With the release of I, Robot, everyone is talking about the terrible damage being done to the ideas of Isaac Asimov. Over at The Fulcrum, for example, Charles2 lists the three Laws of Robotics,

1. A robot may not injure a human being or, through inaction, allow a human being to come to harm.
2. A robot must obey orders given it by human beings except where such orders would conflict with the First Law.
3. A robot must protect its own existence as long as such protection does not conflict with the First or Second Law,

and wonders whether they could be applied to politics and government.

What I wonder is, what kind of lunatic thought that these laws were ever workable? Especially the first one. A robot cannot, through inaction, allow a human being to come to harm? Human beings are coming to harm all the time all over the world, and that’s only if we stick to straightforward physical harm, not to mention more subtle varieties. Every robot with these laws programmed into them would instantly launch on a frenzied quest to change the very nature of reality in order to stop all of this harm from happening. I just want something that will vacuum my floors efficiently, not save the world.

The whole point about robots (or computers more generally) is, they’re very literal-minded. They don’t know the meaning of “within reason.” When talking to each other rather than to machines, human beings are never perfectly precise about what they mean, often for good reason. That’s why we’ll always have literary critics, theologians, and the Supreme Court: to help us understand what was really being said.

I met Asimov once, when he visited my undergraduate university. They thought it would be fun to show him around the astronomy department, much to his bemusement (he was trained as a chemist). He used his advanced age as an excuse for shamelessly flirting with every attractive woman within leering distance. I wonder what he was like before his age was so advanced?

Longtime readers will attest that I am extremely dedicated to sharing my random thoughts with everyone out there in blog-land. But from time to time my jet-setting lifestyle will take me to places where internet connectivity is faint or nonexistent. To deal with this terrible possibility, we are inaugurating a new feature here at Preposterous: the guest-blogger. (I understand that bloggers elsewhere have also experimented with this idea, but it’s new for us.)

Figuring that we might as well start at the top, we are pleased to announce that our first guest blogger will be Gretchen Helfrich. Everyone in Chicago, and many public-radio listeners elsewhere, will recognize Gretchen as the host of the daily radio program Odyssey from Chicago Public Radio. (Anyone with RealPlayer can listen over the web whenever they like.) Odyssey represents exactly what you would like to hear on public radio: a spirited and in-depth examination of ideas, ranging from politics to science to the arts. Sort of like this blog, without as much whimsical self-indulgence and pictures of Godzilla. The best feature of the show is how they make every effort to generate light rather than heat, remaining interesting and entertaining while digging carefully into the issues lurking behind the topics being discussed. The opposite of the O’Reilly Factor in every way.

Gretchen will be taking the reins for about a week starting on Friday, as I’ll be traipsing through the wilds of Wyoming. Everyone play nice, now.

More old-school bands should do this. In celebration of thirty years together, Rush has come out with Feedback, an EP of cover tunes, focusing on the songs they were insprired by back in the Sixties when they were first learning rock and roll. For those of you who know or care, Rush is one of those love/hate bands; a progressive-rock power trio, they are worshipped by their fans for their fantastic musicianship, and belitted by their critics for being ponderous and pretentious. Count me as a fan. Who wouldn’t want to hear Geddy Lee sing Summertime Blues?

In honor of their anniversary, here’s a picture of Neil Peart with his drum kit (click for full glory).

Like Daniel Drezner, I find it necessary to put to rest those unfounded speculations that I will soon be drafted to run as the Republican nominee for the U.S. Senate from Illinois. Now, even on the face of it there are certain manifest obstacles that would have to be overcome. It is true, for example, that I have occasionally implied a favorable attitude towards gay marriage, questioned the existence of God, argued against building a missile defense system, poked fun at the President (also here, here, here, here, here … well, you get the point), and even said nice things about the Big Bang. I’ve also been known to consort with the enemy. Oh yes, and I’ve promised never to run for office. (Now that I think about it, anyone with a blog and a less-than-perfect amount of self-control would have a hard time not leaving such an inflammatory trail of comments that they would be instantly disqualified from any future political career.)

But I’m a believer in a strong two-party system, and the GOP in my adopted home state is kind of on the ropes these days. Democratic nominee Barack Obama has seen all of his opponents implode, has just been tapped to give the keynote address at the Democratic national convention, and is generally being given rock-star treatment by the national media. Attempts by Republicans to inject some celebrity star power of their own have fizzled, and are now becoming increasingly desperate. And, you know, I am well-educated, gainfully employed, and a practiced public speaker. They could do worse (and seem to be trying to).

Alas, it’s not to be. As much as I would love to set an exciting precedent by entering the campaign as a Republican running to the left of his Democratic opponent, I feel too strong a sense of obligation to my students and colleagues here at the University of Chicago, who frankly would be lost without me.

But if Bush does decide to dump Cheney, he has my number.

The cat is out of the bag about Stephen Hawking’s new ideas about black holes. Preposterous regulars were in on the ground floor, of course. We can now speculate somewhat more intelligently about what the ideas actually are, since the abstract for his talk (next week at the GR17 conference in Dublin) is online:

The Euclidean path integral over all topologically trivial metrics can be done by time slicing and so is unitary when analytically continued to the Lorentzian. On the other hand, the path integral over all topologically non-trivial metrics is asymptotically independent of the initial state. Thus the total path integral is unitary and information is not lost in the formation and evaporation of black holes. The way the information gets out seems to be that a true event horizon never forms, just an apparent horizon.

(For more scoop see Not Even Wrong, Smijer, By the Way, and this thread on sci.physics.research.)

It seems as if our initial skepticism might be accurate: even if Hawking’s proposal is ultimately judged to be a fantastic breakthrough, it won’t catch on right away. The Euclidean path integral approach to quantum gravity, which Hawking has been instrumental in developing, is not generally thought to be the most promising approach. One never knows, and it might eventually turn out to be on the right track, but it’s not very popular in the quantum-gravity community.

Let’s try to explain what is going on. Quantum mechanics tells us that the world is described by wave functions, which give the probability for getting a certain result when we make an observation. A path integral is just a certain way of calculating the wave function. Invented by Richard Feynman, the path-integral approach says that we should attach a certain contribution to every possible path the system can take from one configuration to another, and then sum all of these contributions; the result is the wavefunction for being in the final state, given the initial state we started with. Often this sum (the path integral) is hard to do, and a convenient mathematical trick is to allow the time coordinate to be imaginary; this purely formal manouver turns four-dimensional spacetime into a four-dimensional space (no direction is singled out as “timelike”), and the integral turns out to be much easier to do. In gravity, we would like to sum over all the possible geometries of spacetime itself. So “Euclidean quantum gravity” tells us to calculate the wave function for the geometry of three-dimensional space at some fixed time by summing over all the possible four-dimensional geometries that connect to that spatial geometry.

The problems with this approach include: nobody knows what number to attach to each geometry in the sum, nobody knows how to do the integral, and nobody knows how to interpret the result. Significant problems, in other words. Optimists like Hawking think that they can describe a certain set of approximations in which the path integral makes sense; string theorists, on the other hand, would generally say that the path integral is nonsense if you don’t include the fundamentally “stringy” aspects of spacetime on ultra-small scales. In the absence of direct experimental data, we have to judge how well the ideas hang together in their own right; at the moment, Euclidean quantum gravity seems to have serious issues, and hasn’t scored many notable triumphs.

Hawking now seems to be saying that the path integral for black holes can help us understand how information that we thought had disappeared into the singularity can actually be lurking close to the horizon, so that it can eventually influence the outgoing Hawking radiation, and thus allow information to be recovered by the evaporating black hole. He’ll be met with serious skepticism in the physics community, but let’s wait to see how it washes out.

Of course, he’ll also be met with serious awe by the media. This can drive other physicists crazy. I often find myself explaining to non-physicists that Hawking is not the very best theoretical physicist out there, but simultaneously defending his reputation to my fellow physicists. It’s probably safe to say that Hawking was the leading researcher in theoretical gravitational physics in the second half of the twentieth century, and arguably since Einstein; but gravitational physics was not where the action was during that time (it was in particle physics and quantum field theory). A lot of physicists hurry to point out that Hawking is not doing the most influential work in quantum gravity these days; but the truth is that most sixty-year-old physicists aren’t doing the most influential work in their fields, even if they don’t have serious neurological disorders. Like anyone else who has made fantastic contributions, Hawking has earned respect for new ideas he might have, but the ideas themselves will be judged on their own merits.

Okay, can we stop doing this? Where by “this” I mean grasping at any opportunity to ridicule the behavior of Jenna and Barbara Bush, simply because they are the children of our disastrously bad President. And no, the fact that they are campaigning for their father doesn’t make their private lives fair game. If you want to critique their ability as campaigners, or suggest that they have implausible policy views, go right ahead. But to titter about stories of the Bush twins’ bar exploits is tawdry, demeaning, and completely unnecessary.

I would make a distinction that is rather fine, but seems valid: in the context of pure gossipy dirt-dishing (like the original Times article that the Barbara Bush story came from, or nearly every story in Wonkette), I have no objection to mean-spirited snarkiness. That’s the point of those kinds of stories. But when we indiscriminately mix this trash in with serious political disagreements, we are stooping lower than there is any need to stoop. Here we have an administration that has produced so many fiascos that there is increasing talk of “outrage fatigue“; what is the point of muddying the waters with jabs at the personal lives of the President’s kids? There are real things to complain about without following people into bars hoping they’ll embarrass themselves.

Terry Teachout has a nice reflection on the social disapprobation that accompanies an unseemly regard for the artistic and intellectual side of life (especially for children). I have nothing deep to add, except that his mention of a hypothetical waitress who could quiz him knowledgeably on what he was reading reminded me of this well-known math joke:

The first mathematician says to the second that the average person knows very little about basic mathematics.

The second one disagrees, and claims that most people can cope with a reasonable amount of math.

The first mathematician goes off to the washroom, and in his absence the second calls over the waitress.

He tells her that in a few minutes, after his friend has returned, he will call her over and ask her a question.

All she has to do is answer: `one third x cubed’.

She repeats `one thir — dex cue’? He repeats `one third x cubed’.

Her: `one thir dex cuebd’? Yes, that’s right, he says.

So she agrees, and goes off mumbling to herself, `one thir dex cuebd…’.

The first guy returns and the second proposes a bet to prove his point, that most people do know something about basic math. He says he will ask the blonde waitress an integral, and the first laughingly agrees.

The second man calls over the waitress and asks `what is the integral of x squared?’.

The waitress says `one third x cubed’ and while walking away, turns back and says over her shoulder `plus a constant’!

Okay, it’s not very funny if you don’t know much calculus (the waitress was giving a more precisely correct answer than the mathematicians had any right to expect, demonstrating that they were both handicapped by inaccurate stereotypes). But I noticed something else: looking for a copy of the joke through Google, the version I just transcribed is only the second-most-popular version. More popular is the following:

Two mathematicians were having dinner in a restaurant, arguing about the average mathematical knowledge of the American public. One mathematician claimed that this average was woefully inadequate, the other maintained that it was surprisingly high.

“I’ll tell you what,” said the cynic. “Ask that waitress a simple math question. If she gets it right, I’ll pick up dinner. If not, you do.”

He then excused himself to visit the men’s room, and the other called the waitress over.

“When my friend returns,” he told her, “I’m going to ask you a question, and I want you to respond ‘one third x cubed.’ There’s twenty bucks in it for you.” She agreed.

The cynic returned from the bathroom and called the waitress over. “The food was wonderful, thank you,” the mathematician started. “Incidentally, do you know what the integral of x squared is?”

The waitress looked pensive, almost pained. She looked around the room, at her feet, made gurgling noises, and finally said, “Um, one third x cubed?”

So the cynic paid the check. The waitress wheeled around, walked a few paces away, looked back at the two men, and muttered under her breath, “…plus a constant.”

You see the difference? In the first version, with which I was familiar, I always imagined that the waitress was having fun teasing the mathematicians, and walked away smiling. But in the second version it’s clear she is just pissed off and grumbling. Now it seems much less funny to me, although obviously a lot of people prefer this version.

It’s amazing what psychological insights you can reach just be wandering through the web with Google as your only guide. The internet isn’t anything weird and scary, it’s just a window into our brains. Okay, that is pretty scary.

Another young mind enters the community of scholars. Congratulations to Eugene Lim, who just finished successfully defending his Ph.D. thesis, and is now an official doctor. Preposterous readers may know Eugene from his occasional appearance in the Comments, under the nom de blog “Your Hardworking Student.” Eugene is only the second Ph.D. student I’ve had, so I’m still fumbling around a bit, but hopefully my inexperience as an advisor didn’t scar him too badly.

Eugene’s thesis work was about the gravitational effects of vector fields that violate Lorentz invariance by picking out a preferred direction in spacetime. We have one joint paper coming out soon, and he has a longer single-author paper, so I’ll give more details about the research when they are ready. The basic story is surprisingly short and sweet: the vector field acts to change the measured value of the gravitational constant, but in different ways in different circumstances, so you can actually place interesting limits on its magnitude by comparing different experiments.

In the fall Eugene will be heading to Yale to take up a postdoctoral research position. Good luck!

This weekend I saw the first Godzilla movie, in the restored original Japanese version. The Godzilla universe is as complicated and internally inconsistent as they come, but the first movie (1954) was an interesting allegory about the hazards of nuclear weapons. Shot in stark black and white, the movie tells the story of a prehistoric monster who is brought back to life by H-bomb testing and proceeds to terrorize coastal Japan and Tokyo in particular. The original American theatrical release was heavily bowdlerized, both removing some of the harsher scenes of irradiated children (Godzilla was highly radioactive) and splicing in scenes of Raymond Burr as an American journalist. I haven’t seen the American version in a long time (ever? there are so many Godzilla movies it’s hard to keep track), but I suspect the Japanese version is both more coherent and dramatically compelling.

Of course the production quality was not what we are used to these days, nor was the general pacing. To a contemporary audience, this movie seems awfully relaxed, even in the scene where Godzilla is stomping trains and power lines in downtown Tokyo. Part of this is the difference between Japanese and American sensibilities, but much of it is simply the passage of time; those early James Bond films seem just as lethargic. And it’s easy to recognize when a tiny model is being destroyed by waves rather than a full-size town. (Probably much of our ability to tell the difference can be traced to physics — the relative timescales associated with various actions change with respect to each other as a function of length scale. Someone should write a paper about this.) The one effect that remains unmatched is the sound that Godzilla makes; even in the horrible but high-tech 1998 American version, they were unable to create an equally impressive Godzilla sound from scratch and had to stick with the original.

Science plays an ambiguous role in the movie. Obviously, technology is implicated in the original horror of the H-bomb that brings Godzilla to life. Later, the elderly paleontologist is portrayed as heartbroken that there are plans to kill Godzilla (who has been happily rampaging through Tokyo) rather than attempt further study — a standard, although not very complimentary, stereotype of scientists. But at the end, it is a lonely researcher working in his basement laboratory who invents the weapon that ultimately destroys Godzilla — the Oxygen Destroyer, which kills all aquatic life in a wide radius around where it is activated. So science has terrible consequences, but we have no other recourse when we need to address our serious problems. Of course, yet another misunderstanding of how science works leads to the final plot twist, when the lonely researcher (who had been permanently scarred by an atomic blast) commits suicide after the Oxygen Destroyer is used, so that this terrible power cannot fall into the wrong hands. In the real world, if a well-funded group of dedicated scientists have just seen something demonstrated, they will figure it out for themselves before too long. There are no true secrets when it comes to science and technology; the interesting discoveries will all eventually be made, regardless of what any one person chooses to share.

Good news for all you jazz lovers out there: The Great Divide, a new CD from tenor master Von Freeman.

As I’ve previously mentioned, Von is a Chicago legend. Eighty-one years young, he is still blowing as hard as ever. His style owes much of its allure to the ability to absorb many different influences, from Coleman Hawkins to Lester Young to Gene Ammons to Charlie Parker to John Coltrane to Ornette Coleman, and mix in something absolutely unique. For a quick demonstration, run out and buy his 1981 album Young and Foolish. Go to track one, “I’ll Close My Eyes,” and skip right ahead to the 9:11 mark. For the next two and a half minutes you’ll hear one of the most amazing sax solos ever committed to CD. A true solo, the rest of the band sitting out, that stretches from manic bebop phrases to near-dissonant growling, only to suddenly and sharply caress the original melody in startling epiphanies, bringing the audience to a state of near-riot. And that is the true genius: to experiment and test the limits of the music while remaining consistently and compellingly beautiful. (Don’t take my word for it, read the reviews.)

Along with his musical gifts, Von is famous for his generous spirit and mischievous humor. Best of all, he’s extremely accessible, at least if you’re in Chicago. Von and his quartet play the second Saturday of every month at Andy’s downtown, and every single Tuesday at the New Apartment Lounge on 75th Street, in an atmosphere at once informal, authentic, and genuinely welcoming. You will never find music of this caliber for such a low cover charge (zero dollars). Later in the evening, striving young musicians from throughout the city take part in a spirited jam session. (For a lively discussion of the Chicago music scene, opening with an amusing account of the vibe at the Apartment, check out Waking Up in Chicago by British journalist Claire Hughes.) This Tuesday (the 13th) there will be a party to celebrate the new CD; Von will also be playing later this week at the Green Mill and in Millennium Park.

Von’s fans will tell you that the only reason he hasn’t become as well-known as the usual roster of saxophone legends is that he never moved to New York to pursue a recording career, preferring to stay home and play gigs. Whatever the explanation, Chicagoans are truly fortunate to have such a master in their midst.