Thursday, September 30, 2004
Art and theory
Last night I went with a friend to the Harvard Film Archive to see Painters Painting, a 1972 documentary by Emile de Antonio. (The Archive's film copy of the movie had been ruined and they were forced to show it from 80's-era laser disk, as a result of which embarrassment the showing was offered for free). The subject was American painters, focusing on the Abstract Expressionists and their Pop-Art and Color-Field successors. Many of the artists who were alive at the time were featured in interviews (Mark Rothko and Jackson Pollock, of course, had each died violently before the movie was made). Interesting to see how this tight-knit group of people interacted with each other, with the dealers and collectors, and with the outside world.
What stuck me, ungenerous soul that I am, was what terrible theorists the painters all were. By which I mean, they had very strong ideas about what they are doing and what other people should be doing and what kinds of art are good and bad, but these ideas are all visceral and impressionistic (as it were), rather than flowing from some set of basic axioms about what art should be. They would offer various opinions in the guise of fundamental principles, of course, but the principles were often incoherent and never really fundamental, in the sense that they could be reasonably applied to a wide variety of aesthetic moments. Instead, they were rules of thumb that happened to serve this particular person well in their particular set of circumstances. You were as likely to hear, for example, about how it was absolutely necessary to make your brushstrokes vivid and recognizable, as you were to hear that brushstrokes should always be completely imperceptible. I can imagine perfectly good reasons for either position, but these stances were offered as self-evident truths, rather than as flowing from some deeper theory.
And I don't blame the artists in particular; the few critics that were featured (Clement Greenberg and Hilton Kramer) didn't do much better. Again, they had strong opinions justified by appeals to comprehensive-sounding statements, but although their sentences were longer and more complex they didn't seem to come any closer to possessing a set of fundamental axioms from which we could begin to derive their specific judgments. Nor do I by any means think that one needs to be a good theorist to be a good artist; the empirical evidence might argue for the converse. The one artist who seemed to have a full-blown theory was Frank Stella, who spoke convincingly about why the appropriate response to gestural painting was to move toward geometric forms and liberation from the rectangular canvas. Unfortunately, at the level of a personal reaction, I found his actual paintings to be the most lifeless and least beautiful of the bunch. The poor guy couldn't seem to understand why the same people who found his work cold and uninviting were so taken with that Rothko fellow.
This is also not to say that the artists were in any way unintelligent or even inarticulate (although some were); many were very interesting to listen to. Willem de Kooning had provocative things to say about the "lightness" of American culture in contrast with that of Europe, and Jasper Johns and Barnett Newman made enlightening remarks about their use of texture and space. But you nevertheless got the feeling that they wouldn't be able to offer a good reason why, for example, it was interesting to eliminate color entirely from a deeply textured representation of the American flag; only that it seemed to work (which is a fine reason, just not a theory).
The other thing that strikes you (or me, as an underinformed amateur who is making this up as he goes along) is how reflective and tightly-coupled the painting world really is. So many of these works are simply baffling when viewed in isolation, but begin to make sense when viewed as pointed reactions to some specific innovation by some other painter. It gets even better when the artists are dragging each other to shows or even quasi-collaborating, as when Robert Rauschenberg thinks it would be fun to first draw something and then carefully erase it, but realizes that it's no fun to erase his own drawings, so convinces de Kooning to donate one of his. For my next paper, I want to convince Ed Witten to donate an unpublished manuscript, from which I will delete all of the interesting parts -- I think it would be a ground-breaking collaboration.
Wednesday, September 29, 2004
God, A Poem
By James Fenton.
A nasty surprise in a sandwich,Please rest assured that Mr. Fenton is a Major Poet, even if the above example of his work does seem like something Eric Idle should be singing.
Tuesday, September 28, 2004
I am the world's expert
I am sitting in a friend's apartment, a couple Negronis to the wind, in rejuvenation mode after my colloquium this afternoon at Brandeis (convincing the locals that the universe is accelerating, but that we don't know why -- not a hard sell, really). So I'm in no condition to comment on the mild kerfluffle that has broken out, ironically immediately after the announcement of 411blog, in response to Matthew Yglesias' lament that there aren't enough expert bloggers. But I was glad to see my honor (and, incidentally, the honor of some other people) defended by PZ Myers and other bloggy luminaries.
However, given my druthers, I'd prefer to have Fafblog exhort people to send me money. Flattery is nice, but it doesn't pay the mortgage.
(Honestly, there's a pretty basic fact here -- by percentage, most people in the world are not experts. They're not especially good writers, either. This is one of the first things you realize, I thought everyone knew, when you rambled around the internet -- there's a very good reason why magazines have editors, rather than just being first-come-first-published. The worthwhile stuff is there, but you do have to look for it a little.)
Monday, September 27, 2004
Here's an idea: rather than waiting for mistakes to enter the mainstream media and subsequently be jumped on by the blogosphere, why not offer up the expertise of the bloggers (or some delicately selected subset thereof) as a resource to journalists as the stories are actually being written? This turns the standard picture of bloggers-as-manic-guardians-of-accuracy on its head, but the category of "bloggers" is so diverse as to be an overgeneralization almost by definition, so it might work.
That's the notion, anyway, behind 411blog, a new venture set up by Andrew Cline of rhetorica.net and Jay Manifold of A Voyage to Arcturus. They are offering up a list of bloggers who have some credentials in various areas, primarily science-oriented, as a resource to journalists who would like a quick answer on some technical question.
We'll see how it goes. Success will require both that journalists avail themselves of the service, and that the bloggers offer useful input. Most science journalists have their own private lists of trusted experts in the various areas they write about, but good ones are always looking to extend their horizons. Being a blogger doesn't convey any special expertise in and of itself, but it may indicate a willingness to make an effort to reach out to a wider audience. Or, as in my case, it may just serve as a convenient outlet for one's extravagant narcissism. But as long as we can channel our neuroses in socially useful directions, what more can we ask?
Sunday, September 26, 2004
On the road again
I tend to travel a lot for work purposes, spreading the word about the accelerating universe to rapt audiences across the country. And I like the travel, and enjoy giving the talks, especially to people who are still skeptical about this whole dark-energy thing and appreciate a balanced telling of the story. But it does take time, and I am not an efficient traveler; on flights I am more likely to curl up with a good novel than to pull out the laptop and work on a paper or a referee report. So I promised myself that I would do no more than two trips per month from now on. As it turns out, in the next five weeks I will be visiting Boston (Brandeis), Tucson (University of Arizona), Urbana-Champaign, Philadelphia (University of Pennsylvania), Baltimore (Johns Hopkins), Pasadena (Caltech), and San Diego (UCSD). So you can judge for yourself how successful I've been at keeping my own promise.
It's a shame in a way, because this is my favorite time of year to be on campus. For one thing, September is a little oasis of calm in Chicago's playfully rambunctious weather patterns, and the lake and the sky are glowing magnificently. But at any university, it is always a thrill to see the campus come alive with the students returning (or arriving for the first time) after the summer exodus. We start late at Chicago because we're on a quarter system, with one quarter before New Year's and two after, so this week is actually the first week of school. I'm teaching Physics 300, "The Teaching and Learning of Physics," a required course for first-year graduate students in which we help them learn how to be good teachers. It's great for the students, if only because it conveys the impression that the department cares about the quality of teaching. (Sadly, we cannot force the faculty to take the course.) And it's great for me, as I get to meet all of the new graduate students. They are full of enthusiasm spiced with trepidation, and contemplating hard questions like whether they should refer to professors by their first names. (Answer: yes, but with exceptions, and the rules concerning exceptions can only be learned from experience.)
Speaking of traveling: a common prediction of technological triumphalists is that easy access to computers and comprehensive connectivity will eventually do away with the notion of a "conference" at which people physically assemble. From the evidence of the recent DPF meeting I attended, the reality is precisely the inverse. Conferences will continue as scheduled, but members of the assembled audience will each sit with their laptops open, connected through their wireless links to the internet, ignoring the speaker as they always have. The flaw in the triumphalists' prediction is the assumption that people don't like to travel, they just want the content you get from the conference talks. It's just the opposite: people do like to travel, and especially to shmooze at the coffee breaks, but they hate to be stuck in talks. Now that technology has liberated us from that onerous requirement, conferences will become more popular than ever. At the end of each talk, of course, some member of the audience will still ask a question that is really more of a comment.
Friday, September 24, 2004
So here's the problem
An interesting contrast comes to light by jumping around the blogosphere (kind of like playing your CD's on "shuffle").
The good news is: Kerry's problem would seem to be more easily correctible than Bush's (we hope).
By Adrienne Rich:
Thinking of Caroline Herschel (1750-1848), astronomer, sister of William; and others.This is fun, I may just turn this into a poetry blog.
Thursday, September 23, 2004
What is this quintessence of dust?
Something I didn't get around to in last week's discussion of dark energy and its equation of state parameter was the question of priors -- i.e., what do we expect the parameter to be? Physically, this is equivalent to asking how we expect the dark energy to evolve with time, if at all.
We have to admit that there is one special value that the equation of state parameter w might have: namely, w=-1, corresponding to a dark energy density that is strictly constant (equivalent to vacuum energy or Einstein's cosmological constant). In that case, the dark energy is simply a constant amount of energy that is inherent in each cubic centimeter of spacetime. Any other possibility means that the dark energy density is dynamical, and is presumably obeying some equations of motion. In the comments, Serenus was hoping that I would encourage people to be completely open-minded, and not favor w=-1 over any other value; rather, just collect the data and take the results at face value. In other words, he wants a uniform prior, in which the a priori probability of w=-1 is the same as w=-0.99 or w=-1.01.
Although I hate to disappoint anyone, I can't agree. The reason is pretty straightforward; I think it was Tolstoy who said, "Cosmological constants are all alike; every model of dynamical dark energy is dynamical in its own way." Tautological enough, but it points to an important feature of dynamical dark energy candidates -- because they have more features than simply their energy density, there are more ways they could be detected and thus more parameters you need to fine-tune to explain why we haven't noticed them yet.
The simplest example of dynamical dark energy (although by no means the only interesting one) is quintessence, a light scalar field gradually rolling down a potential. Since the field is rolling slowly, the kinetic energy is extremely small and the potential is nearly constant, giving us a nearly-constant energy density, which is just what you want for dark energy. But as soon as you allow for dynamics in this way, there are things you need to explain. For any dark-energy candidate, you need to explain why the energy density is small. But for quintessence, you also need to tell me why it is rolling so slowly; this translates into the fact that the potential must be very shallow, which then translates into the fact that the mass is very small. (The mass is a measure of the curvature of the potential; this is not exactly the same as the slope, but they should be related unless you want to do even more fine-tunings.) In particle physics, masses of scalar fields tend to be very large. The Higgs boson purportedly has a mass of order 1011 electron volts, and a big problem (the "hierarchy problem") is why this number is so much smaller than the Planck scale, 1027 electron volts.
The quintessence field, meanwhile, would have to have a mass of order the present Hubble constant, about 10-33 electron volts. So if 1011 electron volts is very small, how do we hope to explain 10-33 electron volts?
Once you know the mass is so small, you realize that low-mass particles tend to give rise to observable long-range forces. The two forces we know from our macroscopic experiences are gravitation and electromagnetism, mediated by two zero-mass particles (the graviton and the photon); the nuclear forces are less manifest because they are such short-range. So the quintessence field should give rise to an observable, long-range "fifth force." The typical way out of this conundrum is to simply declare by hand that the new quintessence field doesn't interact with ordinary matter, so we can't feel the force. But this is a cheat; we know that quintessence interacts with gravity, and gravity interacts with ordinary matter, and the miracle of quantum field theory tells us that if A and B both interact with C, then A and B will interact with each other. We can even estimate the strength of this interaction, imagining that it is suppressed by the Planck scale. Then we go look for it, for example in the delicate torsion-balance experiments at the University of Washington. The idea is that the strength of the quintessence force will necessarily be different for objects of different compositions; it's a rule that only gravity can couple to objects in a way that is completely indifferent to what they are made of. So by looking for tiny anomalous accelerations of, say, Aluminum and Copper in the direction of the Sun, we can put limits on the strength of any purported new long-range forces.
The answer is that we don't see any such forces, at least not yet. From the upper limits we currently have, the forces must be about 10-5 times less than what you might have expected. That's pretty small, although not so small (especially given the roughness of the theoretical estimate) that there's no reason to keep looking.
What's more, there is another way to constrain the direct interactions of quintessence. If you have a scalar field that is slowly evolving as the universe expands, all of the "constants of nature" tend to change along with it. That's because what we think of as constants of nature, like the mass of the up quark or Newton's constant of gravitation, are actually parameters that depend on the quantum state of the universe (just as the speed of sound depends on properties of the medium through which it is traveling). This is interesting, because there are claims that the fine-structure constant, which determines the strength of the electromagnetic interaction, has actually been experimentally observed to be varying with time. Now, to be honest, these measurements are very hard to do, and people have obtained conflicting results, and the most likely situation is that the experiments are simply in error. So there is some possibility that we have actually already detected the signature of quintessence in a time-variation of the fine structure constant, but it's somewhat safer to simply imagine that we've put a good upper limit on any such variation.
All of the above gives some reason to think that a constant vacuum energy is preferable to dynamical dark energy, simply because it makes more sense that we haven't yet detected any direct interactions (because constant vacuum energy doesn't have any). This is not really the same thing as just using Occam's Razor, which is an important principle but usually only reliable when everyone already agrees on what the correct answer is.
Of course, the idea that dynamical dark energy is a simple scalar field is a nice one, but not unique; there are other possibilities. An especially exciting possibility is that the dark energy does have non-trivial interactions, but only with hard-to-detect particles like dark matter or neutrinos. But the moral of the story remains: once you admit the possibility of dynamics, the models generally allow for all sorts of ways to detect them in principle, and you have to do more fine-tunings to explain why the dark energy hasn't been seen directly. The idea of an absolutely constant vacuum energy (w=-1) is the simplest and most robust; it's therefore perfectly permissible to imagine that it's a little more likely than the other possibilities. Personally, I give about a 10% chance that the dark energy is dynamical. But it's a testable hypothesis, and if you find some variation then you get in line for the Nobel Prize. So even if it's something of a long shot, it's well worth looking for.
Wednesday, September 22, 2004
Tangled Bank in Blue
The latest Tangled Bank is now up at Lean Left. TB is a collection of the (self-nominated) best science writing in the blogosphere over the previous couple of weeks. This edition is especially strong on bugs, in various senses of the word.
The next Tangled Bank will be hosted right here at Preposterous Universe on October 6th. All you have to do is email me (email@example.com) with a pointer to an interesting science-oriented post you have recently written, and our world-class panel of experts will make an impartial determination of your worthiness as a scientist, a blogger, and a human being (not necessarily in that order). If you are fortunate enough to pass through this rigorous screening process, you just may be included in the upcoming edition. (Sure, if you read the ground rules, you might get the impression that it's pretty easy to get accepted into the lofty company of Tangled Bank authors. Don't get complacent, that's all I'm saying.)
The Tangled Bank idea was originated by the redoubtable PZ Myers, and there was a natural slant towards things biological in the early days. (More recently it has been hosted by ornery liberals, a phenomenon still imperfectly explained.) But participation is wide open to those of us in the less squishy sciences, and I want you physicists out there to represent. If you don't volunteer I may have to hunt you down. Let's show the world that we can be lucid and enthusiastic explainers of recondite ideas, not merely the flamboyant show-offs that unfair stereotypes so often paint us to be.
Also, I'm thinking of instituting a dress code.
Men are idiots
I thought I would try to draw some traffic by having a provocative title for folks out there using RSS readers and whatnot. But it's true, I have proof:
Tuesday, September 21, 2004
Cynical thought experiments
Daniel Drezner looks at Russia and Pakistan and wonders whether the Bush administration isn't really committed to democracy-promotion after all.
Notwithstanding my political leanings and well-documented opinions about the President, I really do try (like John Rawls with his philosophical predecessors) to give people the benefit of the doubt, imagining that their hearts are in the right place even if perhaps we differ on certain particulars of strategy. And I make a good-faith effort to steer away from the far fringes of cynicism and paranoia. (Readers are welcome to comment on my success.)
But the following thought experiment occurred to me: Imagine that we were governed by an administration that was truly driven by absolutely nothing other than a desire to increase the wealth of the very wealthiest Americans. They don't care about democracy, terrorism, other countries, any of that. Perhaps they give lip service to such goals as a way of promoting their central agenda, but only for reasons of practical politics. Just imagine how they would act.
Now that you've finished imagining -- is there way in which the actions of such an administration would be incompatible with the acts of the actual administration currently in power? Any way at all? (I'm open to the possibility that there are, let me know if there's something obvious that I'm missing.)
For extra credit, discuss the conclusions that would be drawn from this thought experiment by a Comtean positivist, a Machiavellian realist, a Deweyan pragmatist, and a Popperian natural scientist.
A good day for political cartoons
In honor of Ye Olde Phart, who is going on vacation (hopefully temporarily).
Monday, September 20, 2004
Staring hard questions in the eye
Fafblog! has another hard-hitting political interview, this time with that wacky duo, God and Satan.
FB: What can we do to make sure that American politics is Godly politics?(Is it me, or does Satan sound like Howard Dean?)
But the best part was the link to the always-zany Presidential Prayer Team. With the power of prayer on their side, the visionaries at the PPT are never afraid to confront the difficult questions that bedevil those of us of lesser virtue. Consider for example today's PPT Poll Question: "Have you, personally, grown spiritually stronger since September 11, 2001?" Happily, we click on the link to discover ... Yes! Most of us have grown stronger! Only a tiny fraction have declined, or merely maintained their previous level of spiritual strength (no distinction between these two possibilities was made in the poll). And perhaps they clicked the wrong choice by accident (for example, if they were from Florida).
We fear, naturally, the creeping menace of sample bias -- perhaps only PPT visitors have grown spiritually stronger? What if the rest of the country has weakened in the face of adversity? Pray harder!
Provando E Riprovando
Leave it to Umberto Eco to draw together the recurring themes of the humble blog before you. From Arts and Letters Daily, a link to a rumination by Eco on Stephen Hawking's recantation of his previous stance that black hole evaporation destroys information. Eco uses the occasion of Hawking's flip-flop to draw a distinction between science and idealistic philosophy. (Thanks to Norman Graf for the last link.)
It's a distinction well worth drawing. One of the reasons why it's hard to define "science" is that the nature of scientific theories keeps changing, with concurrent debates about what really counts as scientific (e.g., whether entities we can never in principle observe should be part of a respectable scientific theory). But the distinguishing feature of science is not the theories it produces, but the methodology it uses for getting there. Eco labels the crucial feature of this methodology "provando e riprovando," Italian for "try and try again." That is to say, we propose all sorts of ideas, not because we have convinced ourselves that they are right, but because we don't know what is right and we're searching through all of the possibilities. Ultimately, agreement with the data will be the deciding factor, and often we can be very surprised at what kinds of theories come out on top (quantum mechanics being the most notable example.)
This strategy is something that non-scientists have trouble really believing in, even those who rub up against science every day. For example, I have been heavily involved in studying models of dark energy, or more broadly why the universe is accelerating. One idea that received some attention is the possibility that Einstein was wrong, and we have to modify gravity on cosmological scales. In talking to journalists, they would often ask me to explain why my theory was better than the alternatives. I had to explain that I didn't think it was better than the alternatives -- it was interesting and provocative, and it had a chance of being correct, but I didn't necessarily believe that it had a better chance than anything else. We don't only propose ideas we are convinced are right; we propose lots of things and let the chips fall where they may.
Even scientists and other academics don't always quite get the idea. I recall a talk given by an evolutionary psychologist, about the new center he was trying to found. The point of this center, according to his conception, was to demonstrate how important behaviors can find their explanations in the evolution of adaptive strategies. This is a terribly depressing mistake; the point of science is never to "demonstrate" anything, it's to sift through the interesting alternatives and decide which works the best, keeping an open mind at all times. (There is some art, to be sure, in deciding which alternatives are even worth our attention, and at what point a question can be considered to be satisfactorily settled.) If the "physics envy" felt in other disciplines were directed toward this kind of open-minded methodology, rather than to the impressively quantitative final products of physics, the world would be a better place.
It's not a coincidence, of course, that Eco also wrote the article on fascism that I commented about a sort while back. Nor is it a coincidence that scientists are especially riled up by the transgressions of the Bush administration (much more so than their general liberal tilt can explain). The distrust of indecision and ambiguity that is a hallmark of our current administration is an especially anti-scientific attitude. So you see, the science and politics posts here at Preposterous do share deep connections. Still no explanation for the posts about poker.
Saturday, September 18, 2004
The Uncertainty of the Poet
By Wendy Cope.
I am a poet
Friday, September 17, 2004
A great post by Belle Waring on Why I Was So Totally Wrong About Iraq. Her first few reasons for supporting the war:
1. This is the most personally embarrassing reason, but it has to be said: in the aftermath of 9/11 I lost my head a bit and wanted to take some decisive action. I realize that attacking party B after being attacked by party A shouldn't be satisfying to the vengeful-minded, because it doesn't make any sense. But, having just been in the odd position of agreeing with the Bush administration on a war (vs. Afghanistan), I somehow found the next war more appealing than I should have. Somewhere in here there must also be a kernel of "let's smash something to show how powerful we are." This is really poor reasoning and reflects badly on me personally. Nothing much I can say about it in my defense.Keep reading. I am fervently anti-war, but it wasn't an open-and-shut case; Saddam was a bad guy, and people were feeling frustrated and needing to strike back somehow. I have the greatest respect for people like Belle who can fully admit that they were mistaken on this, more so than I have for people who are anti-war because they are anti-any-war-ever.
One aspect I think is not emphasized enough: the extent to which the desire to go to war was created, rather than just acted on, by the Administration. Invading a country is a big decision, not undertaken lightly, and there really wasn't anything like a close connection between the Islamist fanatics behind September 11 and the secular fascists in Iraq. If a different set of people had been in the White House, the idea of attacking Iraq wouldn't have ever gotten off the ground, even among the most pugnacious fringes of the punditocracy. Everyone would have been in favor of finishing the job in Afghanistan, followed by the tough decisions about how to handle North Korea, Saudi Arabia, and Iran.
Thursday, September 16, 2004
Modern voter education
Via uggabugga, a set of recommendations for what books voters should be reading to prepare themselves for the upcoming election, offered by our leading pundits (in the broadest possible sense of "leading"). To demonstrate that neither end of the political spectrum has any monopoly on self-importance, Ann Coulter and Gore Vidal vie for the title of most self-recommendations.
The best list was offered by the incomparable Jon Stewart, who is funny even when nobody is getting his jokes. Here are his recommendations for what voters should be reading.
I just noticed that Preposterous is getting occasional hits from the University of Chicago admissions site. They are letting the prospective students know that I have a blog, as if that's a good thing!
So I guess I might as well point out that the UofC has been ranked Number One in the Best Overall Academic Experience for Undergraduates by the Princeton Review. Not too shabby for a place known lovingly as "Where Fun Goes to Die."
Wednesday, September 15, 2004
No technological development will result
There's a nice article at the Chicago Sun-Times about the scenario Jennie Chen and I are developing to explain the relationship between inflation and the arrow of time. I promise to say more about it once our paper is actually written. Real soon, honest.
Okay, this was so my idea. For many years I've been pointing out to all who would listen that there are millions of dollars to be made by taking some common food item and tricking it up to be both better and fancier-looking. It's worked with mustard, with coffee, with ice cream, even with water for crying out loud. The missing example was perfectly obvious: ketchup. You could have gourmet ketchup that was thicker and had interesting texture and consistency, and offer it in a variety of flavors: spicy varieties like jalapeno or curry, sweet flavors like honey or cinnamon. Millions of dollars, I promise.
But apparently someone is already doing it (of course). The Sept. 6th issue of the New Yorker has an article by Malcolm Gladwell (not online, sorry) about Jim Wigon and his gourmet ketchup business. Unfortunately, Wigon doesn't seem to be doing it correctly. He's named his company "World's Best Ketchup," which is just silly. Just as Grey Poupon got fantastic mileage out of the faux-French presentation, with ketchup you should hint at some exotic Asian background -- perhaps Indonesian or something. (It's possible that ketchup derives from a Chinese fish sauce brought back to Europe by British sailors -- but the truth is hardly the point here.) You have to sell the lifestyle, not just the condiment.
I'd be disgustingly rich by now if I weren't so devoted to selflessly exploring the secrets of the cosmos.
Update: The New Yorker article is now online, as pointed out by Eric in the comments. Gourmet ketchup afficionados might also be interested in gourmet cheesesteaks.
Click to enlarge.
Not really authentic, I'm afraid. The Sloganator was a little script at the official Bush-Cheney web page that allowed you to type in whatever slogan you wanted, to create a genuine campaign poster. At least, it used to be, until Wonkette and her friends had too much fun with it. For a brief moment yesterday it came back to life, but now it's gone again (you can still make posters, but only with pre-selected group names). There is still an unofficial back-up Sloganator you can use to make posters; I couldn't resist my own Bush-Cheney campaign motto.
Tuesday, September 14, 2004
At the Scientific Indian. Sure, you know that red meat comes from slow-twitch muscles and white meat from fast-twitch muscles. But do you know why they change color in different ways as they're cooked?
Focus focus focus
We have the worst President in at least the last century, perhaps in history. He is quite vulnerable in the upcoming election, purely on the merits. And yet Democrats are obsessed with events of thirty years ago in the candidates' personal histories -- Kerry's medals, Bush's craven irresponsibility. Knock it off! The Republicans would like nothing better than to change the subject from the monumental screw-ups of the last four years. Be like the Poor Man, and focus on the shocking revelations from the new Kitty Kelley book.
It's not so hard to write down a model of phantom energy: just invent an ordinary scalar field, but with a negative kinetic energy. Left to its own devices, such a field will gradually increase its potential energy, leading to a net increase in the energy density, so cosmologists would measure the equation-of-state parameter w to be less than -1.
But just because you can write a model down doesn't mean it makes sense. Remember that, in a model-independent sense, there was a good argument against w<-1: it violates the Dominant Energy Condition, which is the requirement that assures us that energy doesn't propagate faster than light. So could their be something fundamentally sick about theories of phantom energy? Well, yes. In particular, the energy density is not bounded below -- as the field vibrates more and more, you can create a negative energy that is as large as you like. This means that the theory is not stable. Ordinarily in field theory, we like to invent models that have a unique "vacuum state," the state of absolutely lowest energy; all other states are excitations of the vacuum, with an unambiguously larger energy. Then we can be assured that the dynamics don't go crazy; systems will tend to oscillate around the vacuum, or (in the presence of friction or other damping forces) gradually wind down to the vacuum. But if there is no vacuum, the system can simply run away, like a ball rolling down a hill with no bottom. This possibility is not so horrifying in principle, but conflicts with the apparent stability that we observe around us in Nature. Think of it in terms of particles. The world is made of fields, but quantum fields, not classical ones. When you quantize a field, and then observe it, you see particles. For a phantom field, the negative kinetic energy implies that the particle excitations have a negative mass. (In contrast to tachyons, which have an imaginary mass.) This helps us to see why there is an instability: starting from a purported "vacuum" state of completely empty space at zero energy, we can imagine processes that conserve energy while creating large numbers of positive-mass ordinary particles plus compensating numbers of negative-mass phantom particles. Empty space itself is liable to dissolve into a bath of billions of particles!
This is why most particle physicists just laugh at the idea of phantom energy: it seems ruled out before you even start. But because there is so little we know about dark energy, it's a good idea to keep our options open. In collaboration with Mark Hoffman and Mark Trodden, I wrote a paper examining whether the idea of phantom energy could be part of a larger scheme that was not obviously ruled out. The idea is a very common one in field theory: you have some model (an "effective field theory") that describes everything perfectly well, but only at energies below some cutoff where unknown physics kicks in. This is an interesting feature about quantum field theory; the effect of high-energy processes is to change the parameters (the coupling constants) of your low-energy theory, but not to produce qualitatively new phenomena. In other words, dramatic new physics at high energies is basically hidden from our sight, subsumed in the quantitative behavior of the low-energy physics we can actually observe. (That's why the best way to learn new particle physics is to build particle accelerators of ever-higher energy, and also why it's so damned difficult to get any direct experimental handle on string theory or other models of quantum gravity, which live way up at the Planck energy.)
So we asked the question: could phantom energy be right, if only as an effective field theory valid below certain energies? If the phantom theory were valid up to arbitrarily large energies, not only would the vacuum be unstable, the decay rate would be infinite! What we found is that you can indeed imagine that there is a cutoff beyond which the phantom description doesn't apply, and if that cutoff is awfully low (about a milli-electron-volt) the field would be essentially stable over the lifetime of the universe. (Some of our numbers have been brought into question in a paper by Cline, Jeon, and Moore.) An explicit example of the kind of cutoff we were proposing was later investigated by Arkani-Hamed et al.
There's an additional possibility, that I've investigated more recently with Trodden and Antonio DeFelice. This is that there is no phantom energy, and the real equation-of-state parameter w is -1 or larger, but that we can be tricked into thinking that we've measured w to be less than -1. That's because we never really measure w; what we measure is the expansion of the universe, and use general relativity to infer the properties of the dark energy. But general relativity might not be right. We investigated the specific example of a scalar-tensor theory, where some scalar field was causing the value of Newton's gravitational constant to gradually vary with time. Then what you're measuring in cosmology isn't simply the behavior of the dark energy, but some combination of the dark energy and the gravitational scalar field. We found that you can indeed be tricked into thinking that w is less than -1, but only with a very unnatural behavior for the scalar field; most of the time, we would have already detected the variation of Newton's constant right here in the Solar System long before you would measure some unusual behavior of the expansion of the universe.
The lesson is simply this: don't be too dogmatic, but do be honest, when you are inventing theories of something you are as clueless about as the dark energy. Theorists need to be quite careful; if they are going to propose models of phantom energy and so forth, they need to do the hard work of determining whether their models are stable and otherwise well-defined. But observers shouldn't take too seriously the grandiose claims of theorists about what is and is not possible; they should do their experiments and see what the data imply. It would be a shame to miss out on a fantastic discovery because you believed some theorist who told you it couldn't possibly be there.
Monday, September 13, 2004
Habermas, Derrida, and speech
Found at Arts and Letters Daily, an excerpt from an interview with Jürgen Habermas talking about his relationship with Jacques Derrida:
When he received the Adorno Prize, Derrida, for his part, gave a highly sensible speech in the Paulskirche in Frankfurt, in which the spiritual affinity of these two minds was impressively manifested. This kind of thing leaves one not unmoved. Actually, over and beyond all the politics, what connects me to Derrida is the philosophical reference to an author like Kant. Admittedly -- and though we are roughly the same age, our life histories have been very different -- what separates us is the later Heidegger. Derrida's thinking has appropriated the Jewish-inspired perceptions of a Levinas. In Heidegger, I confront a philosopher who failed as a citizen -- in 1933 and especially after 1945. But even as a philosopher, he is suspect to me because, in the 1930s, he received Nietzsche precisely as a neo-pagan, as it was then the fashion to do. Unlike Derrida, whose reading of "Andenken" accords with the spirit of monotheistic tradition, I take Heidegger's botch-job "Seinsdenken" as a leveling of that epochal threshold in the history of consciousness that Jaspers had called the axial age. According to my understanding, Heidegger committed treason against that caesura which is marked, in various ways, by the prophetic-awakening Word from Mount Sinai, and by the Enlightenment of a Socrates.I have no comment to add to this, except that I would love to be able to talk like that extemporaneously.
Last time we talked about dark energy and its equation-of-state parameter, w. This number tells you how quickly the dark energy density changes as the universe expands; if w=-1, the density is strictly constant, if w>-1, the density decreases, and if w<-1, the density actually increases with time. (In equations, if a is the scale factor describing the relative size of the universe as a function of time, then the density goes as a-3(1+w).) For comparison purposes, cosmological "matter" (slowly-moving massive particles) has w=0, and "radiation" (relativistic particles, including photons) has w=1/3.
Einstein's cosmological constant is just the idea that there is a fixed minimum energy density everywhere in the universe; this vacuum energy would correspond to w=-1. It's easy enough to get an energy density that slowly diminishes, with w>-1; all you need to do is invent some scalar field slowly rolling down a very gentle potential, so that the energy is nearly constant but in fact gradually diminishes.
What about w<-1, corresponding to a gradually increasing energy density? It's not what you would typically expect; the expansion of the universe tends to dilute energy, not increase it. So for a some time cosmologists who put observational limits on the value of w would exclude w<-1 by hand. In fact, I am somewhat to blame for this custom. As far as I know, the first paper to constrain w using supernova data is the one by Garnavich et al., the High-Z Supernova Team. I am friends with these guys -- Brian Schmidt, leader of the collaboration, was my officemate during grad school -- and one day they called me up to ask whether there was a good reason why they could ignore w<-1. In general relativity, it often happens that we want to make some general statements about possible solutions without knowing exactly what the matter/energy sources are, so we invoke "energy conditions" that put some reasonable constraints on what the sources can do. The most physically reasonable condition is the Dominant Energy Condition (DEC), which is what allows you to prove that energy can't propagate faster than the speed of light. So I pointed out that imposing the DEC would exclude the w<-1 possibility. I wrote a couple of paragraphs to this effect, and got included as a co-author on the paper; afterwards, people were happily ignoring w<-1 a priori.
Most people, anyway. A notable exception was Robert Caldwell at Dartmouth, who wrote a paper suggesting that w could be less than -1, and built an explicit model. The idea was simple: have a scalar field rolling in a potential, but give it a negative kinetic energy. That means that the field tends to roll up the hill to the top of the potential, rather than rolling down to the bottom. The energy density thus tends to increase, implying w<-1. Caldwell called his idea "phantom energy," both because the Phantom Menace had just come out and also because negative-kinetic-energy fields also appear in the context of quantized gauge theories, where they are called "ghost" fields.
More recently, Caldwell collaborated with Marc Kamionkowski and Nevin Weinberg on the idea of a "Big Rip." If w is less than -1 and constant, the energy density grows without bound and everything in the universe is ripped to shreds at some finite point in the future. This is a fun idea to think about, but some observers took it too seriously, and began phrasing their limits in terms of how many years would have to pass before there would be a Big Rip. That is just silly; even if w<-1, there's certainly no good reason to think it's a constant.
I've gone on too long again. Next time, I promise, I'll talk about my own papers, which are what you really care about, I know. Maybe I'll even talk about what w probably is, in addition to what it is allowed to be.
Saturday, September 11, 2004
Sorry, this post isn't about dark energy, it's making fun of John Kerry. (We always taunt the ones we love.) So what is it with his policy of not talking to the media? Does he think this is a good way to get favorable press coverage? It's gotten so bad that the pool reports are regularly making fun of him:
He's got to understand: the Saddam jibe is a softball question! He should have turned to the reporter and said this:
I'm sorry, but I couldn't hear you very well. I think what you just asked was, "If you were president, would one thousand American servicemen and servicewomen still be alive? And would we be fighting the war on terror in places where actual terrorists are located, with the support of the world behind us?" Why, yes. Yes, those troops would still be alive, and we would be fighting a more effective war on terror. Very astute question.
Friday, September 10, 2004
The dark energy equation of state
As Preposterous readers know all too well, about seventy percent of the stuff in the universe is a mysterious substance called dark energy (unless general relativity is breaking down, which is interesting but less likely). We know only two things about the dark energy: it is spread nearly uniformly throughout space, and its density is nearly constant as a function of time. In other words, it doesn't dilute as the universe expands, unlike the energy in ordinary matter and radiation. So as time goes by, the dark energy becomes more and more dominant, as ordinary stuff becomes increasingly rarefied. (Worried about conservation of energy? Don't be.)
But we don't understand the dark energy that well, so we want to measure its properties as precisely as possible to get clues as to exactly what it might be. The simplest possibility is that it's vacuum energy, or the cosmological constant -- a perfectly constant energy density inherent in the fabric of spacetime itself. But it could also be something dynamical, changing in density gradually as the universe expands. In that case, we can hope to measure how fast its changing by looking at the evolution of the expansion rate of the universe; according to Einstein, the expansion rate (the Hubble constant) is proportional to the square root of the total energy density. We can make this measurement using a variety of cosmological probes -- supernovae, large-scale structure, the evolution of galaxies and clusters, the cosmic microwave background, gravitational lensing, gravitational waves, and more -- and there is a grand multi-pronged program under way to do just that over the next decade or two.
There are an infinite number of ways that some quantity (the energy density of the dark energy, or equivalently the expansion rate of the universe) can change with time, but we don't measure things with infinite precision. So we need to decide how to simply characterize the results of what we measure. Cosmologists have settled on quoting the equation-of-state parameter w, defined as the ratio of the pressure of the dark energy to its energy density. The interesting thing about dark energy is that it has a negative pressure, a/k/a a tension. This isn't so surprising all by itself; a stretched rubber band has tension, too. It's this tension that allows the density to persist as the universe expands. (Said another way, not necessarily more helpfully, the deceleration/acceleration of the universe depends on the energy density plus three times the pressure; so a large negative pressure induces acceleration, while a positive energy density without any accompanying pressure would cause the universe to decelerate.)
The equation-of-state parameter governs the rate at which the dark energy density evolves. For a perfect, unchanging vacuum energy, we have w=-1: the pressure is equal in magnitude and opposite in sign to the energy density. If w is a little bit greater than -1 (e.g., -0.9 or -0.8), the dark energy density will slowly decrease as the universe expands. This would be the case, for example, if the dark energy were the potential energy of some slowly-rolling scalar field (sometimes called "quintessence"). Current experimental bounds tell us that w=-1 is the central preferred value, but there is room for improvement; see the plot at the bottom of Licia Verde's page for the latest results.
This is all preliminary to mentioning the most recent paper I've written, which I'll do in the next post. (For a preview, see these slides from a recent talk [pdf].) If w is less than -1, the energy density of the dark energy is actually increasing as the universe expands. Is this okay? Have cosmologists gone crazy? Stay tuned for our exciting conclusion!
Thursday, September 09, 2004
The latest Tangled Bank is now up at archy. I humbly submitted my Q&A about testing general relativity. Maybe some anti-evolutionists will read it and start wondering if perhaps GR is "just a theory."
The next Tangled Bank will be hosted at Lean Left. As PZ Myers notes, there seems to be a general leftward tilt in the scientific slice of the blogosphere, at least that part which contributes to TB; this isn't intentional, it just works out that way. Probably because liberals believe in objective truth, while conservatives have been forced by recent events to become shifty relativists.
Wednesday, September 08, 2004
The Genesis spacecraft, a NASA mission designed to collect particles from the solar wind and bring them back to Earth for study, has crashed into the Utah desert. Apparently there were at least two problems, likely to be related: the craft was not correctly rotating so as to maintain its attitude during descent, and the parachutes that were supposed to break its fall never opened. The original plan was for a daring rescue in which stunt pilots would snag the vehicle as it fell to Earth. It's not clear at the moment whether the samples will be able to be recovered; scientists are examining the craft carefully, as the parachutes may still be explosively deployed.
How would Jesus vote?
From Crooked Timber, the local political news is fraught with religious significance: Alan Keyes says that Jesus wouldn't vote for Barack Obama. (Presumably, He would vote for Alan Keyes, although Keyes is too humble to draw the obvious conclusion.)
For we non-believers, these esoteric theological discussions are all very confusing. I've gotten the wrong impression countless times by simply reading the Bible without an expert commentator at my elbow to help me along. Consider for example the famous passage in Matthew 19:24:
And again I say unto you, It is easier for a camel to go through the eye of a needle, than for a rich man to enter into the kingdom of God.(The story is repeated in the other synoptic gospels, Mark and Luke.) Now, the meaning here seems pretty straightforward to the uneducated reader -- rich people are going to have a really hard time getting into Heaven. An impossible time, actually; as Jesus surely knows, camels don't fit through the eyes of needles. (Some weasels try to claim that the "eye" was really a gate outside Jerusalem, or the "camel" was really "rope," but these ideas have been rightfully smacked down.) But that's only because I'm a naive reader of the scriptures. At least I am quicker on the uptake than Jesus' disciples, who dutifully play the straight man:
When his disciples heard it, they were exceedingly amazed, saying, Who then can be saved?Here I would have expected Jesus to slap the disciples, aggravated at their cluelessness. If rich people won't enter the kingdom of God, it seems pretty obvious that Heaven would be populated by (formerly) poor people. But that's why I'm a physicist rather than the Messiah. Jesus explains:
But Jesus beheld them, and said unto them, With men this is impossible; but with God all things are possible.So the point is not that rich people won't enter Heaven; it that's they can only enter with the help of God (just like everybody else)! All those parts of the Bible where Jesus appears to be saying disdainful things about wealth are really just a smokescreen -- what's important is not how much money you have, but how deeply you believe in Him. Otherwise how could our President stand a chance?
So I'm not going to offer an opinion about who Jesus would vote for. For all I know, He may think that the good citizens of Illinois should walk around carrying concealed machine guns. Sure would make the morning commute on the El more exciting!
Tuesday, September 07, 2004
Disagreement is Treason
Brian Leiter, prompted by Jessica Wilson, who was prompted by an essay at That Good Night, wonders whether recent events in the U.S. can usefully be thought of as proto-fascist. Specifically, are there interesting parallels between the U.S. today and Germany in the 1930's? Let me go out on a limb here and provide a straightforward answer: yes and no.
"No", in that I think there is essentially zero danger of the U.S. transforming into a fascist dictatorship any time in the foreseeable future. For one thing, as wrong-headed as they may be, nobody in the Bush administration actually wants to overthrow democracy. (Okay, maybe Ashcroft, but he's only one guy.) It's true that they want to paint everything in black and white and portray any kind of disagreement as treasonous, but that's not enough to qualify as fascism. More importantly, democratic ideals are simply too deeply ingrained in U.S. society to allow any realistic chance of transforming into a dictatorship.
So, one's first response is to think that even asking the question is somewhat alarmist, if not hysterical. But we should keep in mind that historical fascism was quite popular at certain times in certain places, and it's perfectly reasonable to ask whether the impulses that led to some of the dramatic movements of the past are at work in our present situation. In a more recent post Leiter points to this short essay by Umberto Eco, discussing the universal characteristics of fascist societies. I have to say, some of the features Eco identifies are uncomfortably familiar. For a while now, like many other liberals, I've been trying to understand how any reasonable person could possibly support the current administration, which makes wrong choices nearly every time by any sensible criteria. Of course there are many answers to this question, but I think one huge factor (reflected quite explicitly in the campaign rhetoric) is the valorization of certainty (or "decisiveness") over nuance or complexity ("flip-flopping"). There seems to be a strong feeling among Bush supporters that taking a definitive stand is more important that what that stand is. I don't mean to be condescending, but this point of view is so alien to me that I can't really do it justice. To these people, the war in Iraq was justified because Saddam was our enemy, regardless of the absence of weapons of mass destruction or any connection between Iraq and 9/11. It is taken as a sign of strength, rather than a bumbling approach to diplomacy, that our nominal allies are predominantly aligned against us across a range of foreign-policy questions. It is to these people that Dick Cheney's smirks at Kerry's "sensitive war on terror" are directed -- in this view, the last thing you want to do in a war on terror is to understand the minds of the enemy.
To get back on track: Eco makes a strong case that a main theme of fascism is to establish a comfortable zone of certainty in which dissent, and even ambiguity, are considered traitorous. It is a feeling fed by resentment, both of ruling elites generally and of intellectuals in particular. You can see how such a stance might be compelling -- it feels good to be a virtuous Everyman, defending one's way of life against enemies at home and abroad. In a complicated world, there is comfort to be found in leaning on simple, strong, patriotic truths, whether decorating the town with American flags or lashing out with the armed forces. When Ann Coulter labels liberals as treasonous, or Zell Miller gives soldiers credit for freedom of speech, or Rick Santorum demonizes gays and atheists, they are appealing to exactly this feeling of unreflective anger.
After reading Eco's essay, I am no more convinced than before that we are in any danger of becoming a fascist state, but I do think that the underlying principles of proto-fascism have something important in common with the motivating philosophies of the Bush administration. It explains much of what is otherwise confusing about Bush's policies, especially to more libertarian-leaning conservatives. From the crusade against gay marriages, to the dramatic undermining of independent scientific advisory councils in policy making, to the cheerful disregard of judicial due process, to the sanguine acceptance of budget deficits and protectionist trade policies, we see a consistent appeal to a resentful and frustrated middle class.
There is a danger in throwing around scare words like "fascism", that we will denigrate the level of political discourse even further. But we shouldn't forget that historical fascism really was attractive to a large number of people, and for strong reasons; it's not impermissible (yet) to think soberly about what those reasons were, and what relationship they have to political currents that still run strongly today.
Moment of silence
A nice gesture from the director of Fermilab.
Date: Tue, 07 Sep 2004 09:31:35 -0500
Monday, September 06, 2004
As a Labor Day special here at Preposterous, we offer some advice for anyone out there who might be thinking of becoming a professional academic physicist. Fortunately, since the spirit of Labor Day is that you're not supposed to do any work, I can just link to other people who have already written various pieces of good advice.
Sunday, September 05, 2004
Sunday song lyric
With apologies to Juan Non-Volokh, it's time for another Sunday song lyric. This time from progressive-rock supergroup Emerson, Lake & Palmer, with bonus theological commentary!
The Only Way (Hymn)Okay, not the most sophisticated statement of the problem of evil (and Lake is trying to sing way outside his range). But when I was younger, hearing this song was what made me realize it might actually be okay to not believe in God.
Saturday, September 04, 2004
I'm late learning this, but Fred Whipple passed away on August 30th at the age of 97. He was best-known for his work on comets, and played an important role in U.S. astronomy as director of the Smithsonian Astrophysical Observatory (now merged with the Harvard College Observatory to form the Harvard-Smithsonian Center for Astrophysics). I met him a couple of times as a graduate student in the Harvard Astronomy Department; he was a warm and friendly spirit as well as a major figure in astrophysics.
Update: My Ph.D. advisor, George Field, was close friends with Whipple. George mentions with pride how the speakers at the funeral stressed Whipple's atheism.
Friday, September 03, 2004
Probability of discovery
I'm always on the lookout for ways to make money off of my esoteric physics knowledge. Here's one: you can bet on the chance that a big physics experiment will discover something by a certain date. Inspired by an article in New Scientist on large physics experiments, Ladbrokes betting agency is placing odds on various possibilities, and taking cash bets up until Sept. 6th. The four bets up there now are: LIGO discovering gravitational waves by 2010 at 2-1; understanding the origin of cosmic rays (presumably they mean ultra-high-energy cosmic rays) by 2010 also at 2-1; discovery of the Higgs boson by the ATLAS experiment at CERN's Large Hadron Collider by 2010 at 3-1; and completion of a working fusion power station by 2010 at 40-1. Personally I would happily wager 100 pounds to win 300 on the Higgs being discovered, although I'm not sure what happens if the CMS experiment finds it rather than ATLAS. A fusion power plant is very unlikely. I don't know what counts as "understanding" cosmic rays, so I'd be a little leery of that one. LIGO finding gravitational waves by 2010 is a trickier one -- everybody things gravitational waves are out there, so the bet depends more on the technological progress (and funding) of the observatory, which is hard to predict.
Thursday, September 02, 2004
Blogs are the best thing ever
As someone with his finger firmly on the erratic pulse of the American body politic, I might at some point in the past have thought of it as my patriotic duty to watch at least a tiny portion of the Republican convention. But in these enlightened and blogospherical times, ordinary folks are saved from the need to torture themselves by the generous sacrifice of intrepid souls with a modem and a sense of humor; between Michael Bérubé and Fafblog!, it's better than being there.
Since this seems to be Provocative Day here at Preposterous, I might as well throw this one out there: the Search for Extraterrestrial Intelligence (SETI) project has found a signal they can't explain, possibly originating from an extraterrestrial civilization. This is something I'm truly not an expert on, so I'll just point you to some commentary from Simon DeDeo, who brought this to my attention. (Original data here.) The basic idea is that they've found a signal at 1420 megahertz (a very noisy part of the electromagnetic spectrum) that has appeared a few times, starting at a fixed frequency and slowly drifting (as if Doppler-shifted from a moving source). Certainly the most likely explanation is some perfectly mundane, although interesting, source of emission in atomic hydrogen. I would put the chance that we've actually found some intelligent life to be about one in a million. But that's a chance worth exploring.
Interestingly, the signal was first identified via the SETI@Home project, running as a screensaver on countless home computers. I have it on mine. We physicists are introducing Einstein@Home, a way you can help search for signals of gravitational waves from LIGO data, but if we've found aliens that will never catch on.
Now, what I want to know is, do these aliens feel emotions?
Update: Ooops! Almost before I finished typing, Simon points me to this disclaimer. Now I know how Matt Drudge must feel all the time.
At a big multi-disciplinary conference like the European Forum at Alpbach, the real fun is not giving your own presentations but sitting down over some Hefeweizen and chatting with some of the other participants. One of the students in our seminar was a Dutch psychologist who explained to us what an emotion really is. Unfortunately I don't remember his name, and also unfortunately I am not at all an expert in talking about these things, but let me try to explain his major idea.
The claim was essentially that true "emotional states" are not distinguished by the kind of response a creature gives, but the timing: emotions are distinguished by persisting long after the stimulus that has caused them has been removed, or by being prompted by conditions that merely recall the original stimulus, rather than duplicating it. The example given was that we get chewed out at work by our boss, get angry, but rather than actually taking it out on our boss (which might be maladaptive behavior) we go home and act cross to our family. In contrast, most animals (chimpanzees perhaps being the only counterexample) are "machines," reacting simply to the stimulus of the moment. They might remember previous stimuli, and react appropriately with fear or joy if it looks like the stimuli might return, but they don't nurse emotions that cause apparently-inappropriate responses long after the stimuli have disappeared.
The empirical support that was adduced for this position was the role of the frontal lobe in the feeling of emotions. Lobotomized patients, whose frontal lobes have disconnected from the rest of their brains, have IQs that are essentially unchanged, but become completely different people as their emotional responses are dramatically altered to the point of almost disappearing. Interestingly, these patients also lose the ability to plan future events, even something as simple as a dinner party. The claim is thus that it's the frontal lobe, which is much more developed in humans than in other animals, that provides us with the ability to experience emotional states. (In 1949 the Nobel Prize was awarded to Egas Moniz for the development of the frontal lobotomy technique for treating patients with schizophrenia; this has often been called the biggest mistake in the history of the Prizes, although the official Nobel website seems less than completely contrite.)
It seems clear that there is some complicated relationship between emotions, persistence, and the frontal lobes, although it's not perfectly clear to me that the idea of maintaining a response even after stimuli are removed is really the most important aspect of emotions. But there are clearly consequences for the question of animal rights, namely that we should not attribute true emotional import to signs of animals' "suffering"; when the lobster is struggling to get out of the pot of boiling water, this is merely a robotic reaction, not analogous to a true human emotion (so the reasoning goes). In fact, our Alpbach friend related amusing stories about how he had been invited to speak at gatherings of animal-rights activists, who had apparently noticed that he had done research on animals and emotions without looking closely at was his conclusions were. Happily, he managed to escape the meetings in one piece.
So if emotions are what separates us and the chimps from the rest of the animal kingdom, what is it that separates us from the chimps? In one sense, not much; I just finished reading Will Self's novel Great Apes, which features a London artist who wakes up one morning to find that the roles of chimps and humans have been miraculously interchanged, complete with horrible puns ("going humanshit" and worse). I tend to agree with Steven Pinker that grammar is what separates us from other animals; the subjunctive mood is what makes us human. This fits in well with my social-contractarian outlook; human beings can get together and make up rules about how we agree to act in certain situations, something other species just can't do.
But I better quit roaming outside areas I know anything about before I completely destroy my credibility in those areas in which I'm supposed to be an expert.
Wednesday, September 01, 2004