Cocktail Party Physics

REPOST: a pirate's life for me

[NOTE: We are seriously under the weather and hence original posting must wait until this godawful headache subsides. "Bring on the magic mushrooms!" sez Jen-Luc Piquant, although we are not quite that desperate. Yet. In the meantime, we feel the need to indulge in silliness, and offer this repost on the science of pirates. Yeah, you heard me: science and pirates!]

If you're anything like me, you thrilled to Johnny Depp's glorious performance as the winsome, piratical rogue, Captain Jack Sparrow, in 2003's Pirates of the Caribbean. In fact, last summer Jen-Luc Piquant and I were waiting on tenterhooks for the next installment in the ongoing saga, Dead Man's Chest, to arrive in the DC area, even though Jen-Luc correctly pointed out that it's a rare case when sequels live up to the original. (She held out no hope whatsoever for the third installment, and if the reviews are accurate, she was right.)

Still, what is it about pirates that holds such universal appeal, for all of us, not just for the lovely Elizabeth Swann? Jen-Luc maintains its all about "the look" -- swashbuckling boots, colorful jacket and bandanna, a jaunty eye patch -- and has adapted her own personal style for the occasion. I would make the case that it's the salty pirate speech; in fact, you can translate this entire blog post into Pirate-Speak by clicking on this link and typing in the appropriate URL. (It's also amusing to type in the URL of, say, the typically fusty George Will's latest column; his conservative musings take on an entirely different flavor when rendered in Pirate Speak.)

British comedic author Gideon DeFoe tackles this very issue in the opening chapter of his most excellent book, Pirates! In an Adventure with Scientists. (The paperback version just released in the US comes bound together with DeFoe's own sequel, Pirates! In an Adventure with Ahab, but in this post, we're focusing on the scientists, for obvious reasons.) The pirates in question, those scurvy knaves, are lolling about the deck of their ship, debating the best thing about being a pirate. One says the looting, another marooning, still another sings the praises of pirate grog, and a fourth insists it's the Spanish Main. A brawl inevitably develops, cut short by the appearance of the Pirate Captain, who settles the dispute by declaring that the best part of being a pirate is... the sea shanties.

This might be a good place to point out that the Pirate Captain is not the brightest bulb in the Yuletide tree, and that pirates are not known for their sophisticated musical tastes. DeFoe's book, however, is bloody brilliant. Sure, it has a silly premise: the pirates mistakenly loot the H.M.S. Beagle -- on its second voyage, to the Galapagos Islands, circa 1831 -- believing it to be carrying gold rather than exotic natural specimens. (Note that Jen-Luc has adopted a cute little lizard rather than the customary parrot, in keeping with the Galapagos theme.) They sink the ship, and feel kinda bad about it. So they agree to transport Charles Darwin, Captain Robert FitzRoy, and Mister Bobo (Darwin's trained "Man-Panzee") back to Victorian London.

Like I said, a silly premise. But DeFoe includes fascinating factual tidbits in the footnotes, so he's no slouch when it comes to history, scientific or otherwise. According to one footnote, Darwin memorably described the Beagle voyage in a letter as being "one continual puke." There is also a footnoted mention of John Venn (born in 1834, a few years after the book's events supposedly took place), a British logician and philosopher best known for introducing "Venn diagrams" around 1881. It's nice to see such a fine meshing of silliness with snippets of serious science, even if the price is an occasional anachronism. It's all in the name of good clean fun. And did I mention there's a feisty damsel in distress named Jennifer, who ends up joining the pirate crew? Really, what's not to love in such a book?

In the course of their adventure, the pirates crash London's Royal Society, donning pens, rulers and white lab coats to disguise themselves as scientists. The pirates show an uncanny knack for engaging in scientific discourse, "nodding politely and saying 'Really?' a lot as they listened to [the scientists] drone on about their latest inventions and discoveries." Sounds like the average scientific press conference, doesn't it? Personally, I think the technical sessions at meetings would be livened signficantly if the speakers were clad in Pirate garb. They should also be armed with cutlasses so they could -- as the Pirate Captain is wont to do -- use said weapons to run through any especially obstrepterous colleagues in the assembly.

A bit of the science behind nautical navigation is to be expected, of course. The Pirate Captain's cabin is equipped not just with the usual nautical maps and charts, but also an astrolabe. Astrolabes are very ancient instruments -- possibly dating as far back as the Second Century, B.C. -- for determining the time and position of the stars in the sky. They were mostly used in astronomical studies, not for navigation, but there was a mariner's astrolabe, a simple ring marked in degrees for measuring celestial altitudes.

In DeFoe's book, the Captain likes to fiddle with his astrolabe for show, pretending he can carry out complex calculations in the midst of casual conversation, but he isn't entirely sure of the difference between an astrolabe and a sextant. The sextant wasn't invented until the 18th century, and quickly displaced the mariner's astrolabe for navigational purposes because it was much more precise. A sextant measures the angle of elevation of a celestial object above the horizon. Using this angle, combined with the time of measurement, enables the navigator to calculate a precise position line on a nautical chart. For example, a sextant could be used to sight the sun at high noon in order to determine one's latitude. Hold the thing horizontally, and you can measure the angle between any two objects: say, a couple of lighthouses, giant Galapagos sea turtles, or mermaids lazily sunning themselves on conveniently located boulders.

There's also mention of the famous Beaufort wind force scale, a 19th century means of empirically describing wind intensity based on observed sea conditions. It was the brainchild of Sir Francis Beaufort, a British naval officer and friend of Darwin who sought to remove the subjective measures for windy weather observations at sea by describing wind conditions according to the effect on the sails of a man of war, then the main ship of the Royal Navy. The original Beaufort scale ranged from 0 to 12 (later extended to 16), and its descriptions ranged from "just sufficient to give steerage" to "that which no canvas can withstand." As the albino pirate correctly points out, a Beaufort scale ranking of 6 would be a "strong breeze," while 8 would indicate a "fresh gale" -- or, per the Pirate Captain, "that which will make a pirate's trousers billow about so it looks like he has fat legs." (Hurricanes, in case you're interested, begin at 12 on the Beaufort scale, which corresponds to a Category 1 hurricane on the modern Saffir-Simpson Hurricane Scale. Even as far back as 1712, the Caribbean and Gulf of Mexico were beset by hurricanes. That year, according to DeFoe's informative footnote, a single storm destroyed some 38 ships moored in Port Royal's harbor.)

Beaufort isn't the only historical personage to make a cameo appearance in DeFoe's novel. FitzRoy really did captain the Beagle and select Darwin as the onboard naturalist, despite purportedly not liking the shape of Darwin's nose. (Hey, that could get really irritating on a long sea voyage, particularly on a tiny ship like the Beagle, which was a mere 90 feet long.) He was an amateur meteorologist, eventually heading the British Meteorological Department and pioneering the printing of a daily weather forecast in newspapers. Alas, the unfortunate FitzRoy did indeed commit suicide in 1865 by slitting his own throat, ostensibly in a fit of depression over not being selected as Chief Naval Officer in the Marine Department.

And while crashing the Royal Society, the pirates encounter James Glaisher, an English meteorologist who tells them of his passion for "lighter-than-air" ships, a.k.a. "dirigibles." The concept dates back to 18th century France, when the Mongolfier brothers (paper makers by trade) noticed that smoke from a fire built under a paper bag would cause the bag to rise into the air. The science behind this is simple: the hot air inside expanded, and thus weighed less, by volume, than the surrounding air. The Mongolfiers built the first hot-air balloons around 1782. Another Frenchman, Henri Giffard, built the first dirigible, inflated with hydrogen, a gas that is naturally lighter than air at normal temperatures. Alas, as the 1937 Hindenburg disaster revealed, hydrogen is also highly flammable; modern airships use helium, an "unburnable" gas.

Glaisher was indeed a pioneering balloonist, making numerous ascents between 1862 and 1866 to measure the temperature and humidity of the atmosphere at the highest possible levels. On one such flight, he and his pilot, Henry Coxwell, set a world record of 29,000 feet, nearly losing their lives in the process. Glaisher passed out from the lack of oxygen, while Coxwell's hands were so stiff with cold he could barely manage to free a tangled valve and thereby halt their ascent to even higher (and more deadly) altitudes. (An artist's rendition of Glaisher's harrowing experience can be seen at right.) They still hold a few world records in this area -- not that this was Glaisher's primary motivation, nosiree. As the fictional Glaisher explains to DeFoe's assembled pirates, "What is science for? Pushing back frontiers! The thrill of discovery! Advancing the sum total of human knowledge and endeavour! And looking down ladies' tops!"

I actually learned something new from DeFoe's footnotes regarding dirigibles, namely, that helium wasn't technically "discovered" on earth until about 1895, despite being abundant in the universe. I also learned that America, in particular, faces a looming helium shortage. It turns out that almost all of the global supply of helium is located within 250 miles of Amarillo, Texas; it's distilled from accumulated natural gas, extracted during the refining process. Since the 1920s, the US has considered its helium stockpile as an important strategic natural resource, amassing some 32 billion cubic feet in an underground bunker in Texas, but now, it's selling off that stockpile bit by bit to interested industrial buyers.

Helium is used for arc welding and leak detection, mostly, although NASA uses it to pressurize space shuttle fuel tanks. Liquid helium cools infrared detectors, nuclear reactors, and the superconducting magnets used in MRI machines, too. The fear is that, at current consumption rates, that underground bunker will be empty within 20 years, leaving the earth almost helium-free by the end of the 21st century. This could be bad for US industry, not to mention future patients in need of MRI diagnostics. It's also bodes ill for the prospect of fusion using helium-3, a rare isotope that is missing a neutron. Physicists have yet to achieve pure helium-3 fusion, but if they did, we'd have a clean, virtually infinite power source. Or so the theory goes. Still there is hope: the moon's lunar soil is chock-full of helium reserves, thanks to the solar wind. In fact, every star emits helium constantly, suggesting that one day, spaceships will carry on a brisk import and export trade to harvest this critical element. And I daresay it will pave the way for a lucrative "space pirate" business as well.

Perhaps my favorite scene is when the Pirate Captain chases a villainous Bishop through London's Natural History Museum. The latter flings armloads of trilobites culled from the display cases at him, and when the chase moves to the Mineral Room, both men resort to projectiles of various mineral elements, choosing them according to atomic weight. For example, the Bishop hurls a chunk of iron (atomic weight: 55.85), and the Pirate Captain counters with a chunk of nickel (atomic weight: 58.69). Really, how many authors who write silly books about pirates can rattle off the atomic number (44) and atomic weight (101.07) of a rare transition metal like ruthenium? (Jen-Luc pipes in with the pointless information that trace amounts of ruthenium are often added to titanium to improve its corrosion resistance.) Or osmium -- atomic weight: 190.2 -- for that matter?

A few winks at Darwin's expense are inevitable. To make room for Darwin and his crew on the pirate ship, the Pirate Captain makes a few crew members walk the plank. When Darwin objects to the brutality, the Pirate Captain assures him that only "fools and lubbers" would be sacrificed, concluding, "It's for the good of the species." And upon arriving in London, and visiting the Royal Society, the Pirate Captain nobly puts his gift of showmanship to work on Darwin's behalf, assuring the young naturalist that good science isn't enough: "You need a gimmick! A bit of controversy! It's all about the presentation."

These days, of course, Darwin doesn't want for controversy, as that thinly-veiled form of creationism, Intelligent Design, simply refuses to die in school districts across the country. When On the Origin of the Species was first published, Darwin wasn't especially surprised that people -- even his fellow naturalists -- resisted many of his conclusions; there's a letter now up for auction by Sotheby's of London that says as much. But I think he'd be more than a little dismayed to see how people continue to resist the modern theory of evolution, in the face of overwhelming scientific evidence to support it. There's certainly no debate among respected scientists: just last week, the national academies of some 67 countries issued a joint statement urging schools, parents, teachers, etc. to stop denying the scientific facts of the origin and evolution of life on earth.

The problem is that evolution has been vilified as a lie propounded by godless heathens -- you know, like P.Z. Myers, who routinely incurs the ire of Believers (not just Creationists, either) with his staunch scientific atheism. In fact, there's a big brouhaha fomenting over at P.Z.'s blog right now over his stance on science and religion, specifically over his recent post about whether it's possible for any good scientist to be anything other than an atheist. P.Z. might have a sharp-ish way of expressing himself at times, but it's pretty tough to argue with the sense of this comment:

If a scientist applies the same kind of critical thinking she uses in her work to religion, she gets the same answer an atheist does.... [S]he doesn't have to apply that kind of thinking to every aspect of her life, of course, and none of us do. If she wants to claim she's happy to be a Presbyterian and accepts it as a matter of simple faith, there is no argument, the case is closed, and she can go about her business unhassled by science.

(Admit it, now you're just dying to hop on over there and see for yourself. But please -- not before you finish this post.)

Darwin himself, it should be noted, wasn't an atheist; he described himself in his autobiography as a theist at the time of writing Origin of the Species, although by then he had summarily rejected William Paley's famed "argument from design" which had so influenced him in his youth. In his later years, Darwin was resolutely irreligious, moving firmly into the agnostic camp by the time he died. But he never seemed to feel there was much conflict between science and religion provided -- and this is a critical proviso -- that religion remained a strictly personal matter and was kept separate from science. For Darwin, "the question of god's existence was outside the scope of scientific inquiry."

That seems an eminently sensible viewpoint. Unfortunately, lots of people seem incapable of making these critical distinctions, which is why we end up with situations like the controversy that erupted over setting science standards in Kansas, for example, or the recent landmark court case in Dover, Pennsylvania. That decision stated unequivocally that Intelligent Design was not a science, and should not be included in the science standards set by state Boards of Education. It doesn't get more clear than that, yet the manufactured "controversy" rages on. What's it gonna take to stamp out this pseudo-scientific nonsense once and for all?

We could always make the particularly pig-headed walk the proverbial plank: natural selection in practice, not just theory. Or perhaps scientists should follow the Pirate Captain's lead in DeFoe's novel, and stage a WWF-style showdown between science -- represented in the novel by Darwin's Man-Panzee, Mister Bobo -- and religion, personified by the "Holy Ghost" (actually a pirate named Scurvy Jake in disguise). "The science you are doing is too shocking by half!" the Holy Ghost declares with righteous indignation. "I will lay the smackdown on your wicked ways!" Then Mister Bobo hits him over the head with a folding chair, knocking him out cold, and is declared the victor. See? Science always triumphs in the end. Darwin becomes the toast of London and quite a favorite with the ladies, while Mister Bobo gets featured on the cover of Nature. It's as good a strategy for combating Intelligent Design as any. I say let's set up a booking in Vegas right now and put the smackdown on pseudoscience.

down the rabbit hole

While vast numbers of Angelenos stormed the malls in search of holiday shopping bargains over the weekend, the Spousal Unit and I attempted to inject a bit of culture into our Saturday evening by meeting local pals at the Los Angeles County Museum of Art to take in the new Salvador Dali retrospective. Dali is my favorite of the Surrealist painters, but the experience proved even more surreal than expected. Also shorter. I never made it past the halfway point of the exhibit, thanks to a sudden onset of illness. (Yes, I'd been feeling odd earlier. I just didn't realize I was getting genuinely sick.) I was standing there, taking in the dream-like imagery of early sketches and paintings and intermittently watching dueling film screens showing Un Chien Andalou (really disturbing stuff!) and L'Age d'Or, when there was a roaring in my ears and the images started blurring together into a kaleidoscope of color. I barely made it to the ladies' room without passing out. The Spousal Unit gallantly took me home shortly thereafter, whereupon I proceeded to sleep for the next 14 hours.

In retrospect, it was rather fitting that I saw the exhibit (okay, the first half of it) in what amounted to a semi-fugue state, since Dali incorporated his own dream-like imagery in his paintings -- clearly much more Freudian and twisted than my own dreams, which tend to focus on more mundane frustrations, like trying to pack in time for a flight. (This might explain why I am a science writer with a practical bent, rather than a famous Surrealist painter.) The only thing that might have been more appropriate would have been to view the exhibit while under the influence of LSD or magic mushrooms. Speculation about Dali's possible use of LSD or 'shrooms abounds, but LSD didn't appear on the scene until the late 1930s,  and didn't become popular until the 1960s. Dali's paintings were weird long before that. The artist liked to experiment, but didn't advocate habitual drug use: "Everyone should eat hashhish, but only once," he observed. He didn't need drugs to be creative. As he once wrote to LSD advocate Timothy Leary, "Why do you need LSD, when you have Salvador Dali?" Leary himself admitted that Dali was "the only person who can paint LSD without having to take LSD."

Personally, I have never dropped acid, or eaten magic mushrooms, or ever done much in the way of drugs apart from a few exploratory puffs of marijuana in college -- not for moral reasons, it just didn't interest me. I was more about exploring and experiencing reality than escaping it, and I suspect Dali was, too. This was a man with a powerful lust for life -- maybe a bit too powerful at times. But his passion and appetites extended beyond the physical to the intellectual: early on, he was devoutly Freudian, clearly evidenced in his paintings from that era, but he was also fascinated by mathematics, geometry, and physics. The famed melting clocks in The Persistence of Memory may have been at least partially inspired by Einstein's theory of relativity (time is relative, not absolute), and in the 1950s, Freud was supplanted by Werner Heisenberg (particularly the Uncertainty Principle) as Dali's intellectual father-figure: Dali painted The Disintegration of the Persistence of Memory in 1954 to symbolize that transition from his early to his later work. (The painting almost looks like it's being quantized.) He was one of the first modern artists to incorporate holography into his work, and also experimented with visual representations of a fourth spatial dimension.

And if his comments about hashhish are to be believed, he also had an interest in chemistry. I wasn't able to find any record about whether Dali ever tried LSD, but I wouldn't be surprised if he had -- just once. It's a fascinating substance in its own right. Technically, it's lysergic acid diethylamide, a member of the tryptamine drug family. It's derived from ergot, a grain fungus commonly found on rye, and was first synthesized in 1938 by a Swiss chemist named Albert Hoffman. He wasn't looking for psychedelic drugs; initially, at least, he had hopes that it could be used as a circulatory and respiratory stimulant. (He did eventually develop another ergot derivative that became a widely used medication in obstetrics, called Methergine.) However, animal tests showed no such effects -- although he did notice that the animals became "restless" under the compound's influence.

Hoffman didn't realize what he'd synthesized for another five years, when he accidentally absorbed some of the compound through his skin. He became dizzy (just like me in the Dali exhibit... hmmm...), went home to bed, and experienced a "dreamlike state" filled with intense, kaleidoscopic colors and "extraordinary shapes." Those effects were just from trace amounts of the stuff. Three days later, Hoffman repeated the experiment with a much larger dose of 150 micrograms (20-30 micrograms is sufficient to cause mild effects).

That day -- April 19, 1943 -- became known in his journals as Bicycle Day, because Hoffman was so incapacitated by the dosage that he had to ask his lab assistant to give him a ride home on the latter's bike. Hoffman had a pretty bad trip to start with, becoming convinced he was demon-possessed, that his next-door neighbor was a witch, or that he had gone insane, but after a few hours, the pleasant pretty images and psychedelic colors returned, along with a bit of synesthesia: he wrote that every sound was transformed into optical perceptions. And far from being hungover the next day, he was a bit tired, but cheerful and optimistic, with heightened senses.

Hoffman's discovery was initially embraced as a possible drug treatment for mental illness, most notably schizophrenia, but by the 1950s this proposed connection had been disproved. The CIA notoriously -- and controversially, since the subjects didn't know they were participating in such a trial -- experimented with LSD as a possible mind control drug during the Cold War, eventually concluding that it was of little practical use in that application. (So did the British government; in fact, one 19-year-old British test subject reported seeing "walls melting, cracks appearing in people's faces... eyes would run down cheeks, Salvador-Dali-type faces...")

It wasn't until 1961 that Leary, then a psychology professor at Harvard, and his colleague Richard Alpert, brought the substance into the popular culture at large. They conducted a study of 400 test subjects who were administered LSD, and noted that 90% wanted to repeat the experience, 83% said they had "learned something or had insight," and 62% believed the experience had changed their life for the better. As Leary and Alpert delved deeper into the drug's effects, they became less about the science, and more about spiritual enlightenment, turning into hallucinogenic gurus of the Flower Power movement with their slogan, "Turn on, tune in, drop out." By 1971, LSD had been banned in the US, even for scientific study, and many other countries followed suit.

And yet, LSD has, if not exactly flourished, done a pretty brisk business over the years, maybe because it's pretty easy to make. You just take the liquid solution and spray it onto a substrate of some kind. Initially, people soaked sugar cubes in the substance, and then started encapsulating the LSD in pill form. Next came thin squares of gelatin, dubbed "windowpanes," and finally, makers hit on the idea of using blotter paper: sheets of paper soaked in LSD, which is dried and cut into small individually dosed squares that the user could simply pop onto his/her tongue, or swallow. This approach appealed artistically, as well, since the various distributors could print their own unique designs on the blotter paper -- kind of a trademark, or signature. LSD-related blotter paper is kind of an art form all its own

For all its reputation, LSD isn't particularly addictive. Most users are young (18-25), and their interest quickly wanes, especially if they have a bad trip. Tobacco, cocaine, and alcohol produce far more addictive behaviors. True, LSD is powerful stuff: a single dose between 100 and 500 micrograms, about one-tenth the mass of a grain of sand, is sufficient to induce several hours of psychedelic visions. But while people may be injured while under its influence, there are currently no fatalities on record directly attributable to an overdose of the drug. We always hear about LSD-related flashbacks, but there is evidence that these tend to occur primarily in those already prone to some psychological problems. And the tales that LSD crystallizes in spinal fluid or in fat cells where it can dislodge and cause nasty flashbacks many years later isn't supported by medical evidence. LSD breaks down completely in the body within hours, and any metabolites are purged within a few days.

In fact, there is evidence that it might be an effective treatment for cluster headaches. (This was actually featured in an episode of House, wherein magic mushrooms were used to treat the cluster headaches of a young chess champion.) Cluster headaches are like migraines, only much, much worse: they are characterized by excruciating pain that can last from 15 minutes to three hours, and attacks can occur anywhere from two to eight times a day in the midst of a cycle. Peter Goadsby, the world's leading researcher on cluster headaches, has described the pain as being "worse than natural childbirth or even amputation without anesthetic." Given that, and the profound ineffectiveness of most conventional drug therapies to date, it's not surprising that chronic sufferers are turning to illicit substances like LSD and magic mushrooms (technically, psilocybin).

The Multidisciplinary Association for Psychedelic Studies (MAPS) supported one of the first scientific studies of this reported efficacy, conducted by Andrew Sewell and John Halpern of the Alcohol and Drug Abuse Research Center at McLean Hospital in Belmont Massachusetts. It's affiliated with Harvard, where Leary and Alpert did their controversial LSD research in the early 1960s, but the similarities end there. Sewell and Halpern show no signs of turning into New Age gurus of any sort; they're interested in the science. They interviewed over 50 sufferers of cluster headaches who admitted to self-treating with psychedelics to alleviate their symptoms (medical records verified that those studied did indeed have the condition). And they found that ingesting psilocybin or LSD reduced cluster headache pain, and even could interrupt cluster headache cycles to that no more headaches occurred. Eighty-five percent said that the illegal drugs aborted attacks, stopping them altogether in 52% of those surveyed.

The study is admittedly flawed in its design, since there are so many potential sources of bias, but Sewell and Halpern think their findings warrant greater study, and applied to the FDA for permission to conduct a randomized, double-blind, carefully controlled experimental study of the effects of LSD and psilocybin on cluster headaches. No one is quite sure why the drugs might be effective, but the working hypothesis is that LSD and psilocybin are both tryptamines, with chemical structures very similar to natural neurotransmitters like serotonin. MAPS is partially funding the study, as well as investigations into psilocybin as a treatment for obsessive-compulsive disorder, or ecstasy as a treatment for post-traumatic stress disorder. Not surprising, MAPS describes itself as "a nonprofit alliance of scientists and campaigners that funds research into the benefits of psychoactive drugs, and lobbies for changes in US laws." I guess we'll all have to stay tuned in to see what transpires next.

All that research into LSD from my sickbed (*cough, moan*) made me grateful that I don't suffer from cluster headaches, and placed my own mild discomfort and general wooziness into proper perspective. And I'm almost feeling back to my normal self, although that might partly be due to euphoria over the shiny new iPhone the Spousal Unit purchased for me as an early Christmas present. That, and plying me with bowls of chicken soup and pomegranate juice, seems to have kicked that nasty ol' virus to the curb. We have the bestest Spousal Unit ever. Now I can answer email, make calls, and download nifty YouTube videos, like this clip of the incomparable Grace Slick performing "White Rabbit" with Jefferson Airplane -- a song she has publicly admitted is in part about LSD, albeit mostly inspired by (and openly alluding to) Lewis Carroll:

One pill makes you larger
And one pill makes you small
And the ones that mother gives you
Don't do anything at all
Go ask Alice
When she's ten feet tall

And if you go chasing rabbits
And you know you're going to fall
Tell 'em a hookah smoking caterpillar
Has given you the call
Recall Alice
When she was just small

When men on the chessboard
Get up and tell you where to go
And you've just had some kind of mushroom
And your mind is moving low
Go ask Alice
I think she'll know

When logic and proportion
Have fallen sloppy dead
And the White Knight is talking backwards
And the Red Queen's "off with her head!"
Remember what the dormouse said:
Feed your head*

*Actually, the Dormouse never said that, per Chapter XI of Alice in Wonderland: "'But what did the Dormouse say?' one of the jury asked. 'That I can't remember,' said the Hatter." So the Divine Ms. Grace took some artistic liberties.

asphalt jungle

In 1769, Gaspar Portola, the Spanish governor of Baja California, led an excursion across the Los Angeles River and down what is now Wilshire Boulevard in modern-day La-La Land. According to a journal kept by one of the expedition members -- a priest named Juan Crespi -- the travelers "saw some large marshes of a certain substance like pitch, they were boiling and bubbling... and there is such an abundance of it that would serve to caulk many ships." This is the first recorded sighting of the famed La Brea Tar Pits.

The landscape has changed a bit since then. Okay, it's changed a lot. Shortly after I moved to Los Angeles this past April, we were driving down Wilshire Boulevard en route to the city's high-end shopping mecca, Rodeo Drive, when we passed a sign reading "La Brea Tar Pits." Initially I assumed it was an advertisement, but the Spousal Unit assured me that no, in fact, the tar pits were right there, just off Wilshire, and couldn't I detect that telltale whiff of methane in the air? So one of the most well-known U.S. sites for paleontological fossils is located smack in the middle of suburban sprawl, amid condominium complexes, a Rite-Aid, and various fast food joints like Baja Fresh, Koo Koo Roo and IHoP. You can admire the pretty Pleistocene fossils, then pop on over to LA's Disney-esque shopping complex, The Grove, stopping off at Whole Foods for some organic produce on the way home.

You'd think that with the place so close, and me being such a big science geek and all, it would be one of the first places I'd visit. Alas, you'd be wrong. We didn't get around to visiting the La Brea Tar Pits and accompanying Page Museum until last weekend, when fellow physics blogger Chuck (a.k.a., that lounging Lab Lemming from the Land of Oz) blew through town with his family, on their way to visit relatives elsewhere in the U.S.  We had a great time strolling through the exhibits, admiring the rather seedy (by now) animatronic mammoth, and placing bets on whether the ground sloth or the saber-toothed tiger would win their sculpted pitched battle. True, they are frozen in time in the Page Museum, but I maintain that the tiger is on the verge of victory: its enormous canines are in the perfect position to rip out the sloth's jugular.

Technically, that substance oozing out of the ground in Hancock Park isn't really tar (a byproduct of the distillation of coal or peat); it's asphalt, the lowest grade of crude oil. The bubbling is due to methane gas, a byproduct of the decomposing remains of plants and animals trapped in the pits, which turn into crude oil. Which explains the origins of the large petroleum reservoir, the Salt Lake Oil field, located just below the surface, north of Hancock Park. According to the museum's various informative placards, the oil was formed from marine plankton that found themselves summarily deposited in an ocean basin between 5 and 25 million years ago, and eventually time and pressure converted that organic matter into oil. Beginning some 40,000 years ago, petroleum began seeping to the surface around Hancock Park, forming hundreds of sticky pools of ooze. And the La Brea Tar Pits were born.

Anyway, for tens of thousands of years, animals would come sniffing around the pits -- usually predators and scavengers drawn by animals already trapped in the tar, thinking them easy prey -- and would in turn become trapped in the sticky ooze themselves. They would gradually get sucked down into the pit and asphyxiate, and over time their remains became fossilized as the lighter fractions of the petroleum evaporated, leaving the bones trapped in a more solid substance. And there they stayed, awaiting discovery by modern archaeologists thousands of years later. The centerpiece of the La Brea grounds is a large Lake Pit outside, where methane gas still bubbles to the surface every few minutes or so, making the whole place smell like freshly laid asphalt. To capture the tragedy of senseless animal deaths, traumatizing young children in the process, the Lake Pit also features a diorama of a mammoth vainly struggling to free itself from the  muck, while what can only assume are its mammoth-y family members look on in helpless horror.

One might be forgiven for thinking, "C'mon, how hard can it be to get out of a tar pit?" After all, Arnold Schwarzenegger fell into the tar pits in Last Action Hero and just swam out and wiped himself clean. The museum knows we're thinking this, and has helpfully set up a terrific hands-on demonstration of just how sticky this gooey stuff really is. We struggled mightily to pull metal plungers of different sizes and weights out of a vat of molten asphalt. Point taken. And the pits have their own form of camouflage, since they're covered by a layer of water, or dirt, or dust. It would be very easy to think you were just strolling through a marshy sort of puddle, and suddenly find, too late, that there's sticky asphalt underneath.

The local Native Americans used the sticky asphalt as a glue and to waterproof their baskets and canoes. When Westerners arrived, they mined the tar and used it as a roofing material. From the beginning, bones were occasionally found in the tar, usually dismissed as belonging to unfortunate cattle who'd become trapped in the pits. It was not until 1875 that the geologist William Denton visited the tar pits and identified the canine tooth of a saber-toothed cat. The rest of the scientific community just ignored his conclusion. Timing is everything, and Denton was too far ahead of the curve. The first bona fide scientific excavation of the pits didn't begin until 1901, when William W. Orcutt, a geologist who was investigating oil resources in the vicinity, noted that the bones in the asphalt seeps belonged to many extinct species.  

And so the pillaging of these priceless artifacts began. Between 1905 and 1915, literally millions of bones were taken out of the ground. In 1913, the landowner, George Alan Hancock, feared that the fossils would be taken from the community and scattered widely. So he granted exclusive rights to excavate the fossil resources to Los Angeles County’s fledgling Natural History Museum—but only for two years. Between 1913 and 1915, museum crews made nearly a hundred excavations, collecting roughly a million bones. The work was messy, and not without its perils: excavators used boiling kerosene to clean the sticky bones, which would sometimes accidentally catch fire and singe the eyebrows of workers. But it was worth it. In all, the species count from the excavations in the early 1900s included 133 birds, 63 insects, 43 mammals, and 29 plants, plus a handful of amphibian, mollusk, reptile, and water flea species.

Surprisingly, there's a lot more fossils of carnivores and predators than there are of herbivores -- roughly 9:1, nowhere near the ratio most likely typical of the animal population living in the area back then. Scientists think it's because of the aforementioned hypothesis that predators and scavengers were drawn to the scent of trapped, rotting corpses and became trapped themselves. That's the prevailing hypothesis among scientists, although predictably, those wacky Young Earth Creationists maintain that the tar pits are evidence of a global flood. Noah's Ark totally happened, dude! Just like in Evan Almighty! By their "logic" (note judicious use of scare quotes to indicate sarcasm), the high ratio of carnivore fossils is due to the fact that theyw ere carried there from somewhere else by a huge flow of water. The fact that the tar pits date back some 40,000 years and are therefore older than the supposed Young Earth by a factor of 4, is considered to be a trifling dating error, or some mischievous test of faith by the Deity. Sigh.

Anyway, the animals didn't seem to learn from their mistakes, which could explain why they eventually became extinct: camels, mammoths, mastodons, long-horned bison, and the saber-toothed cat are no longer found in North America, and Chuck informed me (and the museum exhibit confirmed) that the horse, originally native to the area, died out and was introduced to the region by Spanish settlers. The dire wolf, in particular, seems to have been a bit lacking on the brain trust front: skulls and fossilized remains of the dire wolf are among the most common finds in the La Brea tar pits (over 3000 found to date, and still counting), and the Page Museum has an entire wall displaying nothing but hundreds of dire wolf skulls recovered over the years.

There's one species that is not well represented among the fossilized remains recovered from the tar pits: homo sapiens. You'd never know that from how often the tar pits feature in various thrillers and murder mysteries. For instance, in the forgettable 1990 film Bad Influence, the two men try to cover up a murder committed by a third friend -- why? misplaced guy loyalty, I guess -- by tossing the dead woman into the La Brea tar pits, where she is discovered the following day. In fact, there has been only one human being recovered from the pits, known as La Brea Woman; carbon dating revealed she died some 9000 years ago. Technically, just her skull and a few other bones were recovered, and even so, the femur was stolen in the 1970s while the remains were in transit from their original home at the Natural History Museum to the newly constructed Page Museum. (Jen-Luc Piquant wonders aloud what kind of sick mind would steal a fossilized femur, and then recalls that her pal El Finster brazenly sports a bona fide human skull on his bookshelf. Authorities might want to check his office for any missing fossilized remains.)

Anyway, scientists believe La Brea Woman didn't end up in the tar by accident: there's strong circumstantial evidence that she was murdered, her skull bashed in with a blunt instrument, most likely with an artifact conveniently found a few inches from where her skull was found. This makes her the first documented murder victim in Los Angeles. They killed her little dog, too: canine bones were also found near her remains. Other than that, very little is known about La Brea Woman; the most extensive discussion I could find was this 2006 article in the Los Angeles Times by Amy Wilentz. That's where I learned that the museum used to have an exhibit devoted entirely to La Brea Woman until just a few years ago, when the curator decided to remove it amid concerns of offending local Native Americans. Like many of the exhibits in this woefully under-funded museum, the original exhibit was a bit archaic, featuring mirrors and spotlights to create a "Pepper's Ghost" kind of illusion: people would see her skeleton, then the special effects would kick in to create a mannequin version of how she might have looked in life.

Wilentz's article also informs us that the skeleton on display wasn't actually La Brea Woman; after all, most of her remains weren't found. Instead, they obtained the body of "a modern Pakistani female" of similar age and height, treated the bones so they looked like the dark bronze color that typifies tar pit bones, shortened the femurs, and attached the original skull. And the artistic depiction of how she would have looked in real life? Not so much with the accuracy. Far from being, in Wilentz's words, "a young, attractive sensuous tanned brunette with long, long hair strategically covering her nipples," La Brea Woman was a bit on the homely side, and probably considered middle-aged by 20 (most "elders" from that period were around 30; life was cheap and very, very short in the Pleistocene). She had an ectopic tooth protruding above her lip -- one of her few remaining teeth -- and an impacted molar in her jaw. Yet her remains have inspired subplots in at least two novels: Michael Connelly's City of Bones, and Robert Masello's The Bestiary. Something about La Brea Woman and her all-too-human fate speaks to us across the ages.

One might assume that after nearly a century of digging, the La Brea Tar Pits would be picked clean by now, but such is not the case. The focus has merely shifted from the large skeletons of mammoths, ground sloths, and saber-toothed tigers, to birds, bone fragments, seeds, pollen, insects, fish, rodents, and other objects so tiny, it's hard to believe the scientists were even able to identify them. The focus of the museum's current excavation activities is Pit 91, measuring 28 square feet and descending about 14 feet into the earth. Every summer, the pit is open for business from June to the beginning of October, so visits can stand in a special observation area and watch local paleontologists and a few lucky volunteers sift through the muck armed with dental picks, trowels, small chisels and brushes, in search of fossilized treasure.

And what a treasure trove the pit continues to be! In 2006 alone, the teams collected over 1000 in two months, ranging from three saber-toothed cat skulls, four dire wolf skulls, bones from sloths, horses, bison, coyotes and birds, insects, and a few plant fossils.  (Since excavation of Pit 91 began in 1915, over 250,000 fossils have been recovered.) After the fossils are removed, the surrounding sediment is placed in screen baskets, then boiled in solvent to remove the asphalt, revealing a mix of sand, pebbles, small pieces of fossils, and microfossils like seeds. I feel for whoever has the thankless task for cleaning, sorting identifying and labeling this flotsam and jetsam.

Okay, I'm being prematurely dismissive: those bits and pieces can actually tell us a lot about the area during the Pleistocene, specifically, the habitats and climate (apparently LA was cooler and moister in the Pleistocene). Most recently, scientists have discovered 200-300 previously unknown species of bacteria, extremophiles who flourish in the harsh conditions of the asphalt pits: no water and very little oxygen, but loads of yummy toxic chemicals! They chomp away at the petroleum, breaking it down with special enzymes (e.g., polychlorinated biphenyls, or PCB) and then releasing the telltale methane that bubbles to the surface. (Technically, the bacteria suffer from gas and post-meal bloating, and no wonder, considering their diet.) A team from University of California, Riverside, led by David Crowley, identified the bacteria by sequencing recovered DNA. They froze the tar with liquid nitrogen and pulverized it into a powder, exposing the bacteria, and thus were able to extract the DNA. It's quite possible that this discovery could lead to new methods for cleaning up oil spills and enhancing oil recovery.

The tar pits have had more than their share of 15 minutes of fame in popular culture, usually in wildly speculative contexts, none so much as in 1997's Volcano, in which a volcano sprouts out of the Lake Pit and spews a river of hot lava down Wilshire Boulevard -- no doubt engulfing loads of unsuspecting well-heeled shoppers. (Young Earth Creationists would most likely attribute this to the avenging hand of a wrathful Deity.) But the reality is haunting in its own quiet way, with no need for exaggerated pyrotechnics. Wilentz describes the museum, for all its noble educational intentions, as "an homage to an oil reserve where millions of creatures died," a structure that has been built "above what can only be described as a mass grave." The La Brea tar pits are LA's very own heart of darkness, the epitome of "Nature, red in tooth and claw." After all, asphalt doesn't much care how many species perish in its sticky depths.

the incredible vanishing antenna

Orlando, Florida, is best known as a family vacation destination thanks to the megacomplex of Disney World, but last week both locals and out-of-towners had another option for wholesome "edu-tainment": a Plasma Science Expo, held in conjunction with the annual meeting of the American Physical Society's Division of Plasma Physics (DPP). This is the second time (at least) the DPP has done something like this, and once again it was hugely popular. The event ran for two days, and offered loads of hands-on activities and demonstrations to teach the Orlando populace about this ubiquitous fourth state of matter known as plasma.

I should point out, for non-physics types, that this is not the blood-related plasma we hear about on various TV forensics shows, but a cloud of gas that becomes "ionized," i.e., the gas is heated to the point where the electrons are ripped free of atoms and molecules, making the gas highly conductive, just like certain metals. Jen-Luc Piquant is still mourning having missed out on making her own impressive lightning arc, or manipulating a glowing plasma with magnets. We hope Orlando residents appreciated the opportunity in our stead (grumble, whine).

Plasmas pop up semi-frequently at the cocktail party (see prior posts here and here), in part because we think they're really cool. Mostly, though, it comes up because plasmas are pretty darned important in all kinds of different ways, not least of which would be fluorescent lighting, and that cutting-edge plasma TV some lucky readers might have in their homes (although rumor has it those TVs are a major energy suck). Those are just two examples of things we make with man-made plasmas. We also use them for arc welding and in various semiconducting manufacturing processes. Nature makes her own plasmas. Did we mention the sun? I'd say that's a pretty crucial object. Solar flares, lightning bolts, and vivid natural displays like the Northern Lights are all examples of naturally occurring plasmas, which make up 99% of the visible universe. (One used to be able to just say plasmas were the most abundant state of matter in the universe, but thanks to dark matter and dark energy, we must now qualify that statement by specifying "the visible universe." A bit tiresome, but science marches on, and one must keep pace with the change.)

It's the conductance capability of plasmas and the similarity to certain metals that make plasmas attractive as an alternative material for the antenna of the future. The 1500+ DPP attendees heard all about it from Igor Alexeff, a professor emeritus of the University of Tennessee and currently chief scientist of a small start-up company in Brookfield, Massachusetts called Haleakala R&D. (You can find a press release on this and several other DPP session topics here.) He's developed a series of prototype plasma antennas that are, per the meeting press release, "stealthy, reconfigurable, and jamming-resistant." Nor is Haleakala the only company working to develop a viable product: there's a British company called Plasma Antennas in Oxford, England, and a strong research effort underway at Australian National University, for example.

We're all familiar with conventional metal antennas because they're everywhere: in our satellite dish, on our cell phones, atop radio transmission towers, built into our laptops, etc. Most of us rarely stop to think about how all this wireless connection really works. An antenna is just a conductive, solid metal wire sized in such a way to emit and receive electromagnetic radiation at one or more selected frequencies -- usually in the radio end of the spectrum (which is actually a pretty broad range).

Everything vibrates at a natural resonant frequency, and an antenna exploits this effect to transmit and receive electromagnetic waves at a selected frequency. Basically, the energy of the incoming wave couples to the tuned structure, just like those old Memorex commercials where Ella Fitzgerald shatters a crystal wine glass with her voice. She can do it because she sings and holds a note that resonates at the natural resonant frequency of the glass. (Admittedly, they cheated a little and amplified the decibels, but you could call that artistic license.) You "tune" a simple dipole antenna, for instance, by splitting the metal wire or rod into two equal arms insulated from each other. The basic rule of thumb is that its total length should be half the wavelength of the desired incoming signal wave you wish to receive. Which is why a transmission antenna on a radio tower (680,000 Hz) might stand 361 feet, while your 900 MHz cell phone is only about 3 inches.

Metal antennas have withstood the test of time because scientists really haven't found anything that works better, once all the technological, economic, and practical use parameters are figured into the equation. But there are some niggling drawbacks to metal antennas, like "ringing" and vulnerability to interference, not to mention a pronounced lack of "stealthability"; plasma antennas can address those issues. A plasma antenna replaces the metal wire conducting element of a standard antenna with ionized gas enclosed in a sealed glass or ceramic tube: argon, neon, helium, krypton, mercury vapor, or zenon, to name a few gases that have been used in experiments to date. Apply a voltage at a radio-wave frequency to the tube, and you get that all-important coupling effect, resulting in the gas inside becoming ionized. Voila! You've got yourself a working plasma antenna!

Physics history buffs might recognize the concept as a high-tech version of a Crookes tube. Invented by Sir William Crookes (who mistakenly believed they were producing something akin to ectoplasm from the "spirit world"), these devices were all the rage in the mid-19th century, when traveling science lecturers -- the physics equivalent of wandering bards -- used them to wow audiences with demonstrations of these mysterious "cathode rays." A Crookes tube is just a glass tube in which most of the air has been pumped out to create a vacuum. Apply an electrical current to the glass tube, and the interior would glow in pretty fluorescent colors -- the result of energized electrons interacting with residual gas inside the tube and emitting radiation. The modern cathode ray tube operates on the same principle. (You can see a Java animation here.)

We mentioned earlier that plasmas have very high densities of electrons, ergo, they are excellent conductors. But they only conduct when the voltage is turned on, unlike metal antennas, which conduct all the time. This means that once you turn off the voltage that creates the plasma in the first place, the substance reverts to a neutral gas. The "antenna" essentially disappears, until you turn the voltage back on again. Now you see it, now you don't. Behold, the Amazing Vanishing Antenna!

Perhaps this sounds like a bad thing, but depending on the application you have in mind, it's actually a huge advantage -- for, say, US Navy ships keen on avoiding detection by enemy radar. A regular metal antenna will backscatter any incoming radar signals, giving away the ship's presence and enabling a potentially hostile craft to pinpoint its location. In times of warfare, this is very bad. So it's not surprising that the US military is keenly interested in developing plasma antenna technology.

Ships using surface wave radar also often experience problems with the high metal masts installed on board, since they can interfere with each other. Conventional metal antennas pick up interfering signals quite easily, along with noise bouncing off nearby objects. The fact that a plasma antenna ceases to exist when it is turned off and not in use significantly reduces this type of interference. Metal antennas also tend to "ring" because they continue to radiate energy even after the incoming energy stops; the oscillations need to die down. This is especially problematic for short-range ground penetrating radars used in petrochemical and mineral exploration. Thanks to their rapid switchability, plasma antennas don't ring.

That on/off switching ability also reduces a plasma antenna's vulnerability to "jamming," a common military counter-measure. It involves deliberately confusing the radar signal by hitting it with intense signals at just the right frequency to make its readings unreliable. There's a nifty example of this kind of thing in Nature: Bats hunt and navigate by emitting ultrasonic pulses and using the returning echoes to determine the location, speed and distance of nearby objects or prey. But certain insects have evolved a kind of frequency jamming ability to disorient a hungry bat. I wrote previously about the big brown bat's unique strategy for protecting itself against jamming. Although they prefer higher frequencies, when something jams their preferred range, the bats shift down to lower frequencies to compensate. 

Both sonar and radar systems are vulnerable to this kind of jamming; they just use different frequency ranges (ultrasound versus radio).  And since the US military relies heavily on both these technologies, they are keenly interested in anything that can reduce that vulnerability. Some scientists are studying the big brown bat in hopes of figuring out how to combat jamming in the ultrasonic frequency range; those interested in combating radar jamming are looking to things like plasma antennas. "Plasma antennas have a high frequency cut-off that can be adjusted electrically," says the DPP press release. "Thus, a plasma antenna can be transmitting and receiving signals while intense incoming high-frequency signals pass freely through it without interacting."

Loose translation: you can configure a plasma antenna to be receptive to certain frequencies while blocking out others. Plasma antennas boast terrific reconfigurability thanks to the development of so-called plasma "windows" -- again, something made possible by the fact that the plasma antenna "disappears" once it is turned off, or its electron density becomes too low for efficient conductance. Plasma windows are "apertures," or areas around the antenna's surrounding plasma "blanket" that "open" when the electron density in the plasma is lowered or turned off entirely, making it transparent to antenna radiation. The "windows" will "close" when the plasma density becomes high enough again to reflect antenna radiation well. One window creates a single antenna "lobe," while multiple windows can create multiple antenna "lobes." So you can "tune" your plasma antenna to whatever frequency you wish.

That's another huge advantage, because one plasma antenna can perform the same function as several conventional metal antennas. Either you can reduce the number of antennas you need, cutting down on clutter and weight, or you can exploit this feature to build an array of many small plasma elements that the user could reconfigure simply by turning one (or more) of the various elements on or off. The various windows can even be opened and closed in a particular sequence to steer the antenna beam. Alexeff is currently developing a "smart" plasma antenna that essentially steers the antenna beam 360 degrees to scan a given region for transmitting antennas, then locking onto that signal -- much like your built-in wireless connection in your laptop scans the vicinity for the strongest wireless network signal.

An array of such smart plasma antennas, when coupled with cutting-edge signal processing software, could maximize signal strength and reduce interference of signals from cell phone towers. This means fewer dropped calls and less "Are you still there? Can you hear me now?" moments for cell phone users everywhere. That steering mechanism could be handy for consumers, too. Figure out how to control a miniaturized plasma antenna array with your wireless laptop, and it may one day be possible to share your computer data wirelessly with just one other user in a crowded room filled with wireless laptop users. You'd just need to close or create "windows" as needed in order to direct the signal to your targeted user.

If one didn't understand the underlying science at work, that last bit would sound suspiciously like mental telepathy: you know, the ability to direct your thoughts in such a way that only the intended recipient can "hear" them. There is, needless to say, no scientific basis for such a thing, or for its partner in Pseudoscientific Crime, telekinesis. This is something I discussed at length in one of the chapters in The Physics of the Buffyverse: for starters, electromagnetic brain waves aren't remotely powerful enough to send a strong enough signal to reach a distant recipient, even assuming you could focus the mental signal like a laser beam -- or "steer" it to one's intended target.

Sure, we can measure brain waves using electroencephaolography (EEG), but these signals are so faint they have to be amplified thousands of times over before our cutting-edge machines can detect them and turn them into readable data. You then must figure in the inverse square law, which basically says that a signal will be strongest at its source and spread outward rapidly until it dissipates entirely, because the same amount of energy (it's conserved!) is being divided across a greater area. And it decreases fast, y'all! If the intended recipient of the telepathic signal is twice as far from the person trying to send the "communication," the energy of the signal will decrease by four times as much. So just as with an EEG, you'd need to amplify the signal a lot. (Incidentally, this is an issue also faced by the plasma antenna.)

The upshot is that unless a telepathic (and/or telekinetic) person had a means of amplification, not to mention embedded implants to serve as transmitter and receiver, plus that all-important directivity (i.e., "steering ability), such a feat is quite frankly impossible. Sorry if that bursts anyone's bubble. I know, I know, the idea of mental telepathy is so very seductive, but wishful thinking does not good science make. The world is not magic, remember?

That said, science offers something better than magic. Mental telepathy might be a silly notion, but the concept has inspired some pretty exciting new technology. Researchers really are experimenting with implanted computer interfaces, such as the folks at Duke University who outfitted macaque monkeys with the things in 2000 so the monkeys could move a robotic arm from a remote location, or the Emory University researchers who implanted a transmitting device into the brain of a stroke patient, linking the motor neurons to silicon so he could move a cursor on a computer monitor just by thinking about it. Plus, we have just learned -- courtesy of Greg Laden -- that some wacky researchers at the University of Arizona have built robots driven by the tiny brains of moths.

Wow. That's some pretty awesome stuff right there. Add in breakthroughs like the configurability, switchability, and directivity potentially offered by plasma antennas, and one day we might not have telepathy and telekinesis, per se, but the technological equivalent. And it will have nothing whatsoever to do with magic.

from the minds of babes

We've all become so accustomed to seeing CT scans and MRI procedures performed on TV medical dramas, or in film, that we rarely give much thought to what happens when the patient, for whatever reason, can't have one of those standard imaging procedures. Babies, for instance, are small, squirmy, and especially vulnerable to the ionizing radiation associated with many medical imaging procedures. Fortunately, researchers all over the world are hard at work developing alternative imaging techniques all the time, many quite similar in concept, but tailored for specific applications -- like imaging the infant brain.

Let's just take the three most common medical imaging technologies as a reference point: X-rays, CT scans, and magnetic resonance imaging (MRI).Conventional X-rays have been around for more than a century, after Wilhelm Roentgen first discovered the invisible rays in the 1890s and realized they could be used to image bone. It took awhile for folks to realize the rays were, in fact, quite dangerous in high doses, but thanks to improved technologies and shielding measures, for normal, healthy adults, X-rays aren't too problematic. CT scans are similar, in that they rely on X-rays, except instead of imaging the outlines of bones and organs, a CT scan machine builds a fully 3D computer model of the inside of a patient's body, by taking a series of images one narrow "slice" at a time and then reconstructing those slices into the final image.

When MRI came along in 1977 -- the first human scan took place on July 3rd of that year, and the machine that took the image, dubbed "Indomitable," is now on display at the Smithsonian Institution -- it became possible to take clear and detailed images of internal organs and soft tissues for the first time, without the use of ionizing radiation. A quick summation (for those who've never taken the time to peruse this handy explanation at How Stuff Works): MRIs use radiofrequency waves combined with a strong magnetic field to take images by manipulating the "magnetic moments" of hydrogen atoms -- one of the most abundant atoms in the human body because of the body's high water content. The rf waves get the protons in the hydrogen atoms all excited (okay, not "excited" in the colloquial sense, but that is the technical term for it), but eventually they relax back into their normal state, and when they do so, they emit powerful radio signals. These are detected and fed into a computer, which translates the data into a high-contrast image showing differences in the water content and distribution in various bodily tissues.

There are some drawbacks to MRI, though, namely the powerful magnetic fields: on the order of 0.5 to 2 tesla (5000 to 20,000 gauss, just to confuse the issue with more scientific units). So any metal object can become a dangerous projectile if it finds its way into the scanning room: paper clips, pens, keys, even medical equipment like stethoscopes, IV poles, or oxygen tanks. In this day of implants and prosthetics, metal objects can actually be inside the body of the prospective patients: certain older dental implants, for example, or aneurysm clips in the brain, or pacemakers. The latter are used to treat arrhythmia (abnormal heart beat), which affects as many as 2.2 million Americans alone, but older models can be made of magnetic materials. There is also a risk of burning heart tissue, because some devices use leads: electrical components capped with metal to connect the device to the heart muscle.

A year or so ago, a team at Johns Hopkins University figured out some ingenious ways to safely perform MRI scans on people with implanted defibrillators and pacemakers. It wasn't a single solution, but rather a combination of methods: some very simple and obvious, like turning off a defibrillator's shocking function for the 30 to 60 minutes it takes to complete the scan; lowering the strength of the electromagnetic field and the amount of electrical energy used at peak MRI scanning; and figuring out how to "blind" the implanted devices to their external environment, making them impervious to misfiring from the MRI machine's rf field.

But babies still present a sticky wicket when it comes to medical imaging. X-rays are just too potentially dangerous to infants because of the ionizing radiation (ditto for pregnant women), so doctors are reluctant to use that tried-and-true technology. Babies tend to find CT scanning equipment big and loud, and therefore upsetting; also, again, the x-ray exposure isn't really a good idea for their tiny developing bodies. MRI is equally big and loud, made more difficult because babies tend to squirm in distress at being confined in the Big Magnetic Donut From Hell. (Heck, plenty of adult patients find the MRI procedure a bit upsetting, and/or have trouble holding still long enough to take a decent set of images.)

If the infant is premature and confined to an incubator, getting a decent brain scan to check for possible damage or irregularities is especially daunting. Doctors understandably want to minimize any time the "preemie" must be handled or exposed to loud noises (or to the germ-laden environment outside the incubator), since either can cause irregular heart rate and breathing patterns -- potentially life-threatening to such a fragile creature. And yet, as many as half of early premature babies suffer from very subtle abnormalities of the brain that can be linked to later developmental problems -- which often don't manifest until at least 10 months of age, at which point it may be too late to medically intervene. It's quite common for premature babies to fall victim to infection from the wall of the uterus or placenta, or have an inflammatory response at birth that affects the brain. Sometimes the damage is caused by something so simple as an under-developed cardiovascular system that just isn't strong enough to pump enough blood to the brain during those crucial few weeks after premature birth.

So getting an MRI scan early on could alert doctors to such conditions much more quickly. Fortunately, a couple of years ago, scientists at the University of California, San Francisco (UCSF) collaborated with General Electric to design a special incubator compatible with MRI machines. It's made entirely of plastic, aluminum or brass -- i.e., non-magnetic materials -- and small enough to be easily transported. We're talking about a double-paned Plexiglass capsule, with fresh air piped in from the outside. The infant is usually sedated, since the MRI scan can take an hour or so. Also, it's still very noisy. At least it's now easier to get the images needed to identify potential problems while effective treatment is still an option.

But what about imaging the brain when we're awake? For decades, even after the invention of CT scans and conventional MRIs, there was no way to image or observe the brain in action. Then came functional MRI. It's pretty much the same technology, with a twist: it identifies those regions of the brain where blood vessels are expanding and other chemical changes are taking place, or perhaps a few extra shots of oxygen are being delivered. That's important information, because it's an indication of metabolic activity: that region of the brain is processing information and issuing "commands" to the body. So by studying which areas show increased activity, scientists can learn which areas of the brain are activated as the patient performs any given task. There have been rather large numbers of fMRI studies performed in recent years, on everything from glossalia (speaking in tongues) and how the brain reacts to chocolate, to the rather breathlessly reported news of an fMRI study of political affiliations that threw some folks in the scientific blogosphere into a tizzy this week over the questionable reporting.

Electroencephalography (EEG) has been the mainstay for infant brain imaging because it's safe and registers changes in brain activity very quickly. Alas, the technique can't reliably and precisely pinpoint where in the brain the activity originates. There have been a few fMRI brain scans of infants performed while said infants were asleep or sedated, but this doesn't tell researchers as much as they'd like to know about the developing infant brain. Ideally, they would like to be able to scan babies' brains as they sit comfortably on a parent's lap and/or interact with their environment. Then they could really see the baby brain in action. Infancy, after all, is a critical developmental period. That's when connections between neurons first form and break, nerve cells branch out to form networks, and various parts of the brain take on their specialized roles in vision, language, and other complex cognitive functions. When that early processing goes wrong, it can lead to learning disabilities of language impairments, among other complications.

In more recent years, high-density diffuse optical tomography (DOT) and its cousin, diffuse optical spectroscopy (DOS) have come into favor for infant brain imaging. This approach was originally developed in the 1990s by various research groups in the US, Europe, and Japan, and innovations have come fast and furious ever since. Last year, researchers at the Washington University School of Medicine in St. Louis (WUSTL), for example, announced they had developed a DOT system specifically to study the infant brain. Their system is much smaller --about the size of a small refrigerator -- quieter and more portable than MRI or CT scanning machines, and the goal is shrink the size down even more, to about the size of a microwave. It's not just useful for basic research, either: the WUSTL system makes it possible to monitor infants with brain injuries in their incubators, making it easier to keep track of their progress and provide better treatment.

Instead of ionizing radiation like x-rays, DOT uses harmless light from the near-infrared portion of the electromagnetic spectrum. Unlike x-rays or ultrasound, near-IR light passes through bone with little attenuation, so scientists can use the diffusing light to determine blood flow and oxygenation in the blood vessels of the brain. When these characteristics increase, it indicates that the particular area of the brain being scanned is contributing in some way to the mental task at hand.

Ah, but how does one scan an infant? You can see the system in action here. It's as simple as attaching a flexible cap to the baby's head, covering whatever area the doctors want to image. (I should note that this nifty image isn't the WUSTL system, but a similar approach using near-infrared spectroscopy developed at Helsinki University of Technology in Finland. It's just such a cool, slightly creepy photo, I had to use it.) The cap might look simple on the outside, but inside it contains fiber optic cables. Some of those shed light on the head; by determining how the light is diffused or scattered, researchers can glean useful information about brain activity.

Light passes out of one fiber optic cable, diffuses through the tissue, and is received by another cable. Yes, light does diffuse through tissue, as anyone who has ever held a flashlight up to his hand can attest. According to Joseph Culver, an assistant professor of radiology at WUSTL, "The flashlight's white light becomes visibly reddened because there's a window in the near-IR region of the spectrum where human tissue absorbs relatively little of the light." Anyway, based on this diffusion data, the machine's computer creates a 3D tomographic image based on whether the hemoglobin in the blood is oxygenated or deoxygenated to determine brain activity.

I mentioned the Helsinki NIRS technology above; that's certainly another strong contender in the drive for safer infant brain imaging, although it's pretty much diffuse optical spectroscopy, as far as I can tell. (A rose by any other name, and all...) It's already commonly used to monitor cerebral blood flow in preemies, and now it's moving into studies of brain activity during specific cognitive or sensory tasks. Here in the US, researchers at Texas A&M University worked with neuroscientists at Massachusetts General Hospital to develop a DOT imaging apparatus that also uses a cap or headband. Theirs employs a number of light-emitting diodes and light-sensing detectors to emit and detect near-IR light, looking, as always, for changes in blood oxygen levels to form the images. (Massachusetts General is also developing a DOT system designed to work in conjunction with conventional x-ray mammography to detect breast cancer earlier, with fewer false positives and less need for follow-up biopsies, but that's a bit off-topic for this post.)

The WUSTL system is a little different from other approaches because it combines diffuse optical imaging with tomography -- i.e., a computerized approach to the data analysis that makes it possible to image sections at greater depths. It's thanks to the greater density of the fiber optic cables they used that this is possible. All this is great news, but the WUSTL system isn't quite ready for prime time: it's still being tested for safety and effectiveness. The researchers did conduct one study on human volunteers to demonstrate their system could achieve sufficient resolution for functional brain imaging. They were able to link stimulation of parts of the visual field to the activation of corresponding areas in the brain's visual cortex -- a classic functional brain imaging technique called retinotopic mapping that was also used to test the validity of earlier technologies like fMRI and positron emission tomography (PET).

I think it's safe to say that the innovations will continue to develop. Some day, all those parents wondering, "What is my baby thinking?", might be able to turn to cutting-edge, non-invasive, optical imaging technology for the answer.

the photon has two faces