I have a long-percolating post that I hope to finish soon (when everything else is finished!) on “Why String Theory Must Be Right.” Not because it actually must be right, of course; it’s an hypothesis that will ultimately have to be tested against data. But there are very good reasons to think that something like string theory is going to be part of the ultimate understanding of quantum gravity, and it would be nice if more people knew what those reasons were.

Of course, it would be even nicer if those reasons were explained (to interested non-physicists as well as other physicists who are not specialists) by string theorists themselves. Unfortunately, they’re not. Most string theorists (not all, obviously; there are laudable exceptions) seem to not deem it worth their time to make much of an effort to explain why this theory with no empirical support whatsoever is nevertheless so promising. (Which it is.) Meanwhile, people who think that string theory has hit a dead end and should admit defeat — who are a tiny minority of those who are well-informed about the subject — are getting their message out with devastating effectiveness.

The latest manifestation of this trend is this video dialogue on Bloggingheads.tv, featuring science writers John Horgan and George Johnson. (Via Not Even Wrong.) Horgan is explicitly anti-string theory, while Johnson is more willing to admit that it might be worthwhile, and he’s not really qualified to pass judgment. But you’ll hear things like “string theory is just not a serious enterprise,” and see it compared to pseudoscience, postmodernism, and theology. (Pick the boogeyman of your choice!)

One of their pieces of evidence for the decline of string theory is a recent public debate between Brian Greene and Lawrence Krauss about the status of string theory. They seemed to take the very existence of such a debate as evidence that string theory isn’t really science any more — as if serious scientific subjects were never to be debated in public. Peter Woit agrees that “things are not looking good for a physical theory when there start being public debates on the subject”; indeed, I’m just about ready to give up on evolution for just that reason.

In their rush to find evidence for the conclusion they want to reach, everyone seems to be ignoring the fact that having public debates is actually a good thing, whatever the state of health of a particular field might be. The existence of a public debate isn’t evidence that a field is in trouble; it’s evidence that there is an unresolved scientific question about which many people are interested, which is wonderful. Science writers, of all people, should understand this. It’s not our job as researchers to hide away from the rest of the world until we’re absolutely sure that we’ve figured it all out, and only then share what we’ve learned; science is a process, and it needn’t be an especially esoteric one. There’s nothing illegitimate or unsavory about allowing the hoi-polloi the occasional glimpse at how the sausage is made.

What is illegitimate is when the view thereby provided is highly distorted. I’ve long supported the rights of stringy skeptics to get their arguments out to a wide audience, even if I don’t agree with them myself. The correct response on the part of those of us who appreciate the promise of string theory is to come back with our (vastly superior, of course) counter-arguments. The free market of ideas, I’m sure you’ve heard it all before.

Come on, string theorists! Make some effort to explain to everyone why this set of lofty speculations is as promising as you know it to be. It won’t hurt too much, really.

Update: Just to clarify the background of the above-mentioned debate. The original idea did not come from Brian or Lawrence; it was organized (they’ve told me) by the Smithsonian to generate interest and excitement for the adventure of particle physics, especially in the DC area, and they agreed to participate to help achieve this laudable purpose. The fact, as mentioned on Bloggingheads, that the participants were joking and enjoying themselves is evidence that they are friends who respect each other and understand that they are ultimately on the same side; not evidence that string theory itself is a joke.

It would be a shame if leading scientists were discouraged from participating in such events out of fear that discussing controversies in public gave people the wrong impression about the health of their field.

Gravitational lensing - the phenomenon in which diverging light rays from a source are refocused due to the warping of space by a massive object - has in recent years evolved from a beautiful test of General Relativity to a precision tool with which to measure quantities of astrophysical and cosmological importance.

A particular example of this is the use of weak lensing of far away background galaxies by an intervening galactic cluster to allow the reconstruction of the two-dimensional mass profile of that cluster, and a measure of its total mass. The rough idea is represented in the figure below, which I took from NASA’s web page on lensing.

(A good place to find out more about the subject is on Joanne Cohn’s lensing page, and links therein.)

When this technique is applied to actual astrophysical images, one is often led to remarkable results, as, for example, in the discussion of dark matter in the bullet cluster, which seems to force us to take particulate dark matter even more seriously.

If one wants to get a more hands-on feeling or how lensing works - strong versus weak; aligned source and lens versus nonaligned; etc. - then there do exist a few options. One is to visit Pete Kernan’s Lens an Astrophysicist page, which allows one to submit the url of an image and then adjust the mass and position of a black hole, returning the (strongly) lensed image. I often use screen captures from this site in my colloquia, and here’s one of a recognizable character.

Last week, I spent a delightful few days visiting U.Penn, and interacting with their cosmology and particle physics groups. My host was Bhuvnesh Jain, who is an expert on lensing, and who told me about a second way = an innovative teaching tool that he and collaborators have developed to illustrate lensing. Bhuv and friends have set up a precision optics system, and had a couple of special optical lenses machined so that their effect is that of a black hole or a galactic halo. Their site presents many of these applications - for example, here’s a four image (ignoring the one at the center, that one typically doesn’t see) one, and an actual astrophysical version or comparison

It’s a wonderful way to allow students to play with the lenses and explore the circumstances under which different types of distortions occur. If you feel like building one yourself, they even tell you how to do it.

Well, it’s hit Slashdot now, so it won’t take long to make the rounds. The Large Hadron Collider project at CERN suffered something of a setback on Tuesday, when, during a test of one of the quadrupole magnets, which focus the beams down to tiny size at the collision regions, the magnet failed catastrophically. Though saying it like that sounds bad, here is a photo:

The failure occured during a test which simulated what the magnet might experience during a “quench” which is when some part of the superconducting cable inside the magnet suddenly goes “normal” and then resists the flow of the huge current in it. This releases heat, of course, causing the rest of the superconducting material to go normal. Liquid helium boils rapidly, creating large asymmetric pressures inside the magnet cryostat. These pressures can reach 20 bar, and it was during a 20-bar test that this particular magnet failed. No one was in the LHC tunnel when it happened - it must have been quite a sight, and sound, though.

I heard about this on Thursday, as did many of my colleagues, and we waited with trepidataion to hear how bad a problem this was. Yesterday at Fermilab, Steve Holmes, an accelerator physicist, gave a talk at our weekly US CMS meeting, and sounded confident that a solution could be found quickly to the design flaw which gave rise to the problem. The magnets were designed and built at Fermilab, and delivered to CERN and installed last year. CERN is leading the effort to find and implement a fix, with Fermilab’s help. Personally, I have little doubt that these world experts will solve this thing rapidly, and hopefully it won’t affect the LHC schedule much, and perhaps not at all.

You can get more details in Fermilab’s statement.

March Madness is winding down and today is the start of the Men’s Final Four games, while the Women’s Final Four have just been determined. This year, science has also participated in March Madness, complete with brackets of its own (via Science Blogs):

(A full screen image is available here.)

Note that science is still on the sweet sixteen stage and has yet to determine the final four. Sometimes the progress of science marches more slowly than we would like. It’s probably a funding issue.

The four regions being represented are physics, scientific methods, biology, and chemistry. Not that I’m biased or anything, but may particles win!

The blog world, and now, timidly, the “real” media (if Netscape News is the real media) are abuzz about a purported attack code named Operation Bite in six days against Iran. Many of the stories are straight cut-and-paste, all pointing back to a single newspaper article in Russia, by Andrei Uglanov in the Moscow weekly “Argumenty Nedeli.”

With tensions at the present level between the US and Iran, it’s not out of the realm of possibility that the U.S. would take unilateral action like this. But is this all just a propaganda leak from the Russians? Apparently an ex-advisor to Putin, former Colonel General Leonid Ivashov, speculated that the US might even use small-scale tactical nuclear weapons against hardened underground facilities. Well, that got people’s attention.

So, anyway, April 6 at 4 am Iran time…

Man, people have even started marching against Cosmic Variance! See if you can identify the individual kvetchmeisters from the comment threads. (Via Crooked Timber.)

Every known object in the solar system larger than 200 miles across. (Via Cynical-C.) Here are Eris (formerly Xena), Pluto, and 2005 FYg (informally “Easterbunny”); check out the rest.

Now tell me that Pluto is a planet. Wherever it may be. Or don’t.

By the way, my Caltech colleague Mike Brown, who is the guy who causes all this trouble by discovering all these extra planets, has just been awarded Caltech’s Feynman Teaching Prize. Congratulations, Mike!

The Catholic League is up in arms about Cosimo Cavallaro’s milk chocolate sculpture of Jesus Christ, naked on the cross, titled “My Sweet Lord”. (the image is from the BBC article)

Personally, I’m offended for two reasons. First, this is gratuitous use of delicious chocolate that could otherwise be savored with espresso, milk or champagne. I wish sculptors would stick to making religious artwork out of things that aren’t so tasty (the virgin Mary partially made out of elephant dung from a few years ago is a fine example).

Secondly, I’m offended that Catholic League head Bill Donohue called the sculpture

“one of the worst assaults on Christian sensibilities ever”.

Really? More of an insult to the supposed Christian ideal of loving one’s brother than the homophobic attitude of the church? More of an insult than the rampant and systematic sexual abuse of young boys by Catholic priests? More of an insult than the poverty and disease exacerbated by the church’s absurd stances on abortion and birth control, particularly in the third world? Somebody needs a new priority list.

If you like the sound of the piece, or are just a little peckish, go see the exhibit Monday onwards at Manhattan’s Lab Gallery.

I spent half of last week at a conference in Irvine on “Astrophysical Probes of the Nature of Dark Matter“. Although the talks (which are on-line, by the way) were extremely interesting and bloggable (once other work stuff settles down), the most memorable discussion was a side conversation on the rules of having a scientific archnemesis. The archetypal archnemesis is someone who, in spite of violating various norms of scientific conduct (ranging from blatant cheating to rudeness), is successful in your subfield, and whose behavior compromises your own ability to get work done. However, you have to be very, very careful when adopting an archnemesis. So, here are the rules:

1. Your archnemesis cannot be your junior. Someone who is in a weaker position than you is not worthy of being your archnemesis. If you designate someone junior as your archnemesis, you’re abusing your power.

2. You cannot have more than one archnemesis. Most of us have had run-ins with scientific groups who range continuous war against all outsiders. They take a scorched earth policy to anyone who is not a member of their club. However, while these people are worthy candidates for being your archnemesis, they are not allowed to have that many archnemeses themselves. If you find that many, many people are your archnemeses, then you’re either (1) paranoid; (2) an asshole; or (3) in a subfield that is so poisonous that you should switch topics. If (1) or (2) is the case, tone it down and try to be a bit more gracious.

3. Your archnemesis has to be comparable to you in scientific ability. It is tempting to despise the one or two people in your field who seem to nab all the job offers, grants, and prizes. However, sometimes they do so because they are simply more effective scientists (i.e. more publications, more timely ideas, etc) or lucky (i.e. wound up discovering something unexpected but cool). If you choose one of these people as an archnemesis based on greater success alone, it comes off as sour grapes. Now, if they nabbed all the job offers, grants, and prizes because they stole people’s data, terrorized their juniors, and misrepresented their work, then they are ripe and juicy for picking as your archnemesis. They will make an even more satisfying archnemesis if their sins are not widely known, because you have the future hope of watching their fall from grace (not that this actually happens in most cases, but the possibility is delicious). Likewise, other scientists may be irritating because their work is consistently confusing and misguided. However, they too are not candidates for becoming your archnemesis. You need to take a benevolent view of their struggles, which are greater than your own.

4. Archnemesisness is not necessarily reciprocal. Because of the rules of not picking fights with your juniors, you are not necessarily your archnemesis’s archnemesis. A senior person who has attempted to cut down a grad student or postdoc is worthy of being an archnemesis, but the junior people in that relationship are not worthy of being the archnemesis of the senior person. There’s also the issue that archnemeses are simply more evil than you, so while they’ll work hard to undermine you, you are sufficiently noble and good that you would not actively work to destroy them (though you would smirk if it were to happen).

Now, what does one do with an archnemesis? Nothing. The key to using your archnemesis effectively is to never, ever act as if they’re your archnemesis (except maybe over beers with a few close friends when you need to let off steam). You do not let yourself sink to their level, and take on petty fights. You do not waste time obsessing about them. Instead, you treat them with the same respect that you would any other colleague (though of course never letting them into a position where they could hurt you, like dealing with a cobra). You only should let your archnemesis serve as motivation to keep pursuing excellence (because nothing annoys a good archnemesis like other people’s success) and as a model of how not to act towards others. You’re allowed to take private pleasure in their struggles or downfall, but you must not ever gloat.

While I’m sure the above sounds so thrilling that you want to rush out and get yourself an archnemesis, if one has not been thrust upon you, count your blessings. May your good fortune continue throughout your career.

I’m taking a brief time out from slacking-off from blogging to point out a nice summary of the world’s favorite beverage from Roger Protz in The Guardian.

Having seen what the New York Academy of Sciences recently did with this topic, I’m thinking of trying to put together a future Cafe Scientifique on “The Science of Beer”. Hopefully, any speaker I get will be able to span the same range of opinions as Protz regarding U.S. beer, ranging from open disdain

Prohibition in the 1920s and 30s destroyed a brewing industry with a rich heritage of British and German-style beers. Only a handful of giants, led by Anheuser-Busch with Budweiser, saturated the vast market afterwards with thin and insipid interpretations of lager. The label on a bottle of Bud, for example, announces it is brewed from the finest rice, barley malt and hops. Rice is tasteless and sums up the beer. Other giant breweries use large amounts of cheap corn.

to outright adulation

… And Goose Island IPA from Chicago, on sale in Britain, may just be the best beer in the world.

Speaking of beer….