Cocktail Party Physics

gone honeymoonin'

REPOST: exquisite corpses

[Cocktail Party Physics is on hiatus until October 9 due to a slight case of marriage. In the meantime, we're resurrecting some older posts for those who might have missed them the first time around. Today's rerun is offered in honor of C.S.I. character Sarah Sidle, who survived last season's cliffhanger and was rescued in the nick of time in last night's episode. Like there was ever any doubt.]

There's a classic scene in an episode of C.S.I., in which Sarah Sidle is flirting with a search-and-rescue worker over a body bag containing a liquefied corpse. The forensics team transports the remains back to their Vegas lab, and Sarah gets the mucky job of sorting through the remnants of clothing soaked in foetid bodily fluids. Halfway through this gruesome task, the handsome search-and-rescue guy shows up to ask her to an impromptu dinner -- and gradually becomes aware that she is enveloped in the unmistakable stench of a badly decayed corpse. Overcome with nausea, he beats a hasty retreat, and poor Sarah is left standing forlorn in the hallway. The DNA technician, Greg, saunters by, pauses, turns back and observes, "You smell like death." Sarah tightly replies, "Yes. I've heard." Greg shrugs and continues on his way, shooting back, "You know, a real man wouldn't mind."

That sets the masculinity bar pretty high, don't you think? There was a time when all a "real man" had to do was avoid quiche and public discussions of window treatments to assert his manhood, bolstered by the odd bit of beer-guzzling and attendance at rugged sporting events. I can't conceive of a single man (or even a woman) of my acquaintance who wouldn't be prone to retch just a little in the presence of squishy human remains -- perhaps because my social and professional circles include no forensic pathologists.

Nor do they include the drug-addicted British rocker Pete Doherty, whose tabloid exploits recently included being arrested for supposedly injecting a young female fan with heroin while she was unconscious in his flat. It turns out the pasty-faced rocker was merely drawing the woman's blood for use in his so-called "blood paintings" (actually crude cartoons scrawled in blood), which have been exhibited in a London gallery and sold for 1000 pounds each. So that's all right. Such a gentleman, that Doherty. By C.S.I. standards, this makes Doherty very manly indeed, but he pretty much tops our list of people we wouldn't want within 10 feet of us with a syringe -- and that list includes Hannibal Lecter. (Jen-Luc Piquant opines that it's one thing for the artist to bleed for his art; it's quite another to insist others bleed for it, too, particularly if they happen to be unconscious at the time.)

Doherty's fascination with bloody art isn't all that unique. Artists throughout the ages have exhibited the odd morbid streak, even when it comes to naming their artistic methods. The Surrealists in the 1920s were fond of a collaborative creative technique known as the "exquisite corpse." It was based on an old parlor game called "Consequences," in which players wrote a composition in sequence, with each person only being allowed to see the very end of what the prior player wrote. The name supposedly derives from a phrase penned when Surrealists first played the game: "Le cadavre exquis boira le vin nouveau." ("The exquisite corpse will drink the new wine.") The technique was initially used to construct poems and short stories, then extended to drawing and collage, even film and music, where each composer is privy to only one measure of music. It's inventive, yes, although there's nothing especially macabre about it, other than its name.

That's not to say corpses can't sometimes double as art, even as they help advance science. Consider the work of German anatomy professor Gunther von Hagens, who made global headlines in 2002 with his traveling exhibition, "Body Works," comprised entirely of 30 skinned and dissected corpses displayed on stands in various poses. The corpses were preserved via "plastination," which involves soaking the corpse in formaldehyde, freezing it, and thawing it -- all prior to actual the dissection and skinning. All fat and water are removed and replaced with plastic, so the corpses don't decay, or stink, and are flexible enough to be "posable." Not everyone found the exhibit appalling: several people volunteered to donate their bodies to von Hagens after death -- their way of achieving some measure of immortality. (Jen-Luc briefly considered offering her own pixelated self for such preservation, but then realized that she is already "immortal" by virtue of inhabiting the Cybersphere.)

Long before von Hagens conceived of "Body Works," a humble 18th century French anatomist named Honore Fragonard specialized in preparing and preserving skinned cadavers. (Yes, he was related to Jean-Honore Fragonard, painter of far more dainty and bucolic scenes; the two men were cousins.) Most were done for instructional purposes, but Fragonard had a decidedly offbeat sense of humor, and also created elaborately posed skinned bodies for artistic display. In all, he may have created as many as 3000 such "sculptures" (called "ecorches" in French), 18 of which are prominently displayed in the Musee Fragonard in France. The surviving works include Fragonard's take on a famous Durer piece, "The Horseman of the Apocalypse," featuring a skinned horse and rider surrounded by tiny human foetuses serving as "foot soldiers." Popular legend had it that the rider was a grocer's daughter whom Fragonard loved, but the rider has the remains of a tied penis, so that rumor is clearly unfounded.

The anatomist dealt with many stillborn children, and used the same technique for those as for his adult subjects. He injected the arteries with red-colored wax (he used blue wax in the veins), or covered them with the wax if the vessels proved to be so small in diameter as to make injection impossible. The skulls were opened to remove the brain -- at the time, too difficult to preserve -- and the muscles and nerves were separated and later dried, often in postures suggestive of movement. That much was purely in the interests of science, but Fragonard couldn't help arranging three such foetuses in a macabre tableau, dancing a jig. Which might explain why he was eventually fired from his position as director of the world's first veterinary school in Alfort in 1771, on grounds of insanity. He disappeared from view until the French Revolution, when he returned to some semblance of favor until his death in 1799. (With so many aristocrats losing their heads, a few skinned cadavers doubling as art hardly seemed shocking.)

Was Fragonard crazy? If so, he was in very good company. There's a long history of dissecting human cadavers in the interests of advancing the science of anatomy -- and that science doesn't preclude a penchant for public display. The ancient Greeks and Egyptians dabbled a bit in human dissection to investigate anatomy, but it was the Roman physician Galen who helped vault the practice into the realm of science around AD 129. He publicly displayed his handiwork, as did the Flemish anatomist Andreas Vesalius during the Renaissance, who was known for dissecting the bodies of criminals in a large lecture theater in Padua before audiences of medical students. It was all highly theatrical -- yet also done in the interests of science and education. Further bridging the divide between science and art, Leonardo da Vinci dissected cadavers, sketching his handiwork in exquisite detail. And Vesalius relied on skilled artists for the illustrations in his masterpiece, De Humanis Corporis Fabrica (On the Workings of the Human Body), which included a justly famous frontispiece (below). Vesalius himself is depicted front and center in an anatomical theater performing a dissection before a packed house.

I'd consider Vesalius and da Vinci worthy of our new working criteria for "masculinity." After all, their mutilations were artistically (and scientifically) justified. But history also has its Dohertys, most notably in the form of the infamous body snatchers or "resurrectionists" that proliferated in the 19th century. They dug up bodies in graveyards and sold them to local medical schools for dissection or anatomy lectures. (Exhibiting decidedly Doherty-esque behavior, modern-day body snatchers allegedly cut up the bones of the late broadcaster Alistair Cooke prior to his cremation.)

Technically, these resurrectionists were only targeting a specialized niche market, and anyway, the bodies in question were already dead. But it was only a matter of time before someone hit on the brilliant idea of saving themselves the trouble of grave-robbing and manufacturing fresh corpses instead. Most people refer to this as "murder," but why split hairs?

The most famous case involves William Burke and William Hare, two Irish immigrants living in Edinburgh who murdered 16 people (via suffocation to avoid damaging the cadavers) in 1828 and sold the bodies to the physician Robert Knox. They might never have been caught, except they got a wee bit lazy and starting knocking off people the medical students actually knew. Eventually the law caught up to them, they were arrested, Hare turned state's evidence and snitched on his former partner, Burke. Burke was summarily hanged; the practice has been known as "burking" ever since. Hare appears to have escaped scot-free, apart from a brief prison stint as an accessory to murder. Fragonard is starting to look downright cuddly in comparison, isn't he?

Perhaps not surprisingly, given their notoriety, resurrectionists have been featured in several literary works, including a character in Dickens' A Tale of Two Cities, Robert Louis Stevenson's short story, "The Body Snatcher," and of course, Mary Shelley's Frankenstein. A more contemporary example is Shelagh Stephenson's new play, An Experiment with an Air Pump, inspired by a famous 1767 painting by the artist Joseph Wright, who often depicted scientific subjects. (I had the privilege of attending a recent performance of said play by a small theater company in Virginia.) At least part of the plot was inspired by Burke and Hare: a young doctor named Armstrong with a single-minded bent towards scientific inquiry first romances, then suffocates the plain-faced, hunch-backed maid so he can more closely examine her hump.

The underlying message of Stephenson's drama is not that scientists are inhumane and therefore evil because they have no respect for life -- although Stephenson draws an intriguing modern-day parallel between the need for cadavers by 17th century anatomists and modern-day genetics research, particularly that involving stem cells and cloning. (It doesn't quite work, but it's thought-provoking, nonetheless.) Armstrong is hardly an heroic figure, and there are other scientifically minded sorts in the play who are not so craven in their pursuit of knowledge.

But Stephenson does seek to emphasize that scientific pursuits, while noble and admirable, must be balanced against compassion and basic human decency, and we ignore that aspect at our peril. There is unquestionably an ethical component to science, whether the research involves the anatomy of exquisite corpses, epidemiology, drug development, nuclear weapons, or the potential unknown risks  of nanotechnology. The trick is determining where to draw that ethical line. It's not always as obvious as the case of Burke and Hare.

(non)focal points

Welcome to Cocktail Party Physics: The ADD Edition! It's three days before the Big Day, you see, and while everything is in place and running smoothly, I'm finding it very difficult to focus on much of anything, including writing those pesky wedding vows which remain half-finished. It's about to get even harder to concentrate as friends and family begin to arrive in droves to join in the nuptial festivities. (Jen-Luc Piquant is completely frazzled, having organized her own massive Cyber-Celebration in honor of her continued singlet state -- which seems to involve subversive satirizing of traditional wedding conventions.) Needless to say, we will be on hiatus for the next 10 days -- or rather, we're resorting to reruns: I've scheduled a few of my earlier posts to appear (duly marked as such) next week, for those readers who might have missed them the first time around -- or completely forgotten they'd ever read them in the first place.

In the meantime, it seemed like a great opportunity to do a bit of housekeeping in the form of emptying out the burgeoning blog fodder file: all those quirky little items I clipped for future reference that somehow never really made it into a bona fide post... until now! So, here are the things I would blog about, if only I had the time:

Gorey Gets Animated! I'm an unabashed fan of the late Edward Gorey, particularly The Gashleycrumb Tinies: his version of an ABCs alphabet book in which 26 children meet horrific fates. My personal favorite? "N is for Neville..." So imagine how thrilled I was when  my pal Lee Kottner (occasional guest blogger at the cocktail party) forwarded me a link to  Book Patrol's post on an animated Gashleycrumb Tinies.  I'm sure I could find a science angle somewhere were I not so distracted these days.

Why Cats Purr. Feline purring is quite possibly the world' most pleasant sound, delivered via a warm, furry body, but it's not necessarily just a sound of kitty contentment. Cats also purr while giving birth or when they're seriously injured, and now Fauna Communications and a sensor manufacturing company called ENDEVCO have decided to resolve the matter once and for all with a novel study. They recorded the purrs of a domestic cat, a cheetah, a puma, a serval and an ocelot to determine whether the "vibrational stimulation" (their words) might have a therapeutic effect that assists cats in self-healing. (Interesting factoid: the record for a cat surviving a high-rise fall is a whopping 45 stories!)

The researchers hooked the animals up (via adhesion) to tiny accelerometers, weighing just 0.14 grams, gave the comfy blankets, and occasionally petted them to encourage purring (Jen-Luc would dearly love to pet a cheetah). And they found that all of them had purr frequencies that fell within the range of low frequencies associated with various therapeutic effects. I doubt this is the final word on the subject, but it's certainly an intriguing theory -- one that I have no time to investigate any further, alas.

What To Do About Those Filthy Frescoes. Way back on September 3, New Scientist ran a fascinating article on the use of nanomagnetic sponges to restore dirty (yet priceless) frescoes by a team of Italian scientists. Basically, they smear the surface with a polymer gel containing cobalt and iron oxide nanoparticles, the presence of which forms cavities that are filled with microemulsions to dissolve dirt on contact. Gel-based systems have been used in the past but they can be sticky and tough to remove -- you don't want to be using solvent-based paint thinners or scrape away at priceless antiquities, after all. That's the beauty of the nanomagnetic sponge: you just wave a bar magnet over the surface after cleaning to remove the gel -- no need to touch the artwork's surface at all. This would be a great springboard for a broader post on the history and future of nanoparticles and their useful applications... but it is not to be.

Why Curly Hair is Better. Also earlier this month, Physics New Update described a paper in the August issue of the American Journal of Physics about a new study of the properties of various types of human hair. Now there's a topic near and dear to my imperfectly coiffed head. The researchers "consulted with hairdressers and got them to count the tangles in people's hair," then analyzed curly and straight varieties using a "geometrical model" that attempts to explain the results -- curly hair has fewer tangles than straight hair -- mathematically. It's a fun topic with ties to our everyday experience, plus it could prove useful in designing better Velcro-like products. Alas, I have not world enough and time; fortunately, the folks at PhysicsBuzz and Peter Steinberg of Entropy Bound had just enough of both to produce short blog posts about it.

Missing the Whole Point of Bicycling. Via the Los Angeles Times comes word of a hot new electric bicycle, called the Pi, that its manufacturer, Electrobike, called "the world's fastest hairdryer," even though its motor has about half the wattage of a hair dryer. (Translation: my hair dryer can beat it!) Technically, Pi is a hybrid: a traditional bike combined with a motor-driven capability for when you're just to lazy to pump your way manually up a steep heel. Pansies.  Lance Armstrong would never stand for such a thing. That's the whole point of bicycling: to get a bit of exercise, maybe even work up a bit of sweat. Your reward for chugging up a hill? Coasting down the other side of a steep hill and seeing just how fast you can go. It's all the sweeter if you suffer a little first. Although we must admit: Pi sure is purty... Check out the video accompanying the article. The fact that the Pi is only available exclusively through Design Within Reach should only make it even more attractive to would-be hipsters who want the appearance of healthy exercise without all that unsightly sweat.

Spelunking on Mars. On Monday, I received a press release from Arizona State University in Tempe, announcing that a heat-sensitive camera it designed for NASA's Mars Odyssey orbiter has helped Martian geologists (geologists who study the planet, not those who are, themselves, Martians) find what appear to be cave skylights on the sides of a giant volcano called Arsia Mons. It's the temperature data collected by the Thermal Emission Imaging System (THEMIS) that proved crucial to differentiating these seven small circular holes from the usual run-of-the mill craters ad volcanic vents that litter the Red Planet. The new holes are warm at night, but cool by day, indicating they may be skylights in the ceiling of underground caves. That's the working theory, at least, and the researchers think the holes formed because faults created stresses, opening up spaces underground. Alien abductees would probably speculate that the holes are literally skylights, built as an energy-saving measure by underground Martian lifeforms.

Meteorite Madness. Meteorites occasionally do hit the Earth, with varying degrees of accompanying drama, but it's always pf passing interest, because few such objects from outer space make it all the way to the Earth's surface -- they usually burn up in the atmosphere. In Peru, a meteor strike earlier this month led to a bit of melodrama: (a) several residents feared that the loud explosion was an indication that the Chileans -- Peru's chief rival -- were attacking, and (b) even once they realized it was a meteor, many villagers in Carancas (the area where the meteorite landed) became convinced they were being poisoned by cosmic radiation, leading a widespread complaints of headaches and nausea. The health department chief in nearby Puno dismissed those claims as "a collective psychosis," but authorities took soil and water samples near the crater just to be on the safe side. One of these days I'll get around to writing about meteors, meteorites (I still get them confused), comets, asteroids, and such, but today is not that day. (heavy sigh)

Imaginary Physicist. Sabine of Backreaction made my week with her clever series of photos musing on Max Tegmark's latest out-there (and vaguely Po-Mo) theories about the universe as a mathematical structure. Check it out. Future Spouse had to explain the technical joke at the very end, but it's quite funny even if you don't quite grasp the punchline -- just for Bee's wonderfully expressive face.

The Science of Foodstuffs. And Drinkstuffs. Shelley Batts of Retrospectacle is featuring a series of entertaining posts on the science behind Japanese delicacies such as fugu (the poisonous blowfish) and sake (staple of fine sushi restaurants everywhere). We love that sort of thing -- check out the sidebar -- and Shelley's series reminded me that I'd meant to write something about mixology after reading this short item on the ABC (Australian broadcasting) Website on whether there's a difference between a martini that's been shaken, not stirred. The original paper is here.

It seems to be all about the antioxidants, in this case, but I think the physicists could weigh in at some point on the actual properties of the drink itself down at the molecular level. Any takers? Future Spouse volunteers as a taste tester -- the martini is his drink of choice. Although he'd be appalled by this recipe for a green tea citrus martini. I liked it when I tasted one, although I vastly prefer a classic sidecar. To win me over to the more manly side of alcoholism, Future Spouse sent me this article in the San Francisco Chronicle arguing in favor of the Manhattan, similar to the sidecar but (he maintains) vastly superior. I remain unconvinced. I like me my fruity girly drinks.

The Power of the Katana. Hiro, my favorite character on Heroes, acquires an ancient Japanese sword in Season 1, which he uses to fulfill his destiny in the final showdown against Sylar. (Don't watch the show? For shame!) You might think such a weapon would be well-nigh useless in the modern age of guns and such, but this video -- courtesy of the Wired blog -- shows just how powerful a katana can be against a high-speed bullet. If the only TV you deign to watch is PBS, be sure to check out the debut of Wired Science on Wednesday, October 3. We'll be honeymooning in Los Cabos, and thus will most likely miss the first episode, but host Adam Rogers graciously sent me a preview DVD, and the show's terrific. I'll definitely be tuning in upon my return.

And finally, given the pending nuptials on Saturday, it seemed appropriate to head over to the Madlibs poem generator, where you can insert various words and the computer turns it into an actual, albeit nonsensical, poem. (Future Spouse nixed the idea of including one in the vows. Wise man.) The one below is actually a combination of two attempts, since, well, results may vary. Enjoy! And remember: the original two poems were far, far worse...

This night I shall dream of your bedazzling crimson hair and fox-eyes.
In my dreams, we fly on the exquisite winged arugula of cobaltness --
skimming vast continents of eyelashes and koalas.
Your skin glows like the mango,
blossoms mottled as the orchid in the purest hope of spring.
My heart follows your lute voice and leaps like a jaguar at the whisper of your name.
The evening floats in on a great sparrow wing.
I am comforted by your beret that I carry into the twilight of bicycle beams
and hold next to my ankle in the darkness.
I am filled with hope that I may dry your tears of wine.
In the quiet, I listen for the last purr of the day.
I wait in the moonlight for your secret bouquet,
in search of the magnificent purple and mystical flute of love.

The End.

this is pong on drugs

Jen-Luc Piquant has been urging me to indulge in a bit of meditation to calm my nerves as we head into the home stretch for the Big Nuptial Event this coming weekend. I suspect she was thinking of something a bit more New Age-y, such as communicating with my molecules of consciousness, but personally, I find playing endless games of Scrabble or Solitaire to be oddly soothing in times of stress. Jen-Luc has her way of meditating, and I have mine. (Some people find exercise meditative, but I tend to draft articles or blog posts in my head in those situations.) And in an earlier era, I could have turned to Pong. You remember Pong, don't you?  At least, you should if you were a kid in the 1970s. It was one of the first video arcade games ever developed, courtesy of Atari, and definitely the first to achieve widespread popularity, moving from the arcades to people's homes soon after it was introduced to the marketplace.

Pong was little more than a computer version of table tennis (or, as we called it growing up, "ping-pong"). It had simple monochromatic visuals and made a "pong" type sound whenever the "ball" (a little white dot) was hit by the "paddles" (two white rectangular bars at either end of the screen). It wasn't the first time someone thought of playing an electronic version of ping-pong: in 1958, a scientist at Brookhaven National Lab named William Higinbotham invented "Tennis for Two," played on an oscilloscope, but it failed to penetrate much further than the lab, perhaps because very few American homes had their very own oscilloscope.

Eight years later, a man named Ralph Baer working for Sanders Associates wrote a short paper describing a system for playing simple video games on a TV set, leading to his development of a computer version of ping-pong -- which he duly patented and licensed to Magnavox. In 1972, the company launched the Magnavox Odyssey, the first home video game console, offering a dozen different games, including table tennis. Nolan Bushnell saw the system demonstrated at a trade show that year, and one month later co-founded Atari with Ted Dabney, each contributing $250 of starting capital. The original idea was to create a video car driving game for arcades, but Bushnell realized this was a pretty tall order, given the limited graphical capabilities available at the time, so he asked his electronic engineer, Al Alcorn, to create a ping-pong game. And thus, Pong was born.

The original arcade version had a coin-operated switch, and the instructions were simplicity itself: "Avoid missing ball for high score." Finally, an arcade game that even those in the most drunken of stupors could play! The system was field-tested at Andy Capp's tavern in Sunnyvale, California (not to be confused with the fictitious town of Sunnydale central to the Buffyverse), and within a day of its introduction, people were lined up outside the bar waiting for their turn. In fact, the machine broke down rather quickly: there was a milk carton placed inside to catch the inserted coins, and when it was overflowing with quarters, they jammed the switch. By March 1973, Atari had sold a whopping 10,000 systems. The home console version proved just as popular: it was the must-have Christmas gift for 1975.   Pong was even featured in several Saturday Night Live segments during the show's first season -- you know, back when it was truly ground-breaking and actually funny.

Pong seems to be riding the nostalgia wave of late, evidenced by last year's hugely popular American Express commercial featuring tennis player Andy Roddick (video clip is here). It's pretty funny. Warned by his trainer in advance that his opponent "returns everything," Roddick walks onto toe court to find himself facing the telltale rectangular white band -- rendered in 3D this time, thanks to our vastly improved graphical capabilities these days. Pong proves to be a formidable opponent, returning shot after shot until Roddick has an epiphany: he realizes Pong can only move side to side, not forward or back. So he jettisons his usual killer power serve and tips the ball neatly over the net in a simple drop shot so that it dribbles into his opponent's side of the court, winning the game -- because Pong can't move forward to return the ball. The commercial even spawned an interactive Web game called Stop Pong. (Try it! S'fun!)

The Roddick commercial serves to illustrate the chief weakness of Pong: as video games go, it was pretty mindless, and quickly got boring. I have dim memories of a Pong console in our home when I was growing up. If memory serves, our favorite thing to do was align the paddles in such a way that the little white "ball" was passed back and forth in a perfectly straight line. Neither side ever missed. We'd leave it like that, and go play a few real games of ping-pong, because we had a bona fide table in the garage, mounted on a couple of sawhorses. (When your grandfather, father, and brother are all in construction, there's always a sawhorse laying about the place.) Pong was an interesting novelty, but it just couldn't beat the real live game in terms of pulse-pounding excitement and unpredictability.

If only we'd had access to today's advanced home computers (never mind graphic-heavy, interactive game consoles like PlayStation and X-Box). Then we could have indulged in the groovy psychedelic permutations of Plasma Pong, described by PC World as "Pong on acid," and recently named one of the top five indie games by Wired.com. The Website (launched earlier this year) has already surpassed one million hits. Plasma Pong has even warranted mention in the hallowed pages of the Washington Post. It's not the first time someone's re-invented Pong; apparently there was a version that featured former president Bill Clinton's head as the ball, and a demo prototype of a system that used body sensors to control the paddles. But Plasma Pong is just whacked-out enough to have the same broad popular appeal as the original. The WaPo reporter described is as being "like playing ping-pong while floating in melted lollipops.... It's over the top, freaky, high-speed, and mellow all at once." What could be better than that? (You can see an actual game of Plasma Pong being played here.)

Plasma Pong is the brainchild of George Mason University student Stephen Taylor, who got bored during a winter break spent at his parents' house (we hear ya, buddy!), and started writing code for a revamped version of Pong. He didn't bother tweaking the basic rules: he re-invented the visuals and added some interesting 2D physics simulations in the form of liquid plasmas. A simple mouse click sends a jet of liquid across the "court" -- or, alternatively, creates a suction effect to draw the ball toward you. The bright colors constantly pulsate and change, occasionally sending particles flying around the screen.

There's also a "sandbox function," to alter the viscosity of the "liquid," for example, to indulge those who can't resist doing their own tweaking. "You can toggle all the controls, turn it into a giant bowl of Jell-O if you want to," Taylor told the Washington Post. The game was an instant success: when Taylor first posted it online, the GMU serve slowed to a crawl because the game had been downloaded 50,000 times.

Kids today. Sheesh. I don't know what Taylor's majoring in, but it's pretty clear he's well-versed in math and science, not to mention being extraordinarily creative: his game required him to create algorithms for such advanced calculations as viscosity, gravity, vorticity, and other physical forces that affect the movement of a liquid. And trust me, that's no small feat. That's because plasmas -- ionized gases that technically make up a fourth state of matter because the ionization gives what would otherwise be a gas distinct fluid properties -- are extremely difficult physical systems to model. (I wrote about lab-based simulations of space plasmas in a post last year.)

There's an entire field of physics (fluid dynamics) devoted to gaining better understanding, and developing better predictive models, for complex fluids (plasmas, smoke, fire, or typical liquids). There are so many variables, and the systems can change so rapidly in response to the tiniest variation in just a single variable, that it's extremely difficult to predict a fluid's behavior beyond the near-term, or effectively manipulate it to one's advantage. Taylor, it turns out, relied on a research paper written by Jos Stam, a well-known scientist in the gaming industry, to develop Plasma Pong.

The complexity of fluid behavior is what makes Plasma Pong so much fun: not only do you get bright pretty psychedelic colors, but the addition of fluid dynamics means the system creates sudden, unpredictable movements: the ball can easily get caught in eddies and currents. Sometimes you can use this to your advantage. For example, firing a plasma into your opponent's playfield can create an eddy, enabling you to score. But it's not 100% controllable -- some players might find that frustrating. I think it's a great introduction to the unpredictability of Nature.

Still, Taylor's already moved on to the next version of the game. First, he'll graduate from college. Then, he'll launch his own company to market a new version of Plasma Pong under a different name (to avoid trademark infringement concerns). He's working on making a multi-player version of the game to enable a GMU student to play someone in Tokyo, for example. And he'd love to upgrade the graphics to 3D, rather than 2D, plasma simulations -- an even more difficult feat than what he's already accomplished. If he succeeds, it'll be like playing Pong inside a lava lamp. Jen-Luc can't wait...

shiver me timbers

Argh! Avast, me hearties, yo-ho! And pass the rum! It be Talk Like a Pirate Day again, and Jen-luc Piquant is thrilled to be able to don her spiffy piratical duds to celebrate. There's all kinds of festive Cybersport taking place, including a nifty guide with tips on how to convincingly talk like a pirate, and a program that will translate an entire website (including every entry at the cocktail party) into Piratese. In need of piratical reading material? Last year, I wrote a lengthy post in praise of Gideon Defoe's highly amusing Pirates! series, focusing on their adventure with scientists, although there's now three such books, and they're all loads of fun. Alas, my proposed Talk Like a Physicist Day has yet to gain momentum, in part because nobody's bothered to set an actual day -- Einstein's birthday on March 14 should suffice. That gives us several months' advance notice to prepare. Jen-Luc sez we're all on notice!

If talking like a pirate isn't your bag, you can always emulate the young Pat Boone's disastrous attempt at a Scottish accent in the 1959 flick Journey to the Center of the Earth, based on the famed sci-fi classic by Jules Verne, and supposedly filmed on location in New Mexico's Carlsbad Caverns. Future Spouse rented the DVD a couple of nights ago, and we watched in appalled fascination at the spectacle unfolding before us. Hard to believe the film was nominated for three Oscars (for sound, special effects, and set decoration); now it's definitely fodder for the MST3K treatment. It has it all: bad science, silly experimental apparatus, and gratuitous sexist slurs made by the chief scientist against the Widow Goteberg (Arlene Dahl), a feisty smokin' hot chica in a whalebone corset who insists on tagging along on the expedition in exchange for donating her late husband's supplies. (Jen-Luc thinks all explorers should all be so well-dressed.) You also have an evil nemesis who says things like "I never sleep. I hate those small slices of death," plus a big blond Icelander who's a bit too fond of his pet duck, Gotrun. The duck is actually the smartest member of the expedition, and the film's saddest moment is when poor Gotrun gives her life to save the silly inept humans. Either that, or she was driven by suicidal despair at having to be around them that long.

The mere presence of 1950s singing sensation Pat Boone (in a kilt, no less) means there must be occasional bursting into song, such as serenading his professor's daughter with a schmaltzy musical rendition of the Robert Burns poem, "My Love is Like a Red Red Rose." For much of the journey, he carries a small accordion, so there's always the chance he could start singing at any moment, just for a bit of added suspense. (A bit of musical accompaniment would have been welcome during the sudden halt in the action to debate the ethics of capital punishment.) Future Spouse particularly enjoyed the opening scene where James Mason's professor has just been knighted, and is greeted by his graduate class as he enters the lab with a celebratory choral bit in perfect harmony: "How come my students never burst into song when I walk into the classroom?" Although he'd be just as happy with the occasional gift of a Bacon Chocolate Bar from Vosges.

In all honesty, we rather enjoyed watching the film, even though it got a bit tedious towards the end. Our intrepid scientists find the lost city of Atlantis, are nearly drowned, lose their way, are menaced by giant lizards once they reach the Earth's "center" -- remember, those special effects were deemed Oscar-worthy in 1960! -- and ultimately escape by setting off explosives to cause the volcano they're in to erupt, hoisting them to the surface in a makeshift stony saucer just big enough to fit the four of them (minus poor Gotrun). Jules Verne had an excuse for his questionable science: geological knowledge in the late 19th century hadn't progressed very far regarding what truly lay at the Earth's center, so he was free to let his imagination run wild. But by 1959, didn't we know better? I can't imagine anyone watching this not being reduced to giggles at the premise -- except perhaps for Sherri Shepherd, new co-host of The View, who apparently isn't sure if the Earth is flat. She probably thinks Journey to the Center of the Earth is a documentary, and lies awake some nights fretting that the giant lizards will one day escape and devour her brood.

The entire impetus for Verne's fictional expedition is the accidental discovery that a bit of lava-rock presented to the newly-knighted professor as a gift turns out to contain a metal surveyor's plumb, indicating a possible lost civilization. That part is far more believable than the giant lizards, because such serendipitous discoveries occasionally do happen in science. In 1900, a Greek sponge diver named Elias Stadiatis discovered the wreck of an ancient cargo ship off the coast of Antikythera island in Greece. He and other divers recovered all kinds of artifacts from the ship. A year later, an archaeologist was studying what he thought was just a piece of rock recovered from the shipwreck, and noticed there was a gear wheel embedded in it. It turned out to be an ancient mechanical device -- perhaps the earliest example of a geared device -- now known as the Antikythera mechanism and housed in the Bronze Collection of the National Archaeological Museum of Athens. The device was originally housed in a wooden box roughly the size of a shoebox, with dials on the outside and containing a complex assembly of gear wheels within. Its very existence offers strong evidence that such technology existed as early as 150-100 BC but the knowledge was subsequently lost. Similar machines with equivalent complexity didn't appear again until the 18th century.

Not surprisingly, scholars have been fascinated by the Antikythera mechanism ever since its discovery. It took decades just to clean it off, and in 1951, a British science historian named Derek J. de Solla Price began his life's work investigating the theoretical workings of the device. Based on X-ray photographs of the fragments, he published a handful of minor papers before the first major paper appeared in Scientific American in June 1959 (the same year Journey to the Center of the Earth was released, although we are sure this is purely coincidental). Entitled "An Ancient Greek Computer," the article detailed Price's hypothesis that the mechanism had been used to calculate the motions of stars and planets -- making it the first known analog computer.

Another person who has extensively studied the mechanism, Michael Edmunds of Cardiff University, had this to say about it: "The design is beautiful, the astronomy is exactly right. The way the mechanics are designed just makes your jaw drop. Whoever has done this has done it extremely carefully." The Antikythera mechanism was found on a Roman cargo ship, but historians believe it is Greek in origin, possibly from the island of Rhodes, which was known for impressive displays of mechanical engineering. Pindar, in his seventh Olympic Ode, paid tribute to that Rhodian skill:

"The animated figures stand
Adorning every public street
And seem to breathe in stone,
or move their marble feet."

Researchers are still making surprising findings about the Antikythera mechanism. In 2002, Michael Wright, the curator of mechanical engineering at the Science Museum in London, made headlines with his new, more detailed X-ray images of the device taken via linear tomography -- which means that only features in a particular plane come into focus, enabling closer inspection and pinning the exact location of each gear. And he found that the device was even more complicated than Price originally thought.

Apparently Price did a bit of "massaging" of his analysis to get the requisite significant astronomical ratios to add support to his thesis, although in fairness, the deteriorated condition of the gear teeth didn't make this an easy task. A little guesswork is to be expected. Wright's closer analysis found a fixed central gear in the mechanism's main wheel around which other moving gears could rotate. He concluded that the device was specifically designed to model "epicyclic" motion, in keeping with the ancient Greek notion that celestial bodies moved in circular patterns called epicycles. (The fixed point around which they moved was generally believed to be the Earth, until Copernicus realized it was, in fact, the Sun.)

The device seems to have been designed well enough to reproduce the motion of the sun and mood fairly accurately, as well as the planets Mercury and Venus. But that leaves out Mars, Jupiter and Saturn, which were also known in antiquity. Wright speculates that there may have been an upper layer to the mechanism, now lost, with extra gears to model the missing planets. Wright eventually built a pretty darned impressive reproduction of the Antikythera mechanism, stacking the gears like layers in a sandwich. By winding a knob along the side, the various celestial bodies can be made to advance and retreat to determine their positions on any chosen dates. Wright used modern tools for his reconstruction, but has argued that it would have been possible to build it using ancient tools: the Greeks apparently had saws with teeth that were cut using v-shaped files, similar to cutting teeth on a gear wheel.

Some things are still a mystery, such as the purpose of two dials on the back of the original device, one of which may have been used to indicate the year. Wright hypothesized that the lower back dial might have been used to predict eclipses. There's an ongoing Antikythera Mechanism Research Project devoted to undertaking, among other tasks, more advanced 3D X-ray imaging with the help of X-Tek Systems in the UK, and Hewlett Packard, among others. For instance, HP built a new 3D surface imaging device, the PTM Dome, which surrounds the object to be examined -- a critical factor in the current project, given the fragility of the Antikythera mechanism. X-Tek's contribution was a 12-ton microfocus computerized tomographer. These were used to examine the original fragments, plus new pieces discovered in October 2005 (there are now 82 fragments that have been recovered).

A year later, the scientists announced that the new images had revealed much more of the original Greek transcription, which was subsequently translated -- from about 1000 characters to 2000 characters, or roughly 95% of the surviving text. A November 30, 2006, article in Nature included a new reconstruction of the device based on the high-resolution X-ray tomography conducted by the study. Based on the new discoveries, the mechanism has been pretty much confirmed to be an astronomical computer used to predict the positions of heavenly bodies in the sky. Current predictions are that it once had 37 gears, of which 30 survive, and its front face had graduations showing the solar cycle and the zodiac, along with pointers to indicate the positions of the sun and moon.

Of course, there have been all manner of similar celestial and/or navigational devices developed throughout the ages: everything from astrolabes and the medieval torquetum (dating back to the 13th century), to the elaborate mechanical orrery, which serves a similar purpose as the Antikythera mechanism, namely, illustrating the relative positions and motions of the planets and moon in the solar system. In fact, if you're loaded, you can order your own custom-made orrery from this guy. They can be small, tabletop models, or take up entire rooms, like the giant orrery Professor Lupin had in his office in the third Harry Potter movie. The models are frequently found in planetariums, and some people have been known to stage a "Human Orrery," in which people are assigned to represent the various celestial bodies and match their movements to those cycles. (Jen-Luc thinks it would totally suck to be assigned the role of, say, Neptune, because the outer planets move so verrry slooowly....)

I would love to have my very own functioning orrery, but space in our Los Angeles loft is limited, particularly given my hopes of adding a working cloud chamber to the decor. But we now have a spiffy tabletop armillary sphere, which serves roughly the same purpose, gracing the premises. Ironically, a rudimentary, sad excuse for an armillary sphere (they probably made their own on the set) also graced the office of the chauvinistic professor in Journey to the Center of the Earth -- just to establish that he was a bona fide respectable scientist, don't you know, should the recent knighthood leave any doubt. There's a reason so many portraits from the Renaissance depicted their science-minded subjects in rooms containing such objects. Prior to the invention of the telescope, an armillary sphere was pretty much de rigeur for any astronomers aiming to determine celestial positions. Plus, they look really cool. Should we ever commission an official "portrait" of Future Spouse, you can bet we'll include our armillary sphere.

search lights in the sky

We are now well into Day 13 of the search for missing millionaire-cum-adventurer Steve Fossett, whose plane disappeared off the radar -- literally -- somewhere over the vast expanse of the Nevada wilderness. A planned three-hour private excursion turned into a immense manhunt to rescue the missing man. Dozens of aircraft have scoured a whopping 20,000 square miles, with a small army of online volunteers poring over satellite imagery, courtesy of Google and Amazon, and yet Fossett and his single-engine plane remain missing. Searchers have found wreckage from seven prior unrecorded crash sites, however -- a testament to just how difficult it can be to locate small planes in that region, a task made even more difficult by (a) an apparent malfunction in the plane's transponder/emergency locater, and (b) Fossett's failure to file a flight plan. (In fairness, it was supposed to be a very short, routine flight, and Fossett is/was a highly experienced pilot who has survived plenty of harrowing crash landings in the past.)

I don't know if the airborne searchers are employing just conventional  aerial and satellite imaging, or whether they're also making use of more innovative techniques, notably Light Detection and Ranging (LIDAR), but I hope they'll at least consider doing so, just to improve the odds that much more. LIDAR is an optical remote sensing technology that exploits the same basic principle as radar and sonar -- sending out pulses that bounce off objects and analyzing the returning signals to determine an object's distance from the source -- except it uses light wave pulses instead of radio waves. (Yes, I know, radio waves are technically just another form of electromagnetic radiation; in this instance, "light" refers to the visible and near-infrared frequencies in the spectrum.) It's not so much a replacement technology, as a complementary one -- just one more tool in our growing arsenal for remote sensing and mapping, and for finding things like Fossett's downed plane.

A LIDAR instrument transmits pulses of light to a target, and the parts of the spectra that are not absorbed by the target are reflected back (known as backscatter) to the system, which then are detected, stored and analyzed. It's the changes in the properties of the light when it scatters back that enable scientists to measure specific properties of the target. Bats use ultrasonic pulses to hunt for their prey, emitting a series of pulses that become more frequent the closer it gets to its target, climaxing in a kind of "feeding buzz" as it locks in for the kill. Similarly, the more frequent the light pulses emitted in a LIDAR system, the more information is gathered, and the more accurately a target area can be mapped. For airborne topographical mapping, as many as 33,000 laser pulses can be transmitted every second.

LIDAR has been around for quite a long time, having been invented shortly after the first lasers appeared in 1958. But the technology was a bit ahead of its time, and languished for several decades until a whole bunch of other enabling technologies emerged. Early lasers were too expensive, frankly, and too heavy, too big, and required too much power, to make them practical for airborne applications. When the solid-state diode pumped laser emerged, that changed: they were cheap, rugged, and compact, with comparably low power requirements. Computing technology also needed to advance to the point where it was fast enough, and cheap enough, to perform the kind of advanced data analysis required by a LIDAR system.

Most notably, early LIDAR systems could make accurate measurements in the centimeter range, but only for lasers fixed on the ground. This strictly limited its useful deployment, since once anyone placed a laser on a moving platform, all bets were off. Then came the Global Positioning System (GPS), and suddenly it became perfectly feasible to figure out exactly where a moving object might be in relation to a ground-based coordinate system. And LIDAR was finally dusted off and brought into the marketplace.

For remote sensing applications, the LIDAR system is mounted onto an aircraft equipped with a GPS receiver (de rigeur these days in just about any vehicle) to track its exact location and altitude. It also needs a high-accuracy inertial measurement unit (IMU) to track the pitch and roll of the airplane so that movement can be accounted for in the final analysis.  Basic physics tells us that objects spinning at a very high rate tend to maintain their relative position in space, so an IMU incorporates several spinning gyroscopes. By measuring the angle of tilt as each spins a spherical mass within a gimbal (or cage), and coupling that with an accelerometer to keep track of shifts in velocity, the system can tell us how far, how fast and in what direction a target is moving relative to a given starting point. Usually, all the data collected from the various instruments, when combined, can give an elevation that is accurate to within 6 inches.

Generally speaking, we can usually only image a feature or object roughly the same size as the wavelength of the EM radiation being used, or larger. Radio waves used in typical radar systems are great at detecting things like metallic objects -- which is why they're so useful for military and aviation applications -- but rocks or raindrops might not produce much in the way of detectable reflections at all, making them well nigh invisible to radar. But because the wavelengths used are much shorter than radio waves, LIDAR systems are much better at detecting very small objects, like particles in the atmosphere. In fact, they are already used to study atmospheric conditions, notably the densities of various particles, not to mention all kinds of emerging applications in geology, seismology, and even archeology. Also, lasers use a very narrow beam, so LIDAR allows for mapping of physical features with much higher resolution than conventional radar. It can have a "footprint" of less than 1 meter, making it possible to map the floor underneath a forest canopy, or the urban canyons between tall buildings.

There's more than one kind of LIDAR system, each suited to a specific kind of application. If you just want to measure the distance from your instrument to a solid target, range-finder LIDAR should suit your purposes just fine. If it's a moving target, and you want to figure out how fast it's moving, you'll probably want to use Doppler LIDAR, which -- as its name clearly implies -- relies on the Doppler shift effect  to determine an object's velocity. If you're a meteorologist interested in measuring the specific concentrations of chemicals and such in the atmosphere -- ozone, water vapor, and pollutants -- or if you want to map a shallow river bed underwater, you're better off using differential absorption LIDAR. Underwater imaging in particular can be difficult using infrared  and near-infrared preferred for terrestrial mapping, since water absorbs those wavelengths; only the blue-green end of the visible spectrum can penetrate water, for the most part.

Small wonder so many applications have emerged in the past decade for LIDAR systems. In geology and seismology, they're used to detect faults -- most famously, to locate the fault in Seattle, Washington -- and to measure "uplift"  at Mount St. Helen's in Oregon. (I assume this refers to plumes of ashes that the mountain occasionally burps out from time to time, which is an indication of whether its internal distress is reaching a critical eruption point.) Airborne LIDAR is used to monitor glacial melting and other coastal changes, while in forestry, LIDAR is used to study canopy heights and measure biomass, not to mention making the surveying process that much faster. On a more mundane scale, there are now handheld LIDAR systems for traffic enforcement. Whereas radar relies on Doppler shifts to directly measure speed, LIDAR actually calculates the speed, making it easier to isolate particular vehicles from a heavy stream of traffic. Remember that next time you're tempted to weave in and out of lanes at high speeds.

LIDAR has been used for search and rescue before, most notably in the wake of the terrorist attacks of September 11, 2001. For several days after the World Trade Center fell, a small plane made several passes over Ground Zero in Manhattan (and also over the damaged Pentagon in Washington, DC) taking LIDAR readings of the debris -- courtesy of a company called EarthData, which used the collected data to produce topographical images of the sites. This in turn helped rescue workers navigate the often-treacherous terrain by identifying unstable areas likely to shift or collapse. The maps also enabled building and utility workers to locate foundation-support structures, elevator shafts, basement storage areas, and so forth. As workers moved deeper into the WTC's basement wreckage, LIDAR mapping showed where the integrity of the underground walls might have been compromised, thus making those areas more at risk of flooding. The maps were even able to measure the volume of the debris and how much reach the cranes would need to efficiently remove it.   

In the realm of atmospheric studies, LIDAR systems could bring some relief to frequent fliers who have spent way too many wasted hours in airports with chronic delays (*cough* O'Hare *cough*) because our flights were grounded. Scientists at RL Associates in Pennsylvania presented a paper at the recent meeting of the Optical Society of America on their new near-infrared LIDAR system, now in its prototype phase and slated for testing in about 18 months. According to Mary Ludwig, one of the leading scientists on the project, the system will provide better images in foggy, rainy, or extremely hazy conditions, thereby making it a whole lot easier for pilots to take off an land in those conditions, as well as giving more advance warning of potentially hazardous atmospheric conditions, such as icing. This in turn could help reduce weather-related flight delays .

There are other experimental LIDAR systems for similar purposes, using visible green light to detect different kinds of particles in the atmosphere, but most commercial planes aren't equipped with such systems. Ludwig's team has developed a system that uses a polarized laser light beam, i.e., its electric field points in a specific direction. The system beams this polarized infrared light outwards, and then records the amount of polarization that returns to the sensors. The data is then processed to form an image of the ground. If need it be, it can also be translated into verbal commands. This is especially useful for atmospheric applications because ice crystals, for example, are highly depolarizing, while mere water droplets are not. Hard, manmade objects will depolarize the returning signal less than natural objects, so it's possible to get enhanced images of targets in a obscured or camouflaged environment -- say a small, crashed aircraft hidden in dense underbrush. Ergo, Ludwig et al.'s system is better at detecting different types of atmospheric particles, such as ice, supercooled liquid, or water vapor, plus it can also tell the different between water vapor and other substances (metal, or the human body, for example).

The system also incorporates something called a "range-gated detector" that is only turned on for very short periods of time, rather than continuously -- namely, whenever the return signal is expected. The detector is turned off when the laser pulse is first emitted from the system, so it doesn't pick up all the near-field backscatter from things that might be in the pulse's path to the target -- usually the major source of noise for such a system. This means there's a lot less noise in the resulting data so you get better images, particularly in foggy or hazy conditions. All of which spells welcome news for frequent airline travelers.

Perhaps the niftiest new application of LIDAR is in archeology. In England, Cambridge University is collaborating with the UK Environment Agency in the use of LIDAR imaging to produce terrain maps for large swathes of the countryside. It started out as a way of assessing flood risks, but then an organization called English Heritage contracted with the EA to conduct a LIDAR survey of Stonehenge -- one of the most studied landscapes in all of Europe, and a certified World Heritage Site. See the nifty LIDAR image of Stonehenge below, courtesy of English Heritage? How cool is that? It turns out that LIDAR is terrific for recording terrestrial features that have been leveled by many years of ploughing: the WHS survey revealed several previously unrecorded banks in and around the Stonehenge site.

LIDAR mapping isn't just about mapping positions and elevations anymore (although that's definitely the primary focus); newer systems seek to integrate other aspects of feature recognition to make map production ever more automated. A few years ago, scientists from Sweden and Italy teamed up to use LIDAR to image the various types of stone used in the construction of Lund Cathedral. Located in Sweden, the cathedral is an impressive 12-century edifice that ranks as the largest Romanesque building in northern Europe. (Whether you're impressed probably depends on your fondness for the Romanesque period.) Not only could they "see" the differences between the stone used, but they could also tell, from a distance, which of the walls had moss and lichen growing on them.

As intensity recording is incorporated into LIDAR systems, scientists should be able to improve even further on this type of analysis. Intensity recording not only measures the distance between the LIDAR and the target, but it can determine the features of a landscape based on the strength of returning signals. That's because every reflective surface will absorb some wavelengths and reflect others. A concrete block, for instance, reflects almost every wavelength and absorbs very little, so the returning signal is very strong. Leafy vegetation, however, absorbs quite a bit more of the light, and hence returns a weaker signal. These data can also be turned into a visual image.

So light and lasers are an increasingly important tool in archaeological mapping. And the innovations just keep coming. An article a couple of months ago in the San Francisco Chronicle profiled a retired civil engineer named Ben Kacyra, who invented "a camera-like device that uses lasers to scan three-dimensional objects -- such as archaeological ruins -- to create digital blueprints accurate to within a few millimeters." (You can see many such images taken with the instrument here.) At the heart of his device is a laser that emits light with sufficient power to bounce off a distant object and return to a sensor, capable of timing the intervals between signal and response. In this way, "the laser maps the surface of objects by taking millions of measurements at different angles." Sounds like a LIDAR system to me.

Kacyra's system -- which he sold to Swiss company Leica Geosystems in 2001 -- has been used to study pre-Incan Peruvian ruins, the buried Roman city of Pompeii, and the cliff dwellings of the extinct Anasazi people in southwest Colorado. And once these digital blueprints are created and stored, it becomes so much easier to recreate portions of those sites and edifices in a virtual framework -- perhaps, one day, in Second Life. Kacyra has already created a small reproduction of an ancient frieze that he scanned, using his mapping tool. As the Chronicle article put it, "Think of the archaeological equivalent of a reprint of a famous painting, a chance to hold a piece of history." Indeed. There lies the future of LIDAR.

sneak attack

Hypochondriacs must have a love/hate relationship with the TV series House. On the one hand, the nonstop parade of obscure diseases and strange symptoms that feature in every episode are like crack cocaine to a person constantly worrying that s/he has some life-threatening condition. On the other hand, the same litany of disease breeds paranoid fear that what most people would dismiss as a slight case of the sniffles is, in reality, a harbinger of a painful imminent death. I'm a fan of the show, especially Hugh Laurie's portrayal of the irascible, addicted-to-pain-killers-and-sarcasm title character, but even I sometimes find myself Googling the odd nonexistent symptom after watching a particularly unsettling episode. WebMD is my friend, oh yes...

Here's a differential diagnosis worthy of Gregory House. A patient checks into the ER complaining of mild, flu-like symptoms: fever, fatigue, body aches, headache, loss of appetite, diarrhea and/or vomiting. But there's also a slight rash. Is it flu, or the onset of Something Far More Serious? A cursory physical examination reveals a slightly enlarged liver, and swollen glands, and you note that the patient also has a mysterious slight swelling of the eyelids on one side of his face. Then he mentions he has just returned from an six-month archaeological expedition in Guatemala.

If you guessed the patient was in the initial acute phase of Chagas' disease, congratulations! You win Cyber-bragging rights at the cocktail party for, oh, at least the rest of the week. I've only just heard about Chagas' disease, having spent my science writing career covering physics rather than epidemiology (although I wrote a post on cholera back in May). But it's a fascinating disease. It gets its name from a Brazilian physician, Carlos Chagas, who discovered, in 1909, that the intestines of the Triatominae sub-family of insects, commonly known as "kissing bugs," harbored a parasitic flagellate protozoan in its gut, that he called Trypanosoma cruzi (T. cruzi for short), in honor of famed epidemiologist Oswaldo Cruz (credited with fighting off epidemics of yellow fever, smallpox and bubonic plague in Rio de Janeiro at the start of the 20th century) . Chagas conducted experiments with marmoset monkeys and squirrel monkeys and determined that the parasite could be transmitted if a subject were bitten by an infected bug.

Chagas sketched out a pretty complete description of this new infectious disease, identifying its pathogen, vector, host, symptoms, and so forth. The only aspect he got wrong was the means of infection. He assumed the parasite was transmitted into the victim's bloodstream by the actual bug bite, when in fact, it's a bit more complicated. The kissing bug is a stealthy nocturnal critter. It lurks in the nooks and crannies of  adobe homes in Mexico or the thatched roofs common in Guatemala, for example, dropping down at nightfall onto your face like a silent, Ninja assassin from above (hence Jen-Luc Piquant's Ninja attire).  The bugs are attracted to the carbon dioxide exhaled by sleeping mammals, which is why it tends to bite near the mouth (hence the nickname "kissing bug"). It's got a long, nasty-looking proboscis the better with which to pierce your skin and drink heartily of your rich, red blood. Kissing bugs are gluttonous gorgers: they'll feed for a good five minutes straight, stuffing themselves with your blood until they are twice their normal size, and then, as the final ignominy, they will leave a "fecal droplet" at the site.  Yes, they defecate. On your face. Ewww!

Okay, the droplet is mostly water, but it also contains a nasty surprise in the form of the T. cruzi  parasite, which up to that point has been comfortably ensconced in the gut of the kissing bug. You will be blissfully unaware of all this as you sleep, of course, and in the morning will rub your eyes, wipe your mouth, maybe scratch at a slight itchy spot on your face --  and the parasite enters your bloodstream.  You become  one of between 16 and 18 million infected persons worldwide, most (as many as 11 million, according to the Center for Disease Control) residing in Mexico, Central America, and South America, and most of whom won't even know they're infected until the disease eventually kills them. Charles Darwin is suspected to have suffered from the disease, recording being bitten by the Great Black Bug of the Pampas in The Voyage of the Beagle. A year after returning to England (1837), he began to suffer from odd symptoms consistent with chronic Chagas' disease, which continued for the rest of his life.

It's also possible to acquire the parasite through eating uncooked food contaminated with the feces of infected bugs; from a pregnant woman to her baby (although breastfeeding after birth is safe, unless the mother has cracked nipples of blood in the breast milk); via organ transplantation; and via infected blood transfusions. In fact, the FDA just approved new tests last December for screening units of blood for Chagas' disease. Estimates vary, but between 100,000 to 500,000 people in the US are infected already,  mostly immigrants. In Los Angeles, with such a large immigrant population hailing from Central and South America, the chances of getting a unit of potentially infected blood is a whopping 1 in 2000. I say, bring on the more stringent blood screening tests. Because make no mistake: Chagas' disease is  nasty, killing some 50,000 people each year.

The good news for our fictitious patient is that the early acute phase is quite treatable with conventional antiparasitic remedies if it's caught right away, although in rare cases, infants may die from swelling of the brain if there's a delay in treatment. The news is not so good if the patient dismissed his symptoms as "just the flu" (something I would totally do, being of the "It's just a flesh wound" mental framework when it comes to my own health).

That's because the acute phase runs its course within a couple of weeks, and he will then enter the chronic phase of the disease, which is much sneakier, and far more deadly in the long run. He might not have another symptom for the next 10 years or so, but gradually he will develop cardiac complications (an enlarged heart, arrhythmia, even sudden cardiac arrest), as well as intestinal complications (enlarged esophagus or colon) and in rare cases, neurological difficulties such as swelling of the brain and/or dementia. The available treatments for the chronic phase tend to be highly toxic, and ineffective. Jack Hitt, writing about Chagas' disease for the New York Times in 2001, described the initial "symptom" as "a slight itching on your face. When you scratch, you rub the parasite into the tiny wound nearby. Twenty years later... your heart will explode." Or your intestines will rupture. And all because of a seemingly innocuous occurrence of a single bug bite. You might want to rethink that planned excursion to Central America.

Several countries managed to pretty much eradicate Chagas' disease for awhile by spraying rural areas with massive amounts of pesticides, most notably in Guatemala and Argentina. But the toxic pesticides brought the bad with the good: in Guatemala, rates of pediatric asthma are much higher in homes treated with pesticides, with corresponding higher rates of neurological effects like weakness and numbness. Pesticides are also a bit on the pricey side for the average developing country -- or even an otherwise prosperous country fallen on hard times, like the economic crash of Argentina around 2000. Faced with tough decisions on where to spend its limited funds, the government cut back on the pesticide program. The result: increasing cases of Chagas' disease are showing up, particularly in the Grand Chaco region. Even worse, the insects gradually develop resistance to the pesticides, making them far less effective.

So pesticides work as a short-term fix, nothing more, which is why scientists are keen on finding an alternative control measure, preferably one that focuses on the transmission phase, rather than just wiping out the kissing bugs (who, after all, aren't inflicting their gut parasites on us in malice). Enter Ravi Durvasula, an associate professor of medicine at the University of New Mexico, who's been working the problem for almost a decade now, and come up with a truly ingenious strategy for combatin