Miscellany

NASA Administrator Sean O’Keefe’s decision to cancel future servicing missions to the Hubble Space Telescope has been met with an outcry from scientists, politicians, and ordinary people all over the world. It’s been very difficult to figure out what O’Keefe’s response really is. On the one hand, he has agreed to request a new National Academy of Sciences report that would study the pros and cons of future servicing missions. On the other, he continues to say (for example in today’s New York Times) that he won’t authorize a new Shuttle mission that is inconsistent with the guidelines set forth by the Columbia Accident Investigation Board — which an HST servicing mission would be, since there is currently no way for a Shuttle crew visiting HST to inspect the orbiter for damage.

Safety is the most common argument against future servicing missions — fortunately for those of us who favor new missions, it’s a completely ridiculous argument. True, manned missions to space are dangerous, no matter what precautions we take. But does anyone in their right mind think that a visit to HST is more dangerous than a trip to Mars? The astronauts who comprise shuttle crews understand the risks, and would be more than eager to get the chance to upgrade Hubble. The only real argument is about money.

Which is completely ludicrous, since the budget includes a hefty chunk of change for future missions and upgrades to the International Space Station. The ISS has been a sad boondoggle from start to finish, a laughingstock in the scientific community. A combination of international obligations and a politically-astute dispersion of ISS contracts throughout multiple congressional districts make this beast impossible to kill. Apparently the Administration’s plan is to spend a huge amount of money finish building it (just barely), and then declare victory (“Mission Accomplished”?) and let it rot up in orbit.

Meanwhile, clever folks at NASA are examining all sorts of imaginative proposals for servicing Hubble robotically, without a manned mission. These guys are good, and it may be possible to keep the observatory orbiting and operating for longer than its current expected lifespan of 3-4 years. But it’s nearly impossible to imagine upgrading the telescope with the new instruments that have already been built. Regardless of this effort, it’s absolutely worthwhile to keep pushing for another servicing mission to HST.

(I suppose posts like this don’t help my chances for future NASA funding very much.)

Related: Ultra Deep Field.

Donald Rumsfeld was apparently very fastidious when he first toured the Pentagon after 9/11; enough that he walked away with a piece of the crashed airplane as a souvenir. (Original link from Fark.com.) He keeps it on his desk, and shows it to visitors as a reminder of the tragedy. Which, I guess, might otherwise just slip his mind completely.

That last post I put up was in a hurry (catching a plane back to Chicago), and it didn’t quite form the crystalline structure of unassailable logic that, you know, all the other posts do. So let me elaborate a little. (I could just go back and edit the thing, nobody would know; the technology lets me, but it seems like cheating. I bet Robert Novak wishes he could do that.)

First, why the ad is bad: not because it suggests that the terrorists responsible for the 9/11 attacks were Arabs, but because it appeals to irrational fears rather than making a reasonable argument for certain policy choices. (Probably “xenophobic” would have been a better adjective to use than “racist” in the original post.) It’s an emotional cheap shot; those are trite but unobjectionable when they are sugary and uplifting (“Morning in America”), but odious and inexcusable when they appeal to our less-lofty sides.

Second, is it a good campaign strategy? I really don’t know. But it does seem to be a little early to be stooping that low. As I understand the conventional wisdom, a negative attack (such as this obviously is) may initially be effective, but over time can lead to backlash. So in the last few weeks of a campaign, they can be quite useful, but at this early stage Bush is going to take so much grief from the ad that it hardly seems worth whatever benefit he might get. Another good question I don’t know the answer to: of the people an ad like this might hope to influence (swing voters who actually haven’t made up their minds, and mildly-apathetic folks who need to be prodded to vote), how many will see the ad but not hear the accompanying media commentary, and how many will get the commentary without the ad? I’m sure the pros have calibrated this backwards and forwards. (Right?)

Ever since Homicide went off the air, my TV viewing is largely limited to NBA games, Queer Eye, and occasionally the Iron Chef. So I don’t get to see a lot of the new campaign ads. Blogosphere to the rescue, however, as we can easily dissect every new ad without ever reaching for the TV remote.

The latest Bush ad takes a step that nobody should find surprising, but some find upsetting: using an image of an olive-skinned, vaguely Arabic-looking man to symbolize the threat of terrorism. (The ad is discussed, with screenshots, by Ryan Lizza at TNR and Billmon at Whiskey Bar.)

Bush supporters can say (and already are saying, e.g. at Little Green Footballs) that this is no big deal — after all, the Sept. 11 terrorists were olive-skinned Arabs. This is a true statement, just as it is true to say that the DC snipers were African-American, or that Timothy McVeigh, the Unabomber, and Jack the Ripper were all Caucasian. Under the hypothesis that all statements of fact are equally appropriate, I suppose there’s nothing more to say. But this is a blatantly racist appeal: Bush will protect us from the scary Arabs. Not only is it repulsive, it’s also not a sensible long-term strategy for fighting terrorism (which comes in all colors, as folks in Ulster will tell you). But who knows, maybe it will work as a campaign theme.

Atrios points to this post from Poor Man, reconstructing the ad the Bush campaign would really like to have made, if the liberal media would let them get away with it.

I’m visiting the Perimeter Institute, a swanky Canadian center for theoretical physics. They’re open to speculative ideas here, so I gave a talk yesterday about the arrow of time.

The celebrated Second Law of Thermodynamics tells us that entropy, a measure of the disorder in a system, tends to increase with time (unless some outside influence acts to increase the order). The first person to understand this phenomenon was Ludwig Boltzmann (who later committed suicide). Boltzmann realized that the entropy was a measure of how many ways a system could be arranged that were basically indistinguishable. For example, if we have some gas distributed uniformly throughout a box, we can move individual atoms around in many different ways without affecting basic features like the density and pressure; so a uniform gas has a high entropy. But if all the gas is squeezed into one corner, there are fewer rearrangements that leave the system basically unchanged, so the entropy is lower. We therefore expect that gas can easily spread from a single corner to fill the box, but it’s very unlikely that uniform gas will suddenly congregate in one tiny region. Thank goodness, or breathing would be a constant adventure.

But Boltzmann also realized the major unsolved problem: entropy only increases because it was very low in the past. Why did the universe start out that way? We still don’t really know the answer. In my talk I proposed an answer, that I’ve been working out with Jennifer Chen. We make the very simple suggestion that the entropy is increasing because it can always increase — in the real universe, there is simply no state of maximum entropy. So the fact that the entropy is going up is very natural, since it can always do that. The crucial ingredient we use is the idea of eternal inflation. “Inflation” is the idea that a tiny region of space can expand at a super-accelerated rate, growing into a size much larger than our entire observable universe. Eventually this process ends in most places, and the inflating universe converts into a more conventional Big-Bang cosmology; but “eternal” implies that it never ends everywhere, there’s always some region far outside what we can observe where inflation is still going on. This process of inflation both constantly generates more and more entropy, and creates large regions that look just like our observed universe in the process.

The title of the post refers to the fact that memory relies crucially on the second law of thermodynamics. Why do we remember the past and not the future? Because, as entropy increases, we develop correlations between the external universe and our brains; if our universe was in a state of maximum entropy (thermodynamic equilibrium), we wouldn’t be able to remember the past or the future. (We wouldn’t really exist as complex organisms, for that matter; thank the universe for small favors.)

The Hubble Space Telescope, in a spiteful attempt to make NASA look silly for canceling future servicing missions, continues to crank out wonderful new results.

This is a detail from the new Ultra Deep Field. They point the telescope at one small region of the sky and just let it sit there, gradually collecting the tiny number of photons that are coming to us from these galaxies in the early universe. The objects seen here formed approximately 500 million years after the Big Bang; in a 14 billion year old universe, that’s pretty young. Besides being a pretty picture, images like this help astrophysicists to figure out the processes by which galaxies became assembled out of the nearly-uniform plasma of the earliest times.

Looks like both Kerry and the media are going after Bush for only spending an hour with the Sept. 11 commission. Here’s Kerry, from Eschaton:

Kerry, who has accused Bush of impeding a federal commission investigating the terrorist attacks of Sept. 11, 2001, said Monday while campaigning in Florida, “If the president of the United States can find time to go to a rodeo, he can spend more than one hour before the commission.”

And here’s an excerpt from the White House press briefing, from Talking Points Memo:

Q: You just said, “all the questions they want to raise.” That means he’s no longer going to limit it to an hour?

McCLELLAN: Well, that’s what it’s scheduled for now. But, look, he’s going to answer all the questions they want to raise. Keep in mind that the commission —

Q: If they’re still asking at one hour, he’ll still answer them?

McCLELLAN: Keep in mind that the commission has already had access to all the information they requested, as I just pointed out, including our most sensitive national security documents. That’s what I’m talking about when I’m talking about unprecedented cooperation. And the commission has also — yes, let me finish —

Good.

Election day in Illinois is a week from now, March 16th. As usual we are too late to have any impact on the Presidential nomination process, but there’s an important Senate race. Republican Peter Fitzgerald is retiring, and chances are good that he’ll be replaced by a Democrat.

I’ll be voting for Barak Obama. (He seems to be leading the race at the moment, but my preferences are usually the kiss of death, so he’ll likely be issuing a press release declining my endorsement.) Not only was he president of the Harvard Law Review, he also has the grooviest campaign song of any of the candidates. (Via Crescat Sententia.)

I’ll be traveling for the next week — first the Perimeter Institute, then the University of North Carolina — so blogging may be spotty. Hang in there.

I promised earlier that I would talk about the Big Rip, but never got around to it, so here you go.

Since Edwin Hubble discovered in 1929 that the universe is expanding, cosmologists have suggested two possible ultimate fates for our currently-expanding universe: it could cease expanding and recollapse, eventually reaching zero size in a Big Crunch, or it could expand forever, but gradually more slowly (the Big Fizzle?). In a universe dominated by ordinary matter and radiation, these were really the only choices. Now we know that most of energy in the universe is some persistent dark energy that doesn’t diminish as the universe expands, and can continue to feed the expansion rate; therefore another possibility becomes likely, that the expansion will continue at a constant rate forever. Confusingly, a universe with constant expansion rate is said to be “accelerating,” because any individual galaxy appears to be accelerating away from us. That’s because Hubble’s Law says the recession velocity is the expansion rate times the distance (v = Hd), so a constant expansion rate H implies an increasing velocity v.

But there’s a lot we don’t know about dark energy, so it’s prudent to keep an open mind. The simplest dark energy model is an absolutely constant “vacuum energy,” but we can consider dynamical models in which the energy density is slowly decaying. Robert Caldwell and others have even suggested that the dark energy density (the amount of energy per cubic centimeter) might be increasing with time, a possibility he dubs phantom energy.

This opens the possibility of a Big Rip, in which the expansion rate increases without bound until it reaches infinity at some finite time in the future. This scenario was explored by Caldwell, Kamionkowski, and Weinberg. The consequences are dramatic: first galaxies, then stars and planets, then atoms and nuclei are ripped apart by the expansion of the underlying spacetime. The recent supernova results that were in the news indicate that the dark energy density is changing very slowly, if at all, so the Big Rip would have to be some time in the distant future (if, once again, at all).

It’s important to realize that the quoted numbers depend on an enormous extrapolation, one we have little reason to trust. Phantom energy density increases as the universe expands; but the above analyses made the simplifying assumption that the increase proceeded at a constant rate. In other words, imagine hopping in your car and accelerating to the speed limit, but then estimating your arrival time by guessing that your acceleration (rather than your speed) remains constant. You’d be able to get across the country awfully quickly if that were true; but it’s not a safe assumption.

The truth is, we can’t predict the future of the universe with any reliability at all until we understand much more about the underlying physics of the dark energy. If it is increasing, it might only do so temporarily, before leveling off to a constant value (see my paper with Hoffman and Trodden). If it’s currently a constant, it may decay completely away in the future. So, the choice between Crunch, Fizzle, and Rip is one we have no way to decide between right now. (But “Crunch, Fizzle, and Rip” is a great name for a band, or maybe a law firm.)

Here is why I could never be a politician. (Not that there are any movements afoot to draft me for major public office.)

A few weeks ago some friends and I went to the Lesbian Community Cancer Center Project Annual Ball (or the “Lesbian Prom” for short). True, I lack the traditional prerequisites for being a lesbian (female, homosexual), but it was a tolerant atmosphere, and my eccentricities didn’t seem to bother anyone.

The whole event was great fun. About a thousand people attended, festive, well-dressed (not as many outrageous costumes as Jerry Falwell would expect, but enough to be entertaining), and generally enjoying themselves in an easygoing and friendly atmosphere. It was a party, not a political event, and activism was in the background for the evening. It wasn’t until brief remarks associated with the presentation of some awards that anyone mentioned the same-sex marriage controversy. It only then struck me (I know, I’m slow) that all of these people around me, cheerfully having a good time, are systematically classified as second-class citizens in our country.

I doubt that anyone could get elected President today if they came out and said “This issue is completely ridiculous, of course same-sex couples should be allowed to marry.” But I wouldn’t be able to say anything else. We all know that progress in real-world politics sometimes relies on strategic compromise, and an ability to carefully prioritize efforts on controversial issues is absolutely necessary. But this one is simply not a close call. Furthermore, I don’t even think it’s especially interesting to talk about the arguments pro- and con-. It would be like debating whether apartheid was good or bad. (Racial discrimination is different than discrimination against gays, and drawing analogies between them isn’t generally useful, but one is just as obviously wrong as the other.)

To be fair, we’re not talking about what people should be allowed to do in the privacy of their bedrooms, but about whether society should extend a certain legal status to couples for whom the status was not originally intended. “Marriage” is an invented institution, originally intended to apply to male/female couples. There are undoubtedly all sorts of interesting historical/anthropological/sociological questions to be investigated about how the concept of marriage arose and what purposes it served in early societies. So what? In our actual world, marriage serves as a legal imprimatur to a romantic bond between two people in love. Some married couples have children, some don’t; some marriages last a long time, some don’t; some marriages are equal partnerships between two people, some are not. There is absolutely nothing about the contemporary idea of marriage which doesn’t make just as much sense when applied to same-sex couples as applied to opposite-sex couples. Convoluted rhetoric aside, the only possible ground of opposition to same-sex marriage is a conviction that homosexuality is wrong — a conviction which I don’t think deserves any respect.

Here is one example of an attempt at reasonable discussion of the issue, from Eugene Volokh:

[T]here’s an eminently legitimate argument that society would be better off if male-female couples were set up as the preferred, most legally and socially sanctioned mode. It is plausible to think that future generations would be better raised by male-female couples than by same-sex couples. And it is plausible to think that on the margins the laws related to marriage may subtly shift some people, either through incentive effects or through the law’s effects on social norms, towards male-female coupling and childrearing.

Now as it happens I’m not persuaded that these arguments are actually correct. I suspect that a same-sex couple that has gone through substantial effort to have a child will probably be at least as good parents as the average male-female couple, which might have had the child with much less forethought, work, and desire for a child.

I found this excerpt on Alas, a blog, who pointed out:

The problem with this analysis, as I see it, is that it fails to acknowledge that men and women are individuals, and should be given the opportunity to live their lives as individuals, not just as representatives of their sex.

Well, yeah. Do we really need this pointed out? I actually find it completely implausible that children raised by same-sex couples would necessarily (or even usually) be worse off than those raised by male-female couples. Does anyone in the world really believe that, given information about the psychological and socio-economic status of some selection of individuals chosen randomly off the street, they would be able to accurately judge which ones had been raised by single parents, which by divorced and remarried parents, which by same-sex parents, and which by traditional nuclear families? The argument might be logically coherent, but I can’t agree that it’s plausible. It would actually be more plausible to claim that children are better off if they are raised by wealthy parents than by poor ones; should we have minimum income requirements for prospective couples? Somehow I believe that the rights of the individual parents should be more important than some ham-handed social engineering.

Volokh continues:

But the arguments against same-sex marriage mentioned above are not ridiculous arguments, nor arguments that can only be justified by irrational hostility or contempt. These are arguments that sensibly cautious and methodologically conservative people can reasonably make against proposed changes in a fundamental social institution.

That’s precisely where I can’t agree. And I am convinced that, a few decades down the road, anyone who today is against same-sex marriages will be judged just as badly as everyone else throughout history who has fought to preserve discrimination of some minority on the basis of an irrational aversion on the part of the majority. (I don’t mean to single out Volokh, who is simply explicating the least-unreasonable arguments for the wrong side.)

Discussion of various aspects of the same-sex marriage controversy can be found at Andrew Sullivan, Angela Vierling, Dispatches from the Culture Wars, and Galois. There’s certainly a lot to say, from articulating defenses of basic rights to strategizing about the best balance between principle and politics. But I don’t personally have the patience to participate.

So that’s why I could never be a politician; on issues like this I find it impossible to be diplomatic. It’s possible to have reasonable disagreements about all sorts of things, from free trade to education reform to fiscal policy to foreign-policy strategies. I just don’t see how it’s possible to have reasonable disagreements about this one.

Besides, the idea of spending the winter months in Iowa, trudging between town meetings to declare my support for ethanol subsidies? No, thank you.