Cocktail Party Physics

nonsequitur girl

Focus is not our strong suit at the moment, at least when it comes to blogging. The Spousal Unit and I spent last weekend visiting family in Seattle -- chaos reigns, in a good way, when the whole loud rambunctious clan meets up for the annual family BBQ -- and now I'm furiously playing catch-up. Jen-Luc Piquant is on a Diet-Coke bender after finding out just how much of her favorite caffeinated beverage she can drink without croaking. Answer: a lot. Blame Tom at Swans on Tea for drawing Jen-Luc's attention to a handy little online calculator: just plug in your weight and caffeinated beverage of choice! (A few more details on just how fast you'd have to drink those beverages to reach the deadly levels can be found here.)

So, uh, yeah -- we're not focusing well, and it's turning me into Nonsequitur Girl, darting from topic to topic with no readily apparent pattern to my thought process. But there are a couple of things in the blogosphere on which we've been pondering, plus the Spousal Unit reminded me this morning that I totally suck at self-promotion, namely, providing an occasional update on my blog posts at Twisted Physics. (And did I mention I've written books? Um, yeah. I've written books. See sidebar.) Perhaps I place too much faith in my readers, but I just assume y'all would be reading it on your own, if interested. Such an assumption doesn't take into account the huge amounts of information floating around out there in the Internet firehose, however, so it probably doesn't hurt to list the latest posts here. Just skip this part if it's old news:

Gravity Wave Blues. The latest results from LIGO are null. (I'd meant to have a more coherent wrap-up paragraph about why null results aren't necessarily bad things, even if they're disappointing. But that lack of focus intervened, so it kinda ends with a vague whimper.)

We the Particles. Subatomic particles should have rights, too, in the form of their very own Bill of Rights.

Always Chasing Dust Devils. Some scientists have all the luck, getting to chase down dust devils in the desert in hopes of learning more about how they might behave on Mars.

Ghost Story. Hanny's Voorwerp, a.k.a., the "Green Goblin," is a nifty new kind of celestial object.

Rockets Red Glare. A bit of rocketry history illustrated by painter Lia Halloran.

Monumental Quirks. A bizarre monument to nuclear decay in the Netherlands, and an object lesson in why bloggers shouldn't try to dash off tricky science explanations at the last minute.

A Clockwork Antikythera. The latest news on the Antikythera Mechanism -- way better than your average ancient sundial.

A Mighty Wind. Revisiting the day the solar wind disappeared. Really. One day it just vanished.

(Anti)Material World. A bizarre new film being co-produced by NASA spurs some ruminations why antimatter isn't intrinsically evil.

Gravity's Telescopes. Why Hans Lippershey wishes he'd known about gravitational lensing back in the 1590s.

And then there's today's post, Paging Professor Frodo, all about a physics professor in Connecticut who uses the works of Tolkien to teach her students astronomy. Good times!

Moving on, here's some of the random stuff I've been pondering over the last few days, in no particular order. (If I were a normal blogger, I'd make them all separate posts. But instead, I dare to be different!)

In Which I Expound on Minor Points Concerning that Whole Science = Sexy Debate. There's been some excellent discussions going on over the whole Nerd Girls debate, both here at the cocktail party and elsewhere, including Bioephemera and Sciencegeekgirl's place. I've found the whole exchange tremendously thought-provoking. I just wanted to comment briefly on a couple of points. First, Sciencegeekgirl rightly points out that perhaps the real issue here is that female-ness simply isn't valued in our culture; "women's" books, magazines, TV shows and the like are considered silly and trivial, even when they tackle serious social issues. As Matt points out in a recent comment, nobody derides the male obsession with sports teams and the like with anywhere near the same level of ridicule. I direct interested readers to Carol Tavris' excellent book, The Mismeasure of Woman, which is the most even-handed (eg, she doesn't go in for simplistic man-bashing) exploration of this phenomenon I've read to date.

I also want to take a moment to address this notion of how we give our kids positive feedback, via telling them they are pretty or smart (preferably both). As I mentioned in my original post, this alone does not guarantee healthy self-esteem. I think it's just as important to teach kids how to fail -- because sooner or later, no matter how lovely or gifted they are, they are going to fail. We have a horrible attitude towards failure in our culture, but the truth is, failure is how we learn -- provided we pick ourselves up and plug along until we do succeed. That's probably the most important life lesson I gained from the martial arts.

And this leads into one last observation. Jongleur provocatively asks, what if someone is ugly and dumb? I made a somewhat joke-y response about how they should work on their personality, but in truth, the question itself is somewhat misguided. "Ugly" and "dumb" are in the eyes of the beholder. Maybe a person isn't conventionally "smart" -- as defined by being intellectually oriented and/or doing well in school -- but that doesn't automatically mean they are stupid. (They might be anti-intellectual and willfully ignorant, which is a different matter entirely.)

It's all about perspective; standards of beauty, for example, change with every age. There is always someone smarter or better-looking, and everyone is smart and beautiful in somebody's eyes. At least I hope so. And while my "work on the personality" comment was flippant, I'm a big proponent of fostering "inner beauty" -- those qualities that have nothing to do with being either smart or beautiful, but invariably add to a person's overall likability and attractiveness. Someone can be drop-dead gorgeous, or breathtakingly brilliant, and still be utterly intolerable as a person. Really. I've met them.

In Which I Question Whether a Scientific Study is Good Use of Technological Resources. Those wacky German scientists are at it again, per a recent item on the Improbable Research blog. Scientists at Munich University have tackled the nefarious problem of how to tell whether some prankster has replaced the jam or custard in your German Mardi Gras donut with something nasty, like mustard. Apparently this is a common prank during the German Mardi Gras celebration. Clearly, one needs a way to figure out what the filling is before one bites into the donut. And the best way to analyze donut innards involves CT scans and MRIs. The Munich scientists took CTs and MRIs of donuts filled with jam, custard and mustard, respectively, and then "diagnostically evaluated" them.

It's a fun, whimsical item, and in general, I'm in favor of doing things like this; it makes those big intimidating science machines a little more familiar to the general public. I love the images taken through optical microscopes of burgers and fries, beer (organized by country of origin) and cocktails over at Molecular Expressions, for example. But those are -- for the most part -- common scientific instruments they're using, not pricey diagnostic techniques.

I've known a couple of women over the past year who've been diagnosed with breast cancer, as has 36-year-old actress Christina Applegate. In all cases, the cancer was caught very early because their doctors recommended MRI screening in addition to a conventional mammography -- and (more importantly) all three had insurance coverage for the pricey procedure. But what about the tens of thousands (if not millions) of women who can't afford that additional screening? Not to be curmudgeonly or anything, but given the choice between finding out if a donut filling is jam or mustard, or whether or not I have breast cancer, I'll take the latter, thanks very much. I might feel differently if everyone had access to MRIs. Until then -- I will find this vaguely troubling.

In Which the Hotel Industry Falls Far Short of a Blogger's Minimal Expectations. Finally, Bora channels every traveling blogger's pet peeve in this post about how slow the hotel industry has been to catch up to the 21st century when it comes to high-speed Internet and wireless technology. This is one of my pet peeves, and I suspect many others feel the same. No more poky Internet connections and crappy wireless that fades in and out! No more exorbitant daily fees for sub-par Internet services! Bora is leading the revolution, and I say, Speak it, brother!

UPDATE: I almost forgot to give a shout-out to Tim Lambert at Deltoid for igniting a new meme of LOLDenialists. He very generously gives me partial credit for the idea because of an offhand comment I made on his blog, but really, I lacked the focus to take it to the next level. Tim's the one who came up with this gem:

smart = sexy

Phil Plait is taking some heat from commenters over at Bad Astronomy after posting about the Nerd Girls: a Website, blog, and collection of curricula  aimed at celebrating "smart-girl individuality" and challenging "stereotypes and myths about women in science and engineering." Their mantra includes such radical statements as "Brains are beautiful," "Smart is sexy," and "Geek is chic." Apparently this site is controversial because it depicts smart women who are pretty, have a sense of style, and like to wear heels and a nice dress in the evenings when they go out dancing (at least a couple of them do). There's even a page where they're all posing for glamour head shots wearing the same pair of nerdy glasses -- a send-up of the stereotypes they're trying to smash, although some of Phil's commenters appear to have missed the irony.

The audacity! How dare smart women engage in such frivolous matters! They're supposed to be dour, humorless, scruffy dressers, I guess, in keeping with their seriousness of purpose, so they can prove to the world that they don't care what people think of them. Or something. Who knew that wearing makeup and wanting a pair of nice shoes automatically made you shallow and a slave to our appearance-obsessed society, no matter what your other brainy accomplishments? Apparently life imitates Legally Blonde.

Anyway, it was very brave of Phil to tackle the subject at all, since it's one of those damned-no-matter-what-you-say kind of topics -- particularly (but not exclusively) if you're male. That's because it's a complex, nuanced issue that many people try to treat as if it were black-and-white. But it does make for a fascinating comment thread, so take a gander if you've got a moment. There's one or two trolls, natch, and the odd bit of teh stupid, but for the most part, folks make some excellent points.

It is true, for instance, that young girls in particular are subjected to immense social pressure to look and act a certain way, and this can lead to low self-esteem, eating disorders and the like. As someone who struggled with anorexia in my 20s, and was shy and socially awkward and ill-dressed throughout high school and college, I can totally relate. But frankly, my repudiation of all that "girly" stuff had more to do with insecurity than with embracing my individuality and "not caring what people think." In truth, I cared a great deal and just didn't want to admit it, because doing so would mean facing up to my own shortcomings in those areas -- and having to change. (Sometimes we need to change.) I suspect the same is true for others as well. How can you tell the difference between that and genuine individualism? By the level of judgmentalism and hostility -- and sometimes outright venom -- aimed at women who do enjoy fashion, shopping and pretty pink nail polish. A truly secure individualist feels no need to tear down those whose values might be different than her own.

It's also true that there is an annoying tendency for guys in science and engineering fields to act surprised and become, shall we say, overly enthusiastic at discovering a girl is both science-y smart and "teh hawt." I have blogged about this before. And Randall Monroe captured the problem perfectly in the classic XKCD comic to the right. But just because some guys can be immature jerks is no reason to teach our young girls that therefore, they shouldn't wear pretty clothes and makeup because it's just asking to be harassed and/or not be taken seriously. If the guys' attitudes are the problem, why are we placing the onus for behavioral modification on the girls? We should be enlightening the guys instead, not making excuses for them ("That's just how men are"). Dudes! It's the 21st century! Evolve already! (And incidentally: girls dress more for other girls than to please the gazes of men. Hate to break it to you...)

Don't get me wrong: these are serious issues. The mistake many people make, however, is to over-compensate too far in the other direction, wherein anything remotely "girly" is somehow exerting undue pressure on young girls, with no thought to the possibility that maybe some girls genuinely like this stuff. Maybe this is part of who they are. Maybe they also like science and math. Ergo, we are putting a whole different kind of peer pressure on them that also squelches their individuality, by insisting they simply can't be both interested in science and in clothes and makeup. ("Accessorizing is evil and will turn you into a bubblehead! Put down that Coach handbag and back away slowly! Do it for science!")

That attitude is showing up a lot in Phil's comment thread; I've heard it before. Danica MacKellar was sharply criticized when Math Doesn't Suck was published last year for using math problems involving, say, shopping for school clothes. (She's pretty, and stylin', and rocks at math, plus her book sold a gazillion copies. So much for the naysayers. Go, Danica!) When physicist Lisa Randall posed for Vogue a couple of years ago, there were all sorts of outrageous criticisms of how she was playing into appearance-obsessed stereotypes and hurting the image of women in physics, blah, blah, blah. No one stopped to marvel at how incredible it was that Vogue -- which reaches millions of women around the globe each month who would never, in a million years, pick up a book or article about science -- chose to feature a woman scientist in its pages at all. If even a fraction of those millions of readers worldwide had their perceptions of female scientists changed for the better, huzzah!

Here's why I have a problem with over-compensating in the other direction. There's a scene in the film G.I. Jane, where Demi Moore's character -- the first woman to go through the Navy Seals brutal boot camp -- decides to shave her head, symbolically renouncing her femininity in her quest to make it through the camp. I didn't do anything so extreme when I was earning my black belt in jujitsu -- my life is not a Hollywood movie, and my Brooklyn dojo was not the Navy Seals -- but I did find myself renouncing many aspects of being a woman, in order to succeed in a harsh male-dominated environment.

On the one hand, I did what I had to do: I packed on 30 pounds of muscle to better fight toe-to-toe with the guys (many of whom topped 200 pounds). I kept my hair short and slicked back with gel -- a practical decision because it's easy to get hair yanked out in tufts while ground-fighting. (Several of the guys did shave their heads.) I stopped wearing jewelry and make-up. I mostly dressed in workout gear -- again, practical, since I was training several hours a day. I endured broken fingers and toes, a sprained wrist, bloody noses, one spectacular head injury, and countless bruises without complaint because there's just no crying in jujitsu, y'all. And I succeeded. Yay, me. It was an invaluable experience that taught me much about myself, and I wouldn't trade it for the world.

On the other hand, I lost something precious along the way. My female-ness is an integral part of who I am, and if I have to give that up in order to succeed, how is that being true to myself? I spent a good two years reclaiming my femininity in bits and pieces, trying to find just the right balance between gutsy and girly. It ain't easy, especially since there are so many people out there -- on both sides of the debate -- more than willing to opine and criticize and judge you harshly for every perceived violation of their chosen creed. I'll bet the Nerd Girls can relate. But it can be done. Today I can be smart and self-sufficient and still be sexy and rock my Prada boots on a good hair day if I feel like it. It's tremendously liberating.

Yes, we should be telling young girls they are smart, and that they shouldn't base their self worth on their looks. That way lies chronic unhappiness. But you know, I grew up hearing I was smart quite a bit, and while I'm grateful for that, it didn't save me from struggling with self-image and self-worth. That's just part of growing up. Since hardly anyone (other than my mom, and who can believe their mom?) ever bothered to tell me I was pretty as well, I concluded I was ugly. Ergo, I just didn't bother with anything involving my physical appearance, figuring it was hopeless. In so doing, I ignored an important part of my identity. It's true that looks aren't everything, but it's false that appearance doesn't matter in the least. Our physical appearance is part of our identity. It matters. And it can matter without having it be the sole foundation for our self-worth. It's not an either/or situation, or an automatic sign of mindless conformity -- another of the Nerd Girls' maxims.

This is issue is near and dear to my heart for another reason: I have two 15-year-old nieces currently navigating their way through the minefield of adolescence. Both are smart and beautiful, in completely different ways. One is the quintessential blonde, bubbly, blue-eyed, All-American prom queen; the other is dark, dramatic, highly individualistic, writes fanfic and loves science fiction and fantasy -- a budding Gothling. Their respective appearances reflect those differences. They both  love hair, clothes, and makeup, but they use them in very different ways, choosing styles and colors that reflect their personalities -- or at least who they believe themselves to be on a given day.

They've chosen different paths, based on where they feel most comfortable, and neither choice is the "wrong" one. I'm immensely proud of both, but I can't spare them the inevitable growing pains. Each will face their own set of challenges in the boot camp that is high school. (Navy Seals have it easy in comparison.) My hope is that when they grow up and have their own daughters, or nieces, or whatever, this question of whether a girl can be both smart and sexy, girly and geeky, science-y and sleek, will have become entirely moot.

death becomes him

Dying
Is an art, like everything else
I do it exceptionally well
I do it so it feels like hell
I do it so it feels real
I guess you could say I've a call
      -- "Lady Lazarus," Sylvia Plath

The poet Sylvia Plath has always held a fascination for me, not because of her repeated suicide attempts (she succeeded on the third) and obviously troubled nature, but because of the stiletto-sharp clarity of her poetry, and how much raw emotion she managed to convey in such tightly minimalist phrasing.  "Lady Lazarus" is one of the most famous poems in her final collection, Ariel, brimming over with barely controlled white-hot rage. Scholars have analyzed it endlessly for autobiographical references to Plath's life (her daddy issues alone would fill tomes) and self-induced brushes with death, but what comes through for me in the poem is Plath's thinly-veiled contempt for those who were drawn to her precisely because she kept chasing after, and miraculously cheating, death.

The imagery presents the poem's persona as the featured act in a carnival sideshow, a person craving attention who is as addicted to the applause of the audience when she survives as they are fascinated by her death-defying (or seeking) feats. Plath tapped into a disturbing facet of our celebrity-obsessed culture: the glorification of nihilistic behavior, particularly of the "live fast, die young, and leave a good-looking corpse variety." There's something almost cannibalistic about our fascination with tragic figures in popular culture: we can't get enough news about their personal weaknesses and tragedies. Nowhere is this more evident than in the music industry, which is littered with the corpses of talented musicians who bought into this empty philosophy and paid dearly for it: Jimi Hendrix, Janis Joplin and Kurt Cobain spring immediately to mind, but they're in very good company.

The most recent train wreck in the music industry is pop singer Amy Winehouse, whose LP Back in Black showcases an extraordinary talent -- and whose personal life is a shambles, to say the least. These days, she looks more like a strung-out homeless junkie than one of the biggest stars in the world. The drinking, the smoking (both cigarettes and crack), the ecstasy, the ketamine, have taken their toll: at age 24 Winehouse shows early signs of emphysema and an irregular heartbeat. On July 28, she was rushed to the hospital for an "adverse reaction to medication" -- a claim that was greeted with more than a little skepticism, given her public touting of her drug use.

Sure, it's a waste of talent and human life, but it's her choice, so why even bring it up? You might be thinking. But I can't help feeling twinges of compassion for Winehouse, who has bought into that false philosophy, just as I have compassion for anyone who has despaired so completely that death seems a reasonable option to their current life. Clearly, a new role model is needed to show us how to live, and how to die -- not with a nihilistic shaking of the fist in defiance of god-knows-what imagined enemy, but with grace, good humor and dignity. We have that role model in former Carnegie-Mellon University computer scientist Randy Pausch, who died of metastasized pancreatic cancer two days before Winehouse was rushed to the hospital for her "adverse reaction to medication."

Pausch needs no introduction, really: his famous "last lecture" at Carnegie Mellon has been downloaded and viewed by millions all over the world, and his passing was marked by every major media news outlet, and all throughout the blogosphere. If you are one of the three people who haven't seen the lecture yet, it's an hour or so well spent.

Pausch was breathtakingly candid and accepting of his fate,  joked about being able to do lots of pushups (which he ably demonstrated), and wisely refused to talk about his wife and children, who would be most affected by his death. Mostly, he talked about life: how to live well by pursuing your childhood dreams, not getting discouraged by the brick walls (they're there to test how much you want something), and how to leave some sort of personal legacy behind... even if it's just for your wife and kids. His is a memorable example of a life well-lived, and in choosing to share his lecture (and his fate) with the world, he also showed us how to die. As Wall Street Journal columnist Jeffrey Zaslow memorably observed, "His fate is ours, sped up."

I simply can't watch that lecture without getting all choked up, and I couldn't bring myself to blog about Pausch's passing until now. He gave us something very precious, you see, and we couldn't return the favor by saving his life. The cancer was inoperable; as it is, he lived five months longer than doctors expected. As Pausch knew better than anybody, there is no magical deus ex machina enabling us to cheat our common fate. But that doesn't mean scientists aren't trying. The day after he died, the American Association of Physicists in Medicine (AAPM) kicked off their annual meeting in Houston, Texas.

Just this past March, a very ill Pausch summoned the strength to testify before a House committee, requesting more funding for pancreatic cancer research. So the only way I can think to honor him is by highlighting some of the research presented at the AAPM meeting. Currently celebrating its 50th anniversary, the AAPM is dedicated to advancing the application of physics to the diagnosis and treatment of human disease -- including cancer. As Pausch's family were making funeral arrangements, speakers at the AAPM meeting were describing the latest batch of innovative R&D that may one day make cancer a thing of the past.

One of the major obstacles to removing tumors via surgery is that not all of them have very well-defined borders, making it difficult to remove the tumors entirely without leaving a few errant cancerous cells behind -- which continue to grow and multiply wildly until more tumors appear. There's also greater risk of complications, with long recovery periods. Researchers have been experimenting for years with various nanoparticle-based therapies. The basic concept is this: tailor the nanoparticles to gravitate towards cancerous tumors and lodge inside them, then deliver laser heat to that area; the nanoparticles will burn away the tumor and leave the healthy cells behind.

The latest twist on this sort of thermal ablation therapy comes from a group of researchers at the University of Texas' cancer center, who are also working on better ways to precisely guide and concentrate laser-generated heat in targeted tumors. It would help if we could see the process while it happens. In this case, they injected gold silica nanoshells  into brain cancer models. As expected, the nanoshells made a beeline for the target tumors and were handily taken in like long-lost friends. Then the UT scientists applied low-power laser light to selectively heat and burn away the tumor but not the surrounding healthy tissue. The twist: they added iron-oxide cores to the nanoshells, thereby making it possible to visualize them using magnetic resonance imaging (MRI). Their conclusion? "[T]he use of magnetic resonance temperature imaging and gold nanoshells hold the very real possibility of meeting the long-sought goal of improving the precision of thermal ablation, while sparing healthy tissue."

Since not all parts of a tumor will respond the same to conventional radiation therapy, which uses a uniform dose to the entire tumor. In the future, it might be more effective to target the more resistant parts of a tumor with stronger doses. It's known as "dose painting" in medical physics circles -- or, more technically, as intensity modulated radiation therapy (IMRT). This means we'd need to be able to measure the degree of resistance in those different parts accurately -- right down to the molecular level -- and it turns out that this is no small feat, according to a new analysis by scientists at the Institut Jozef Stefan in Ljubljana, Slovenia, and the University of Wisconsin, Madison.

The conventional method relies on PET scans, which can be quite useful in measuring radio-resistance if the radio tracer fluoro-L-thymidine (FLT) is used. Cells grab onto FLT as they divide, and since cancer cells divide so rapidly, they pick up more of the FLT, and hence look brighter on a PET scan.(It's called a standardized uptake value.) If those cells in that region are still bright after a round of radiation therapy, it's pretty clear they're radio-resistant, and the therapy is ineffective on those cells.

IJS's Urban Simonic thinks there is another, more precise way to find the radio-resistant cancer cells by using a more dynamic approach: modeling how the radio-tracer travels through the body and is collected by cells over time. He and his Wisconsin colleagues compared the two techniques using the same set of PET scans, and found that the two approaches selected different regions as being resistant to radiation therapy. Oops. Whether or not one agrees that Simonic's approach is more precise or not, the discrepancy clearly needs to be addressed if dose painting is ever going to clinically effective.

Researchers haven't been idle on the dose painting (or IMRT) front either. Another paper at the AAPM meeting dealt with a new variant called volumetric modulated arc therapy (VMAT). Developed by researchers at the Memorial Sloan-Kettering Cancer Center, the method offers the same treatment as IMRT in roughly half the time. That's because, with IMRT, a computer-controlled linear accelerator sweeps a narrow slit of radiation across the tumor from various angles around the patient, one angle at a time. The VMAT technique -- at least the variant described at the meeting -- breaks that arc into 360 evenly divided beams. The researchers developed a computer program that adjusts the aperture shape and radiation does for each one of those 360 beams. And because the resulting aperture beams are much larger than in IMRT, treatment time is reduced significantly (up to 50%), along with the patient's exposure to any radiation leakage (down from 5 minutes to 2-1/2 minutes).

That's literally just the tiniest smattering of the fascinating research being done in this area, by PhD physicists, doctors, pharmacologists, oncologists, neurosurgeons, and so forth crossing disciplinary barriers to fight a common foe. None of this new cutting-edge technology came of age in time to save Pausch and the the millions of other people around the world who die from some form of cancer each year -- all of whom have friends and family and colleagues devastated by their loss, even they don't warrant front-page obituaries in all the major newspapers. But we can honor them by continuing to fight the onslaught of disease, and we when we lose -- as indeed, we must -- by dying exceptionally well.

what lies beneath

Since we're dallying at the science/art interface this week, here's some breaking news via AIP's Physics News Update: a group of Italian and German scientists have used nuclear magnetic resonance -- the underlying physics behind MRI machines -- to non-invasively map out the layers of historical fine paintings, and announced their results in the July 21 issue of Applied Physics Letters. Apparently this is known as "stratigraphy." Who knew? (Hint: not me! We live and we learn.) That includes any preparatory layers, under-drawings, the actual layers of paint, and in many cases, a layer of varnish.

The rationale for doing this at all is that this sort of precise analysis helps establish age, origin and authenticity of works of art, in much the same as geologists learn about the Earth's history by studying the various geological strata. The new technique does much the same thing for paintings as it does for the human body, except instead of using x-rays, detectors, and cutting-edge computers to provide information about soft tissue and the possible presence of tumors, it provides information about the binding agents used in the painted layers. Those agents were often made of things like egg yolk or oil.

How good is the technique? Well, just knowing the nature of the binding agent can usually distinguish between a naturally-aged painting and one that has been artificially aged (a polite euphemism for "forged"). It's non-invasive, and the magnet used in single-sided, unlike MRI magnets which have to surround the patient (and/or limb) for imaging. So scientists can bring the scanner right up to the painting without ever touching the surface. Ease of use counts for a lot when it comes to marketable applications! Furthermore, the technique can determine the thickness of various paint layers, too, and while it can't definitively "date" each layer, it can tell which ones are older than others. It's easy to see why this might be a useful tool for art historians.

There's a strong tradition in science already of using x-ray imaging to study art, ancient manuscripts, even archaeological objects, although these don't penetrate to the same depths as the new MRI technique. I've blogged about that approach previously here. For about a year, scientists at the University of San Diego have been collaborating with an Italian engineer named Maurizio Seracini to analyze 500-year-old bricks from a wall in Florence's Palazzo Vecchio.

They're looking specifically for a lost fresco by Leonardo da Vinci called the "Battle of Anghiari" that was never completed and -- until recently -- presumed to have been destroyed. Leonardo began the project to commemorate the 15th century Florentine victory over Milan at Anghiari in Tuscany, but he left the following year without completing the mural. And they're bringing all the ammo they can muster to the task: laser scanners, thermal imaging, radar, and neutron beams, among other techniques

About 30 years ago, Seracini noticed a cryptic message on another fresco in the hall by another 16th century artist, Giorgio Vasari: "Cerca, trova," or "Seek, and you shall find." (The image above is a scene from Vasari's fresco entitled "The Castration of Venus by Saturn." Truly an edifying image, or at least one guaranteed to strike the fear of god into the hearts of men.) This made him suspect that Vasari preserved Leonardo's unfinished fresco rather than destroying it. He also found bricks and stonework in a storeroom that were once part of the enormous hall, the Salone del Cinquecento ("Hall of the 1500s) in the Palazzo Vecchio. With the permission of Culture Minister Francesco Rutelli, he shipped off the bricks to UCSD so that scientists could analyze their structure and composition.

Just a few years ago, they used radar and x-ray scans to locate a cavity behind Vasari's fresco, indicating a space between walls, and last November they used a laser scanner to construct a 3D model of Vasari's wall. Since then, they've been working on chemical analysis of Vasari's paint pigments, and thermal imaging to better delineate the wall structure. This will give them a better understanding of what might lie behind that wall in preparation for the final step: sending a flux of neutrons through the entire structure. Everything they've learned about the pigments and walls can be subtracted from the overall neutron analysis, thereby establishing the composition of the wall Leonardo worked on. If it's there, Seracini thinks the mural should be found right on top of the original stone wall of the hall. He could be wrong -- there might not be a lost Leonardo there at all. But at least art restoration can benefit from all these snazzy cutting-edge technologies.

And just a couple of weeks ago that a team of European scientists have used synchrotron radiation to reconstruct the portrait of a peasant woman painted by Vincent van Gogh that the artist had then painted over when he created 1887's "Patch of Grass." It lay there, dormant, for 121 years until we finally had the technology to nondestructively analyze the painting and reproduce the hidden image. And we owe it all to the Deutches Elektronen-Synchrotron (mercifully known by the acronym DESY) in Hamburg, Germany.   

Synchrotron radiation is a bit different from conventional x-rays; it's a thin beam of very high-intensity x-rays generated within a particle accelerator. The Cliff's Notes version of how it works is this: You fire electrons into a linear accelerator (linac), boost their speeds in a small synchrotron and inject them into a storage ring, where they zoom through at near-light-speed. A series of magnets bend and focus the electrons, and in the process, they give off x-rays, which can then be focused down beamlines. This is useful for imaging purposes, and for analyzing structure, because in general, the shorter the wavelength used (and the higher the energy of the light), the finer the details one can image and/or analyze.

Someone already used conventional x-rays to reveal the rough outlines of the underlying portrait, but that technique just wasn't sufficient to distinguish between the many layers of paint. Also, pigments made from heavy metals tended to obscure the colors derived from other elements, resulting in what Joris Dik, a materials scientist and art historian at the Technical University of Delft in the Netherlands, described as "a very partial, fragmentary, color-blind view."

Dik and his colleagues took "Patch of Grass" to DESY and exposed the painting to the x-ray beams. The radiation excited the atoms on the canvas, which then emitted x-rays of their own, picked up a fluorescence detector. Each element in the painting had its own x-ray signature, so they were able to identify the distribution of metals in the many layers of paint, construct a 3D model, and then peel off the layers one by one in the virtual image until what lay beneath was finally revealed. Per the Los Angeles Times: "The top layer consisted of paints made with zinc, barium, sulfur, and other elements. Behind that they found a uniform distribution of lead, which was used as a primer to hide the portrait and prepare the canvas for a new painting. Once that was removed, they combined the distributions of two more elements -- mercury and antimony -- to produce the outlines of the hidden portrait."

They found the remains of a portrait of a woman bearing a striking resemblance to the model van Gogh used while composing his famous "The Potato Eaters" in 1885, and used computer software to recreate the painting using their own version of a "paint-by-numbers" technique. Van Gogh, apparently, was known to recycle his canvases, which was quite thrifty and environmentally correct of him. Clearly, a man ahead of his time. In fact, some art experts think that as many as one-third of his earlier paintings have older ones underneath them; many of these might find there way to Germany for synchrotron analysis over the next few years, as funds permit. (I'm guessing time on a major synchrotron facility ain't cheap!)

It's nice to see new uses emerging for the big machines of science -- especially when those new uses span across traditional disciplinary boundaries. Synchrotron light is a burgeoning research area, finding use in physics, chemistry, materials science, medicine, geological and environmental science, structural genomics, and (as we have seen) archaeology. No wonder various European countries are collaborating on building a brand-new fourth-generation synchrotron light source at DESY, called the X-Ray Free-Electron Laser (FXEL).

Alas, the Synchrotron Radiation Source (SRS) based at the Daresbury Laboratory in Warrington, UK, was switched off earlier this week. But fear not! Its good work will continue at a shiny new facility: the Diamond synchrotron in Oxfordshire, part of a growing number of world-class research facilities in that area. In fact, scientists from the University of Cardiff have already developed a new technique for the Diamond synchrotron for analyzing the hidden content in ancient parchment without having to open them, such as the  original musical scores of Bach, or the Dead Sea Scrolls (some of which are so fragile and badly damaged, they haven't been unrolled yet).

Cardiff's Tim Weiss explained that many manuscripts, such as those in the 12th century, used iron gall ink made from oak apples, but the parchment on which they were written contains collagen (since the parchment was made from the thinly stretched skins of cows, sheep, or goats), and collagen naturally degrades to gelatin. Iron ink speeds up the process. It's a wonder so many parchments survived, frankly.

Anyway, they're using the synchrotron's powerful x-ray beams, to create 3D images of iron-inked documents. Because the inked lettering contains iron, the result is an absorption image, much like how one's bones show up so vividly on a standard x-ray. Rolled parchment works the best with the technique; books are flat and thick, which is a bit more challenging. Apparently, per Weiss, "You really end up with a stencil rather than the lettering," in those cases.

Isn't technology wonderful? I can't wait to see what else science finds lurking beneath the surfaces of other paintings and manuscripts.

but is it art?

We're very tickled today because the Mars Phoenix lander has "friended" us on Facebook, which makes us feel very special, even though Phoenix has over 2000 such close personal friends (including the Spousal Unit and several fellow science bloggers). I was a bit late to the party, but happy to finally be included in all the festivities -- no doubt with DJ Spock providing the groovy tunes. And now I feel like I really know my new friend, after reading this two-part interview with the Neural Gourmet. Apparently Phoenix even has a Twitter account, making this particular NASA excursion a bit of an experiment in interactive performance art.

But the subject of today's image-heavy post is about more traditional visual art, and how so many artists have found inspiration in the concepts of science -- and maybe even vice versa. Because why should Jessica Palmer over at Bioephemera have all the fun? For the all the fuss about C.P. Snow's infamous notion of "two cultures," art and science have a rich long history of feeding into each other, despite certain differences in what each deems most important. For instance, a scientist mostly cares that the science is correct, and if an image is also aesthetically beautiful, well, that's just a bonus. Many people refer to this sort of work as "scientific visualization." (If your name was Leonardo da Vinci, the boundary was a bit more blurred, but even Leonardo would, I think, distinguish between some of his engineering and anatomical sketches -- exquisitely rendered though they are -- with fully realized works like the Mona Lisa.)

The undisputed queen of scientific visualization today is MIT's Felice Frankel, whose stunning images of things like colonies of bacteria or the behavior of water molecules have graced many a cover of the leading scientific journals (Nature, Science, Physics Today, and so forth). She co-authored a book, Envisioning Science, with George Whitesides, which is well worth checking out if you're at all interested in science imagery. And you can read an extensive online interview with Frankel here.

Perhaps her most famous photograph is the one below, depicting a drop of ferrofluid on a glass slide atop a slip of yellow paper, under which are seven small circular magnets that affect the form of the drop. The shape of the fluid, the color contrasts, please our visual senses on a purely aesthetic level, while the underlying scientific concept remains uncompromised. That's a pretty tough thing to do, which explains why the image is the most reproduced of any of Frankel's work. In fact, she claims to be "sick of it." So naturally we have to reproduce it here, with apologies to Frankel for proliferating her artistic meme.:

Frankel's work is aesthetically pleasing, as well as scientifically accurate, but is it art? When she was profiled in the New York Times last summer, that question prompted quite a bit of debate. I pondered it heavily myself: what makes a science-inspired image truly "art"? Perhaps there is a debate, not so much because Frankel is blurring boundaries, but because she has raised the standard for scientific visualization to an unprecedented high level, making it much harder to tell the difference. Few others have even come close to the caliber of her work. University of Chicago physicist Sidney Nagel is known for his stunning photographs of liquid drops eerily in suspended in time, making him a notable exception:

Nagel's primary focus, however, is the science: he's an expert on the physics of fluids and granular materials, and his photography -- while both skillful and visually stunning -- serves the purpose of his work. There's absolutely nothing wrong with that; but is it, therefore, art? Frankel herself says no. "My stuff is about phenomena," she told the New York Times. "So I don't call it art. When it's art, it's more about the creator, not necessarily the concept in the image." During my own ponderings, I concluded something similar: visualization accurately renders the science, preferably in an arresting, artful manner; an artistic work transforms it to reflect the creative impulse of the artist. Both, however, can make you look at familiar phenomena in a strikingly new way. Some people were kinda bothered by Frankel's seeming dismissal of her work, but this implies a value judgment: that art is somehow more "pure" or important than visualization. I don't agree. Frankel is at the top of her field (scientific visualization), and we do her no disservice by recognizing what her work is... and what it isn't.

Not that scientists can't become highly accomplished artists, mind you. I just learned about Frank Malina, an aeronautical engineer, rocketry pioneer, and first director of the Jet Propulsion Laboratory, while reading M.G. Lord's excellent book, Astroturf: The Private Life of Rocket Science. After World War II, Malina fell victim to McCarthyism and wound up working for UNESCO in Paris. Always a bit of a polymath, with broad cultural interests, later in life, Malina ended up drawing upon his engineering expertise to become one of the early pioneers of kinetic art -- which really flummoxed the federal agents charged with keeping tabs on his supposedly subversive activities -- simply because he was interested in expanding "the limitations of paint."

For instance, he'd add actual depth (as opposed to illusory) by placing wire mesh or string over the surface of a painting. Then, while taking down the family Christmas tree in 1955, he thought it would a marvelous idea ("Zoinks!") to incorporate blinking Christmas lights into the wire mesh to add a sense of movement to his art. Per Lord:

"Soon Malina began 'painting' with electric motors. These drove wheels that were divided into colored sections. Images were formed through the overlap of colors and shapes and were in constant flux. The apex of Malina's technical innovations may be what he termed his Lumidyne system. It involved light projected onto and through Plexiglass screens to form fluid, soft-edged, ever-changing patterns. Malina's Lumidyne pieces often evoked astronomical phenomena. Not dependent on external illumination -- electricity drove their lights and motors -- the radiant compositions suggest swirls of gas and dust around distant stars."

Apparently, the European art world was a bit slow to appreciate Malina's artwork; he had equal numbers of fans and detractors, and the FBI, frankly, didn't get it at all. (I mean, if he wasn't encoding secret messages to his imaginary Commie cronies in his artwork, what could possibly be the point?) Here's a slightly grainy picture of his 1956 piece, "Point Counter Point":

Malina also founded Leonardo, a journal dedicated "to documenting work at the intersection of the arts, science and technology." I'm guessing he wasn't a big believer in that whole "Two Cultures" thing either. He makes a nice addition to my growing "collection" of artists inspired by science. And so does Lia Halloran, an LA-based artist whom I met over the weekend at a friendly gathering of scientists and artists in Pasadena (the spirit of Malina would have smiled upon the scene).  She's a big physics-fan, and it very much informs her art: she's figured out visually arresting ways to make the abstract and/or invisible apparent to the viewer. Her 2007 show at DCKT Contemporary gallery at Bowery and Spring Street in New York City was called The World is Bound with Secret Knots. The exhibit featured six figure paintings exploring the interaction of unseen physical forces of nature with human figures, like this one, entitled "Centripetal-Centrifugal":

For those in the NYC area -- or if you're planning on attending the SciBling meetup of SEED Science Bloggers and readers -- head on down to the DCKT gallery in Soho to take in Halloran's latest show, Dark Skate. (Those living elsewhere can view most of her work on her Website.) Yep, she's an avid skateboarder, and knows darn well that this involves a heck of a lot of physics. The new show features a series of photographs taken at night in various locations around Los Angeles where skaters (or "sk8ers" as the kids today call them) converge. She used light (how? I dunno, but I'll be sure to ask) to trace a line while Halloran skateboarded around the venues. The result: images that clearly show the trajectory of her movements over time -- evidence of past action, but with no trace of the figure that left the pattern. (Particle physicists can probably relate.) Here's one of those images, taken in nearby Griffith Park:

Long-time readers might recall my blogging about the work of Connecticut-based painter Nash Hyon in 2006, who works primarily with encaustics (wax-based paints). I'd seen her paintings included in an exhibit at the National Academy of Sciences in Washington, DC, and have been a fan ever since. As often happens in this Internet age, Hyon stumbled on my blog post several months later, and invited me to visit her studio in Connecticut, where I got to see the whole encaustics process in action. She still had my favorite painting: "Gadolinium." With the Spousal Unit's permission, we bought it, and it now graces our Los Angeles bedroom.

Hyon just put up her own Web site (and a blog!), which is well worth checking out. Because all her paintings are striking. One series is called ATCG, drawing on biology/genetics to explore what it means to be human. With her "Elements" series, she cherry-picks certain aspects from the scientific properties or history of an element in the periodic table and uses that as a basis for her painting. Sometimes the connection is fairly obvious, as with "Lithium" (#3), a soft alkali metal commonly found in mood-stabilizing drugs to treat, for example, bipolar disorder:

Sometimes the connection is less clear (or not entirely scientific in nature). For instance, thanks to Hyon, I discovered an element I didn't even know existed: "Tantalum" (#73), a rare, hard, blue-grey transition metal found in many electronic components (or at least used in their manufacture). The name derives from the Greek myth of Tantalus, whom the gods punished after death by having him stand knee-deep in water with tasty fruit above his head. If he bent to drink the water, it drained beyond his reach. If he reached up for the fruit, the branches moved out of his reach. (Those Greek gods were right bastards, weren't they?) Hence our verb "to tantalize." And here's how Hyon transformed those random bits of information:

Thanks to a few links from various Sciblings, a few months ago, I discovered the work of Glendon Mellow, a.k.a., "The Flying Trilobite." He's an artist/illustrator with a quirky sensibility (and a style that calls to mind Dave McKean, among others), based in Toronto, Ontario, with his wife and a hermit crab named Shiny. At least that's his bloggy bio sez. His pieces aren't just about trilobites, but the creatures are often incorporated into many of his paintings, such as this one, called "Life as a Trilobite":

Artists aren't always so obvious with their nods to scientific inspiration, but that doesn't mean it isn't there. New York City artist Adam Cvijanovic made a splash a couple of years ago with his gigantic, room-sized multi-paneled mural, "Love Poem, 10 Minutes After the End of Gravity," showing a section of Los Angeles in the process of breaking up and floating away. "Love Poem," by his own admission, is certainly not a treatise on the force of gravity, nor is it 100% scientifically accurate. That was never the point. But he did successfully imagine a fanciful scenario of what might happen if, indeed, gravity suddenly disappeared (barring all the other apocalyptic stuff that would most likely have to accompany such a disastrous event)

I've known Cvijanovic for over a decade (he was married to one of my closest friends until recently, and he painted a gorgeous mural for my living room when I was still based in Washington DC -- and yes, I still miss it, thanks for the painful reminder). I  have always been impressed with the degree of research and deep thought he puts into even the smallest element of a painting -- all artists do, to be sure, but folks like me rarely get an inside peek into that creative process, unless we know the artist personally. For instance, when he was working on a project that mimicked medieval illuminated manuscripts, he experimented for weeks at making his own parchment for ultimate verisimilitude.

Lately, he's been specializing in these giant installations of murals painted on Tyvek, so it works just like wallpaper: easily applied, and then removed. He just had a show this spring at Bellwether Gallery in New York called Colossal Spectacle: one giant installation inspired by D.W. Griffith's failed celluloid epic Intolerance, depicting the court of Babylonian king Belshazzar. This big climactic scene is what apparently bankrupted Griffith before his film could be completed. Cvijanovic is fascinated by this sort of hubris: spectacular display followed by a crash and inevitable decay. He's also keen on popular culture: I dimly recall a series of sketches he did of the James Bond (Connery era) movie Thunderball, just for fun: he'd pause the movie and give himself however long the DVD player gave him to sketch the outlines of the scene, and fill in the blanks from there. Just like scientists, artists can take their inspiration from any number of unlikely sources.

I bring the pop culture thing up because we all shared an inordinate fondness for Dogs Playing Poker, a campy series of oil paintings commissioned in 1903 to advertise cigars. Those darn dogs have become a significant cultural reference point, despite being of questionable artistic merit. For instance, in The Thomas Crown Affair, a stolen Monet turns out to be a fake, painted over a canvas of one of the Dogs Playing Poker series. Sure, it's funny, and more people are likely to recognize one of those paintings than your average Monet -- but is it art?

Probably not, or maybe we need to expand our definition still further to incorporate this particular subgroup of commercial art, which has other merits beyond the purely aesthetic. The Spousal Unit alerted me to an hilarious series of print ads for the Toyota Prius -- not official ones, some advertising dude just created them to plump up his portfolio -- recently featured on the blog Sociological Images (part of Contexts magazine). I think they're actually pretty brilliant, depicting folks engaged in all kinds of despicable behavior next to the car, with the tagline, "At least s/he drives a Prius." This one is my favorite, called "The Body Dump":

I think this series might be the next "Dogs Playing Poker." It's just the sort of thing I need to grace my office walls. I might not know anything about art, y'all, but I dang sure know what I like. Feel free to leave a comment, with links, to tell me about a science-inspired artist that you like. I need to add to my collection....

the root of the matter

The "Physical Theories as <Blank>" meme continues to ricochet its way around the science blogosphere, with entries from Chad and Emmy, Confused at a Higher Level, and Steinn's personification of physical theories as characters in the Harry Potter books over at Dynamics of Cats. It could go on forever at this rate! The various humorous iterations -- and ongoing comment threads -- provided some welcome distraction, as this was the week one of my teeth decided it was time to die. Did it embrace its fate with quiet dignity? It did not. My tooth refused to go gentle into that good night, and instead went kicking and screaming into oblivion ("Why me? Why now? Why, Flying Spaghetti Monster, why?!??"). Apparently it had so much to live for....

My dentist finally put the tooth out of its misery yesterday morning with emergency endodontic therapy, more commonly known as a root canal. And since this has been a week of following memes, I decided to blog about my medical procedure, because all the cool SciBlings are doing it: Abel Pharmboy liveblogged his own vasectomy last year, Janet Stemwedel just blogged about her mammogram, and PZ Myers is threatening to blog the colonoscopy he has slated for next week. (Go on over to Pharyngula and encourage him to do so! C'mon, it's PZ, so you know it'll be irreverent and funny. Maybe there will be pictures!) These are all common medical procedures that tend to give us the heebie-jeebies, and blogging about the gory details can help remove some of the associated fears -- because we mostly fear the unfamiliar. Root canals are one of the most dreaded dental procedures, so I figure I'm performing a public service, as well as cathartically venting my pain.

Because damn, it was painful -- not the procedure, thanks to the generous application of Lidocaine (lovely, lovely Lidocaine!), but the death throes of my expiring tooth that led up to the procedure. It's easy to forget that teeth are not just static bits of bone embedded in our jaws; they are a crucial functioning part of the human body. They're hollow, for starters, and contain a mass of soft tissue known as pulp that includes nerves and blood vessels and connective tissue. The pulp is vital to maintaining tooth health, since it keeps the tooth supplied with nutrients and moisture. And it alerts the body when something goes horribly wrong: a cavity, or an infected abscess, for example. Pain is a message from the body saying "FIX ME!"

That mass of nerve tissue is rather pink and worm-like in appearance, which is ironic when you consider that a Sumerian text from 5000 BC describes tooth decay as resulting from a "tooth worm" -- a belief that spans several cultures (India, Egypt, Japan and China) and persisted into the Western European Age of Enlightenment. There is evidence of rudimentary dentistry techniques dating as far back as 7000 BC, although the father of modern dentistry is 17th Century French physician Pierre Fauchard, who was the first to treat cavities with dental fillings. (According to the Code of Hammurabi, dating to the 18th century BC, tooth extraction was a common form of punishment. That probably doesn't count as "dentistry.")

Of course, we now know that the nerve is not an invasive worm responsible for tooth decay, but the actual victim of such decay, brought about by invading acid-producing bacteria. A root canal removes that soft tissue, which ends the pain, but also removes the blood supply to the tooth, undermining its structural integrity. That's why most dentists follow a root canal with an expensive porcelain crown.

Anyway, a dying tooth isn't always painful. I've only had one other root canal, and I didn't even know the nerve tissue had died until it -- ahem -- started rotting in place, causing an icky infection. It didn't actually hurt, but something was clearly wrong. When I called my dentist, the assistant, George, asked me to describe the sensation.

Me: "Well, it feels kinda spongy when I bite down..."

(*pause*)

George: "Okay, that's very bad...."

Maybe it was (I had an infected abscess, which complicated matters), but it wasn't painful. But my most recently deceased tooth caused quite the ruckus. It started as a bit of sensitivity whenever I bit down in a certain area, and then progressed to a mild dull ache -- which is when I consulted with my dentist. Whereas before, I sought help quite late, in this case, I was a wee bit early. The x-rays showed nothing amiss, except the replacement filling done last year was ominously close to the nerve. So my dentist sent me home with a prescription for Tylenol with codeine, and told me to call him when the pain "localized" and/or became unbearable.

Does that sound a bit cold and uncaring to you? It's not; my dentist was being responsible and cautious. Turns out it can be rather difficult to pinpoint exactly where the pain originates when it comes to teeth. The reason is anatomical, per my friend (and former jujitsu instructor) Kent, who is himself a dentist. He was still in dental school when I became his student, and invited me to the dissection lab one Saturday morning to practice joint locks on cadavers -- yes, it sounds morbid, but it's easier to understand why certain techniques work with a peek into the body's underlying structure. That's also when I learned that dental students are required to study not just the structure of the head and neck, but the entire upper torso, because a problem with one's teeth or gums can actually affect many different parts of the body one might never suspect were connected.

See, nerves don't exist all by themselves; they're part of a complex system that includes connective tissue and blood vessels; where there's a blood vessel, you can be sure to find at least one nerve accompanying it. Bunches of nerves and vessels are collected into so-called neurovascular bundles, like the intricate roots of two intertwining trees. The "nerve" inside a tooth is a neurovascular bundle, and when it gets inflamed, this sometimes affects the neurovascular tissues all along the course of the nerve trunk. So pain emanating from on tooth may be felt in another tooth altogether -- or even in the ear, eye, or temple, since the Trigeminal nerve on each side of the head branches out to all those areas -- leading the dentist to treat the wrong tooth, particular if (as in my case) there is no clear evidence of a problem on the x-rays. Freaky!

Root canals are expensive and time-consuming, so it's in everyone's best interest to make sure they've got the right tooth. I went home and nothing much happened for five days. Then, almost overnight, the tooth went from being just a wee bit sensitive, to being that hysterical hypochondriac everyone tiptoes around for fear of setting him/her off. ("What's that you're drinking now? Pure filtered water carefully warmed to room temperature? ARE YOU TRYING TO KILL ME?!?? Why not just drink battery acid?")

The pain went from a barely noticeable light, dull ache, to a throbbing undercurrent of inflamed rage, punctuated by vengeful outbursts of excruciating pain. I'm pretty stoic when it comes to physical discomfort; yet that damned tooth had me curled up in a fetal position and whimpering quietly at 3 AM, waiting for the fistfuls of codeine to kick in so I could sleep. Had I been of a religious bent, I might have found myself praying to Apollonia, the Roman Catholic patron saint of dentistry. But I'm not, so I mostly moaned through my distress.

At least now we could be sure I had "localized" the pain to the appropriate tooth, and my dentist hastily scheduled an appointment for my procedure. Never have I been so happy to receive a shot of Lidocaine; in fact, I thanked the dental assistant, who stared at me in shock and stammered, "No one has ever said thank you before...." I actually got a little extra Lidocaine, just to be on the safe side. Inflamed tissue tends to be a bit acidic, and this can slow or stop the diffusion of the anesthesia through the nerve fibers. Lidocaine is the most common anesthetic used today, replacing nitrous oxide (laughing gas) and Novacain, if not the odd shot of whiskey in a pinch (a perennial favorite). Back in 1884, Dr. William Steward Halsted injected cocaine into a sensory nerve trunk as a surgical anesthesia, and while the patients probably enjoyed the accompanying euphoria, the highly addictive nature of cocaine meant it was quickly replaced by other forms of anesthesia.

The actual procedure for endodontic therapy is pretty straightforward. Once I was all numbed up, my dentist opened up the tooth and removed the nerve tissue and blood vessels (pulp), scraped it all clean, decontaminated the hollowed-out chamber, and then filled it with gutta percha -- carefully taking x-rays each step of the way to make sure (a) all the pulp was removed, and (b) the material filled the entire cavity all the way down to the ends of the deepest roots. Then he plugged up the hole with cement. I go back next week for the porcelain crown procedure, but in the meantime, the worst is over. If I were a truly dedicated blogger, I would have pix and videos to post. I'm not that dedicated. But you can watch a sample procedure here, with the sound of the drilling and scraping mercifully removed -- that tends to be what freaks people out when it comes to visiting the dentist.

However, apparently there's a new technique being developed that could reduce the need for drilling and filling by catching tooth decay before it gets so advanced, it requires major dental intervention. It's based on Raman spectroscopy, a technique used to distinguish between different chemicals by identifying each molecule's unique spectral fingerprint. The technique points a tiny optical fiber at each individual tooth, and if there' decay, the chemical changes in the tooth would be detectable by analyzing how the light is scattered when a laser is fired at the tooth. (Bacteria responsible for tooth decay scatter light differently than healthy teeth.) The dentist can then "remineralize" the area before a filling becomes necessary. Conventional x-rays usually don't detect decay until it's too late.

Hmmm. I predict it might be a helpful addition to the dentistry toolkit, but cavities are kinda inevitable. Sooner or later, you'll still find yourself in that dentist's chair, nervously awaiting the dreaded drill. And when that day comes, remember to thank your hygienist who administers the anesthetizing shot for his/her trouble. It'd hurt a hell of a lot more without it.