Preposterous Universe

 
Full disclosure

Brian Leiter reports on an example of absolutely shameful pettiness. He compiles a very well-known list of the best law schools, which is competitive with the famous US News rankings in influence (and noticeably superior in methodology). Now he finds out that his law school alma mater, the University of Michigan, has been "explaining" their decline in his rankings by pointing out that they denied him a faculty job. He convincingly explains why this is just ridiculous (or preposterous, as we say around here).

But it got me thinking about a potential conflict-of-interest issue -- if I denigrate some institution or person, could someone assume it was just because they didn't give me a job? Hopefully I could avoid being so shallow, but full disclosure is probably the best policy. In that spirit, here is a list of universities to which I applied for jobs but was turned down, before being offered my current position:

• UC Berkeley
• Cornell
• Penn State
• University of California-Irvine
• Duke
• Stanford
• Harvard
• Princeton
• University of Chicago
• Rutgers
• University of Kansas
• California Institute of Technology
• Brown
• University of Illinois, Urbana-Champaign
• Johns Hopkins
• University of California, Davis
• University of Pittsburgh
• University of Minnesota
• Northwestern
• University of Wisconsin, Madison
• Canadian Institute for Theoretical Astrophysics
• SLAC
• Williams College
• University of California, Santa Cruz
• University of Victoria
• State University of New York, Stony Brook
• MIT
• Swarthmore
• Yale
• Dartmouth
• University of Toronto
• University of Minnesota
• Institute for Theoretical Physics
• University of British Columbia
• University of Wisconsin, Milwaukee
• University of California, Santa Barbara
• Oxford University
• New York University
• University of Michigan (!)
• University of Texas, Austin
• UCLA
• University of Maryland
• Columbia
• University of Pennsylvania

There might be others, I forget. And that's only including faculty jobs, I didn't bother to include postdocs. And I only listed places once, even if they rejected me more than once. So, just to be safe, you might want to be skeptical of any disparaging remarks I might make about any of these universities or people affiliated with them.

Some of these places, like the University of Chicago, eventually saw the error of their ways and made me an offer on some later occasion. But still, a long list. Perhaps this will be heartening to some younger people on the job market today -- keep plugging, for a while anyway.

Somehow I suspect this will not become a popular meme.

~ posted by Sean Carroll at 3:52 PM ~ link ~ ~ ~

 
Scoop

Here is a rare chance for me to provide actual information rather than warmed-over opinion. A New York Times story reports that NASA instructed its employees not to comment on "The Day After Tomorrow", an upcoming movie in which global warming sets off all sorts of disasters. The natural worry is that the Bush administration is concerned about lending credibility to anything that suggests global warming might be something to worry about. This has been commented on by David Harris, John McKay, Charles Perez, Patrick Nielsen Hayden, and Fred at the Dead Parrot Society. (For some discussion of the film itself, have a look at Chris Mooney.)

My inside contacts at NASA (really, I'm not kidding) have forwarded me this more recent email that has been sent around:

Movie Support Clarification

News reports in recent days have suggested that NASA has attempted to "muzzle" researchers from responding to the issues raised in the upcoming movie "The Day After Tomorrow." To the contrary, NASA expects that as colleagues, we will speak our minds, regardless of whether those views work to the advantage of the agency or not.

Diversity of opinion is a valuable resource and plays an important role as we work to successfully fulfill our mission objectives.

To clarify the specific issue, a number of NASA colleagues assisted with the film's development. However, we require producers to sign a cooperation agreement before offering any formal advance promotional support. This is a standard agency policy that has successfully worked with other entertainment blockbusters such as "Armageddon" and "Space Cowboys."

But, the producers of "The Day After Tomorrow" have not signed an agreement. As such, NASA does not plan any specific support of this production.

This direction should not be interpreted as an attempt to keep scientists from speaking out on the issue of climate change. We encourage our researchers to openly answer all appropriate questions regarding the science explored in the movie.

Glenn Mahone
Assistant Administrator for Public Affairs

I don't know if this is an embarrassed reversal of policy, or if the original intent was simply distorted. But it's important to understand that "The Day After Tomorrow" lacks the detailed NASA input that made "Armageddon" and "Space Cowboys" such plausible and artistic films.

~ posted by Sean Carroll at 7:20 PM ~ link ~ ~ ~

 
The eye of the beholder

I'm late as usual to noticing this, but Brian Leiter and Alas, a Blog have picked up on the most recent poll demonstrating how shamefully ill-informed most Americans are, especially those that lean to the right.

A majority of Americans still believes Saddam Hussein was in cahoots with al-Qa'ida and that Iraq either had weapons of mass destruction or a programme for developing them, according to a new opinion poll.

[...]

A staggering 82 per cent of respondents believed most experts supported the notion that Iraq was providing "substantial support" to al-Qa'ida - a contention that President Bush has been forced to disavow. Almost 60 per cent were unaware that world opinion was against the war in Iraq, with 21 per cent saying the world was behind the US-led invasion and 38 per cent saying views were "evenly divided".

(See also here.) One way to spin this is "liberals are better informed," but I think that misses the underlying mechanism. I suspect that what's going on is something like this:

• People are more likely to believe claims that reinforce their political views.
• Our current conservative administration has been spreading lies, or at least intentionally misleading statements, about important issues of the day.
• Therefore, conservatives today are more likely than liberals to believe these untrue statements, and thus come off as uninformed.

But the real question to me is, how could the American public be this wrong? Whose fault is it? Certainly the media must bear a large fraction of the blame. People complain back and forth about the media being biased against their favorite group, but the important problem is the opposite: in an attempt to appear "neutral," our major media outlets prefer to report statements that can be attributed to someone rather than statements that are true. If Official X claims that 2+2=5, they will try to find some other Official Y to claim that 2+2=4, or perhaps that 2+2=7, then report both and consider their job well done. (Or if time is running short, the first claim will be reported as is.) It goes beyond politics; if a manager at the cable company claims that their new policy will cut rates for customers, and a consumer-rights advocate claims that the rates will effectively go up, you will most commonly just find both claims reported and left at that, rather than the journalist simply plugging in some numbers and telling us what the truth is. This overly-cautious approach to objectivity is why average people on the street might not know that there has been no link found between Saddam and Al-Qaeda; right-wing sources make the suggestion/implication often enough that the contradictions from left-wing sources seem like just so much partisan back-and-forth, rather than straightforward statements of fact.

~ posted by Sean Carroll at 5:43 PM ~ link ~ ~ ~

 
The cost of discovery

Good news and bad news. First the good: David Appell has restarted his blog, Quark Soup. Good links to all sorts of science stories, with interesting commentary.

Now the bad: in one of David's recent posts, he brings to our attention a slightly loopy screed about experimental gravitation by Gregg Easterbrook. It's a tired argument, sloppily made: we shouldn't spend government money on speculative scientific research without any tangible benefits to society. In particular, he picks on the LIGO experiment to detect gravitational radiation.

But while we're counting tax-funded abstract science boondoggles, let us not forget the Laser Interferometer Gravitational Wave Observatory, a $365 million government project that is all but certain to have no practical result, other than as a jobs program.

He stoops as low as you might fear, suggesting that we should be spending the money on trying to cure AIDS. (I'm sure that, absolutist as he apparently is, Easterbrook donates all of his above-subsistence-level income directly to medical research. Those of us who think that we can try to help sick people and pursue other interests at the same time will presumably lead more complicated lives.)

Now, Easterbrook has long ago forfeited any right to be taken seriously when talking about science, for example in his classic discussion of extra dimensions, in which he can't see why scientists are happy to talk about spatial dimensions but not spiritual ones. I wasn't blogging at the time of that travesty, but he was justly ridiculed by Kieran Healy, Atrios, and many others.

But it's a shame that he makes so little sense, because the question itself is well worth asking. How much money should we, as a society, devote to basic scientific research? It is undoubtedly expensive, and getting more so -- the next big step in particle physics (after the Large Hadron Collider in Geneva) will be a twenty-mile long Linear Collider, whose cost will be measured in billions of dollars. The cost will be spread out over multiple countries and many years, but it still represents a substantial chunk of change. (I gave a talk on the connections between a linear collider and cosmology.) In a well-ordered society, it's worth spending some fraction of our money on projects of this sort; but what should the fraction be? Libertarian fantasies aside, private donations just aren't going to cut it.

You could talk about technological spinoffs from basic science, but that misses the point. The reason why it's worth spending people's money on research into the fundamental workings of the universe is because people want to know the answers. They might not understand the details, and more often than not they've been traumatized by science classes from high school, but ordinary people really care about these deep questions. That's why they buy books and go to lectures by Carl Sagan, Stephen Hawking, or Brian Greene. The amount that gets spent on this kind of research is small compared to numerous other government projects (bridges in Alaska, anyone?), and the results are an unambiguous good for society. And the unfortunate fact is, some experiments aren't worth doing at all unless you're willing to spend the money. For half the cost of the Linear Collider, you won't get half the science -- you'll get nothing. Maybe that's the choice that the country wants to make; but that's not the impression I get from talking with people on airplanes who are fascinated by what I do.

Here is my favorite part of Easterbrook's latest:

Today's science community is pressuring Congress and the legislatures of Europe to fund incredibly expensive mega-projects almost certain to benefit no one but the scientists themselves. It's hard not to conclude that physicists and their universities are using mumbo-jumbo about Einstein and the universe--knowing not one member of Congress has any idea what a "gravity wave" is supposed to be or whether this matters--to hoodwink taxpayers into providing cushy jobs for tenured researchers and their postdocs.

Ah, yes, the cushy jobs. I'm so jaded by now, it's nice to be reminded about how easy my life is. Just last night (Sunday), when I bumped into one of my students in the office around 10 p.m., and we talked about modifications of the Friedmann equation in the presence of Lorentz-violating vector fields, here I thought we were working hard just because we cared so much about the research we were doing. I had completely forgotten that we were really in it for the extended vacation time, exorbitant salary, and total absence of responsibility that comes with an academic appointment.

Don't get me wrong; I love my job, wouldn't trade it for anything. But "cushy" isn't the word I (or anyone in their right mind) would use to describe it. Almost anyone who grinds through grad school and postdocs to get a faculty job as a scientist could be making more money for less work doing something else. But there are a lot more people trying to get these jobs than there are positions, for the same reason why the public is willing to support basic research -- we want to know how our universe works. It's the only one we have.

Update: Damn it, more evidence that administration is strangling NASA's pure science budget, in favor of going to the Moon and Mars. Paul Krugman said it best: "Money-saving suggestion: let's cut directly to the scene where Mr. Bush dresses up as an astronaut, and skip the rest of his expensive, pointless — but optimistic! — Moon-base program."

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

 
Landed gentry

The big news is that, despite previous misgivings, I've gone ahead and signed a contract for a condo. Signing the contract is not the final step; that would be closing, later in June. Closing is like getting tenure, while signing the contract is like landing a tenure-track faculty job; it's not the end of your worries, but it is the single biggest hurdle.

As you can see from the satellite image (found at TerraServer), I am already being spied on. The Man knows that I'm a troublemaker, and wants to keep an eye on me at all times.



In other news, my alma mater has chosen Big Bird to speak at commencement. Not in costume, but the actor who plays the character on Sesame Street. Not all of the students are happy. They shouldn't complain; the only real dimension along which commencement speeches should be judged is that of brevity. Once students have had four years of education and have typically made plans for jumping into the real world (or into grad school) it must be too late for a few well-crafted words of wisdom to have much impact on their subsequent trajectories.

~ posted by Sean Carroll at 4:55 PM ~ link ~ ~ ~

 
Precession

The irony is thick out there in low-earth orbit these days. Mere days after finally launching Gravity Probe B, equipped with the most precise gyroscopes ever built, NASA has lost one of the gyroscopes on the International Space Station. This leaves them with two functioning gyros (out of four), the minimum number necessary to keep the ISS from tumbling (which wouldn't be a disaster, but would require the expenditure of fuel to keep it the station in alignment. Yes, I know that the gyros on the ISS are completely different from those on GPB; we can't blame the failure on conservation of angular momentum.

Bob Park in the What's New newsletter from the American Physical Society put it this way:

SPACE TURKEY: GYROSCOPES ARE NOT COVERED BY DEALER'S WARRANTY. Two of the four gyroscopes on the International Space Station have now failed. The ISS can maintain orientation with only two gyroscopes, but what if there's another failure? We called the customer-service desk to ask how long repairs would take. They connected us to Hi Rodomontade, who sets NASA schedules. "You're in luck," Hi said, "we have one in stock. We'll send it up on the next shuttle." We asked when that would be. "Well, that's a problem, the shuttle fleet is being fixed. We use the Russian Soyuz to get to the ISS." But the Soyuz just traveled to the ISS on Wednesday for a crew change, "Did it deliver a new gyro," we wondered? "Unfortunately, the gyroscope is too large for the Soyuz. You'll just have to wait for the shuttle." When will that be? "It's scheduled for May," there was a pause, "May 2005."

~ posted by Sean Carroll at 1:09 AM ~ link ~ ~ ~

 
The Stairway at St. Paul's

This morning I was listening to Eight-Forty Eight, a local magazine show on Chicago public radio. They were talking with two video artists about Video Mundi, a festival currently playing at the Chicago Cultural Center.

Apparently one short video has become quite a sensation on the video-art circuit. Swedish artist Jeroen Offerman practiced for months to learn how to sing Stairway to Heaven backwards. And he learned how to play air guitar backwards, whatever that means. The resulting video shows his performance played backwards -- so you hear the words forwards. He includes an instrumental track for Stairway to Heaven playing behind him. You can certainly understand every word he's saying (at least as well as Robert Plant's original). But there is something creepy and different about it. I'm not sure I would have been able to decode what was going on if I had heard it without explanation.

One of the artists being interviewed said that work like this gave him hope for society. That is not exactly the conclusion I might have drawn.

Update: Jeroen Offerman is Dutch, not Swedish -- my mistake. Thanks to Arjon Dunnewind for the correction (in the Comments).

~ posted by Sean Carroll at 1:37 PM ~ link ~ ~ ~

 
Strategic withholding

Is it just possible that the Kerry campaign is being very clever?

If there is one thing we have learned about the Bush administration/campaign, it's that they fold instantly under political pressure. To prevent stories from festering, they happily reverse direction under the slightest provocation, or at least claim to. Think of military records, only giving one hour to the 9/11 commission, Rice's public testimony, the appointment of outsourcer Tony Raimondo as assistant secretary of Commerce, etc. And basically, the strategy has worked; what might have been long-lasting criticisms of the administration rapidly drop off the radar screen.

That's why the Kerry campaign should not make too big a deal out of Bush and Cheney appearing before the 9/11 commission together -- at least not yet. Let them actually do it, first. It's such a ridiculous situation, easily made fun of in debates (or on late-night talk shows), and speaks so directly to one of Bush's weaknesses, it would be a shame to lose it. Let them wound themselves, and take advantage later.

I was reminded of this when the cry went up from Republicans for Kerry to release his military records. I hadn't realized that they weren't already public, and certainly there's always the possibility of some lurking embarrassment. But now they've been released, and what do you know -- they make Kerry look great. And all of the articles about it will obviously offer a comparison to Bush's sad record, which brings that story back into the news. (Explicit comparison made over at Daily Kos here and here.)

Could it actually be that the Kerry people had purposefully not released the records, hoping that at some point the Republicans would notice, and provide an opportunity for some free publicity for how wonderful Kerry is? I'm reluctant to give them that much credit, but it's a possibility.

~ posted by Sean Carroll at 8:07 PM ~ link ~ ~ ~

 
Speaking of shameless self-promotion

Now that I have blog stats to check, I have lost valuable time that could be spent checking the amazon.com sales rank for my book. Thank goodness, because the book is tanking, to be perfectly honest. I am currently about 70,000th on the bestseller list, which is sobering. I started out somewhere below two million, and peaked around 3,000. I don't really think these rankings are a very good indication of sales for textbooks, since most people buy them at their college bookstore, but a higher ranking is nevertheless to be preferred over a lower one.
For those of you who haven't heard, the book is a graduate-level introduction to general relativity. There are many good books on the subject already, but I thought there was a niche for a modern book that focused on providing a clear, pedagogical introduction to the subject, rather than being overly ambitious and including too much advanced material.

The book came about in an interesting way. I first taught GR when I was a postdoc, and at the time I was young and foolish enough to think it would be fun to type up very detailed lecture notes and hand them out to each class. (Now that I am old and wise, the very thought makes my head spin.) Word got around that the notes were useful, and I began to receive requests for copies, so I just went ahead and put the whole collection online. They've been quite popular; the counter on the web page for the notes has passed 100,000, and that doesn't include the many folks who download them directly from arxiv.org. Of course not nearly that many people have read them, or even printed them out, but it's nice to be noticed.

The actual book is an expanded version of the lecture notes; what's in the notes comprises perhaps half of the finished book. And of course the exposition is cleaned up and improved throughout in the book version. Still, it has been questioned whether anyone would pay for a book if much of the material was available online for free; indeed, certain publishers insisted that I would have to take it off of the internet (as if that were possible) if they were to publish it. But the nice folks at Addison-Wesley loved the idea of keeping the notes online, as basically free advertising for the book. They did a great job at the actual book production (spiffy cover etc.), although the price is somewhat high ($80). So this is something of an experiment in the relation between free online content and expensive tangible content.

By the way, I did not review my own book for amazon.com, like some people do. Even though my reviews have been good, I would have gone into much more loving detail.

~ posted by Sean Carroll at 4:46 PM ~ link ~ ~ ~

 
GPB

One of the great things about the internet (one of the things, anyway; great or not is up for dispute) is that I can surround myself by only those voices that I want to hear. For example, I tend not to spend much time lingering at The Corner at National Review Online; I'll trust others to point to anything interesting that goes on over there.

Impearls has just pointed to one such thing: a short dialogue between Peter Robinson and John Derbyshire on the imminent launch of Gravity Probe B, a satellite designed to test general relativity. This satellite has a long and checkered history; scientists started working on the idea in the late Sixties, and it has since grown over-budget and out of control, but has been kept afloat by the persistence of its supporters in lobbying Congress. It is infamous for suffering delays in being launched, and we are in the midst of one such delay as I type this; the current plan is to launch on the morning of April 20th.

The Robinson/Derbyshire discussion was more interesting than I would have thought. (I've honestly never read anything by these guys before, although their names are familiar from rants by people I do read.) Derbyshire clearly knows something about the science, and gives an essentially-correct account of the usefulness of testing general relativity. (Okay, a quick lookup on the web: Derbyshire is the author of a popular-level book on the Riemann hypothesis, and also a self-described racist and homophobe. Takes all kinds, I guess.)

Robinson, on the other hand, is pretty much in the dark, but in a very revealing way. In the very first post in the exchange, he expresses surprise that there would be any such thing as experimental relativity:

Test Einstein? When I first learned about all this a few days ago, the idea shocked me. Einstein, I'd always assumed, must already have been proven correct. But apparently not, or at least not completely. In any event, full marks to the old man for providing us with a theory that meets Karl Popper's test of falsifiability, which is a lot more than Freud or, as best I can make it out, Darwin ever did.

Whew, where to begin? Robinson seems to have deep-seated misconceptions about how science works, ones that are very revealing in the context of debates about evolution. It is interesting to see Popper's criterion of falsifiability brandished with such confidence, when he clearly misses the most fundamental point of Popper's philosophy: the reason why "falsifiability" is a necessary quality is because it is impossible to "prove" any scientific theory correct. You can do all the experiments you like, and have them be perfectly consistent with your theory, but then someone tomorrow does a new experiment which isn't.

Not only can we not prove Einstein's theory correct, nobody believes that it actually is perfectly correct. It's not consistent with quantum mechanics (see long-promised post that hasn't yet been written), at the very least. But it could easily break down much sooner than we might expect from considerations of quantum gravity, which is why we need new tests in every regime. General relativity isn't sacrosanct, it's something people try to modify all the time. I've done it myself. (Another great thing about the internet -- the effortlessness of shameless plugs.)

It was also amusing to see Freud and Darwin mixed together. Of course Darwin's theory is eminently falsifiable, in a million possible ways. There could simply be no evidence whatsoever for alteration in the fossil record through time, or species could never appear or disappear, or we could demonstrably pass on developed characteristics to our offspring, or the necessary timescales for evolution could be much larger than the age of the Earth or the universe. None of these is true, though. Here we see one of the big reasons why it is so frustrating to argue with anti-evolutionists. Real scientists know perfectly well that all of our theories are approximations, and that every theory should be tested, and that no theory is perfect; but they are comfortable with the existence of different levels of approximate truth, and understand that evolution and the Big Bang and general relativity can be "true" in a way that doesn't mean they can't be improved upon. Anti-evolutionists cling to a more Manichean view of scientific knowledge, in which evolution isn't all that great because it's "just a theory." Like what isn't?

Meanwhile, hopefully Gravity Probe B will be successfully launched by the time you read this. They have constructed the world's most precise gyroscopes, to look for a subtle effect known as "frame-dragging." To be honest, the experiment will only yield modest improvements over existing limits on deviations from general relativity; that's why an anonymous physicist was opining that the only possible outcomes are agreement with GR, or nobody believing the experiment. Maybe; we'll have to see. This particular satellite cost a lot of money, much of which was appropriated outside the conventional peer-review process. If anything, the lesson worth emphasizing is that prioritization of scientific projects is a task best left to scientists, not to politicians. Once a satellite is on the launch pad, however, we can all cross our fingers and hope for some impressive new results.

Update: It's been launched! First science results are expected late in 2005, if all goes well.

~ posted by Sean Carroll at 10:12 PM ~ link ~ ~ ~

 
Does size matter?

I'm back from my brief visit to Swarthmore. Renowned as a liberal-arts college, Swarthmore (like many similar schools) has been placing increased emphasis on having science faculty that do research, with impressive success. We talked a little about the pros and cons of being a science major at a small school vs. a big school. At a big research university you definitely get the feeling of being at the center of a lot of action, with great work being done all around you. More pragmatically, you can take advanced courses in special topics that won't generally be offered at a smaller place, and there will (or should) be grad students and postdocs lurking around to ask for advice. But your contact with professors will be nothing like it is at a liberal-arts school, and your place in the totem pole is correspondingly lower. I think the happy truth is that there's no right answer; different students will respond differently to the different environments. (This is part of a larger secret that we don't like to tell prospective students when we are recruiting them: namely, that the success of their education depends much more on them than it does on what school they go to.)

Update: Victoria Swisher of the Swarthmore student newspaper wrote a nice article about the talk I gave.

~ posted by Sean Carroll at 9:59 PM ~ link ~ ~ ~

 
Reconsidering

Not much time for posting this week. In addition to taxes and teaching, I've been traveling too much; earlier this week in Texas, tomorrow giving a colloquium at Swarthmore. Somewhere in there it would be nice to fit some research, but you can't have everything.

I know that I earlier denied any interest in politics, but it sure would be nice to have a job with lots of vacation time, like President of the United States. Now that I think about it, that would probably mean I would pay a lower tax rate, too. Maybe my decision was too hasty.

~ posted by Sean Carroll at 7:57 AM ~ link ~ ~ ~

 
Secrets revealed

Will Baude, when he isn't blogging full speed over at Crescat Sententia, fills his free time by writing occasional columns for the Chicago Maroon. (He is also a University of Chicago undergraduate, but apparently that doesn't take much time out of your week.) His recent column deals with some interesting issues about privacy in an academic setting. But the really interesting question is asked right at the beginning: How much do professors talk about their students?

The inverse question is also interesting: How much do students talk about their professors? My best answer would be, more than they (the professors) suspect, but less than they would like. You would think that professors would know the answer perfectly well, since they were presumably students themselves at one point. But anyone who has ever actually taken a class can attest that professors tend to completely forget what it's like to be a student.

So what about the professors talking about students? It's probably the same answer: more than they suspect, less than they would like. Professors talk about students all the time, to be honest. Very often it's quite abstract: the new incoming class looks pretty good, kids today don't work as hard as we did, etc. But individuals certainly do get talked about. (Hope I don't get kicked out of the union for revealing this. If we had a union.) And here's another secret revealed: some students are more interesting than others, and they get talked about more. The anti-titillating news is that the talk is almost exclusively drily academic: that student is struggling, this one is amazing, the other one really should switch to another field. Except, of course, for the tremendous amount of griping that goes on about students who are somehow difficult (usually because they are complaining about grades). But very little, in my experience, about students' personal lives, unless some disaster is causing them trouble in school. Most professors have enough trouble managing their own personal lives (low-key though they may be) that there's little thought of delving into those of the students. Unless I'm just excluded from those conversations.

As an advisor of both graduate and undergraduate students, I suspect that they don't always appreciate how much their advisors worry about giving them proper guidance. Or, conversely, how much pride they take when the students do well. (I know that my own students read this, but I think I can tell the truth without getting in trouble here.) This pride is largely undeserved; if a really talented student chooses to work with me and I don't completely screw them up, they will do well just as if they had had some other advisor. But that won't stop me from feeling somehow responsible for their success.

~ posted by Sean Carroll at 8:08 PM ~ link ~ ~ ~

 
Bubble

Much of my mental energy these days is going into trying to buy a condo. Nerve-wracking stuff for anyone who finds financial matters somewhat distasteful, as the average academic tends to do. Now they say we might be in the midst of a housing bubble, analogous to the internet bubble of recent memory. There's even a website devoted exclusively to the possibility. Bubbles, of course, tend to burst, leaving the chewer all sticky and embarrassed. (Or poor, as the case may be.) But on the other hand there's a claim this could never happen in Chicago, what with our diversified economy and benevolent dictatorship. Is this a crazy thing to be doing right now?

~ posted by Sean Carroll at 11:16 PM ~ link ~ ~ ~

 
Thinking scientifically

PZ Myers at Pharyngula is defending scientists against the pernicious charge of "methodological naturalism." This is an accusation levied by intelligent-design enthusiasts eager to show how closed-minded the scientific community actually is. This idea is just that scientists begin by assuming the existence of a purely naturalistic explanation for the natural world, and are therefore cognitively unable to recognize evidence of design when it is staring them in the face.

It's an interesting question, actually, one that addresses what it means to be thinking scientifically. We often think of science as searching for a simple set of rules governing the behavior of the world; what if there is no such set of rules that suffices to cover all circumstances? What if some aspects of the world can't possibly be explained by a mechanistic working-out of simple patterns, but instead arise from the actions of a conscious supernatural being that isn't subject to any rules at all? Would science be able to recognize this, or would it always assume that there were rules, just that we hadn't yet figured them out?

As I argued in my paper on cosmology and atheism, I think that the search for immutable laws is not the hallmark of science; rather, it's the search for a simple, complete, and coherent explanation for all we see. We should distinguish between the methodology of science, which is really what defines it, and the product of science, which is the worldview that methodology leads us to. Naturalism and theism are two competing worldviews -- nothing but rules vs. intervention by one or more supernatural beings. But the defining characteristic of science is its method, which involves observing the world, framing and testing hypotheses, and so on. The scientific method stands in contrast to other possible ways of trying to understand the world, including contemplation and revelation. The ID types actually do understand this distinction, which is why they are accusing scientists of "methodological naturalism." Their criticism could in principle be correct, but in fact doesn't describe real scientists.

This is basically Paul Myers' argument as well -- if our methods led us to the conclusion that an intelligent designer offered the best explanation for the world we see, that's what we would conclude. Physics can offer an example of how scientists are willing to toss out their absolutely most cherished principles if the method demands it: the origin of quantum mechanics. If there has ever been a principle that physicists thought they would never have to give up, it was the clockwork determinism of Newtonian mechanics, in which the outcome of any experiment could be predicted with arbitrary precision. Eventually it became clear that this idea just wasn't going to work any more, and (after much wailing and gnashing of teeth, to be sure) quantum mechanics was born. Scientists wouldn't necessarily be very happy if their research began to point them in the direction of intelligent design, but they would certainly accept it if the data forced them to.

Of course, the data force us to exactly the opposite. Long ago David Hume wrote in On Miracles about why there is a fantastic prejudice against claims of supernatural intervention: when the laws of nature work perfectly well over and over again in essentially all of our experience, any claim for miraculous violation of those laws would require absolutely overwhelming and incontrovertibly unambiguous evidence. This is not what we are getting from the ID folks.

Still, I imagine that there are scientists who would claim that naturalism is a necessary component of being a scientist. Don't believe them. Scientists are constantly speaking rashly about what is and is not science, but the sad fact is that scientists don't always understand how science works, even if they are very good at doing it. We shouldn't be too surprised. It's like Ted Williams said about Ty Cobb: he was the best hitter of all time, but if you followed his advice about how to hit you'd never make contact with the ball.

~ posted by Sean Carroll at 8:58 PM ~ link ~ ~ ~

 
Diversity II

In the last post I lamented the dearth of women in physics, but there is another group that is even less well represented: conservatives in academia. Not to fear, David Horowitz has come up with a straightforward solution to this glaring inequity: he wants to legislate ideological balance in university departments, under the rubric of "intellectual diversity."

This is obviously a brilliant idea, although it suffers from one obvious flaw: it takes the influence of academia far too seriously. What we really need to do is to legislate mandatory ideological balance in all areas of human endeavor. Personally I think that large corporations tend to affect our daily lives more than university faculties do, so I'd be happy to see affirmative action for under-represented politics among CEOs. All sorts of institutions could be opened up to greater balance: lawyers, bankers, football coaches, the Joint Chiefs of Staff. I look forward to the day when all sectors of America have attained perfect ideological diversity.

As a side project (how does he find the time?) Horowitz wants to help leftists keep in touch with each other, through a database of leftist people and organizations. The site will eventually be at www.followthenetwork.org, but the pages are currently unavailable while they work some of the kinks out. If you're impatient, someone has mirrored an early version of the site before it went quiet. I was happy to see the University of Chicago appear, although apparently the Enrico Fermi Institute didn't make it. Thanks for the help keeping the left-wing conspiracy intact, David.

~ posted by Sean Carroll at 7:50 PM ~ link ~ ~ ~

 
Diversity

Our physics colloquium today was a departure; instead of a distinguished visitor telling us about forefront research, we had a talk by our own celebrated cosmologist Michael Turner. But he wasn't talking about cosmology; for the last six months Michael has been in charge of the Mathematics and Physical Sciences Division at the National Science Foundation, and came back to tell us what life was like at the NSF.

At the end of his talk he left us with assignments: what tasks, in his opinion, were most important for the physics community at this moment. Number one in order of importance was to "broaden who we are," by which he means to diversify away from domination by white males. To get an idea of the importance he was placing on this, the number two task was "do great science."

Physics has been dominated by white men throughout its modern history. This fact doesn't necessarily set it apart from other disciplines; but the depressing reality is that the situation in physics is improving only exceedingly slowly, if at all. Michael showed this picture of the University of Chicago physics faculty in 2000; more than thirty faces, none of them female. (At the time we actually had two women faculty, neither of whom happened to be present for the photo; now we have three, out of more than fifty faculty total.) We are not unrepresentative; less than ten percent of physics professors in the US are women, and it's much worse at the senior level.

The graph shown on the right plots the percentage of women earning Ph.D.'s in selected fields, between 1980 and 1998. (Click the figure for more details.) It illustrates that the situation seems to be getting a little bit better, but also highlights how far we are from most other fields.

Why is it like that? I really don't know. Anyone who has actually interacted with bright female physicists and students knows that the best women are just as good as the best men. There are also dramatic differences from country to country in the percentage of women in physics. So whatever the problem is, it's not inevitable; there is something about our system that dissuades women from going into physics (and math, and engineering, and computer science).

My suspicion is that there is no one focused obstacle, and this is what makes the problem so hard to solve. Certainly there is sexism within the physics community, in all sorts of manifestations. I have seen straightforward examples of outright discrimination, where a male physicist would downgrade the abilities of a student or colleague simply because she was female; more commonly, a kind of unconscious sexism is at work, in which insecure men will simultaneously flirt (awkwardly) with women while not taking them seriously as researchers. This is the hardest to eradicate, since the perpetrators would never possibly accept that they weren't extremely supportive of women in science. But in addition to direct sexism, there are elements of the scientific environment that are hostile, or even just uninteresting/unattractive, to female students, who subsequently leave the field of their own accord.

Unfortunately, the situation won't be fixed by well-intentioned university departments aggressively pursuing the best women students or faculty (although they should). The problem begins back when children are very young, and girls are gently but persistently diverted away from science by a million subtle pressures. It might be that the only way to achieve gender equality in science is to completely overhaul the society, which strikes me as a big project (although worth undertaking).

Of course women are not the whole story when it comes to diversity; African-Americans, for example, are equally badly under-represented. But in that case the problem seems less subtle to me; it just doesn't seem very surprising, since the economic conditions in which African-Americans grow up are often much worse than for whites, and the educations are correspondingly poorer. Physics, or academia more generally, is not a common career choice in families where it's a struggle just to get a decent education. So to increase the representation of African-Americans in physics, all we have to do is to end economic inequality between the races in America. Easier diagnosed than accomplished, I suppose.

~ posted by Sean Carroll at 11:03 PM ~ link ~ ~ ~

 
Secret speeches

We all know what a mess the Administration got itself into by refusing to let Condoleeza Rice testify in public and under oath before the 9/11 commission, eventually being forced to give in. One of the main reasons their position was so silly is that Rice was constantly giving interviews to news shows at the very time she was refusing to testify in public and under oath; the obvious implication being that it was okay to talk, so long as you weren't sworn to tell the truth, or if you were, so long as nobody would know what you said.

Now they are refusing to release the draft of the speech that Rice was scheduled to give precisely on September 11, 2001 -- a major address outlining the administrations foreign-policy strategies. We all know why they wouldn't want it made public; the painful truth that the administration was focused on state-based threats and swooning over missile defense systems, when they should have been concentrating on asymmetric threats from terrorist organizations, would be glaringly obvious. (See Josh Marshall's post from last week, based on excerpts from the speech.) But do they really not see how dumb this looks? How secret can it be? It was a speech she was going to deliver! One presumes there would have been people in the room, listening to it and stuff.

Update: Tbogg says much the same thing. Not that I thought this point was so subtle you had to be an overeducated theoretical physicist to figure it out or anything.

~ posted by Sean Carroll at 4:50 PM ~ link ~ ~ ~

 
Branding

And now I'm on the road again (giving a colloquium in Rochester), so still no time for a substantive post. But I did find out that the pie chart that serves as the unofficial logo of this blog will appear on the nametags and program for this conference next week. Not because of the blog (I presume), but because it represents our inventory of the universe: ordinary matter, dark matter, dark energy. Representing the inventory as a pie chart is almost too obvious, but people sometimes ruin the idea by making it too complicated. The universe is actually a simple place, although a subtle one.

There really should be a way to make money off of this blogging thing. Perhaps Preposterous Universe coffee mugs with the pie-chart logo? Is it possible to finance a new car this way?

~ posted by Sean Carroll at 11:54 PM ~ link ~ ~ ~

 
Lorentz

I would love to write my promised post on quantum gravity, but duty interferes, and I need instead to write a lecture on special relativity for class. Instead, here are two interesting facts about Hendrick Antoon Lorentz, one of the founding fathers of relativity.

First, although he was the inventor of Lorentz transformations, he went to his grave (1928) not believing in Lorentz invariance! He thought his transformations were just a trick for transforming between inertial frames and the one true ether frame. Einstein figured out in 1905 that the ether frame was unnecessary, and that's when special relativity really got off the ground. For more info, look at the bottom of this page for Michel Janssen's dissertation.

Second, he did not invent the Lorenz gauge of electromagnetism (note the spelling). That would be Ludwig Lorenz, a Danish physicist. Poor Ludwig's reputation was lost in the glow of someone with awfully similar name and interests.

~ posted by Sean Carroll at 11:22 PM ~ link ~ ~ ~

 
Thank God for Atheism

The most recent issue of The New Republic has an article about the Pledge of Allegiance affair by Leon Wieseltier. It's an insightful piece -- Wieseltier, who seems to be religious himself, puts the issue in better perspective than I ever could have. His main point is simply that the defenders of keeping "Under God" in the Pledge are actually undermining religion, since their main tactic is to claim that the phrase doesn't really refer to anything specific, just a warm and fuzzy feeling we all have as Americans. Wieseltier correctly points out that it is the atheists who, by not buying into such a meaningless notion of God and religion, are the ones who take God seriously.

For this reason, American unbelief can perform a great quickening service to American belief. It can shake American religion loose from its cheerful indifference to the inquiry about truth. It can remind it that religion is not only a way of life but also a worldview. It can provoke it into remembering its reasons. For the argument that a reference to God is not a reference to God is a sign that American religion is forgetting its reasons. The need of so many American believers to have government endorse their belief is thoroughly abject. How strong, and how wise, is a faith that needs to see God's name wherever it looks?

I think he's exactly right -- religion only makes sense if it pleads guilty to making claims about how the world works. I also believe that those claims fall far short, but I have more respect for believers who stand by the manifest consequences of their belief.

~ posted by Sean Carroll at 8:45 PM ~ link ~ ~ ~

 
Of course...

Just so we don't get too uppity, keep in mind that the subject matter of the previous two posts might be completely discredited within a few years, due to the ceaseless efforts of the supernatural movement. (Link from Panda's Thumb.)

~ posted by Sean Carroll at 6:37 PM ~ link ~ ~ ~

 
Quantum hermeneutics

Wow, with a title like that, I should just end the post right now; it's going to be all downhill from there. You could make a lot of money from a book with a title like that. Or did Deepak Chopra already write it?

Okay, I'm delaying the inevitable. I was hoping today to write about quantum gravity, after once and for all explaining the mysteries of quantum mechanics in the previous post. But I carelessly brought up the issue of the interpretation of the theory, which deserves more nuanced discussion. Not that I'm qualified to give it. You can read something about the issues at Michael Nielsen's blog (two posts).

But I would like to at least say some words about what I think the issue is, even if I don't want to make a strong case for any particular resolution. There certainly is an "issue," which may or may not be a "problem."

Every scientific theory comes in two pieces: a formal structure, and an "interpretation" that maps this structure onto what we see. Usually the interpretation is perfectly obvious, and we don't worry about it. But in quantum mechanics, what we see is not what there is, so we need to think more deeply. What is it that really happens when we do a measurement? For example, consider an unstable nucleus. Its wavefunction is a combination of two classical possibilities: the nucleus has already decayed, or it hasn't. But when we observe it, we don't see this superposition of possibilities; we see that it has either decayed or not. What really happens when we look at it? The Copenhagen interpretation says that the wavefunction collapses to the possibility that we have observed, while the many-worlds interpretation says that the observer+nucleus system evolves smoothly to a superposition of "nucleus decayed, observer saw decay" and "nucleus intact, observer did not see decay."

The MW interpretation is nice because everything is smooth evolution obeying the laws of physics (in this case the Schrodinger equation). But it's tricky because, since "I" actually do or do not see the nucleus decay, I need to identify "I" with a certain "branch of the wavefunction," not with the entire wavefunction. This is hard to do, both technically and conceptually. ("What does "I" mean? How does this branching process take place?)

I'm in the camp that says it's fair to call this a philosophy problem, not a physics problem. But it's a perfectly legitimate philosophy problem, not a silly waste of time. Fortunately for physicists, we don't need to know the answer to make progress on the questions we really care about. (Apparently, anyway; statements like that have a way of showing up in future textbooks as evidence of how misguided past generations were.)

~ posted by Sean Carroll at 5:47 PM ~ link ~ ~ ~

 
Beyond clockwork

The joint is jumping over at Peter Woit's Blog, even though his is even newer than mine. (Blog statistics are just what academia needs: another quantitatively precise and wholly meaningless measure of worth.) I suspect it's because Peter tends to say provocative and controversial things that people readily disagree with (about emotional topics like, say, string theory), whereas I am so sweetly reasonable that everyone cannot help but agree with everything I say.

Peter did ask a question to cosmologists that I didn't get to, so I thought I should take a swing: "What is 'string cosmology'?" If the response were to make any sense, I should explain something about string theory, which means explaining something about quantum gravity, which means explaining something about 'quantum' even without gravity. I don't know how far we'll get, but explaining quantum mechanics is a worthy goal in its own right.

Quantum mechanics (QM) is one of the top two most profound ideas in the history of physics. The other member of the top two is classical mechanics, the system developed by Galileo and Newton and their friends, which was eventually superseded by quantum mechanics. (The ordering of the top two is tricky, and there's no consensus on number three.) Nevertheless, QM is consistently misrepresented (or even misunderstood) by professional physicists, and its basic ideas aren't nearly as clear to people on the street as they should be.

Classical mechanics is simple. For any physical system (balls on a billiard table, planets moving around the sun, the whole universe) you tell me the "state" that the system is in at some time, and I can use the laws of physics to predict what the state will be at any other time. Specifying the state typically means specifying the positions and velocities of all the components. This kind of system is at the heart of the "clockwork universe" that came out of the Enlightenment.

Quantum mechanics came about in the early 20th century. Surprisingly, the description of classical mechanics in the previous paragraph also applies perfectly well to quantum mechanics: you tell me the state, I'll use the laws of physics to evolve it forward in time (or backward, for that matter). The crucial difference lies in a feature so profound that it's hard to conceptualize: in quantum mechanics, what you can see (the observable properties of the system) is related to, but not the same as, what there really is.

So, for a single particle, classical mechanics tells us that it has a position and a velocity. The lesson of quantum mechanics is sometimes garbled into the idea that "we can't be perfectly certain where the particle is or how fast it is moving." The truth is more profound: there is no such thing as "where the particle is," or "how fast it is moving." Instead, there is something called the wavefunction that describes the state of the system. The wavefunction answers the question, "when we observe the system, what is the probability we will observe it to have a given position or velocity?" In classical mechanics we can observe anything we want about the state, but in quantum mechanics we can't, we can only predict probabilities for what might happen when we make an observation.

What actually happens when we make an observation is the source of great philosophical angst. The old "Copenhagen interpretation" held that the wavefunction changed instantaneously and non-locally, into a state that was concentrated around the result of our observation. The newer (but still pretty venerable) "many-worlds interpretation" says that we the observers are also described by wavefunctions, and the measurement process mixes up our wavefunction with that of the thing we're looking at in such a way that we only ever experience unique outcomes for observations, even though everything is evolving smoothly. As crazy as it sounds, most working physicists buy into the many-worlds theory (and, like approval for gay marriage, there is a significant demographic slant, in which younger people are more open).

Quantum mechanics is not so much a theory as it is a framework in which we can propose all sorts of specific theories. The most empirically successful are quantum field theories, in which the elements of our physical reality are fields defined on spacetime (quantities that take on values at every point, like an electric field). In quantum field theories, the actual field values are one of these unobservable things; what we can actually see is discrete excitations of the fields that we call "particles." Quantum field theory successfully describes every experiment ever performed and every phenomenon ever observed, with one glaring exception: gravity. For a force that is so important, it's truly embarrassing that we can't fit it into our favorite framework. That's why so many physicists think that the search for a consistent quantum theory of gravity is so interesting and vital.

P.S. (When reading Peter's most recent post, please keep in mind the date posted.)

~ posted by Sean Carroll at 10:06 PM ~ link ~ ~ ~