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.

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.

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.

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.

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.

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.

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?

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.

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.

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.