U.N. Refugee coordinator for President

The folks at Wonkette, finger on the pulse as usual, have noticed this important Business Week poll concerning the Presidential prospects of leading statespeople of a certain gender. You know, the gender that some people don’t think have as much intrinsic aptitude at science (or blogging about politics, it would appear) as that other gender. Whatever, one day one of those folks is going to be President, and we should decide now who it’s going to be.

Like Wonkette, this blog is impressed with Business Week’s ability to think outside the box in including Ms. Jolie among the list of Presidential aspirants. Unlike Senators Clinton and Dole, she first made a name for herself on her own merits, rather than through a relationship with a powerful male figure. (Although her relationships have been rather public and somewhat, um, colorful.) And unlike Secretary Rice, her expertise is in helping refugees, not in starting preemptive wars. (Both have impressive fashion sensibilities, one must admit.) And unlike any of the other contenders, Ms. Jolie has won an Academy Award and multiple Golden Globes. Which is better than Ronald Reagan ever did.

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More unsolicited campaign advice

Apostropher has a revealing quote from Representative Chris Shays (R-CT):

“My party is demonstrating that they are for states’ rights unless they don’t like what states are doing,” said Representative Christopher Shays of Connecticut, one of five House Republicans who voted against the bill. “This couldn’t be a more classic case of a state responsibility.”

“This Republican Party of Lincoln has become a party of theocracy,” Mr. Shays said. “There are going to be repercussions from this vote. There are a number of people who feel that the government is getting involved in their personal lives in a way that scares them.”

Meanwhile, Sisyphus Shrugged documents the strange alliance between conservative Republicans and the ACLU, brought together by the overreaching provisions of the Patriot Act:

It was a Washington rarity to see the American Civil Liberties Union line up with conservative lions like David Keefe of the American Conservative Union and former Rep. Bob Barr, R-Ga. But they were among those at a Washington press conference held to assail such Patriot Act provisions as those allowing law enforcement agents to look at library users’ records or to conduct unannounced “sneak-and-peek” searches on homes or private offices.

“It is not, and never should be necessary, to surrender our rights under the Bill of Rights to fight the war on terrorism,” said Barr, who as a House member voted for the Patriot Act, which passed overwhelmingly in the House and provoked only one dissenting Senate vote.

I think the Democratic campaign philosophy in the next few elections should be obvious: smaller government. A government that is more responsible, less intrusive, more humble. Under the Bush administration, the national debt has escalated alarmingly; we have become aggressively unilateralist abroad, alienating people worldwide; protections of the privacy and human rights of citizens have been steadily eroded; and the federal executive and legislative branches have been increasingly willing to trample on prerogatives of the states and the judiciary. It’s time to put some grownups in power who know how to balance a budget and will keep their noses out of people’s personal lives.

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Doing away with dark energy?

The universe is accelerating, and we don’t know why. The most straightforward explanations involve dark energy — some source of energy that is spread smoothly throughout space, and whose density constant (or nearly so) as the universe expands. But there are problems with the dark energy idea, especially in its magnitude; a back-of-the-envelope calculation says that the amount of energy in the vacuum should be larger than what we observe by a factor of about 10120. Inexcusable, even by cosmology standards.

So we might try to be even more dramatic — maybe Einstein was wrong, and we have to modify general relativity on cosmological scales. But of course we should keep in mind the possibility of less dramatic resolutions; maybe an explanation for the acceleration of the universe can be found in the context of conventional physics, without invoking dark energy at all. That’s the hope expressed in a recent paper by Kolb, Matarrese, Notari, and Riotto (KMNR).

The paper has already garnered some attention — here’s the press release, and a note at Peter’s blog. And it’s reached the media, albeit with some skeptical notes: here’s an article that quotes Michael Turner, and here’s one that quotes me. (Poor Rocky hasn’t even convinced his Chicago colleagues!)

Why the skepticism? My original notion was not to comment in any detail until I actually understood the paper better. But then I remembered — this is a blog. Withholding comment until I understood what was going on would be unbloggy of me.

So, even though I certainly haven’t gone through their equations, the basic idea seems to be clear. We often talk about the fact that our universe is very smooth (homogeneous and isotropic) on large scales, but of course it isn’t perfectly smooth. There are slight differences in the density of matter from place to place, even when we average over huge distances. It is convenient to think of the actual deviation of the density from its background value as arising from a sum of many contributions, each taking the form of a sine wave with some specific wavelength and amplitude; we can then describe the effects of each of these modes independently. These perturbations are thought to originate in the early universe, and are responsible for the existence of galaxies and clusters today.

The KMNR idea is simply this: there is some fluctuation mode with a wavelength that is much larger than the radius of our currently observable universe, that also has a large amplitude. The effect of this mode is to alter the relationship between our conventional cosmological parameters, such as the mass density and the expansion rate. In particular, it is possible to find realizations (so the claim goes) in which we would observe our local patch of universe to be accelerating, even if there weren’t any dark energy.

The derivation of this result involves a lot of math. But it should be possible to understand the reason why people are skeptical. In general relativity, no influence can travel faster than the speed of light. Since there is only a finite time since the Big Bang (14 billion years), there is only a finite piece of universe that possibly could affect what we see today. (The observable universe actually has a radius of about 46 billion light years, not 14 billion light years, because of sneaky expansion effects.)

Now, it’s certainly possible for some perturbation with a wavelength much larger than our observable universe to have an effect on us, but the effect only comes from the piece of that perturbation that is inside our patch. KMNR claim that the effect is to change the relationship between the observable cosmological parameters (such as the density, spatial curvature, expansion rate, etc.). I find it hard to believe. My hunch is that such a perturbation should change the values of the parameters, but they should keep the same relationships that they had before. For example, if we measure the density and the curvature of space, conventional cosmology tells us that we can figure out the expansion rate using the Friedmann equation. I think that an ultra-long-wavelength perturbation will shift the values of the density/curvature/expansion from their values in the unperturbed background, but will do so in a way to preserve the Friedmann equation. KMNR claim otherwise.

Even though I haven’t gone through their math, I do have some evidence on my side. A long time ago cosmologists developed the “vacuole” models as ways to understand cosmological perturbations. (See e.g. this paper paper by Hammer.) To make a vacuole, start with a spherical region of a perfectly uniform universe. Now take the matter inside your spherical region and squeeze it a little, rearranging it into a smaller uniform spherical distribution with a higher density. There will be a region in between your overdense sphere and the external universe that is completely empty. It turns out that you can solve Einstein’s equation exactly for this situation. The outside universe acts completely conventionally with whatever cosmological parameters it had to start, unaffected by your rearrangement. The empty thick shell you have created will be the Schwarzschild solution, since Birkhoff’s theorem says that any spherically symmetric vacuum solution to Einstein’s equation is Schwarzschild. And the interior region will behave exactly like a homogeneous and isotropic universe in its own right, except with different values of the cosmological parameters. These parameters will exactly obey the conventional Friedmann equation, and someone who lived inside there would have no way of telling that those parameters didn’t describe the entire universe.

This is by no means a proof that KMNR are wrong; the vacuole model describes one very specific type of perturbation, and it may be that only other kinds of perturbation give their effect. But before I buy into it, I would need to understand better how local physics inside my observable patch can violate the conventional Friedmann equation. The good thing about science is that there is a right answer; in the case of the accelerating universe, it’s well worth exploring all possible avenues to getting it.

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So you want to be an astrophysicist?

Yet more science blogging. All the cool kids are doing it.

Steinn Sigurðsson is an astrophysicst at Penn State, with a new blog called Dynamics of Cats. He already has some good posts up on the crucial question of how to become an astrophysicist: Part 0, Part 1.5. Okay, so he’s an astrophysicist, not a mathematician.

I should also point you to Electron Blue, where Pyracantha explains how your world-view changes when you begin to think in terms of vectors. I would describe it as a shift from Aristotelian to Galilean intuition — the world is a different place once you’ve internalized the conservation of momentum. Quantum mechanics is another shift entirely.

And another thing: as mentioned in the comments to the previous post, Kriston at Grammar.police found some great negatively-curved spaces, made of yarn. (For mathematical details see section 3.9 of Spacetime and Geometry.)

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Astro-therapy

You can’t spend all your time reading about torture and the rule of law and creeping superstition. Take a break and read a little about astronomy, why don’t you? And pause to admire this perfectly useless, somewhat grainy, but undeniably beautiful picture.

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Contrary intuitions

The Volokh Conspiracy, one of the places you hope to be able to go for intelligent conservative commentary in the blogosphere, is on a roll. And not a good one.

First, Eugene Volokh comes out in favor of torturing especially heinous criminals before they are executed, like they do in Iran. As a law professor, he understands that this would run counter to the prohibition we have against cruel and unusual punishment, so he suggests amending the Constitution.

I am being perfectly serious, by the way. I like civilization, but some forms of savagery deserve to be met not just with cold, bloodless justice but with the deliberate infliction of pain, with cruel vengeance rather than with supposed humaneness or squeamishness. I think it slights the burning injustice of the murders, and the pain of the families, to react in any other way.

Many responses back and forth. Eventually, after considering arguments made by Mark Kleiman, Volokh slightly retreats, but only because he doesn’t think his proposal would be workable; not because he thinks it’s horrifying.

As Volokh himself says, this actually isn’t an issue that is likely to be resolved by rational argumentation; it’s a matter of “moral intuitions and visceral reactions.” He’s right. My own moral intuition wishes that people in general, and law professors in particular, understood retributory bloodlust as a natural human reaction, but one that we should learn to suppress, not to indulge in. That’s supposed to be one of the features that makes this a better country to live in than most.

Yesterday, David Bernstein expressed outrage that the public schools are wasting money on actually paying salaries to teachers — as much as $45,000 per year for starting teachers. Kleiman again took him to task. (This could become a full-time job.) Not as morally repugnant as Volokh’s intuitions, but another remarkably depressing position.

It’s the usual set of arguments: teachers get summers off, work short hours, get raises that are not based on merit, generally aren’t as smart and talented as, say, lawyers. I think there’s a case to be made that a combination of the teachers unions and the bureaucratic tendencies of local governments introduce a degree of sclerosis into the system. But really, do the people who make these arguments sit down and think about the directions in which the causal arrows are pointing? Yes, teachers can get summers off. Are they supposed to pick up a part-time lawyering job over the summer to supplement their income? The fact is, there’s very little reason under the present system for a talented and ambitious college student to aim at a career as a public school teacher. Isn’t it an important job, for which we should try to attract the brightest practitioners possible?

Elementary and secondary school teaching is one of the worst-paying jobs that a college student can shoot for. Are we surprised that such a system produces some teachers who are under-qualified or under-motivated? And do we really think that cutting their salaries is the way to make it better?

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Outrage calibration

Sometimes my expectations need to be re-adjusted, and other times they’re right on.

Even in the face of all the assaults against teaching evolution in this country, this story mentioned at Pharyngula took me by surprise: science museums that won’t show IMAX films that mention evolution, the Big Bang, or geology.

The fight over evolution has reached the big, big screen.

Several Imax theaters, including some in science museums, are refusing to show movies that mention the subject – or the Big Bang or the geology of the earth – fearing protests from people who object to films that contradict biblical descriptions of the origin of Earth and its creatures.

The number of theaters rejecting such films is small, people in the industry say – perhaps a dozen or fewer, most in the South. But because only a few dozen Imax theaters routinely show science documentaries, the decisions of a few can have a big impact on a film’s bottom line – or a producer’s decision to make a documentary in the first place.

Okay, science museums. That are afraid to talk about evolution, the Big Bang, and geology. Institutions whose nominal purpose is to educate people about science. I just can’t quite wrap my head around this idea. And somehow I don’t think that squeals of outrage from elite Northern liberal bloggers are going to make them change their minds. I’m going to redouble my efforts to help promote the Project Exploration science center that we’re planning here in Chicago, and suggest a greater emphasis on traveling exhibitions of some sort or another.

On the other side of the ledger, we have the Terri Schiavo melodrama. (Good articles at Majikthise and Alas, a Blog.) The last thing the blogosphere needs is more comment about the case. But I was struck by the mention by Ezra Klein (that he got from No More Mister Nice Blog) of a set of talking points being passed around by Republicans.

ABC News has obtained talking points circulated among Republican senators explaining why they should vote to intervene in the Schiavo case. Among them: “This is an important moral issue and the pro-life base will be excited…” and “This is a great political issue… this is a tough issue for Democrats.”

In all honesty, my reaction upon reading that was, “That seems like a pretty straightforward memo; I’m not sure what is so notable about it.”

Finally I realized: the thing that was supposed to be shocking is that the GOP is consciously using the case to score political points. The thought that they weren’t — that Frist and DeLay were actually motivated by concern for the woman — had simply never occurred to me.

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Sidneyfest

Sidney Coleman is one of my heroes, too. So you should go read Jacques Distler’s liveblogging of the mini-conference being held in Sidney’s honor.

Sidney was not my thesis advisor (that was George Field, another hero), but he was on my dissertation committee. I had arguably the briefest defense in the history of Harvard’s astronomy department. Bill Press asked all of the questions, and Sidney answered all of them, while I stood there politely. Eventually Bill gave up and they awarded me my degree.

I spent a lot of time in Sidney’s office, and he was always ready to answer questions. This little recognition is long overdue.

Update: Luboš also has a report, with pictures. Also Peter Woit, Serkan Cabi, and David Guarrera.

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Deepen the Mystery

Blogging is breaking out all over! Lauren Gunderson, a playwright and actor from Atlanta, has started a blog called Deepen the Mystery. (Aside: why is someone who “writes” “plays” called a “playwright“? I mention this only as an excuse for consistently misspelling this elementary word.)

I met Lauren at the Santa Barbara conference; her special expertise is writing plays with scientific themes. One of them, Background, tells the story of Ralph Alpher, who, along with Robert Herman and George Gamow, pioneered the Big Bang model. They more or less figured out the whole story, including predictions for primordial nucleosynthesis and the cosmic microwave background. Absolutely ground-breaking work, well above the conventional standard for winning the Nobel Prize and much more — but when the CMB was actually discovered by Penzias and Wilson in 1965, there was practically no recognition of their work. To this day, although the names of Alpher, Gamow, and Herman are certainly mentioned, they aren’t emphasized as much as they should be. (Alpher and Herman have written a slightly bitter book about the whole thing.) The play tells Alpher’s story backward in time — just as we reconstruct our understanding of the Big Bang.

Lauren’s new blog features a picture of the author jumping with enthusiasm for the new medium. Mark Trodden’s does not. Does this reflect a difference between women and men, or between humanists and scientists? Whatever the explanation, we should be grateful.

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Ten-dimensional black holes created?

Black holes? On Long Island? The Relativistic Heavy Ion Collider at Brookhaven National Laboratory smashes together heavy ions (no surprise there) in an attempt to re-create the quark/gluon plasma state of the early universe. Horatiu Nastase, a bold theorist, has suggested that certain features of the resulting fireball can be understood in a “dual” description, in which the fireball becomes a ten-dimensional black hole! Duality in this sense means that there is a one-to-one map between the dynamics of the real-world fireball and the completely-imaginary black hole. This seems to be a long-shot suggestion, at best; but certainly an intriguing idea, and worth pursuing. But not in any sense an honest black hole here on Earth. (Not that we should be worried, as the little guys would presumably just evaporate away in a jiffy.)

Peter Steinberg at Quantum Diaries has a fuller explanation.

Update: in the comments, cvj (the nom de internet of Clifford Johnson) mentions that he and his collaborators have been pushing similar ideas for quite some time now. Clifford has set up a web page that talks about the phase diagrams of charged black holes in anti-de Sitter space, which could be dual to hot nuclear matter.

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