A More Perfect Union

Barack Obama gave a major speech on race in Philadelphia today. Inflammatory statements by his pastor, Jeremiah Wright, have been receiving a lot of media attention — they feed into fears that many Americans have about a black guy with a funny-sounding name. Obama has strongly condemned the statements, but refused to dissociate himself from his pastor.

Instead, as evidenced in this excerpt from his speech (which he wrote himself), Obama is choosing to respond with a nuanced and honest assessment of race-based resentment in America. It’s a novel strategy; we’ll have to see if the collective attention span of the media and public is up to the task of absorbing something like this.

… This is the reality in which Reverend Wright and other African-Americans of his generation grew up. They came of age in the late fifties and early sixties, a time when segregation was still the law of the land and opportunity was systematically constricted. What’s remarkable is not how many failed in the face of discrimination, but rather how many men and women overcame the odds; how many were able to make a way out of no way for those like me who would come after them.

But for all those who scratched and clawed their way to get a piece of the American Dream, there were many who didn’t make it – those who were ultimately defeated, in one way or another, by discrimination. That legacy of defeat was passed on to future generations – those young men and increasingly young women who we see standing on street corners or languishing in our prisons, without hope or prospects for the future. Even for those blacks who did make it, questions of race, and racism, continue to define their worldview in fundamental ways. For the men and women of Reverend Wright’s generation, the memories of humiliation and doubt and fear have not gone away; nor has the anger and the bitterness of those years. That anger may not get expressed in public, in front of white co-workers or white friends. But it does find voice in the barbershop or around the kitchen table. At times, that anger is exploited by politicians, to gin up votes along racial lines, or to make up for a politician’s own failings.

And occasionally it finds voice in the church on Sunday morning, in the pulpit and in the pews. The fact that so many people are surprised to hear that anger in some of Reverend Wright’s sermons simply reminds us of the old truism that the most segregated hour in American life occurs on Sunday morning. That anger is not always productive; indeed, all too often it distracts attention from solving real problems; it keeps us from squarely facing our own complicity in our condition, and prevents the African-American community from forging the alliances it needs to bring about real change. But the anger is real; it is powerful; and to simply wish it away, to condemn it without understanding its roots, only serves to widen the chasm of misunderstanding that exists between the races.

In fact, a similar anger exists within segments of the white community. Most working- and middle-class white Americans don’t feel that they have been particularly privileged by their race. Their experience is the immigrant experience – as far as they’re concerned, no one’s handed them anything, they’ve built it from scratch. They’ve worked hard all their lives, many times only to see their jobs shipped overseas or their pension dumped after a lifetime of labor. They are anxious about their futures, and feel their dreams slipping away; in an era of stagnant wages and global competition, opportunity comes to be seen as a zero sum game, in which your dreams come at my expense. So when they are told to bus their children to a school across town; when they hear that an African American is getting an advantage in landing a good job or a spot in a good college because of an injustice that they themselves never committed; when they’re told that their fears about crime in urban neighborhoods are somehow prejudiced, resentment builds over time.

Like the anger within the black community, these resentments aren’t always expressed in polite company. But they have helped shape the political landscape for at least a generation. Anger over welfare and affirmative action helped forge the Reagan Coalition. Politicians routinely exploited fears of crime for their own electoral ends. Talk show hosts and conservative commentators built entire careers unmasking bogus claims of racism while dismissing legitimate discussions of racial injustice and inequality as mere political correctness or reverse racism.

Just as black anger often proved counterproductive, so have these white resentments distracted attention from the real culprits of the middle class squeeze – a corporate culture rife with inside dealing, questionable accounting practices, and short-term greed; a Washington dominated by lobbyists and special interests; economic policies that favor the few over the many. And yet, to wish away the resentments of white Americans, to label them as misguided or even racist, without recognizing they are grounded in legitimate concerns – this too widens the racial divide, and blocks the path to understanding.

A bit more below the fold.

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Science and Unobservable Things

Today’s Bloggingheads dialogue features me and writer John Horgan — I will spare you a screen capture of our faces, but here is a good old-fashioned link.

John is the author of The End of Science, in which he argues that much of modern physics has entered an era of “ironic science,” where speculation about unobservable things (inflation, other universes, extra dimensions) has replaced the hard-nosed empiricism of an earlier era. Most of our discussion went over that same territory, focusing primarily on inflation but touching on other examples as well.

You can judge for yourself whether I was persuasive or not, but the case I tried to make was that attitudes along the lines of “that stuff you’re talking about can never be observed, so you’re not doing science, it’s just theology” are woefully simplistic, and simply don’t reflect the way that science works in the real world. Other branches of the wavefunction, or the state of the universe before the Big Bang, may by themselves be unobservable, but they are part of a larger picture that remains tied to what we see around us. (Inflation is a particularly inappropriate example to pick on; while it has by no means been established, and it is undeniably difficult to distinguish definitively between models, it keeps making predictions that are tested and come out correct — spatial flatness of the universe, density fluctuations larger than the Hubble radius, correlations between perturbations in matter and radiation, fluctuation amplitudes on different scales that are almost equal but not quite…)

If you are firmly convinced that talking about the multiverse and other unobservable things is deeply unscientific and a leading indicator of the Decline of the West, nothing I say will change your mind. In particular, you may judge that the question which inflation tries to answer — “Why was the early universe like that?” — is a priori unscientific, and we should just accept the universe as it is. That’s an intellectually consistent position that you are welcome to take. The good news is that the overwhelming majority of interesting science being done today remains closely connected to tangible phenomena just as it (usually!) has been through the history of modern science. But if you instead ask in good faith why sensible people would be led to hypothesize all of this unobservable superstructure, there are perfectly good answers to be had.

The most important point is that the underlying goal of science is not simply making predictions — it’s developing an understanding of the mechanisms underlying the operation of the natural world. This point is made very eloquently by David Deutsch in his book The Fabric of Reality. As I mention in the dialogue, Deutsch chooses this quote by Steven Weinberg as an exemplar of hard-boiled instrumentalism:

The important thing is to be able to make predictions about images on the astronomers’ photographic plates, frequencies of spectral lines, and so on, and it simply doesn’t matter whether we ascribe these predictions to the physical effects of gravitational fields on the motion of planets and photons or to a curvature of space and time.

That’s crazy, of course — the dynamics through which we derive those predictions matters enormously. (I suspect that Weinberg was trying to emphasize that there may be formulations of the same underlying theory that look different but are actually equivalent; then the distinction truly wouldn’t matter, but saying “the important thing is to make predictions” is going a bit too far.) Deutsch asks us to imagine an “oracle,” a black box which will correctly answer any well-posed empirical question we ask of it. So in principle the oracle can help us make any prediction we like — would that count as the ultimate end-all scientific theory? Of course not, as it would provide no understanding whatsoever. As Deutsch notes, it would be able to predict that a certain rocket-ship design would blow up on take-off, but offer no clue as to how we could fix it. The oracle would serve as a replacement for experiments, but not for theories. No scientist, armed with an infinite array of answers to specific questions but zero understanding of how they were obtained, would declare their work completed.

If making predictions were all that mattered, we would have stopped doing particle physics some time around the early 1980’s. The problem with the Standard Model of particle physics, remember, is that (until we learned more about neutrino physics and dark matter) it kept making predictions that fit all of our experiments! We’ve been working very hard, and spending a lot of money, just to do experiments for which the Standard Model would be unable to make an accurate prediction. And we do so because we’re not satisfied with predicting the outcome of experiments; we want to understand the underlying mechanism, and the Standard Model (especially the breaking of electroweak symmetry) falls short on that score.

The next thing to understand is that all of these crazy speculations about multiverses and extra dimensions originate in the attempt to understand phenomena that we observe right here in the nearby world. Gravity and quantum mechanics both exist — very few people doubt that. And therefore, we want a theory that can encompass both of them. By a very explicit chain of reasoning — trying to understand perturbation theory, getting anomalies to cancel, etc. — we are led to superstrings in ten dimensions. And then we try to bring that theory back into contact with the observed world around us, compactifying those extra dimensions and trying to match onto particle physics and cosmology. The program may or may not work — it’s certainly hard, and we may ultimately decide that it’s just too hard, or find an idea that works just as well without all the extra-dimensional superstructure. Theories of what happened before the Big Bang are the same way; we’re not tossing out scenarios because we think it’s amusing, but because we are trying to understand features of the world we actually do observe, and that attempt drives us to these hypotheses.

Ultimately, of course, we do need to make contact with observation and experiment. But the final point to emphasize is that not every prediction of every theory needs to be testable; what needs to be testable is the framework as a whole. If we do manage to construct a theory that makes a set of specific and unambiguous testable predictions, and those predictions are tested and the theory comes through with flying colors, and that theory also predicts unambiguously that inflation happened or there are multiple universes or extra dimensions, I will be very happy to believe in the reality of those ideas. That happy situation does not seem to be around the corner — right now the data are offering us a few clues, on the basis of which invent new hypotheses, and we have a long way to go before some of those hypotheses grow into frameworks which can be tested against data. If anyone is skeptical that this is likely to happen, that is certainly their prerogative, and they should feel fortunate that the overwhelming majority of contemporary science is not forced to work that way. Others, meanwhile, will remain interested in questions that do seem to call for this kind of bold speculation, and are willing to push the program forward for a while to see what happens. Keeping in mind, of course, that when Boltzmann was grounding the laws of thermodynamics using kinetic theory, most physicists scoffed at the notion of these “atoms” and rolled their eyes at the invocation of unobservable entities to explain everyday phenomena.

There is also a less rosy possibility, which may very well come to pass: that we develop more than one theory that fits all of the experimental data we know how to collect, such that they differ in specific predictions that are beyond our technological reach. That would, indeed, be too bad. But at the moment, we seem to be in little danger of this embarrassment of theoretical riches. We don’t even have one theory that reconciles gravity and quantum mechanics while matching cleanly onto our low-energy world, or a comprehensive model of the early universe that explains our initial conditions. If we actually do develop more than one, science will be faced with an interesting kind of existential dilemma that doesn’t have a lot of precedent in history. (Can anyone think of an example?) But I’m not losing sleep over this possibility; and in the meantime, I’ll keep trying to develop at least one such idea.

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Talk Like a Physicist Day

Choose your favorite frame of reference, collapse your wavefunction, and estimate your error bars — we have a highly nontrivial day ahead of us. After years of contemplation, Talk Like a Physicist Day is finally here, as predicted. (Falsifiably!)

Even the biologists are celebrating (intentionally or not), learning the joys of frictionless surfaces. And some handy reference guides have been provided.

There is also a Facebook group, which I mention so that I can quote the comment left there by Phillip Fernandez:

Wow, this is like being in the ground state of a harmonic oscillator potential. It just doesn’t get any lower than this.

That’s the spirit! On ordinary days, you would goof off by playing video games; but today, you can goof off by simulating special relativity. (Inspired by this post, I am reliably informed.)

relativistic asteroids

And today, instead of getting stuck in traffic, just tell your boss you were captured in a compression wave!

I’m sure you don’t need much more inspiration than that. But just to be sure…

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Culture War By Proxy

John McCain thinks he’s hit on a good strategy for the upcoming Presidential campaign: make fun of scientists.

WEST GLACIER, Mont. — If you’ve heard Sen. John McCain’s stump speech, you’ve surely heard him talk about grizzly bears. The federal government, he declares with horror and astonishment, has spent $3 million to study grizzly bear DNA. “I don’t know if it was a paternity issue or criminal,” he jokes, “but it was a waste of money.”

A McCain campaign commercial also tweaks the bear research: “Three million to study the DNA of bears in Montana. Unbelievable.”

Three million whole dollars! Just think what we could do with so much money.

The Washington Post article goes on to note, what should come as no surprise to anyone reading here, that the grizzly bear study is actually very interesting and worthwhile science. The researchers, led by Katherine Kendall of the U.S. Geological Survey, performed the first accurate survey of grizzlies in the Northern Continental Divide ecosystem. They discovered the happy news that this formerly endangered species had substantially rebounded, thanks in part to three decades of conservation efforts. The kind of thing that you actually have to go out and collect data to discover.

Completely beside the point of course. John McCain doesn’t care about grizzly bears one way or the other, and to him 3 million dollars is chump change. What he cares about his the symbolism — enough to highlight it in his stump speech and TV commercials.

McCain is tapping into a deep strain of anti-intellectualism among American voters. Some of us tend to take for granted that questions about the workings of the natural world should be addressed by scientists using scientific methods, and that attacks on science must be motivated by external forces such as economic or religious interests. What scientists tend to underestimate is the extent to which many people react viscerally against science just because it is science. Or, more generally, because it is seen as part of an effort on the part of elites to force their worldview on folks who are getting along just fine without all these fancy ideas, thank you very much.

In the old-time (1980’s) controversies about teaching creationism in schools, pre-Intelligent-Design, one of the most common arguments was that school boards should have “local control” over the curriculum. Defenders of evolution replied that this was clearly a ruse to disguise a religious anti-science agenda. Which may have been true for some of the national organizations behind the movement; but for many school boards and communities, it really was about local control. They didn’t want to be told what to teach their kids by some group of coastal elitists with Ph.D.s, and creationism was a way to fight back.

Don’t believe me? They are happy to tell you so to your face. Consider the case of John Derbyshire, columnist for the National Review Online. Derbyshire is admittedly a complicated case, on the one hand writing books about the Riemann hypothesis and on the other proudly proclaiming that he reads Blondie and Hagar the Horrible for “insights into the human condition.” And he is also generally pro-science and pro-evolution in particular. But nevertheless — despite the fact that he is smart and educated enough to understand that evolution is “right” in the old-fashioned sense of right and wrong — he will state explicitly (and quote himself later in case you missed it) that

I couldn’t care less whether my president believes in the theory of evolution. In fact, reflecting on some recent experiences, I’m not sure that I wouldn’t prefer a president who didn’t. [Emphasis in original.]

And why is that? I wrote a whole blog post explaining why it is important that the President understand and accept the workings of the natural world, but obviously Derbyshire disagrees. The reason why is that scientific understanding is too often the bailiwick of elite leftist snobs.

Possibly as a result of having grown up in the lower classes of provincial England, I detest snobbery. I mean, I really, viscerally, loathe it. This is one reason I hate the Left so much…

Invited to choose between having my kids educated, my car fixed, or my elderly relatives cared for by (a) people of character, spirit, and dedication who believe in pseudoscience, or (b) unionized, time-serving drudges who believe in real science, which would I choose? Invited to choose between a president who is (a) a patriotic family man of character and ability who believes the universe was created on a Friday afternoon in 4,004 B.C. with all biological species instantly represented, or (b) an amoral hedonist and philanderer who “loathes the military” but who believes in the evolution of species via natural selection across hundreds of millions of years, which would I choose? Are you kidding?

The real point is not who you would choose in such a situation — it’s that Derbyshire sincerely believes that these are the kinds of choices one typically needs to make. One the one hand: character, spirit, dedication, and pseudoscience. On the other: amoral, hedonistic drudges (sic) who believe in real science.

Derbyshire is not alone. Conservative commentator Tom Bethell has published a Politically Incorrect Guide to Science in which he takes down such Leftist conspiracies as evolution, global warming, AIDS research, and (um) relativity. At Tech Central Station, Lee Harris pens a passionate defense of being stupid more generally:

Today, no self-respecting conservative wants to be thought stupid, not even by the lunatics on the far left. Yet there are far worse things than looking stupid to others—and one of them is being conned by those who are far cleverer than we are. Indeed, in certain cases, the desire to appear intelligent at all costs can be downright suicidal…

In a world that absurdly overrates the advantage of sheer brain power, no one wants to be seen as a member in good standing of the stupid party. Yet stupidity has been and will always remain the best defense mechanism against the ordinary conman and the intellectual dreamer, just as Odysseus found that stuffing cotton in his ears was his best defense against beguiling but fatal song of the sirens.

Again: most sensible conservative commentators are quick to say “of course, all things being equal, it’s better to be correct/intelligent/scientific than otherwise.” But they truly don’t believe that all things are equal. The real fight isn’t against science, it’s a much broader culture war. Science is being used as a stand-in for a constellation of things against which many Americans react viscerally — elitism, paternalism, snobbery. Presenting better science and more transparent evidence isn’t going to change this attitude all by itself. We need to address the underlying cause: the relic anti-intellectual attitude that still animates so many people in this country.

The grizzly bears will thank you.

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Bold

External review letters for tenure cases, like recommendation letters more generally, aren’t usually public, so who knows what juicy bits are in there that will never see the light of day? Here is a line from a letter which I promise is genuine:

[Prof. X] is too bold for [his/her] rank, and uses the first person pronoun too freely for a junior scholar.

Not a physicist, not anyone at Caltech or anywhere else I have been affiliated with, so don’t even try to guess. But I’d be tickled to get such a line. (The candidate received otherwise uniformly positive reviews, and was unanimously approved.)

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Scrumptious Bloggy Goodness

We’ve been remiss at updating the blogroll, which I hope to do shortly. Here are some fun new physics-leaning blogs for you to watch out for.

  • Imaginary Potential is a group blog by five young (postdoc/grad student level) physicists in a variety of fields. This should be awesome, would love to see more like it.
  • The Inverse Square Blog is by Thomas Levenson, a science writer, film maker, and faculty member at MIT’s Graduate Program on Science Writing. He obviously needed blogging to fill all that spare time.
  • From the Bench is a new blog by Michael Banks. He is an editor at PhysicsWorld, which for you Americans is sort of like Physics Today, although perhaps a little less boring.
  • Resonaances has been around for a while, and I’m sure I’ve linked there before. But not enough; Jester does a great job in relating particle theory talks and happenings with a spirited style.

Not to mention all the great non-physics blogs that keep popping up, of course. Feel free to promote (yourself or others) in the comments.

Update: Chad Orzel and Michael Nielsen join in the fun, suggesting blogs and asking for pointers to ones they haven’t noticed. So go there too and make some noise.

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Another Scientist in Congress!

billfoster_20080123_14_25_32_61-156-110.jpgPhysicist Bill Foster has been running against dairy magnate and perpetual candidate Jim Oberweis in a special election in Illinois to replace retiring Republican representative Dennis Hastert, former Speaker of the House. The election was today, and with 96% of precincts reporting, it’s been called for Foster, 52% to 48%. This is great news for scientists and for Democrats, and awesome news for those of us who are both. Oberweis’s signature issue is anti-immigrant xenophobia, and a Democratic victory in this reliably Republican district bodes very well for the national picture this fall.

fermilab-recycler-ring.PNG We’ve mentioned Bill’s campaign here before, and think he will be a great Representative. He is not just any old particle physicist, but quite an accomplished one, having been a co-inventor of Fermilab’s antiproton Recycler Ring. Once you’ve mastered antiprotons, the Washington political process should be child’s play. Congratulations!

The bad news is: because this was a special election to replace Hastert, they will have to do the whole thing over again in November. Here’s hoping that Foster can repeat his great showing.

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Being a Heretic is Hard Work

Apparently heretics are, on the aggregate, lazier than I suspected. I had the unusual pleasure of reading a blog post for completely independent reasons and coming across my own name — Ethan Zuckerman was reporting on a talk given by gerontologist Aubrey de Grey at the recent BIL Conference, in which he quotes my line from the Edge World Question Center that “Being a heretic is hard work.” (His other quote was from Gandhi.) It hadn’t occurred to me that such a sentiment was sufficiently unique to deserve being quoted, but as far as Google knows nobody else has pointed this out before. (While we’re at it, did nobody appreciate my previous Google joke?)

So I re-read my own World Question Center entry, and (to nobody’s surprise) I thought it was great. I’m my own most sympathetic audience. But in my post here about the WQC, I linked to the entry but didn’t reprint it in its entirely. Which I will hereby do now, because I’m a busy guy and you are busy blog readers who don’t always have the time to click on a link. Being a blogger is hard work.

———————————————

Growing up as a young proto-scientist, I was always strongly anti-establishmentarian, looking forward to overthrowing the System as our generation’s new Galileo. Now I spend a substantial fraction of my time explaining and defending the status quo to outsiders. It’s very depressing.

As an undergraduate astronomy major I was involved in a novel and exciting test of Einstein’s general relativity — measuring the precession of orbits, just like Mercury in the Solar System, but using massive eclipsing binary stars. What made it truly exciting was that the data disagreed with the theory! (Which they still do, by the way.) How thrilling is it to have the chance to overthrow Einstein himself? Of course there are more mundane explanations — the stars are tilted, or there is an invisible companion star perturbing their orbits, and these hypotheses were duly considered. But I wasn’t very patient with such boring possibilities — it was obvious to me that we had dealt a crushing blow to a cornerstone of modern physics, and the Establishment was just too hidebound to admit it.

Now I know better. Physicists who are experts in the field tend to be skeptical of experimental claims that contradict general relativity, not because they are hopelessly encumbered by tradition, but because Einstein’s theory has passed a startlingly diverse array of experimental tests. Indeed, it turns out to be almost impossible to change general relativity in a way that would be important for those binary stars, but which would not have already shown up in the Solar System. Experiments and theories don’t exist in isolation — they form a tightly connected web, in which changes to any one piece tend to reverberate through various others.

So now I find myself cast as a defender of scientific orthodoxy — from classics like relativity and natural selection, to modern wrinkles like dark matter and dark energy. In science, no orthodoxy is sacred, or above question — there should always be a healthy exploration of alternatives, and I have always enjoyed inventing new theories of gravity or cosmology, keeping in mind the variety of evidence in favor of the standard picture. But there is also an unhealthy brand of skepticism, proceeding from ignorance rather than expertise, which insists that any consensus must flow from a reluctance to face up to the truth, rather than an appreciation of the evidence. It’s that kind of skepticism that keeps showing up in my email. Unsolicited.

Heresy is more romantic than orthodoxy. Nobody roots for Goliath, as Wilt Chamberlain was fond of saying. But in science, ideas tend to grow into orthodoxy for good reasons. They fit the data better than the alternatives. Many casual heretics can’t be bothered with all the detailed theoretical arguments and experimental tests that support the models they hope to overthrow — they have a feeling about how the universe should work, and are convinced that history will eventually vindicate them, just as it did Galileo.

What they fail to appreciate is that, scientifically speaking, Galileo overthrew the system from within. He understood the reigning orthodoxy of his time better than anyone, so he was better able to see beyond it. Our present theories are not complete, and nobody believes they are the final word on how Nature works. But finding the precise way to make progress, to pinpoint the subtle shift of perspective that will illuminate a new way of looking at the world, will require an intimate familiarity with our current ideas, and a respectful appreciation of the evidence supporting them.

Being a heretic can be fun; but being a successful heretic is mostly hard work.

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WMAP 5-Year Results Released

It doesn’t seem like all that long ago that we were enthusing about the results from the first three years of data from the Wilkinson Microwave Anisotropy Probe satellite. Now the team has put out an impressive series of papers discussing the results of the first five years of data. Here is what the CMB looks like, with galaxy and foregrounds and monopole and dipole subtracted, from Ned Wright’s Cosmology Tutorial:


WMAP 5-year sky

And here is one version of the angular power spectrum, taken from the Dunkley et al. paper. I like this one because it shows the individual points that get binned to create the spectrum you usually see. (Click for larger version.)

WMAP 5-year power spectrum

The headline two years ago was “Cosmology Makes Sense.” (That was my headline, anyway — others were not quite as accurate.) This continues to be true — the biggest piece of news isn’t that the results have overturned any foundations, but that the concordance model with dark matter, dark energy, and ordinary matter continues to work. The WMAP folks have produced an elaborate cosmological parameters table that runs the numbers for different sets of assumptions (with and without spatial curvature, running spectral index, etc), and for different sets of data (not just WMAP but also supernovae, lensing, etc). Everything is basically consistent with a flat universe comprised of 72% vacuum energy, 23% dark matter, and 5% ordinary matter. The perturbations are close to scale-free, but still seem to be a little larger on long wavelengths than shorter ones (0.014 < 1-ns < 0.067 at 95% confidence). Probably the most fun result is that there is, for the first time, evidence from the CMB that neutrinos exist! Good to know.

My personal favorite was the constraint in the Komatsu et al. paper on parity-violating birefringence that would rotate CMB polarization. I was in on the ground floor where birefringence is concerned, so I’m sentimentally attached to it. But it’s also a signature of some very natural quintessence models, so this helps constrain the physics of dark energy as well.

Congratulations to the WMAP team, who have done a great job in establishing some of the pillars of contemporary cosmology — it’s historic stuff.

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