Preposterous Universe

Back

I am back from the wilds of Wyoming, having happily scampered through the Jurassic for a few days. A full report will be forthcoming. But first I wanted to thank Gretchen for filling in while I was gone; hopefully she will post again in the future.

A lot can happen in one short week, so I just wanted to hit some high points of the events you had to endure without me.

The big news, my man Barack Obama hit a home run at the convention. I didn't get a chance to see the speech, which I hear was not even broadcast by the networks. Also we were staying at a ranch owned by folks who were quite hospitable, but whose politics didn't really align with mine. The first clue was the large painting of Jesus kneeling in front of the Liberty Bell. I must have missed that chapter in the Gospels. So Democratic-convention-watching wasn't one of the scheduled activities.
But actually, is the lack of coverage by the networks worth all of this hand-wringing? Don't most people have cable TV by now, and don't the cable networks cover the thing to death? I never understood why there was supposed to be a moral imperative for all three networks to provide essentially the exact same pictures. They could just rotate, like with the Olympics (without the dizzying rights fees).
Despite the Dems having apparently stage-managed the convention quite skillfully, the free speech zones are a travesty. (Images found linked at Majikthise.) Their existence is a travesty on basic philosophical grounds, but their appearance is a disaster purely on craven political grounds. I mean, barbed wire?
In one last bit of Hawkingiana, it's worth pointing to this statement by John Preskill about the bet he won with Hawking (found linked at Michael Nielsen's blog). Poor Preskill, who is a world-class theoretical physicist in his own right, but can only get in the newspapers by winning bets with Hawking.
Francis Crick passed away. Most of what I know about Crick comes from reading The Double Helix, which I'm sure isn't the most reliable source. More discussion at the Panda's Thumb.
Atrios unmasked! With his permission. (That's the mysterious Atrios of Eschaton, for you scientists out there.)
Finally, let's give some props to Allen Iverson of my beloved Philadelphia 76ers, one of only two NBA stars (along with Tim Duncan) to fulfill his initial obligation to go to Greece as part of the Olympic team. Iverson has his issues, but he has always been treated far worse than he deserved, just because of his hairstyle and tattoos. Now he's the co-captain of the Olympic team, which has to feel good.

I'm sure other interesting things "happened," but if I wasn't paying attention to them, how real can they be?

~ posted by Sean Carroll at 12:01 PM ~ link ~ ~ ~

Dinosaur hunting

I wanted to mention why I will be in Wyoming next week: I'll be hunting dinosaurs. (Fortunately they will have been dead for millions of years, otherwise it would not really be a fair fight.)

I've blogged previously about the great work that Gabe Lyon and Paul Sereno do through Project Exploration, a non-profit organization devoted to bringing the excitement of science to city kids. Doing good work requires money, so PE has to devote a lot of energy to fund-raising, and has been blessed with a devoted and enthusiastic set of donors. One thing they like to do each year is to take a trip with some of the donors to do some honest fossil excavation at a site in the U.S -- sifting for microfossils, prospecting for larger dinosaur bones, and gently digging up and preserving the major fossils that have been found. (One goal is to build a teaching collection for the University.) So, while the expedition is fun and certainly educational, it's also quite serious; those are the bones of an actual Tyrannosaur that you are digging up and perhaps breaking in pieces if you're not too careful.

All of this seems perfectly sensible; less clear is how they got the idea that it would be amusing to bring along a cosmologist. But far be it from me to ask questions. (I did check that they wouldn't expect me to be able to identify constellations in the night sky, but they said that was okay.) I went last year, had a great time, even found a serious fossil myself. (A hadrosaur, if you must know -- the "cattle of the Cretaceous," a major contributor to T-Rex's diet.) And I'm going again this year. I'll report on any major discoveries when I get back.

Update: Here is the post-expedition report, part one and part two.

~ posted by Sean Carroll at 9:17 AM ~ link ~ ~ ~

Information or just entropy?

Enough talking about Hawking, I would think. There are a bunch more newspaper stories out there (including these from Newsday and the New York Times that were nice enough to quote me). Also, Juan Maldacena and I appeared together today on Odyssey, the program hosted by the very same Gretchen Helfrich who will soon be our official guest-blogger. No quid-pro-quo was involved, I promise. You are welcome to listen to the program if you have RealAudio.

Just to show you that scientists don't always agree, two representative quotes. First, Leonard Susskind in the Times:

Until Stephen's recent reversal, he was about the only person still getting it wrong.

Susskind is a string theorist who thinks that it's already been figured out, nothing to see here, time to move on. Next, from my colleague Bob Wald:

Hawking is completely revising his prior belief that what goes into a black hole is washed out. Now he believes that anything emitted from a black hole can be identifiable back to its source. He's running away from what we still believe.

Wald is a general-relativist, quite skeptical about the claimed mechanisms for getting the information out. This is the problem with thought-experiments; they're not nearly so conclusive as actual experiment-experiments.

~ posted by Sean Carroll at 4:03 PM ~ link ~ ~ ~

Hawking speaks

As anticipated, Stephen Hawking gave his talk on black hole information loss at the GR17 conference in Dublin today; newspaper stories are already popping up, although they don't tell us much we didn't already know. I'll try to have some incisive commentary soon; in the meantime, why not just get right to the heart of the matter? Here are the press release and transcript for Hawking's talk.

Judge for yourselves! At least, if you're up on the background reading about Euclidean quantum gravity and the AdS/CFT correspondence. Thanks to Dennis Overbye of the New York Times for forwarding the material.

Update: Peter Woit has a parsing of what Hawking is trying to say. I think the most direct paragraph is probably this one:

So in the end, everyone was right, in a way. Information is lost in topologically non trivial metrics, like the eternal black hole. On the other hand, information is preserved in topologically trivial metrics. The confusion and paradox arose because people thought classically, in terms of a single topology for spacetime. It was either R4, or a black hole. But the Feynman sum over histories, allows it to be both at once. One can not tell which topology contributed the observation, any more than one can tell which slit the electron went through, in the two slits experiment. All that observation at infinity can determine, is that there is a unitary mapping from initial states, to final, and that information is not lost.

The idea seems to be that, so far as information measured at infinity is concerned, when we integrate over all possible geometries the relevant ones are those that don't have black holes at all, merely apparent horizons. Some evidence for this point of view is adduced from AdS/CFT (the connection, first discovered by Juan Maldacena, between certain configurations of quantum gravity and certain field theories in one less spacetime dimension).

When we ultimately agree on the resolution of the information paradox, this idea may very well be part of the story. For the moment, it doesn't seem like a very practical suggestion, to say the least; it amounts to a promise that, if only we could actually do the path integral for Euclidean quantum gravity, all the information would be preserved and end up in the outgoing Hawking radiation. It remains the case that most people are quite skeptical that we will ever make sense of the Euclidean path integral, especially in the semi-classical regime Hawking makes use of. So one way or another, there's still a lot of work to be done!

~ posted by Sean Carroll at 2:15 PM ~ link ~ ~ ~

Asimov's First Law

With the release of I, Robot, everyone is talking about the terrible damage being done to the ideas of Isaac Asimov. Over at The Fulcrum, for example, Charles2 lists the three Laws of Robotics,

A robot may not injure a human being or, through inaction, allow a human being to come to harm.
A robot must obey orders given it by human beings except where such orders would conflict with the First Law.
A robot must protect its own existence as long as such protection does not conflict with the First or Second Law,

and wonders whether they could be applied to politics and government.

What I wonder is, what kind of lunatic thought that these laws were ever workable? Especially the first one. A robot cannot, through inaction, allow a human being to come to harm? Human beings are coming to harm all the time all over the world, and that's only if we stick to straightforward physical harm, not to mention more subtle varieties. Every robot with these laws programmed into them would instantly launch on a frenzied quest to change the very nature of reality in order to stop all of this harm from happening. I just want something that will vacuum my floors efficiently, not save the world.

The whole point about robots (or computers more generally) is, they're very literal-minded. They don't know the meaning of "within reason." When talking to each other rather than to machines, human beings are never perfectly precise about what they mean, often for good reason. That's why we'll always have literary critics, theologians, and the Supreme Court: to help us understand what was really being said.

I met Asimov once, when he visited my undergraduate university. They thought it would be fun to show him around the astronomy department, much to his bemusement (he was trained as a chemist). He used his advanced age as an excuse for shamelessly flirting with every attractive woman within leering distance. I wonder what he was like before his age was so advanced?

~ posted by Sean Carroll at 11:06 PM ~ link ~ ~ ~

Guest-Blogger Gretchen

Longtime readers will attest that I am extremely dedicated to sharing my random thoughts with everyone out there in blog-land. But from time to time my jet-setting lifestyle will take me to places where internet connectivity is faint or nonexistent. To deal with this terrible possibility, we are inaugurating a new feature here at Preposterous: the guest-blogger. (I understand that bloggers elsewhere have also experimented with this idea, but it's new for us.)

Figuring that we might as well start at the top, we are pleased to announce that our first guest blogger will be Gretchen Helfrich. Everyone in Chicago, and many public-radio listeners elsewhere, will recognize Gretchen as the host of the daily radio program Odyssey from Chicago Public Radio. (Anyone with RealPlayer can listen over the web whenever they like.) Odyssey represents exactly what you would like to hear on public radio: a spirited and in-depth examination of ideas, ranging from politics to science to the arts. Sort of like this blog, without as much whimsical self-indulgence and pictures of Godzilla. The best feature of the show is how they make every effort to generate light rather than heat, remaining interesting and entertaining while digging carefully into the issues lurking behind the topics being discussed. The opposite of the O'Reilly Factor in every way.

Gretchen will be taking the reins for about a week starting on Friday, as I'll be traipsing through the wilds of Wyoming. Everyone play nice, now.

~ posted by Sean Carroll at 10:35 AM ~ link ~ ~ ~

Feedback

More old-school bands should do this. In celebration of thirty years together, Rush has come out with Feedback, an EP of cover tunes, focusing on the songs they were insprired by back in the Sixties when they were first learning rock and roll. For those of you who know or care, Rush is one of those love/hate bands; a progressive-rock power trio, they are worshipped by their fans for their fantastic musicianship, and belitted by their critics for being ponderous and pretentious. Count me as a fan. Who wouldn't want to hear Geddy Lee sing Summertime Blues?

In honor of their anniversary, here's a picture of Neil Peart with his drum kit (click for full glory).

~ posted by Sean Carroll at 5:23 PM ~ link ~ ~ ~

Squelching vicious rumors

Like Daniel Drezner, I find it necessary to put to rest those unfounded speculations that I will soon be drafted to run as the Republican nominee for the U.S. Senate from Illinois. Now, even on the face of it there are certain manifest obstacles that would have to be overcome. It is true, for example, that I have occasionally implied a favorable attitude towards gay marriage, questioned the existence of God, argued against building a missile defense system, poked fun at the President (also here, here, here, here, here ... well, you get the point), and even said nice things about the Big Bang. I've also been known to consort with the enemy. Oh yes, and I've promised never to run for office. (Now that I think about it, anyone with a blog and a less-than-perfect amount of self-control would have a hard time not leaving such an inflammatory trail of comments that they would be instantly disqualified from any future political career.)

But I'm a believer in a strong two-party system, and the GOP in my adopted home state is kind of on the ropes these days. Democratic nominee Barack Obama has seen all of his opponents implode, has just been tapped to give the keynote address at the Democratic national convention, and is generally being given rock-star treatment by the national media. Attempts by Republicans to inject some celebrity star power of their own have fizzled, and are now becoming increasingly desperate. And, you know, I am well-educated, gainfully employed, and a practiced public speaker. They could do worse (and seem to be trying to).

Alas, it's not to be. As much as I would love to set an exciting precedent by entering the campaign as a Republican running to the left of his Democratic opponent, I feel too strong a sense of obligation to my students and colleagues here at the University of Chicago, who frankly would be lost without me.

But if Bush does decide to dump Cheney, he has my number.

~ posted by Sean Carroll at 1:46 PM ~ link ~ ~ ~

Hawking on black holes

The cat is out of the bag about Stephen Hawking's new ideas about black holes. Preposterous regulars were in on the ground floor, of course. We can now speculate somewhat more intelligently about what the ideas actually are, since the abstract for his talk (next week at the GR17 conference in Dublin) is online:

The Euclidean path integral over all topologically trivial metrics can be done by time slicing and so is unitary when analytically continued to the Lorentzian. On the other hand, the path integral over all topologically non-trivial metrics is asymptotically independent of the initial state. Thus the total path integral is unitary and information is not lost in the formation and evaporation of black holes. The way the information gets out seems to be that a true event horizon never forms, just an apparent horizon.

(For more scoop see Not Even Wrong, Smijer, By the Way, and this thread on sci.physics.research.)

It seems as if our initial skepticism might be accurate: even if Hawking's proposal is ultimately judged to be a fantastic breakthrough, it won't catch on right away. The Euclidean path integral approach to quantum gravity, which Hawking has been instrumental in developing, is not generally thought to be the most promising approach. One never knows, and it might eventually turn out to be on the right track, but it's not very popular in the quantum-gravity community.

Let's try to explain what is going on. Quantum mechanics tells us that the world is described by wave functions, which give the probability for getting a certain result when we make an observation. A path integral is just a certain way of calculating the wave function. Invented by Richard Feynman, the path-integral approach says that we should attach a certain contribution to every possible path the system can take from one configuration to another, and then sum all of these contributions; the result is the wavefunction for being in the final state, given the initial state we started with. Often this sum (the path integral) is hard to do, and a convenient mathematical trick is to allow the time coordinate to be imaginary; this purely formal manouver turns four-dimensional spacetime into a four-dimensional space (no direction is singled out as "timelike"), and the integral turns out to be much easier to do. In gravity, we would like to sum over all the possible geometries of spacetime itself. So "Euclidean quantum gravity" tells us to calculate the wave function for the geometry of three-dimensional space at some fixed time by summing over all the possible four-dimensional geometries that connect to that spatial geometry.

The problems with this approach include: nobody knows what number to attach to each geometry in the sum, nobody knows how to do the integral, and nobody knows how to interpret the result. Significant problems, in other words. Optimists like Hawking think that they can describe a certain set of approximations in which the path integral makes sense; string theorists, on the other hand, would generally say that the path integral is nonsense if you don't include the fundamentally "stringy" aspects of spacetime on ultra-small scales. In the absence of direct experimental data, we have to judge how well the ideas hang together in their own right; at the moment, Euclidean quantum gravity seems to have serious issues, and hasn't scored many notable triumphs.

Hawking now seems to be saying that the path integral for black holes can help us understand how information that we thought had disappeared into the singularity can actually be lurking close to the horizon, so that it can eventually influence the outgoing Hawking radiation, and thus allow information to be recovered by the evaporating black hole. He'll be met with serious skepticism in the physics community, but let's wait to see how it washes out.

Of course, he'll also be met with serious awe by the media. This can drive other physicists crazy. I often find myself explaining to non-physicists that Hawking is not the very best theoretical physicist out there, but simultaneously defending his reputation to my fellow physicists. It's probably safe to say that Hawking was the leading researcher in theoretical gravitational physics in the second half of the twentieth century, and arguably since Einstein; but gravitational physics was not where the action was during that time (it was in particle physics and quantum field theory). A lot of physicists hurry to point out that Hawking is not doing the most influential work in quantum gravity these days; but the truth is that most sixty-year-old physicists aren't doing the most influential work in their fields, even if they don't have serious neurological disorders. Like anyone else who has made fantastic contributions, Hawking has earned respect for new ideas he might have, but the ideas themselves will be judged on their own merits.

~ posted by Sean Carroll at 10:48 AM ~ link ~ ~ ~

Let's knock it off

Okay, can we stop doing this? Where by "this" I mean grasping at any opportunity to ridicule the behavior of Jenna and Barbara Bush, simply because they are the children of our disastrously bad President. And no, the fact that they are campaigning for their father doesn't make their private lives fair game. If you want to critique their ability as campaigners, or suggest that they have implausible policy views, go right ahead. But to titter about stories of the Bush twins' bar exploits is tawdry, demeaning, and completely unnecessary.

I would make a distinction that is rather fine, but seems valid: in the context of pure gossipy dirt-dishing (like the original Times article that the Barbara Bush story came from, or nearly every story in Wonkette), I have no objection to mean-spirited snarkiness. That's the point of those kinds of stories. But when we indiscriminately mix this trash in with serious political disagreements, we are stooping lower than there is any need to stoop. Here we have an administration that has produced so many fiascos that there is increasing talk of "outrage fatigue"; what is the point of muddying the waters with jabs at the personal lives of the President's kids? There are real things to complain about without following people into bars hoping they'll embarrass themselves.

~ posted by Sean Carroll at 4:52 PM ~ link ~ ~ ~

Is that a Riemann or Lebesgue integral?

Terry Teachout has a nice reflection on the social disapprobation that accompanies an unseemly regard for the artistic and intellectual side of life (especially for children). I have nothing deep to add, except that his mention of a hypothetical waitress who could quiz him knowledgeably on what he was reading reminded me of this well-known math joke:

The first mathematician says to the second that the average person knows very little about basic mathematics.
The second one disagrees, and claims that most people can cope with a reasonable amount of math.
The first mathematician goes off to the washroom, and in his absence the second calls over the waitress.
He tells her that in a few minutes, after his friend has returned, he will call her over and ask her a question.
All she has to do is answer: `one third x cubed'.
She repeats `one thir -- dex cue'? He repeats `one third x cubed'.
Her: `one thir dex cuebd'? Yes, that's right, he says.
So she agrees, and goes off mumbling to herself, `one thir dex cuebd...'.
The first guy returns and the second proposes a bet to prove his point, that most people do know something about basic math. He says he will ask the blonde waitress an integral, and the first laughingly agrees.
The second man calls over the waitress and asks `what is the integral of x squared?'.
The waitress says `one third x cubed' and while walking away, turns back and says over her shoulder `plus a constant'!

Okay, it's not very funny if you don't know much calculus (the waitress was giving a more precisely correct answer than the mathematicians had any right to expect, demonstrating that they were both handicapped by inaccurate stereotypes). But I noticed something else: looking for a copy of the joke through Google, the version I just transcribed is only the second-most-popular version. More popular is the following:

Two mathematicians were having dinner in a restaurant, arguing about the average mathematical knowledge of the American public. One mathematician claimed that this average was woefully inadequate, the other maintained that it was surprisingly high.
"I'll tell you what," said the cynic. "Ask that waitress a simple math question. If she gets it right, I'll pick up dinner. If not, you do."
He then excused himself to visit the men's room, and the other called the waitress over.
"When my friend returns," he told her, "I'm going to ask you a question, and I want you to respond 'one third x cubed.' There's twenty bucks in it for you." She agreed.
The cynic returned from the bathroom and called the waitress over. "The food was wonderful, thank you," the mathematician started. "Incidentally, do you know what the integral of x squared is?"
The waitress looked pensive, almost pained. She looked around the room, at her feet, made gurgling noises, and finally said, "Um, one third x cubed?"
So the cynic paid the check. The waitress wheeled around, walked a few paces away, looked back at the two men, and muttered under her breath, "...plus a constant."

You see the difference? In the first version, with which I was familiar, I always imagined that the waitress was having fun teasing the mathematicians, and walked away smiling. But in the second version it's clear she is just pissed off and grumbling. Now it seems much less funny to me, although obviously a lot of people prefer this version.

It's amazing what psychological insights you can reach just be wandering through the web with Google as your only guide. The internet isn't anything weird and scary, it's just a window into our brains. Okay, that is pretty scary.

~ posted by Sean Carroll at 11:44 AM ~ link ~ ~ ~

Congratulations to Eugene!

Another young mind enters the community of scholars. Congratulations to Eugene Lim, who just finished successfully defending his Ph.D. thesis, and is now an official doctor. Preposterous readers may know Eugene from his occasional appearance in the Comments, under the nom de blog "Your Hardworking Student." Eugene is only the second Ph.D. student I've had, so I'm still fumbling around a bit, but hopefully my inexperience as an advisor didn't scar him too badly.

Eugene's thesis work was about the gravitational effects of vector fields that violate Lorentz invariance by picking out a preferred direction in spacetime. We have one joint paper coming out soon, and he has a longer single-author paper, so I'll give more details about the research when they are ready. The basic story is surprisingly short and sweet: the vector field acts to change the measured value of the gravitational constant, but in different ways in different circumstances, so you can actually place interesting limits on its magnitude by comparing different experiments.

In the fall Eugene will be heading to Yale to take up a postdoctoral research position. Good luck!

~ posted by Sean Carroll at 4:11 PM ~ link ~ ~ ~

The terrible ambiguity of Godzilla science

This weekend I saw the first Godzilla movie, in the restored original Japanese version. The Godzilla universe is as complicated and internally inconsistent as they come, but the first movie (1954) was an interesting allegory about the hazards of nuclear weapons. Shot in stark black and white, the movie tells the story of a prehistoric monster who is brought back to life by H-bomb testing and proceeds to terrorize coastal Japan and Tokyo in particular. The original American theatrical release was heavily bowdlerized, both removing some of the harsher scenes of irradiated children (Godzilla was highly radioactive) and splicing in scenes of Raymond Burr as an American journalist. I haven't seen the American version in a long time (ever? there are so many Godzilla movies it's hard to keep track), but I suspect the Japanese version is both more coherent and dramatically compelling.

Of course the production quality was not what we are used to these days, nor was the general pacing. To a contemporary audience, this movie seems awfully relaxed, even in the scene where Godzilla is stomping trains and power lines in downtown Tokyo. Part of this is the difference between Japanese and American sensibilities, but much of it is simply the passage of time; those early James Bond films seem just as lethargic. And it's easy to recognize when a tiny model is being destroyed by waves rather than a full-size town. (Probably much of our ability to tell the difference can be traced to physics -- the relative timescales associated with various actions change with respect to each other as a function of length scale. Someone should write a paper about this.) The one effect that remains unmatched is the sound that Godzilla makes; even in the horrible but high-tech 1998 American version, they were unable to create an equally impressive Godzilla sound from scratch and had to stick with the original.

Science plays an ambiguous role in the movie. Obviously, technology is implicated in the original horror of the H-bomb that brings Godzilla to life. Later, the elderly paleontologist is portrayed as heartbroken that there are plans to kill Godzilla (who has been happily rampaging through Tokyo) rather than attempt further study -- a standard, although not very complimentary, stereotype of scientists. But at the end, it is a lonely researcher working in his basement laboratory who invents the weapon that ultimately destroys Godzilla -- the Oxygen Destroyer, which kills all aquatic life in a wide radius around where it is activated. So science has terrible consequences, but we have no other recourse when we need to address our serious problems. Of course, yet another misunderstanding of how science works leads to the final plot twist, when the lonely researcher (who had been permanently scarred by an atomic blast) commits suicide after the Oxygen Destroyer is used, so that this terrible power cannot fall into the wrong hands. In the real world, if a well-funded group of dedicated scientists have just seen something demonstrated, they will figure it out for themselves before too long. There are no true secrets when it comes to science and technology; the interesting discoveries will all eventually be made, regardless of what any one person chooses to share.

~ posted by Sean Carroll at 8:06 PM ~ link ~ ~ ~

The Indomitable Vonski

Good news for all you jazz lovers out there: The Great Divide, a new CD from tenor master Von Freeman.

As I've previously mentioned, Von is a Chicago legend. Eighty-one years young, he is still blowing as hard as ever. His style owes much of its allure to the ability to absorb many different influences, from Coleman Hawkins to Lester Young to Gene Ammons to Charlie Parker to John Coltrane to Ornette Coleman, and mix in something absolutely unique. For a quick demonstration, run out and buy his 1981 album Young and Foolish. Go to track one, "I'll Close My Eyes," and skip right ahead to the 9:11 mark. For the next two and a half minutes you'll hear one of the most amazing sax solos ever committed to CD. A true solo, the rest of the band sitting out, that stretches from manic bebop phrases to near-dissonant growling, only to suddenly and sharply caress the original melody in startling epiphanies, bringing the audience to a state of near-riot. And that is the true genius: to experiment and test the limits of the music while remaining consistently and compellingly beautiful. (Don't take my word for it, read the reviews.)

Along with his musical gifts, Von is famous for his generous spirit and mischievous humor. Best of all, he's extremely accessible, at least if you're in Chicago. Von and his quartet play the second Saturday of every month at Andy's downtown, and every single Tuesday at the New Apartment Lounge on 75th Street, in an atmosphere at once informal, authentic, and genuinely welcoming. You will never find music of this caliber for such a low cover charge (zero dollars). Later in the evening, striving young musicians from throughout the city take part in a spirited jam session. (For a lively discussion of the Chicago music scene, opening with an amusing account of the vibe at the Apartment, check out Waking Up in Chicago by British journalist Claire Hughes.) This Tuesday (the 13th) there will be a party to celebrate the new CD; Von will also be playing later this week at the Green Mill and in Millennium Park.

Von's fans will tell you that the only reason he hasn't become as well-known as the usual roster of saxophone legends is that he never moved to New York to pursue a recording career, preferring to stay home and play gigs. Whatever the explanation, Chicagoans are truly fortunate to have such a master in their midst.

~ posted by Sean Carroll at 11:12 PM ~ link ~ ~ ~

He is a uniter, after all!

As a theoretical physicist, you come to cherish those very few moments when a new idea makes everything snap into place. In politics it almost never happens, so we should be even more grateful. One such idea has been hit upon by John McKay's wife: George W. Bush doesn't want to be President any more. He'd be just as happy to lose. It all makes sense now. He never really wanted to be President in the first place; he only ran because God told him to. But he was never happy about it; more like a reluctant Orestes being egged on by Apollo to do all those nasty things.

The man has suffered enough for the greater good. He'd be happier on his pickup truck back in Crawford. It's really the least we can do for him, after all he's done for us.

p.s. I do have one question. Why is considered humble to think that you've been chosen by God? Doesn't that mean that you think God has chosen you personally, rather than somebody else? It's a funny approach to humility.

~ posted by Sean Carroll at 2:01 PM ~ link ~ ~ ~

The Devil can cite scripture for his purpose

Now would be a good time to brush up on our theology and morality, in preparation for the upcoming debate about the Federal Marriage Amendment. The Senate had a preview this week, as they voted 51-46 to confirm J. Leon Holmes to the Eastern District Court in Arkansas. Holmes was controversial for various reasons, including a 1997 article in which he and his wife Susan argued that it was the duty of a good Catholic wife to subordinate herself to her husband. This angered knee-jerk liberals like Edward Kennedy, who referred to the Holmes' view as "extreme." Kennedy was countered by Orrin Hatch, who pointed out that the argument originated in St. Paul, not in the Holmes article, and that "most everyone" in the country would vote for St. Paul over Teddy Kennedy if they were choosing from whom they should take advice about morality.

The relevant Scripture is from Chapter Five of Paul's letter to the Ephesians, verses 22-24:

Wives should be subject to their husbands as to the Lord, since, as Christ is head of the Church and saves the whole body, so is a husband the head of his wife; and as the Church is subject to Christ, so should wives be to their husbands, in everything.

(From the New Jerusalem Bible, probably the most accurate translation.*) In all fairness, Paul attempts to be evenhanded, when in verse 28 he says

In the same way, husbands must love their wives as they love their own bodies, for a man to love his wife is for him to love himself.

Although, to be absolutely fair, we should also draw attention to Chapter Six, verses 5-6:

Slaves, be obedient to those who are, according to human reckoning, your masters, with deep respect and sincere loyalty, as you are obedient to Christ: not only when you are under their eye, as if you had only to please human beings, but as slaves of Christ who whole-heartedly do the will of God.

Most religious liberals these days would probably not go along with the ideas that wives should be subservient to their husbands, nor that slaves should be obedient to their masters. One would rather interpret these as anachronistic relics of an earlier time when our understanding of morality was less well-developed. The question is then, how do we distinguish between the anachronisms and the useful guides to behavior? Think of it this way: are there any circumstances under which your moral instincts might be in direct conflict with religious doctrine, where you would accept the Church's teaching even though you would have come to a very different conclusion by yourself? And if not, what good exactly is the teaching as a guide to morality?

Update: I should include a footnote about the New Jerusalem Bible, as found at bible-researcher.com: "The idea that a Bible version such as this, which contains introductions and notes that presuppose the acceptance of skeptical views and modernistic theories concerning the authorship and authenticity of the books, would be suitable for all Christians, is very questionable. After fully admitting its good qualities, we must point out that the Jerusalem Bible is not in fact suitable for Christians who are in need of edification in the faith. The theological commentary and critical speculations included in this version, useful as they may be for advanced studies, are likely to have a bad spiritual effect on most readers. This is a Bible suitable only for students who are well established in the faith and capable of using it with discretion."

~ posted by Sean Carroll at 12:42 PM ~ link ~ ~ ~

Ranks of the shrill

Today the quotes will speak for themselves. It's all rabid political polemic, so those of you looking for our regularly-scheduled insights into the workings of the universe will have to wait until next week.

From Chris C. Mooney, more complaints from high-level scientists about the administration's unbelievable politicization of the scientific advisory process. From his notes on a Union of Concerned Scientists press conference:

Janet Rowley, cell biologist at the University of Chicago and President's Council on Bioethics member. Rowley delivered what I consider a startling revelation: That her appointment to the President's Council in 2001 was politically vetted to an inappropriate extent. In her own words, the White House personnel office asked her the following questions: "Had I voted for president Bush's election; also, did I support president Bush's policies." Rowley said she "remonstrated" that these questions had no bearing on her competence to serve on the council. "The response from the White House was that this was a presidential appointment, they wanted to appoint people who supported the president," Rowley continued.

Also links to a new report from the UCS.

From Talking Points Memo, a pointer to an article in The New Republic about the administration's attempts to score a big coup against terror just in time for the election:

This spring, the administration significantly increased its pressure on Pakistan to kill or capture Osama bin Laden, his deputy, Ayman Al Zawahiri, or the Taliban's Mullah Mohammed Omar, all of whom are believed to be hiding in the lawless tribal areas of Pakistan. A succession of high-level American officials--from outgoing CIA Director George Tenet to Secretary of State Colin Powell to Assistant Secretary of State Christina Rocca to State Department counterterrorism chief Cofer Black to a top CIA South Asia official--have visited Pakistan in recent months to urge General Pervez Musharraf's government to do more in the war on terrorism. [...]

This public pressure would be appropriate, even laudable, had it not been accompanied by an unseemly private insistence that the Pakistanis deliver these high-value targets (HVTs) before Americans go to the polls in November. The Bush administration denies it has geared the war on terrorism to the electoral calendar. [...] But The New Republic has learned that Pakistani security officials have been told they must produce HVTs by the election. According to one source in Pakistan's powerful Inter-Services Intelligence (ISI), "The Pakistani government is really desperate and wants to flush out bin Laden and his associates after the latest pressures from the U.S. administration to deliver before the [upcoming] U.S. elections." [...]

But according to this ISI official, a White House aide told ul-Haq last spring that "it would be best if the arrest or killing of [any] HVT were announced on twenty-six, twenty-seven, or twenty-eight July"--the first three days of the Democratic National Convention in Boston.

And from Political Animal (via Brad DeLong), a link to a CNN story explaining (yet!) another reason GWB is the odds-on favorite to be judged Worst President Ever:

President Bush declined an invitation to speak at the NAACP's annual convention, the group said.... NAACP spokesman John White said Wednesday that Bush has declined invitations in each year of his presidency — becoming the first president since Herbert Hoover not to attend an NAACP convention.

It's enough to make even a libertarian like Jacob "I've never cast a vote for a major-party candidate for President" Levy come out in favor of Kerry. As he says here,

This time, it seems very clear to me that the Bush Administration has failed basic tests of competence in policymaking and execution, and of trusteeship of long-term interests like alliances and trade negotiations and moral credibility. I expect to dislike an awful lot of John Kerry's policies. But I don't expect that kind of failure of the basic responsibilities of the office.

Hopefully enough folks in Michigan, Ohio, and Pennsylvania will follow suit (link from Balkinization.)

~ posted by Sean Carroll at 8:57 AM ~ link ~ ~ ~

Quality and quantity

A recent article by Amanda Schaffer in Slate is causing physicists to sit up and take notice (see comments at Gnostical Turpitude, Quark Soup, Not Even Wrong). The article is nominally about Brian Greene's standing in the physics community, although it doesn't really address that question. Brian, of course, is a well-known string theorist at Columbia, but celebrated more widely as the author of The Elegant Universe and The Fabric of the Cosmos, as well as host of a NOVA special on PBS.

The real focus of the Slate article is more about the style of string theory -- in the absence of detailed experimental results, are the criteria of beauty and mathematical coherence that string theorists rely on sufficient guides to doing effective physics? Interesting questions, about which I've previously promised to blog, but haven't gotten around to it yet. But what about the nominal question, of someone's standing as a physicist? It should come as no surprise that physicists, being the hard-nosed quantitative types that they are, have developed an extremely precise (and, often, wildly inaccurate) method for rating the worthiness of their colleagues, and implemented it as a web page to boot. It's the SPIRES high-energy physics literature database, which keeps track of what articles are citing, and being cited by, other articles in physics (or at least in high-energy physics, and increasingly astrophysics and related areas). Coupled with the availability of the papers themselves (in preprint form at arxiv.org or in published form at various online journals), the ease with which one can search through literature citations has become fantastically greater over the last ten years or so. No self-respecting physicist goes to an actual library any more, much less uses a Xerox machine.

But the real fun of SPIRES is to figure out how many citations your friends have (and thus, how good they are). For example, I have about 40 papers listed, with about 2000 total citations -- pretty good for an assistant professor, but by no means near the top of the list. I have no "renowned" papers (more than 500 citations), but I do have seven "famous" papers (more than 100 citations). Even that is a bit of a cheat, since two of those papers are review articles, which are cheap ways to rack up lots of citations. There are numerous caveats to this measure of one's quality -- different specialties have very different rates of citations, certain fields are not covered as well by SPIRES, it's very hard to appropriate credit in large collaborations, not to mention the obvious fact that having a lot of citations is not the same as being a good paper -- but it's just so easy and quantitative that the citation numbers from SPIRES have become very influential.

It's humbling to look at the citation records of the really influential people in high-energy physics. Big names in string theory do especially well in the citation game; string theorists just write a lot of papers. Cumrun Vafa at Harvard has five renowned papers and 58 famous ones; David Gross at KITP in Santa Barbara (who was an extremely successful field theorist long before he became an influential string theorist) has twelve renowned papers and 41 famous ones. In cosmology, Andrei Linde has three renowned papers and 39 famous ones; in particle phenomenology, Howard Georgi has eight renowned papers and 47 famous ones. These are just representative names; I haven't done any systematic searches for who has the most citations. Besides, everyone knows the answer: Ed Witten has an amazing 36 renowned papers and 99 famous ones. Both prolific (over 200 papers) and profound (over 200 citations per paper). Everyone else is just playing for second place.

~ posted by Sean Carroll at 8:46 AM ~ link ~ ~ ~

Policy eigenstates

I wanted to link to this cartoon, but PZ Myers beat me to it.

Kerry should have just shifted the topic to string theory. Aren't politicians trained to answer the question they wanted to be asked, rather than what was actually asked?

Kerry's penchant for hedging is obviously going to be a major GOP talking point in the upcoming election, in stark contrast with a President who doesn't know the meaning of the phrase "on the other hand." Of course, to any reasonable person Bush's single-mindedness and complete lack of doubt is a bad thing; in a complicated world, sometimes a little nuance is called for. Nevertheless, Kerry truly does have a problem with trying to have everything both ways, and deploying lawyerly caveats to make sure he keeps everybody happy. Of course, Clinton had a similar problem, and now he's a bestselling author, so maybe it's not an absolute barrier to success.

The press has already fallen for the stereotype of Kerry as being unable to construct a simple declarative sentence. Slate has a feature called "Kerryisms," in which they strip a quote of its "caveats and curliques." Eugene Volokh (not a typical Kerry voter, I would imagine) has shown how ridiculous the Kerryisms are (here, here, here); the caveats are very often simple and necessary parts of the meaning of the original statement. Saletan has a completely lame apologia for what he is trying to do. (The real reason for the feature is that Slate has an equally silly "Bushisms" feature, where they make fun of the President for his malapropisms, and as you know it's important to be balanced.)

The message to future candidates for public office is clear. Speak in cliches, preferably ones with universal appeal. Stick to nouns and verbs, perhaps with an occasional adjective or adverb; anything at the level of a prepositional phrase is sufficient grounds to suspect insincerity or worse. Avoid complicated issues of public policy; the people need to have their hearts lifted by statements of steely resolve, and there's little time for wonky hair-splitting.

Bush/Cheney '04: Classical leadership in times of quantum uncertainty.

~ posted by Sean Carroll at 3:17 PM ~ link ~ ~ ~

Finding Einstein

Way back in the early history of Preposterous Universe (the second post ever, in fact) we mentioned the lovely animated film Les Triplettes de Belleville, in the context of it being robbed by Finding Nemo for the best-animated-film Oscar. Something I had forgotten about, lost in all the excitement, was the appearance of Einstein's equation in the opening sequence. Nobody is quite sure why. (Einstein's equation relates the curvature of spacetime to the amount of energy and momentum. For details, see my short introduction to general relativity [pdf].)

The good folks at the American Physical Society have noticed this, and have even initiated a contest to help ferret out the reason for the equation's appearance.

If nothing else, the filmmakers should be congratulated on choosing a much more profound equation of Einstein's than the hackneyed old standby E=mc².

By the way, a serious plot flaw in Finding Nemo was pointed out at Rhosgobel:

Clownfish, of Finding Nemo fame, are a good example of a protandrous hermaphrodite: the largest individual fish in a group is female, the next smallest is the reproductive male, and the rest are typically non-reproductive. When the largest female is removed from the population the male becomes female, and a non-breeder becomes male. Thus, in Nemo's case Marlin (Nemo's father) should have turned into Marla once Coral (Nemo's mother) disappeared.

Now that's a Disney movie that might have been worthy of an Oscar.

~ posted by Sean Carroll at 2:07 PM ~ link ~ ~ ~

Blogging makes you smarter

Reflecting about the last post reinforces something I've noticed for a while: that blogging makes you, if not actually smarter, then at least more careful and better-informed. In the past I might have noticed the story about science education and responded with a practiced sigh. But in blogging about it, I went and took the three minutes necessary to find some actual evidence of how much money teachers made compared to other professions. If my opinions don't actually change, at least the quality of evidence I can adduce for them improves a great deal.

By the way, I should have recognized that some people wouldn't take the time to click the link to the study of salaries for different professions of Penn alumni. So, to save valuable time, here are the basic figures in convenient table format:

	Industry	Average Salary
	Communications	$163,414
	Consulting	$147,450
	Elementary/Secondary Education	$47,482
	Financial Services	$471,462
	Government	$82,677
	Higher Education	$58,623
	Law/Judiciary	$186,663
	Manufacturing	$120,324
	Medicine	$197,492
	Non-profit	$68,173
	Other Medical/Health	$100,711
	Other Services	$169,403

I wonder what precisely is included in "Financial Services." Organized crime? Iraqi reconstruction contracts?

~ posted by Sean Carroll at 4:27 PM ~ link ~ ~ ~

Science education

Everyone knows, or should know, that science education in American elementary and secondary schools is a travesty. This long-lamented fact reappeared in the news this weekend, after a group interview with science educators at the National Education Association's annual meeting. People on the street might wonder whether this is a bit alarmist -- is it really worse in the U.S. than elsewhere, or is science education really worse than education in other fields? I don't know about other fields, but anyone on a college science faculty will tell the same story about comparing the U.S. to Europe and elsewhere: our undergraduate experiences are comparable, graduate education here is the best in the world, but secondary education is an embarrassing failure. All those stories you hear about students graduating from high school not knowing how to use a calculator or that the Earth moves around the Sun? Absolutely true.

Often the lamentations surrounding this state of affairs focus on the idea that we need to be training a new generation of scientists to maintain American supremacy or some such thing. I don't care all that much about maintaining our supremacy, and I'm not even worried about a new generation of scientists; there are many more people who want to become scientists than we have jobs for them, and the individuals who are really interested in science will get a good education for themselves even if their schools are failing them. But I strongly feel that it's important for every person to have a basic grounding in science, especially in the basic techniques and methodologies by which science actually works. Everyone should know the basic facts of physics, biology, and chemistry, but they should know how to formulate and test an hypothesis, and the basic notions of understanding data and uncertainties. It's not that hard, really.

What to do? I'm a big believer that some situations really are solved by throwing money at the problem, or at least they won't be solved without throwing money. But you have to throw the money in the right direction. New lab equipment and computers are nice, but aren't in the top three priorities we should be focusing on. To me, these include: 1) Sensible curricula, including realistic studies of methodology, a firm grounding in the basics of each field, and a smattering of exciting modern topics to encourage interest; 2) Vastly improved standards for the training of science teachers, including greater flexibility to allow people with more expertise in science than in education to get involved, and 3) Making elementary/secondary teaching an attractive career option.

It's only the last of these that requires serious money, but can anyone argue that it isn't worth it? Look at this study of salaries of liberal arts alumni of the University of Pennsylvania about fifteen years after graduation. It's a nice sample, since presumably everyone starts with relatively comparable education and employability. And what you find is that elementary/secondary educators are easily the lowest-paid profession (followed closely by college/university teachers!). You can do better working for a non-profit. (You can also generally do better by being male, but you knew that already.) The average teacher's salary is about $47,000, compared to the average salary for the whole sample of $164,000. You do the math. Why would a talented young person choose this field?

If we had any sense, we would embark on a crash program to double teachers' salaries across the board over the next ten years. One necessary step would be to shift the income stream for local schools from property taxes to statewide (or, even better, national) income taxes, so that the burden is distributed more equally. It's not likely to happen, but until it does we're just slapping new coats of paint on a desperately leaking boat.

~ posted by Sean Carroll at 11:23 AM ~ link ~ ~ ~

Finally some perspective

Jon Stewart, being interviewed by Larry King, chatting about Bill Clinton.

KING: So you get angry?

STEWART: You get angry because it's, you are so -- so needing of that inspiration and that leadership and that mind and that intelligence and so angry that it would be wasted on such a trifle thing.

KING: Monica Lewinsky...

STEWART: Not to suggest Monica Lewinsky is a trifle. I certainly don't want to hurt her.

(CROSSTALK)

KING: In an interview with British TV today, she said that Clinton's description of their affairs an insult to anyone who reads it. Also says that Clinton destroyed her once the liaison became known.

STEWART: She is going to come out now with a line of grief handbags. Hopefully she can knit her way to health. I don't know the woman. I'm sure she's very nice, but quite frankly, I find that if I'm embroiled in a scandal I tend to not go on British television if I don't have to. If I want to heal and be left alone, I tend to perhaps go off and try and find my way inconspicuously in the world as opposed to say going to parties where they might describe me as a portly pepper pot?

KING: Would you book her on "The Daily Show?"

STEWART: I would not.

KING: Would not?

STEWART: I would not.

KING: Have no interest, not curiosity about it?

STEWART: I have no interest. Curiosity in what sense?

KING: About her life. About what she got herself into, the events that occurred around her.

STEWART: I am very familiar with what she got herself into. I have gotten myself into that with people that I know.

KING: Elaborate.

STEWART: Sex, isn't it? You never? How many times -- you've been married like 28 times. You never had -- come on, you've got kids!

KING: Okay, yes.

STEWART: Am I going to have to draw this for you?

KING: No. OK.

STEWART: But do you know what I'm saying? Why is anyone interested in what she does?

KING: Because she's a victim and a participant and she's a footnote in history.

STEWART: Footnote in history is the perfect way to describe her and that should close the book. Footnote in history. Thank you. Finally we have some perspective.

Originally linked to at Crooked Timber (pointing to a different quote). Read the whole thing.

~ posted by Sean Carroll at 7:42 PM ~ link ~ ~ ~

Information loss

Imagine that your home is broken into by a group of physicists with mischief on their minds. They grab your collection of books and CD's, but instead of just making off with them, they crunch them together to make a black hole. (Applied physicists, obviously.) In the old days, you might have been quite despondent, thinking that all of the information in your collection of music and literature had been lost forever. However, as we all know by now, almost thirty years ago Hawking showed that black holes don't just sit there, they emit radiation, and in the process of emission they lose energy and eventually evaporate away completely (if you don't keep putting extra energy in). So now you might think that you could be very clever, and recover the information that you thought was lost: just observe absolutely every particle emitted in the Hawking radiation, and use your knowledge of what came out of the black hole to reconstruct what went in. In practice this would be a bit far-fetched, but in principle this is exactly what you could do if, for example, the pranksters had just set your collection on fire instead of collapsing it to a black hole. Physicists tend to believe that information is never really lost in physical processes, even if it gets re-arranged into less useful forms.

But black holes are different, sadly. To the best of our knowledge, there is no correlation between what went into making the black hole and what kind of radiation comes out. Indeed, there are reasonable-sounding arguments that there can't be any such correlation. In that case, the information originally present in your books and CD's has truly been lost.

Of course, we haven't seen any black holes up close and evaporating, so these are all thought experiments thus far. But it bugs people to no end to think that evaporating black holes violate such a cherished notion of physics; this conundrum is known as the black hole information loss paradox. For a long time we didn't even know whether the information could somehow be stored in a black hole, much less retrieved; more recently, however, string theorists have shown that (in many cases) that the amount of information in the black hole really is the same as contained in the stuff that went into making it. And there have been a couple of very clever proposals recently, one of which might turn out to be on the right track: Horowitz and Maldacena have suggested that the Hawking radiation that falls into the black hole is carefully arranged to cancel out the information of the infalling matter, effectively transferring it to the outgoing radiation; while Mathur has suggested that we need to dramatically change our ideas about what the interior of the black hole is like, enough so that the information is actually sitting close to the surface where perhaps it can escape more easily.

I bring this up because I have secret inside information which I now feel empowered to reveal, since the rumors seem to be public anyway. Stephen Hawking has asked to give a plenary talk at a big upcoming conference, where he says he will announce a solution to the information loss problem. As a member of the scientific organizing committee of GR17, I got the email request from our chief organizer; was there any chance we would say "no"? But actually I doubt very much that Hawking will simply announce a solution that everyone will agree with. Theoretical physics just doesn't work that way. Even if he has a clever idea, people will have to wrestle with it themselves before it would catch on. Also, Hawking isn't always right; for a long time he has been insisting that information really is lost, which is certainly a minority viewpoint. Unfortunately I won't be at the conference, which is July 18-23 in Dublin. But I'm sure we'll be seeing news reports about Hawking's talk; the media love him, for good reason.

~ posted by Sean Carroll at 1:59 PM ~ link ~ ~ ~

761 Kelvin

It's generally a good idea to hold people who are on our side to higher, rather than lower, standards than people to whom we are opposed. That is why, for example, prisoner abuses by our own soldiers are upsetting in a different way than equivalent actions by terrorists would be (not that either are okay).

And that's why I didn't think much of Fahrenheit 9/11. I should say that it did live up to my expectations, which weren't that high. Michael Moore is a talented polemicist and agitator, but also someone who is perfectly willing to use cheap ploys and judicious editing to create an emotional impact rather than a reasoned argument.

Moore has an overarching idea that colors everything he does: the conflict between the heroic genius of the virtuous working classes against the self-interested venality of the wealthy. As a result, the first half of the movie concentrates on an issue that is interesting but by no means central: the close connections between the Bush family and the Saudi ruling classes. (See also comments at Crooked Timber, Majikthise and uggabugga.)The connections are real, and worrisome; but even in the context of the movie it is not exactly clear what we are supposed to be concluding from the existence of the relationship. The movie would have been much better if it had concentrated on the war in Iraq and how it could ultimately prove disastrously counterproductive in the fight against terror, but this topic is sacrificed to concentrate on images of Prince Bandar and the Saudi embassy. Furthermore, Moore's singlemindedness prohibits him from appreciating that there were multiple reasons for turning to Iraq; many people in the administration were actually idealistic about the opportunity to establish democracy in the Middle East. They might have been crazy, but the reasons for the Iraq war stretch well beyond the straightforward desire for increased oil revenues.

As far as technique is concerned, Moore has never met a theatrical stunt or piece of sentimental melodrama that he didn't like. Concerned that members of Congress haven't closely studied their own Patriot Act? Drive around in an ice-cream truck reading it out loud. The second half of the movie is driven by interviews with a Michigan woman whose son has been killed in the war. We get pictures of her crying, talking proudly about the military service in her family, worrying about job prospects for the youth of her community, and being dragged to the White House to cry again. From this I think we are supposed to understand that war is hell. I don't see how this should be any more persuasive about the failure of our Iraq policy than interviews with the family of victims of accused murderers should sway our opinion of the death penalty.

Unlike some of my fellow liberals, I do not think that these manipulative rhetorical devices are okay when deployed in the service of liberalism because we all know that conservatives do much worse (an extension of the Lieberman doctrine that the U.S. can do nothing wrong since the terrorists were much worse). This judgment flows from a dramatic new ethical theory I have just now developed, called "two wrongs don't make a right." As has been pointed out elsewhere, Moore's movies are like strident political cartoons; they can make you laugh and feel better if you are predisposed to agreeing with their point of view, but they'll never convince you of anything. Which is too bad, since I'm sure there is plenty of good material out there to make a compelling documentary that sets out well-reasoned objections to our current misadventures. Or is that asking too much?

~ posted by Sean Carroll at 1:08 PM ~ link ~ ~ ~