take my word for it & I need to support that with cites. I don't have time to do that now--I may later, either by revising this post or posting follow-ups.
Before I do, though: if I'm correct about these consequences, was it still worth it?
(2) What if there were no credible, reliable evidence that your hypothetical scenario had ever occurred, but that the facts I discuss above HAD occurred, as a result of the Bush administration's decision to grant the CIA authority to use "scientific" "advanced interrogation techniques" against high level Al Qaeda suspects?
(3) If people insist on basing debates about the ethics of torture on fictional scenarios rather than real ones, though, please discuss the following three hypotheticals (some of these are also taken from comments):
(a) Stipulate that in 2002, Dick Cheney's cardiologist was deeply opposed to the coming invasion of Iraq. Say that based on his conversations with his patient, he was convinced that (1) Cheney was trying to drag the country into war based on lies about Saddam Hussein's weapons program; (2) invading Iraq would lead to the violent deaths of thousands of American soldiers & hundreds of thousands of innocent Iraqi civilians; (3) these deaths would make the United States less safe from terrorist attack, not more so; (4) if Cheney were out of the picture, Colin Powell would be able to talk the President out of this disastrous course, & the intelligence agencies would be able to present accurate information, & the invasion would not occur; (5) he can prevent all this by deliberately sabotaging a heart procedure on Cheney & making it look like an accident; (6) murdering Cheney in this fashion is the ONLY way to prevent the war.
Say the cardiologist is 100% right about all of this. Is he justified in murdering Cheney?
If yes, does this scenario call into doubt whether there's a moral basis for a blanket ban on: (1) murder in general; (2) political assassination in particular; (3) doctors deliberately harming their patients? Is criticism of advocates of murder, assassination & violations of the Hippocratic oath sanctimonious, self righteous hypocrisy against people who just refuse to toe an ideological line?
(b) Stipulate that there is a ring forged in the fires of Mount Doom in the land of Mordor that makes it bearer more powerful than anyone else in your world, which is called Middle Earth. A dark lord named Sauron is trying to take over Middle Earth. Your fair city, Gondor, is his first target. Sauron is preparing to unleash his armies against you. Your people and your city are doomed to horrible, gruesome painful deaths, and the only hope of stopping it is bringing the One Ring to Gondor. However, for reasons passing understanding, a council of elves & wizards has decided that instead of using the ring to send two hobbits on an utterly hopeless quest to destroy it. (Easy for them to say--they're immortal & they can always sail off to wherever). Stealing the ring from the wee hobbitses, and bringing it to your father to protect Gondor, is the only way to the White City, your people, & your world from certain doom. DOOM! What do you do?
(c) The year is 1984. You live in a place that used to be called England & is now called Oceania, a country ruled by a brutal, evil, totalitarian, one-Party government, which has eradicated its citizens' liberty far more thoroughly than Josef Stalin's USSR.You meet a man named O'Brien, a leader of a clandestine liberation movement called The Brotherhood. The Brotherhood is the only organized resistance to The Party in existence. O'Brien asks whether you are willing to do the following to support The Brotherhood:
You believe that joining this organization is the only possible hope of opposing the party, & that you can only join if you answer "yes" the whole list. How should you respond to O'Brien's questions?
Obsidian Wings: On Torture Hypotheticals--Conservative Perspective: I've written on the topic before, but a recent post by Patterico convinced me to revisit it.... My answer to his hypothetical is 'yes, it would have been worth it'. I know that isn't everyone's answer, and it will probably cause me lots of grief here, but that is mine. In extreme situations, where you know that the person knows the information, and you need an immediate answer, IF it were effective, I wouldn't shed too many tears over 3 minutes of waterboarding.... That is my answer to the literal hypothetical. I think torture is wrong, but on a scale of wrongs--in that situation--I'd get over it.
My answer to what I think lies behind the hypothetical is rather different. The hypothetical has nothing to do with the discussion of whether or not we (the United States) ought to be torturing people. One of the key things that conservatives ought to remember (and which we notice all the time in liberal proposals) is that INTENTIONS DO NOT EQUAL OUTCOMES. The government is horribly incompetent at all sorts of things and we ought not abandon that insight when analyzing proposals of people who allege that they are our allies (the idea that Bush is a conservative ally is something I'd like to argue about on another day--but my short answer is that he isn't).
As with limitations on free speech, I don't trust the government to be able to fairly and nimbly navigate the rules that would be necessary to make certain that it only used a legal right to torture when it was the right choice. Sadly this is no longer a hypothetical question. In actual practice, we find that Bush's administration has tortured men who not only didn't know anything about what they were being tortured about, but weren't even affiliated with Al Qaeda.
Let me say that again. Bush's administration has tortured men who were factually innocent.
Not men who got off on technicalities. Factually Innocent.
Your hypothetical demands that the government be CERTAIN of the following things:
This man is who we think he is.
This man knows what we think he knows.
No non-torture technique will work.
Patterico, you work with the government. You know for a fact that it gets things wrong all the time. Even when we go through the huge and complicated process of a trial, it gets things wrong. And we aren't talking anything like a trial here. In reality, we are talking about torturing suspects. That is not a power to be given to the government.
Your hypothetical doesn't speak to the question of what the policy of our government ought to be, because no important part of the hypothetical actually has anything to do with the empirical reality of governmental torture. You pride yourself at not being distracted by stated intentions which have bad consequences in areas like rent control, housing policy, and education policy. Don't let Bush wave the national security flag and make you forget everything you know about how the government actually operates.
Matthew Yglesias: Good Work: Good Work Ryan Avent points to a great New York Times article [by Matthew Wald] that does what newspaper stories so rarely do: really break down and explain an issue:
Carbon dioxide is what economists call an “externality,” something that imposes a cost on somebody other than the manufacturer. At some point, the thinking goes, Congress will force industries to pay those costs, either with a tax or a cap-and-trade system in which allowances will cost money. The consensus in the energy business is that lawmakers will come up with a charge that could start at $10 per metric ton or more.
[...]
At $10 per metric ton, the impact is minimal. But at $50 a ton, for example, the cost of a kilowatt-hour produced by coal goes from about 5.7 cents to about 10 cents. Wind power currently isn’t competitive, according to the institute’s calculation, but it becomes competitive when carbon dioxide costs $25 a ton. [...]
At $20 or $30 a ton, the 1.9 pounds of carbon dioxide emitted in producing that kilowatt-hour costs 2 to 3 cents. That cuts into coal’s price advantage and — when coupled with progress in reducing the cost of solar power through manufacturing and economies of scale — gives solar power “a much larger chance to be relevant,” Mr. Gay said. Solar thermal systems, which use mirrors to concentrate sunlight to boil water, might benefit even sooner.
The trick, it turns out, is that the story ran in the Times's business section where they're trying to make sure an audience of interested parties gets the information they need. Were this to run as a "Washington" or "politics" story in the news section, it'd be all full of dueling quotes from political hacks, obfuscation, horse-race stuff, and pretty much anything other than an explanation of the impact of carbon pricing
Ezra Klein: (i didn't) TOLD YOU SO!: First, as Matt points out, it's demonstrably untrue that Paul Berman was advocating against "Bush's" war in Iraq. But attempts to rewrite history aside, I'm pretty impressed that he would simply write, " it is a matter of satisfaction to me that, in the years since then, I have not made a career of saying 'I told you so.'" That sentence is sort of the braggart's version of, "this sentence is a lie"...
Matthew Yglesias: Did Paul Berman Tell Us So?: In the midst of an argument with Ian Buruma, liberal hawk extraordinaire Paul Berman tries to convince us that he actually called Iraq correctly, and has merely been magnanimous in not pointing that out:
I approved on principle the overthrow of Saddam. I never did approve of Bush's way of going about it. In the run-up to the war, I became, on practical grounds, ever more fearful that, in his blindness to liberal principles, Bush was leading us over a cliff. [...] It is true and it is a matter of satisfaction to me that, in the years since then, I have not made a career of saying "I told you so."
Here's what Berman was actually writing in February 2003:
In my own judgment, Fischer and his fellow thinkers in Europe and even in the United States are making a mistake in failing to press for a harder line against Iraq—a harder line that might bring about Saddam's collapse more or less peacefully or, if need be, not peacefully. It should be obvious that, in the Arab world, fascist and Nazi-like movements-—political tendencies that call for random mass murder in the name of paranoid and apocalyptic ideas-—have gotten completely out of hand. In the last 20 years, Baathist and Islamist movements—-the two branches of what ought to be regarded as Muslim fascism—-have killed millions of people and might well kill many more, and not just in the Muslim countries, as we have reason to know. A war against Muslim fascism ought to be seen as a continuation of the long struggle against Nazism and fascism in Europe—-a continuation of the same decent and necessary cause that people like Fischer have always wanted to support, even if they have not always known how to do so in a sensible way.
He was worried about Bush's failure to embrace liberalism, but it wasn't a worry that this meant the war would go badly, it was a worry that Bush wasn't being as rhetorically persuasive as he should have been:
Maybe Fischer is not convinced because the Bush administration has presented a series of side arguments about weapons, U.N. resolutions, and dark terrorist conspiracies and has failed to present the main argument, which is the single huge argument that has always sustained the Western alliance. This argument is the one about totalitarianism. It is the argument that says: The totalitarians are dangerous to themselves and to us, and we had better fight them. Fight wisely, of course, which the New Left notoriously managed not to do long ago, but fight. Why can't Bush make that argument? I won't speculate. But he could change. He gave up drinking long ago. Let him give up his arrogance, small-mindedness, and aversion to large and idealistic ideas today. It might help.
And here he was in January 2004 when many people still thought the war was going well:
What was the reason for the war in Iraq? Sept. 11 was the reason. At least to my mind it was. Sept. 11 showed that totalitarianism in its modern Muslim version was not going to stop at slaughtering millions of Muslims, and hundreds of Israelis, and attacking the Indian government, and blowing up American embassies. The totalitarian manias were rising, and the United States itself was now in danger. A lot of people wanted to respond, as any mayor would do, by rounding up a single Bad Guy, Osama.
But Sept. 11 did not come from a single Bad Guy—-it was a product of the larger totalitarian wave, and the only proper response was to comprehend the size and depth of that larger wave, and find ways to begin rolling it back, militarily and otherwise—-mostly otherwise. To roll it back for our own sake, and everyone else's sake, Muslims' especially. Iraq, with its somewhat antique variation of the Muslim totalitarian idea, was merely a place to begin, after Afghanistan, with its more modern variation.
In short, Berman was wrong. The reason he hasn't made a career of telling us "I told you so" is that, in this instance at least, he didn't tell us so. But now he's trying to tell us that he did tell us so. But all he told us was that had Bush employed more Berman-style rhetoric then maybe more of Berman's friends would, like Berman, have wrongly deciding that an invasion of Iraq was a good idea.
The AMT Debate: Infuriating | Capital Gains and Games: My column on nationaljournal.com this week explains why the debate is proving to be so difficult in spite of the fact that Congress is talking about providing a tax cut. There are two basic problems. The first is that the Republicans are complete schizophrenic on the issue. The White House is insisting that an offsetting revenue increase is not needed to pay for the $50 billion to $60 billion in lost revenues that would result, and congressional Republicans are insisting that the pay-as-you-go rules the Democrats committed to following which require an offset be followed. The second problem is that the Democrats so far are trying to please everyone by doing both. The column produced an almost immediate response from one reader. In fact, in the more than 10 years I've been writing Budget Battles, this was the fastest reply I've ever received. Here's the key part:
I think you miss the White House's most glaring inconsistencies on the AMT. First, Bush's budget for every year since he took office assumed that he AMT will provide a gusher of revenues over the next decade. This made he administration's deficit forecasts look smaller. If they really believed the AMT should never be collected, the budgets should have assumed the revenue wouldn't be there -- just as his budgets assumed that the Bush tax cuts would be made permanent rather than expire at the end of 2010.
Second, and even more inconsistent: Back in 2004, the president and reasury Secretary John Snow vowed to come up with a real solution to the AMT -- a permanent repeal in the context of a top-to-bottom reform. What's important is that the president explicitly instructed his ax reform panel to come up with tax-overhaul proposals that would be REVENUE-NEUTRAL. In other words: eliminate the AMT, but make up for the lost revenue elsewhere. That's EXACTLY what the Democrats are trying to do. As it happened, the tax reform panel came up with two proposals, both of which would have eliminated the AMT and made up for the lost revenue elsewhere. The Treasury Department promised to respond with its own proposals, as the president had ordered. But that never happened. The administration quietly buried the whole effort, because it was too hard and the president was juggling too many other problems.
Maybe it's not their fault -- tax reform is brutally difficult, no question. But for Bush to clobber Democrats for "increasing taxes,'' when Bush had been demanding exactly the same thing of his own tax-reform panel, is at the very least misleading.
Comment is free: Cancer myth: "I had prostate cancer five, six years ago," begins Rudy Giuliani's new radio ad. "My chance of surviving prostate cancer, and thank God I was cured of it, in the United States? Eighty-two percent. My chance of surviving prostate