Monday, November 29, 2010

Not Impressed With Obama

Is Paul Krugman impressed with Obama's freezing of federal worker's salaries? I'm going to say not favorably:

Yep, that’s exactly what we needed: a transparently cynical policy gesture, trivial in scale but misguided in direction, and in effect conceding that your bitter political opponents have the right idea..

It could be that Obama is just very conservative economically, heavily influenced by the Chicago School at which he taught.

I tend to think though, that this battle is not one he wanted to fight anyway, so acting first might not have been a terrible idea, but Krugman's point that Obama is doing nothing to construct a credible narrative for intervention in the economy seems indisputable.

Sunday, November 28, 2010

The Slaves of Defunct Eonomists

I really like this essay by Delong: The Four Horsemen of the Teapocalypse, and the associated comments. From the comments, this quote from Warren Buffett:

“There’s class warfare, all right,” Mr. Buffett said, “but it’s my class, the rich class, that’s making war, and we’re winning.”

Shorter Harry Potter and the GoF

In retrospect, it was not such a hot idea for a few dozen Death Eaters and their wanna bees to get snockered on fire whisky and stage a major riot at the Quiddich World Cup. Right in the middle of several thousand heavily armed fellow wizards. Hit simultaneously with hundreds of stunning spells, a number were killed instantly, but enough survived to reveal the identities of the ring-leaders.

It wasn't an auspicious start to the big V's comeback plans, but nonetheless his agent managed to penetrate the ludicrous security effort mounted by Hogwarts School's nearly senile headmaster. When the Goblet turned out to have been hexed, though, even Dumbledore's slow suspicions were awakened, and a casual seeming conversation with the Defense-against-the-dark-arts teacher revealed his rather imperfect memory of his many decades of interaction with the headmaster. Veratiserum and legilimency quickly got to the bottom of the plot and He who must not be named got a rather unpleasant surprise when he showed up at his father's graveyard. Hit simultaneously by the dozens of Aurors and members of the Order of the Phoenix he was blasted again out of corporeal existence. For good measure, the grave of his father was exhumed and all the bones utterly destroyed - to prevent a reprise of that particular reincarnation trick.

The remaining Death Eaters were next summoned, using Barty Crouch junior's arm charm, arrested, and sent off to the slammer. The aurors and unspeakables of the Ministry of Magic were ordered to get off their butts and find some Horcruxes. They mostly proved rather easy to locate and identify.

Saturday, November 27, 2010

Banners of the Tribe: Social Studies

Brad DeLong has a long, interesting post on the recent semi-centennial celebration of the Harvard Social Studies program: The Social Studies Major 50th Anniversary Celebration Party and Bitter Internal Ideological Power Struggle There are many highlights and low, but here is one that caught my eye (from a Luncheon talk):

I will give you an answer, by telling you another story, this time from my years teaching at Columbia. In 1968, as some of you will recall, the students occupied several buildings and brought the university to a screeching halt for two weeks. The next semester, I was teaching a course in which I was anguishing over my inability to find, in the text of Kant's GROUNDWORK OF THE METAPHYICS OF MORALS, an absolutely valid a priori proof of the universal validity of the fundamental moral principle, the categorical Imperative. After class one day, one of the students came up to talk to me. He was one of the SDS students who had seized the buildings, and I knew that he was active off campus in union organizing. 'Why are you so concerned about finding that argument?' he asked. Well, I said, if I cannot find such an argument, how will I know what to do? He looked at me as one looks at a very young child, and replied, 'First you have to decide which side you are on. Then you will be able to figure out what you ought to do.'

At the time, I thought this was a big cop-out, but as the years have passed, I have realized the wisdom in what he said.

What they are saying, whether they realize it or not, is that once you swear allegiance to the banners of the tribe - any tribe - you no longer have to think. Somebody or something else will make all the decisions for you.

I will pass.

Europe: Banking Toward Disaster?

This is the way the World ends,
not with a whim
but a banker .......................The Vast Waistband (or something).

The rumblings from the Euro zone grow louder [Worse than a crime]. The story is familiar. Banks borrowed a lot of money from each other, from ordinary rich people, and others, and lent it out to a bunch of yet others (including again each other) who can't afford to pay.

Because banks and bankers have a lot of (other people's) money they find it easy to make friends with politicians. This kind of warm personal friendship tends to pay off when the proverbial s*** hits the fan, as politicians discover an urgent economic necessity to save bankers asse[t]s. Thus, in Ireland, the government decided to put the whole nation on the hook for the unwise investment choices of Irish banks. The problem is that Ireland has the total population of a medium large American city and no particular national resources or other wealth, so they really can't afford that. Diverting such a large part of the national income sucks the economy dry, destroying jobs, income, and future prospects for growth.

Big Europe has extended Ireland a bailout of sorts, but it's a kind of limited, modified bailout - it just loans money to Ireland at lower rates than they could get on private markets. Of course the reason the private markets won't lend Ireland money at low rates is because they have a well founded fear that Ireland won't be able to pay ...

Ireland's problem has become Europe's because (a) there are a bunch of other countries in similar fixes, (b) Ireland and the others owe money to the richer European countries, and (c) although Germany is better off than almost any other Euro zone country, its own banks are weak, are owed a lot of money by the weak countries, and might just collapse too.

A lot of Europe's problems stem from the adoption of the Euro as a currency without adoption of the kind of unified governmental structures needed to support it. These problems were predictable and were predicted by the usual Cassandras (yes, including Krugman).

Friday, November 26, 2010

Don't Miss: Special Relativity, Simply Explained.

Abstruse Goose via Sean Carroll.

Die-No-Might

So a scruffy looking guy walks into the diner, opens up his red and black plaid jacket, and reveals several sticks of dynamite strapped to his chest. He holds up his hand to show the spring loaded detonator, walks over to the counter, picks up the salt shaker and throws it, hitting the waiter.

"Give me a cup of coffee," he says, "and one of those cinnamon thingies."

It seems like a small price to pay, so the staff accomodates him. Unfortunately, he moves into a booth and starts tinkering to build a more powerful bomb - a nuke - while continuing to be obnoxious and extorting free food.

Such is the situation South Korea finds itself in. At the moment, the crazy guy's capability is pretty much limited to blowing up Korea, but he has his sights on the world, and Japan, at least, is very much at risk.

If the South, and the world, fail to respond, the bad behavior will continue and likely escalate, if world history is any guide, and any response risks catastrophe. At the moment, the South Korean response has been very vague. Would it be better for the West if a precise table of responses were published? If you get into that game, you had better be prepared to escalate, and fast.

I suspect that the leadership of North Korea values its nukes and missiles above its people, so if you get into the escalation game they need to be high on the list of targets.

Wednesday, November 24, 2010

Maxwell's Demon

You should call it entropy, for two reasons. In the first place, your uncertainty function has been used in statistical mechanics under that name, so it already has a name. In the second place, and more important, no one knows what entropy really is, so in a debate you will always have the advantage .....................

John von Neumann to Claude Shannon, as quoted by Sean Carroll in From Eternity to Here.


Luboš is busily increasing the entropy of the blogosphere, and his target again is Sean Carroll. At the center of the dispute is Maxwell's Demon. Maxwell cooked the little guy up to test some ideas of statistical mechanics. Imagine a box containing a gas of molecules, with a small hole leading to an empty box and a little guy standing at the hole with a little door he can shut. His job is to open the door when he sees an especially fast molecule coming along and close it for the slow molecules (the other way around would work similarly).

Sean's (imaginary) crime was to (truthfully) claim that information could be used to extract energy from a similar system. Luboš managed to convince himself that this was (a) violating the second law of thermodynamics and (b) claiming that information and energy are the same thing. I don't think that either of these is remotely close to what Sean was saying, and that Luboš has once again allowed his prejudices to overcome his rationality.

That said, Lumo's post is very interesting in it's own regard, mainly for its links to some other interesting papers, but I will send you to him for them.

Back to Maxwell's demon. Can he really do that? Work some kind of little door to cool one box while warming the other? Sure he can. He is doing the work of a kind of refrigerator. Lumo the particle physicist is doubtless familiar with the concept of stochastic cooling used in large partice accelerators. It's a sort of Maxwell's Demon used to cool bunches of particles circulating in the storage rings.

So does this violate the second law? Duh, no. Like any other refrigerator, Maxwell's demon extracts entropy from one part of the universe but dumps it and more into some other part. The system Sean describes, Maxwell's Demon, and the stochastic cooling mechanism all make use of information about details of the system to selectively extract energy from a subsystem of the world.

Question for the student: How about ordinary refrigerators, like the ones in most of our kitchens? Is there any sense in which they do something similar? Use subsystem information to extract entropy, I mean.

Evil Genius

I was driving home listening to the overture to some Wagner opera, Tannhauser, I guess, and it occurred to me that nearly every science fiction story of the cruder type featured an evil scientist bent on taking over the world. How about evil artists? Are they common in reality or fiction? Wagner certainly fits the profile - a very bad man who wrote very good music.

Now I've met a few evil scientists, but none of them actually seemed bent on taking over the world. Mostly they seemed to be focussed on making associate professor or some similarly mundane ambition. Wagner, though, was the sort to be bent on world domination.

Tuesday, November 23, 2010

The Banners of the Tribe

Humans evolved living in small groups, and I suspect that a lot of our mental wiring is still optimized for this sort of thing. We live in groups, large and small, because that gives us an advantage over those who don’t have a group, and because we need the group for protection against other groups. Thus small groups of humans outcompeted solitary families, and once agriculture arrived, big groups outcompeted or exterminated most of the small groups. The invention of agriculture changed our way of living, but probably hasn’t had time to completely rewire us.

Small groups are typically bound together by ties of kinship, but beyond a critical size, that doesn’t really work. Thus large groups of humans (tribes, chiefdoms, nations) needed to invent other kinds of social glue, starting with identification as such a clan, tribes, and so on. The largest kind of grouping, the civilization, requires the strongest adhesive, and I suspect that religion evolved mainly to fulfill this role.

It’s pretty clear that the instinct to identify with a “tribe” is pretty well developed in the human race. High school, at least high school American style, is a good place to observe the phenomenon. Nearly every kid feels some pressure to identify with a group. If you can’t get into one of the prestige groups (jocks, popular kids, rich kids) you pick another one (brains, geeks, Goths, freaks, dopers, thugs, etc.)

Adults have more choices, but the same trends are there: occupation, economic status, neighborhood, religion, political party, sports team, musical preference, etc. I will loosely group all these together as “tribes.” Our affiliations are a big part of our identity, and we are programmed to defend them vigorously. We signal our affiliations by displaying and defending the banners of our tribe. This sort of instinct to defend is atavistic, but not purely so. Around the world Christians continue to slaughter Muslims, Hindus to slaughter Muslims, Muslims to slaughter Christians, Jews, Hindus and Other Muslims, etc. , all in the name of religion – not that the victims are any less dead when slaughtered in the name of more modern sounding causes.

This reality is the reason why I think that the fanatical atheists like Hitchens, the two Seans Carroll, and Dawkins – all writers I otherwise admire – are nuts when they think they can win some sort of crusade against religion by disrespecting its symbols – its tribal banners, if you will. Every ghetto kid understands that if you disrespect the gang – its members, its graffiti, its banners – you threaten it and every member. Disrespecting the banners of the tribe is easily construed as an act of war, especially when there are a whole bunch of wars already going on, and your tribe is the target of many.

Monday, November 22, 2010

Mac(ro) Daddies

Macro economics is a historical science like geology, paleontology, or astronomy, but without their solid underpinnings in the deep theory and rich experimental history of physics, chemistry and biology. So it behooves the economic Mac Daddy to try to extract whatever historical lessons there may be from the ongoing experience of the world. Ireland ought to be a nice object lesson in something or another. A few short years ago it was the latest poster child for free market radicalism: no business taxes, minimal capital regulations, and a booming economy. Now that it's the latest Euro basket case, what lessons can be drawn therefrom? Tyler Cowen (no social democrat he) has some candidates:

1. The Irish had some excellent economic policies, but they needed to regulate their banks more. They were simply too optimistic and too sloppy.

2. Irish troubles could have been contained, at some point over the last two years, had Ireland not been on the euro. They would have devalued, defaulted, and had a rapid bounce back up, within the next three years.

3. Ireland never should have guaranteed the liabilities of its banking sector. Indeed, Ireland (as New Zealand did long ago) should have encouraged larger, more diversified foreign banks to dominate its financial sector.

4. Irish troubles are intimately connected with low corporate tax rates. Revenue starvation induced the Irish government to court and tolerate a real estate bubble. One claim is that Ireland relied too much on property taxes.

5. The good and bad policies are a bundle of sorts, and Ireland needed the mix to rise from squalor and the dominance of anti-commercial interest groups, no matter how painful the present day may seem. I recall vividly, growing up, that Ireland was thought of as not much more than a Third World country.

6. We are overreacting to the Irish failure. It is one of the first European dominoes to fall, but over time many different policy models will look like mistakes.

The rest and the comments are well worth a look.

Sunday, November 21, 2010

Know How: Ball Bearings

One of my favorite science fiction books when I was a kid was Jules Verne’s The Mysterious Island. It’s been a few decades, but I seem to recall a party of intrepid adventurers being stranded on a volcanic island, where they managed to reconstruct modern (1860) technology more or less from scratch. There are a few reasons why this wouldn’t work, starting with the fact that volcanic islands don’t have iron ore, but the problem is still interesting. The modern world is utterly dependent on thousands or millions of technological devices, so I thought I might start finding out how a few of them were made.

One pretty important invention that we probably don’t think much about is the roller bearing, but it plays a critical role in all sorts of machinery. Marble players and others have long admired the shiny and seemingly perfect spherical roller bearing. So how do you make one?

If you have played with wax or clay, you probably have a clue. If you roll that piece of wax between your palms back and forth, it assumes a cylindrical shape, and if you throw in some crosswise motion, it will become roughly spherical. It’s pretty obvious what’s going on: the pressure of your hand pushes down the bumps and tends to fill in the holes.

How stuff works has an excellent description of how ball bearings are made, but it leaves out explanation of one key detail. After rough shaping:

Next the balls go into a machine that removes the flash. This machine rolls the ball between two very heavy hardened steel plates called rill plates.

[See link for pictures of the rill plates and machine]

One rill plate is stationary and the other one spins. The plates have grooves machined into them that guide the balls around in a circular path. You can see that one of the plates has a section cut out of it; this is where the balls enter and exit the grooves. When the machine is running, the grooves are completely filled with balls. Once a ball has traveled through a groove, it falls into the open section in the plate and tumbles around for a little while before entering a different groove. By making sure the balls travel through many different grooves, all the balls will come out of the machine the same size even if there are differences between the grooves.
As the ball travels through the groove, it spins and tumbles, the rough edges get broken off, and the ball gets squeezed into a spherical shape, a little like rolling a ball of dough between your hands. This squeezing of the balls compresses the metal, giving the balls a very hard surface. Because the balls are metal, this operation generates a lot of heat, so water pours over the balls and plates to cool them.

Why spirals, we might ask? This detail is crucial. On the spiral path, the inside contact point of the ball rolls along a shorter path than that on the outside. Consequently, it is continually slipping and changing its rotational axis as it rolls and the lines of contact wander over the whole ball rather than tracing out a circle. Thus the smoothing action affects the entire surface of the sphere. Fine grinding and polishing phases use the same sort of rill plate plus some grinding and polishing compounds.

HP & The Deathly Hallows, Pt I

OK, so I will buy this movie when it comes out. I will probably get a BluRay player so that I can see it in detail. I might even go see it in the theater again. But I'm not happy.

Yes I know that DH is the darkest of the books and the darkest of the stories. It's nice that the kids grew up to be good looking and able to act. It's nice that Britain has lots of improbably good-looking and wild scenery.

I just didn't expect the movie to be so damn flat. One of Rowling's strengths as a story teller is that she knows how to modulate the mood. Director David Yates - not so much. This was a one-tone symphony. The trouble with unrelieved gloom is that it starts to look just boring.

As usual, most of the professional reviews that I've read take exactly the opposite view - they mostly love the movie, the cinematography, and the music. There was music?

My family disagrees too. The professionals don't like the first two movies - my very favorites - so clearly my point of view is hardly likely to be everyone's. It's inevitable that a lot of stuff gets left out when you make a movie - or even two movies - out of a very long book. My complaint is that what got left out diminishes the dramatic tension by failing to modulate it.

Part of my problem, I suspect, is that I know the story too well. In any case it's still a lot better than most movies that I see. Your mileage may vary.

Friday, November 19, 2010

Data: Current Expenditures

Look now at all current expenditures: FRED again




Note that while detrended federal expenditures do uptick sharply, the uptick is almost entirely matched by decreasing (detrended) State expenditures, and only brief and modest bumps above the long term trend appear in the combined data.

Government Spending

Someone, I think, claimed that there had been a "huge" government stimulus since 2008. Let's look at the numbers. Graphs are of government consumption and net investment. Red is total, green is State and local, and blue federal.






These don't include transfer payments which move money from one part of the private sector to another. Nor do they include 2010. From FRED, again.

Output Gap

One trouble with economic arguments is that sarcasm and tribal loyalties always come into play at which point logic goes out the window. So let me start with some data. Here is real US GDP from 2000 to present. (Saint Louis Fed Data).



Macroeconomists have elaborate models for computing the output gap, but a good approximation can be seen just by extrapolating the line from the (relatively slow growth) Bush years before the crash. Note that (a) the GDP was in free fall before TARP and the stimulus, and (b) resumed slow growth during and after. Just sayin'.

Thursday, November 18, 2010

Deep Matters

Wolfgang talks about deep matters concerning the incomprehensible comprehensibility of the world here. I recommend it, but I've got to respond to his included drive-by on Paul Krugman. He links to this author, who begins:

Paul seems to only have one card these days, but he does play it very, very well.

It's the "nothing is ever enough card" and he got it out again in Sunday's NY Times.

The way it works is this:

(A) Lobby for any and all expansionary policies.

(B) Then, when an expansionary policy get proposed or enacted, pitch a fit and say that it's way too small and will never work.

(C) When said policy doesn't work (which of course could well be because the policy is bogus) scream "I told you so" over and over at the top of your lungs.


Let me see if I understand the charge here: (a) Krugman was guilty of correctly predicting the severity of the crash when his freshwater critics were chorusing "don't worry, it's all right." (b) He also correctly predicted the size of the looming output gap and (c) correctly estimated how large a stimulus would be needed to close it, and (d) politicians ignored this and produced a half-size stimulus, which (e) only closed about 1/2 the output gap.

Clearly Krugman is the guilty one here. And in the country of the idiots, Cassandra and other prophets remain without honor. Oddly enough the right wingers did a lot of prophecy too, but they were all wrong, so that doesn't count.

Wednesday, November 17, 2010

Duellity

I think that our politics might be a good bit more civil if duelling hadn't been abolished. I can think of a few Faux News (and other) personalities who would be pushing up enough daisies for royal wedding.

Tuesday, November 16, 2010

Physics and Neoteny

Steven Jay Gould claimed that neoteny, or the preservation of juvenile characteristics in the adult, was a potent source of evolutionary change. I've often read that we humans developed our size extra-large brains to deal with the challenges of language and small group interpersonal relations - e.g., understanding and generating gossip. Plausible as that seems, in the early part of our lives we need to devote some brain power to understanding the behaviors of the other animate and inanimate contents of the world. In some cases, though, normal development is arrested, and the child may fail to outgrow that juvenile behavior even into adulthood, in which case they become what are called scientists, or, in severe cases, physicists.

It's a recalcitrant problem, and treatment options are few, invariably focussing on ameliatoration rather than cure. Remissions, frequently brief, often occur if the victim gets a girlfriend/boyfriend, or wife.

Traditional best practice recommends paliative care with books.

The Lost Weekend

I haven't posted for a while. Blame Belette who introduced me to Harry Potter and the Methods of Rationality.

At least he could have warned me that I would be left hanging (literally) in mid-air...

A sample:

The Professor turned and looked down at him, dismissive as usual. "Oh, come now, Harry. Really, magic? When you say that rationality is your favorite thing ever and read so much about it? I thought you'd know better than to take this seriously, son, even if you're only ten. Magic is just about the most unscientific thing there is!"

Harry's mouth twisted bitterly. He was treated well, probably better than most genetic fathers treated their own children. Harry had been sent to the best elementary schools - and when that didn't work out, he was provided with tutors from the endless labor pool of starving students. Always Harry had been encouraged to study whatever caught his attention, bought all the books that caught his fancy, sponsored in whatever math or science competitions he entered. He was given anything reasonable that he wanted, except, maybe, the slightest shred of respect. A tenured Professor who taught biochemistry at Oxford could hardly be expected to listen to the advice of a little boy. You would listen to Show Interest, of course; that's what a Good Parent would do, and so, if you conceived of yourself as a Good Parent, you would do it. But take a ten-year-old seriously? Hardly.

Sometimes Harry wanted to scream at his father.

"Mum," Harry said. "If you want to win this argument with Dad, look in chapter two of the first book of the Feynman Lectures on Physics. There's a quote there about how philosophers say a great deal about what science absolutely requires, and it is all wrong, because the only rule in science is that the final arbiter is observation - that you just have to look at the world and report what you see. Um... I can't think offhand of where to find something about how it's an ideal of science to settle things by experiment instead of violence or violent arguments -"

His mother looked down at him and smiled. "Thank you, Harry. But -" her head rose back up to stare at her husband. "I don't want to win an argument with your father. I want my husband to, to listen to his wife who loves him, and trust her just this once -"

Harry closed his eyes briefly. Hopeless. Both of his parents were just hopeless.

Friday, November 12, 2010

Probably Not

Captain James Kirk certainly was a silly sentimentalist. Imagine him keeping that old fraud Spock on the payroll despite repeated demonstrations of incompetence in his supposed expertise. Whenever a dangerous mission loomed, Spock could be depended on to pull one of his patented fake probability predictions out of his ... - usually something like a 99.99973% chance of failure. In one way I couldn't blame him - Kirk was a total klutz, always going off half-cocked and without a clue. Still, I couldn't resist my own predictions, namely that Spock was off by about 99.99973%. The poor dolt had no head for figures.

Of course this post is actually about Steve Landsburg - I think he might miss me - who has a series of posts on the question of what should constitute a "reasonable doubt" in a murder trial. There is a certain amount of amusement to be obtained by doing his arithmetic, but fundamentally he is just making Spock's mistake - assigning arbitrary numbers when there isn't any reasonable basis for doing so.

It’s been “reasonable doubt” week here at The Big Questions. We’ve talked about recognizing reasonable doubt when you see it, about what the standard should be, and about what the standard for determining the standard should be.

This raises the question: What is the standard? Here’s the weird part: Nobody knows. The judges won’t tell you and neither will the legislators. If you’re on a jury, you’re on your own.

He wants a percentage, dammit! Perhaps in one trial in a few hundred there might be a special case where a probability can be assigned to some piece of evidence - I'm thinking about the DNA match type evidence. Rest assured, though, that in such a case the lawyers will have made sure to exclude from the jury anybody who has (a)ever heard of DNA and (b) anybody who knows his times tables to 8.

So even if the mathematically competent could make it onto the jury, what are the chances that it would be reasonable to make numerical estimate of the probability of guilt? I will go with 0.3%, but I just made that up, just like Spock, and I would guess, Landsburg, if he were ever to get on a jury.

Come to think of it though, his post might actually be a cunning way to make sure that he never **does** get on a jury.

Thursday, November 11, 2010

Bargains

This headline caught my eye:

Lichtenstein Sells for $42.6M

Not bad, I thought, for a whole country, even if some of my neighbors do have bigger back yards.

Cutting I: Death Panels

One of the proposals of the deficit commission is to raise the social security retirement age, in response to changes in life expectancy. The problem is that life expectancy is lengthening mostly not because people are getting old more slowly but because we are getting better at keeping old people alive. A sixty-nine year old today is essentially just as affected by senile degeneration as his sixty-nine year old paleolithic ancestor - but he has fewer dire wolves to fight off.

It might make more sense, and be more humane, just to decrease the death age.

Words, Words, Words

‘When I use a word,’ Humpty Dumpty said, in a rather scornful tone, ‘it means just what I choose it to mean, neither more nor less.’

‘The question is,’ said Alice, ‘whether you can make words mean so many different things.’

‘The question is,’ said Humpty Dumpty, ‘which is to be master – that’s all


James is amused by the American media:

It does amuse me as an external observer to hear terms such as "socialist", "Marxist", "Maoist", "Nazi", "Fascist", etc bandied around in some areas of the US media, seemingly interchangeably and without any justification. Also, in the US it seems that "conservative" is good and "liberal" is evil? How is liberal defined?

To which I say, if you think it's so damn funny why don't you just take back Rupert f*****g Murdoch - whose minions are among the worst practitioners. I'm pretty sure, though, that this business of trying to tar your opponents with whatever word of bad reputation comes to hand is not an exclusively American rhetorical device. Witness, for example, our Czech friend, whose keen mind can't see any line between Krystallnacht and criticism of climate chicanery. An extreme case maybe, but I will guess that the big continent has its share of similarly spoken nut jobs.

Mr. Dumpty is spot on, though. It's really all about mastery or political power. One manipulates language to attempt to put one's rivals at a disadvantage. Of course the word "ludicrous" comes to mind in many cases, especially for extremes like Prof. M, but it does seem to work ... on some idiots anyway...

Wednesday, November 10, 2010

Physics of Quiddich

It seems that quiddich has become something of an intercollegiate sport, albeit in an attenuated form. (Or on the fight fiercely side, Harvard) Somehow, I don't think the sport is quite ready to get off the ground yet.

At least not without some mechanical muggle help. What's needed is a way to add some levity to the proceedings. Perhaps you've seen a Dyson fan. This very cool device appears to be just a sort of metallic ring that produces a rather laminar wind flow with no visible fan blades. I envision a gigantic version mounted horizontally, encased by a transparent wall surrounding the quiddich pitch. A person sitting on a broom is not very stable aerodynamically, so I think some winglets above the player would be needed for stability and to get vertical speeds to some reasonable rate. What would that rate be?

Non-magical flying requires that the flyer's weight be balanced by the transferring downward momentum to air at the rate, dp/dt = mg. At optimal angle of attack, weight, speed, and wing area are related approximately by S = 2.5 W/V^2, so at 10 m/s, a 500 N (50 kg) flyer needs a wing area of 12.5 meters, uncomfortably large. Tweaking various factors might reduce this a bit, but that still leaves the difficult problem of protecting the wings against other players. I suppose upflowing air at 10 m/s or so would be needed.

Tuesday, November 09, 2010

This Should Cheer Us Up

According to NPR, trade courts have found the US guilty of illegally subsidizing our cotton farmers. Brazilian cotton farmers sued over the violation of our trade agreements, and Brazil threatened retailiation against a wide array of important American exporters.

Cotton subsidies, it seems, were too sacred to be dropped, so the US compromised by paying off Brazilian cotton farmers to the tune of $147 million per year. So now US taxpayers subsidize the American and Brazilian cotton industries - whoopee. How long till everybody gets on this bandwagon.

More Religious Strife

How much religious strife is just the battle for control of land and resources?

Arundhati Roy on Kashmir:

A good example of how occupation and violent resistance interact.

Unclear on the Concept

Bee thinks that Americans are unclear on the concept of socialism. True Dat?

Dictionary.com says:

so·cial·ism   /ˈsoʊʃəˌlɪzəm
[soh-shuh-liz-uhm]
–noun
1. a theory or system of social organization that advocates the vesting of the ownership and control of the means of production and distribution, of capital, land, etc., in the community as a whole.


For reference.

Monday, November 08, 2010

School Day Anxiety

My high school class is having its (big Roman numeral) reunion next year and I decided to go, but now I'm having performance anxiety. It's not just that I've gotten old, fat, and uglier (though that's part of it). Worse is the fact that I'm reminded of all my deficiencies back when - all the stupid, dorky, uncool, or otherwise uncouth things that I did in my youth. It's possible, I thought for a minute, that everybody feels that way about high school, but I doubt it. How about the football captains and cheerleaders who ruled the HS world? They, I suspect, look back on halcyon days.

It's not like I had a good excuse. I participated in football, basketball, and track, albeit in undistinguished fashion, was only bullied enough to be able to call it a rounded high school experience, and had popular siblings. I was pathologically shy, though. Oddly enough I found it entirely doable to speak to an audience of a hundred or a thousand but was utterly unable to ask a girl for a date - what a loser - I can sympathize with Dr. Koothrappali.

Oh well - we do grow out of some of those failings even while others catch up with us. Aside from the memories, though, there is always the fear that seeing the same people again, and finding that we share as few interests now as we did then (how many of them will care about quantum mechanical wavefunction collapse), I will revert to the mute and terrified student.

Of course it would be nice to see some of my old friends, but most of them were either a year ahead or a year behind me. I even joined facebook in the hope of contacting a few, but most weren't on it - my generation mostly hasn't caught the wave, I guess. I did manage to locate a few of my old debate team partners, though only one was on facebook, and she hasn't responded to my friend request. Maybe I should write to a couple of the others.

Sunday, November 07, 2010

Republican Goals

The principal Republican goals we hear about: repealing Health Reform, repealing regulation of Wall Street, and big tax cuts for the rich all seem to be at best minimally popular, even with those who voted Republican this time. It seems to me that if Obama and the Democrats have any guts whatsoever, they can exploit and demonize these efforts. Unfortunately, Obama has yet to show any hint of fighting instinct - we shall see if he can get beyond "Can't we all just get along?"

Medicaid

Like other States, Texas is feeling our economic pain, and casting around for stuff to cut. the governor has floated the idea of eliminating Medicaid. That might be an interesting experiment, since it would probably trigger the flight of Medicaid patients to other States and perhaps a nationwide collapse. I wonder if anyone has analyzed how this might work.

Saturday, November 06, 2010

Nancy Pelosi

I am a bit puzzled over how the right managed to so successfully demonize Nancy Pelosi. Sure, the last several Republican Speakers caught some flack as well, but they were each caught in public or private scandal - e.g. Newt's habitual womanizing, his disgraceful treatment of his cancer stricken wife, and his ridiculous shutting down of the government - not to mention his persecution of Clinton for sins he was more guilty of himself. Nancy, I'm pretty sure, hasn't done any of those things.

What she did do was pass legislation that offended insurance companies and Wall Street. And that did it??

Anybody have a better idea?

Religion and Violence

Wikipedia has a list of countries by murder rate. The top nineteen nations are all mainly peopled by practitioners of the same great world religion. Care to guess which religion that is?

If you guessed "Christian," you would be right. The twentieth nation on the list, Madagascar is mainly indigenous religions, but Christians are a strong second. The US is a bit lower than the average, and rather more than ten times less murderous than the worst country - El Salvador. It's also more than ten times as murderous as the safest nations.

The twenty least murderous nations include nine Muslim nations, eight European Christian nations, Japan, Hong Kong and Singapore.

Of course some countries' statistics may be more reliable than others.

Emergence of the Classical World

A persistent puzzle of quantum mechanics is the emergence of the classical world from its quantum substrate. How is it that the world of everyday experience appears to follow classical rather than quantum laws? This was a mystery to the founders of quantum mechanics, and ultimately they mostly adopted the so called Copenhagen interpretation, which just sweeps the mystery under the rug by declaring that two must be kept separate, pushing all the weirdness into the measurement process.

Over the last three decades an alternative interpretation, known as consistent histories or de-coherent histories, introduced by Robert Griffiths and further developed by Roland Omnes, Murray Gell-Mann, and James Hartle, has attracted widespread interest and support. Its great virtue is that it does away with the Copenhagen division of the world into quantum systems and classical measurement apparatus. All get treated on the same quantum mechanical basis.

The most mysterious quantum phenomena are those associated with non-local behavior and quantum entanglement. A photon fired at two slits somehow manages to go through both of them and interfere with itself in the process of forming an interference pattern on a screen beyond. Quantum systems manage to be in superpositions of quantum states.

These superpositions are very unclassical. Schroedinger was disturbed enough to invent his cat, who paradoxically manages to wind up in a state that is a superposition of dead and alive. The way decoherence deals with the cat is one of its triumphs.

If we were to do the cat experiment in fact, putting the cat in a chamber with a cyanide solution that would release only with the decay of a quantum system, the classical result would be that we would either open the chamber and find a dead cat smelling of bitter almonds or not. In classical Copenhagen, we might, like Schroedinger, imagine that the cat is in a superposition of dead and alive states until we open the chamber and collapse the state function to one of its eigenvalues. So how could we tell the difference? The answer is, that we couldn't, unless we could somehow get the dead and alive states to interfere with each other - somehow showing an interference pattern.

Decoherence says that this can't happen, because even if such a superposition forms, the quantum coherence between the states which could allow such interference is very rapidly destroyed by the random influences of the environment - the heat bath of photons, neutrinos, and gravitons in which we live.

As usual, I am writing about this because I'm trying to understand it, so critique and comment is welcome - as are questions, especially those I haven't thought of.

Wednesday, November 03, 2010

Concentrate!

A blogger, this one at least, is a person who can't learn anything without developing an urgent impulse to communicate it. Have you ever wondered how an oxygen concetrator works? (If not, you can safely skip the following) An oxygen concentrator, if you are wondering, is one of those devices you see people with clear plastic tubes in their noses using - recognizable by it's own characteristic raspy breathing - sort of a pssst, pssst, pssst with a period of a few seconds. As its name indicates, it concentrates oxygen from the air and delivers it to the wearer, usually an ill person, but also to some pilots flying at high altitudes.

Knowing that air is 78% nitrogen and about 21% oxygen, how does it do that? What difference between the molecules is being exploited to do the separation. This stumped me, so I had to look it up, but if you don't know the answer, try to guess.

It turns out to be molecular size. Oxygen atoms, with 8 protons, are about 5% smaller than the 7 proton nitrogen atoms - both have partially filled outer electron shells. The separation is effected by running the air through a zeolite - a microporous mineral structure with appropriately sized pores, making it a good molecular sieve.

So you run the air under pressure though some zeolite and oxygen gets through, but nitrogen can't. The nitrogen quickly clogs the pores, so they need to be depressurized and backflushed with a bit of the oxygen to clean them out. Usually a two bed system is used so that one can be used while the other is being flushed. I assume that it's that cycle that produces the characteristic pssst, pssst, pssst.

Now What?

The Plutocracy got most of the Congress it wanted. Let's see what they do with it.

There seems to be some stepping back from the apocalytic rhetoric of shutdown...

Big tax cuts for the rich and endless deficits seem built in ...

Tuesday, November 02, 2010

Hilbert Space: Reply to James

I wanted a bit more space here, since you guys are teaching me a lot.

James wrote:

The most common states in your Hilbert spaces don't actually live there: such as position and momentum states. Rigged HS combines a nice space (physically realistic - nice and smooth), with your HS, and the nasty (generalised functions usually) dual of the nice guys.


James, I don’t dispute your mathematical point, and perhaps I misunderstood it, but when you said that position and momentum states don’t live in the Hilbert space, I assumed that you meant that it was position and momentum eigenstates that didn’t live in the HS. My point was that real physical systems can’t be prepared in position or momentum eigenstates (i.e., with infinitely precise position or momentum) – they are always superpositions with some uncertainty in both position and momentum. Those superpositions, I think, can and do live in the Hilbert space – or am I totally confused on this point?

I hadn’t heard of a “rigged Hilbert space” previously, but if I understood Wikipedia on the subject, it’s pretty much just Hilbert space augmented by the necessary mathematical machinery to implement Dirac delta functions and permit us to do calculus with them. Is that right?

The "rigging" (or additional structure) is made necessary by the bad behavior (not square integrable) of the Dirac delta functions corresponding to position and momentum eigenvalues, but these can't be prepared anyway - a precise position requires infinite momentum uncertainty and vice versa.

Nice Article: http://en.wikipedia.org/wiki/Quantum_mechanics

James later wrote:

Classical mechanics is a fibre bundle: the base maifold R^1 (time) and the fibre space (E^3). Or we could go Lagrangian with relaivity where a n-D system becomes 2D-d, (or we could Legendre Trans his and go H) but the point is that none of this fancy geometric-ballet will make classical stuff quantum-mechanical...


Consider the following:

Hermann Weyl, discussing the Hamiltonian formulation of quantum mechanics (The Theory of Groups and Quantum Mechanics, pg. 95, Dover edition):

It is a universal trait of quantum theory to retain all the relations of classical physics; but whereas the latter interpreted these relations as conditions to which the values of physical quantities were subject to in all individual cases, the former interprets them as conditions on the quantities themselves, or rather on the Hermitian matrices which represent them...

I think for our purposes we would replace “matrices” with “operators in Hilbert space,” but he is making a very specific claim about the relation between the classical formulation and the quantum. My interpretation: the symplectic manifold of state vectors in Hamiltonian classical mechanics becomes a structure on the operators in Hilbert space – does that make mathematical sense? If I understand correctly, that's why Lie groups are fundamental to QM.

Monday, November 01, 2010

A View of Hilbert Space

According to quantum mechanics, physics takes place in Hilbert spaces. Bizarre as this notion might be, we have learned to live with it as it continues to be verified whenever experimentally tested. Surely, this abstract identification of a physical system with a state vector in Hilbert space will eventually be found to be incomplete, but in a presently unimaginable way, which will involve some other weird mathematical structure. That Nature uses the same mathematical structures invented by mathematicians is a profound mystery hinting at the way our brains are wired.

Pierre Ramond in Group Theory: A Physicist's Survey.

The Green Wave

I see the great green wave rising and Numenor looks doomed - at least to two more years of utter folly.