Cocktail Party Physics

doomsday redux

"It's the end of the world as we know it,
And I feel fine...."
       -- R.E.M.

We interrupt posting the final installment of "Brainiacs" week at the cocktail party to bring you this special announcement: the world is not going to end when CERN finally turns on the Large Hadron Collider (LHC) later this year. Seriously. I wrote about this issue way back in September 2006, and tried really hard to resist commenting further in the wake of last week's news that a lawsuit has been filed in Hawaii's U.S. District Court (Hawaii?!?) seeking a temporary restraining order against CERN and its partners in building the LHC. You are reading this because I discovered that resistance is futile. The self-styled Prophets of Doom never rest in their single-minded mission to halt scientific progress around the globe and quash the spirit of free inquiry and discovery wherever it threatens to bloom. In this case, the plaintiffs want to postpone start-up preparations for "at least" four months in order to "reassess" the collider's safety. Because, you know, it could destroy the world by creating mini-black holes, magnetic monopoles, or converting all the matter in the universe into exotic strangelets.

(*cue exasperated eye-rolling*) Oh, give me a break already. This is nothing more than the latest round of fear-mongering that always seems to accompany the start-up of a new accelerator. In fact, one of the plaintiffs is none other than "former nuclear safety officer" Walter Wagner, who spearheaded the attempt to create panic surrounding Brookhaven's Relativistic Heavy Ion Collider (RHIC) -- that lawsuit was dismissed, and rightly so. News flash to Wagner (and his ilk):  RHIC has been  operating since 2000. The world has not yet ended.  Nor did it end when Fermilab's Tevatron turned on -- not a single artificial supernova appeared, despite all the preliminary hand-wringing by fear-mongers -- or when the Stanford Linear Accelerator came online.

Perhaps some of you think I am a bit too hasty in pooh-poohing the risks associated with a big powerful machine like the LHC. Let me assure you that this is not the case: I believe very strongly that science has a responsibility to evaluate the safety of its experiments, particularly for something as massive as the LHC. LHC scientists have done so. Wagner's concerns are nothing new to anyone who has followed the development of the accelerator's design and construction over the last decade or more. The inherent risks have been fully and fairly considered by the best scientific minds in the world, who take their responsibility for ensuring safety of operation very, very seriously. To suggest otherwise is, frankly, an insult to the world high-energy physics community.

There have been two safety assessments already, and a third update has just been completed.  ("The possibility that a black hole eats up the Earth is too serious a threat to leave it as a matter of argument among crackpots," one CERN theorist told The New York Times.) We're talking about the most expert testimony any court could hope to have on record.

Why bring the courts into it at all? Because Wagner refuses to accept the scientific consensus on the issue, that's why. Apparently, he thinks he knows better than all those world-class physicists who have participated in three (to date) safety assessment reviews. Hey, he studied physics and "worked on cosmic ray research" at the University of California, Berkeley, according to Dennis Overbye's article in The New York Times, although there's no mention of Wagner earning an actual degree, apart from a doctorate in law from the the University of Northern California in Sacramento. And then he spent several years working as a radiation safety officer for the Veterans Administration. In short, he knows just enough to foster panic, and not enough to make a scientifically rigorous assessment of what the true risks are. A little learning is a dangerous thing, indeed. Pardon me for finding the "testimony" of world-class experts in particle theory more convincing than that of a retired radiation safety officer, however well-meaning.

Wagner's mysterious co-plaintiff, Luis Sancho,  might not even have that much background: he is described as an "author and researcher in time theory," living somewhere in Spain, "probably in Barcelona." Probably? If Wagner can't even locate his own co-plaintiff -- never mind give us any information about Sancho's scientific credentials -- why should we believe his statements about the LHC? Answer: we shouldn't. All the cool bloggers agree. But don't take our word for it, either. CERN has specifically addressed this issue on their Website, where you can find lay-friendly summations of the salient issues, as well as links to other relevant official documentation. There's no big conspiracy to hide the "truth," and this is not, as Wagner claims, mere "propaganda." If anything, it's Wagner who's peddling the propaganda. In fact, part of the LHC's current PR problem is that physicists are so darned honest in their assessments, they are reluctant to go on record as definitively ruling out even the most unlikely of scenarios. And that gives folks like Wagner the ammunition they need to foster unfounded panic.

Perhaps my favorite comment on the whole LHC Doomsday scenario appeared in a thread at Shakesville, where a poster identified as Astaea wrote, "Wasn't this an Angel episode? We aren't in danger till one of the scientists gets dumped by his girlfriend." Astaea is referring to a Season 2 episode of Angel entitled "Happy Anniversary," in which a brilliant physics grad student's experiment on freezing time nearly ends the world. It actually has very little to do with fears surrounding the LHC (although Sancho is apparently working on theoretical aspects of time), but I had a lot of fun analyzing the episode in a chapter of (shameless plug alert!) my book, The Physics of the Buffyverse.

In the episode, Gene (the physics student, dubbed "Time Boy" by a jealous colleague) assures a curious co-worker that his experiment isn't really about freezing time, "although that's how it would look to an outside observer." Rather, he's trying to carve out a teensy-tiny piece of space-time and remove it from reality. Anything contained within that moment would exist in its own bubble universe, forever unchanged. Time would have no meaning. He just can't get his experimental apparatus to work correctly; his math isn't quite right, apparently. I'm sure there's lots of physicists out there who could relate to Gene's dilemma. He has something they lack: a technologically advanced, fanatical demon sect intent on ridding Earth of the pesky human race once and for all. They correct his math, and when he returns to the lab and enters the new parameters, voila! A tiny drop of mercury is suspended in a timeless bubble, right there in the lab, until he turns off the machine.

Like any respectable scientist, Gene has taken safety into consideration: his experiment is equipped with various safeguards to contain the experiment, lest that tiny bubble universe escape its confines, spread, and eventually engulf the entire world. But then he overhears his girlfriend confessing her intent to break up with him after their anniversary dinner (and requisite "sympathy bone," as the girlfriend's confidante succinctly puts it).

Frankly, Gene kinda loses perspective for a bit at this depressing news. He decides to set up the experiment in his bedroom and triggers the device at the (ahem) climactic moment. Things might still have been okay, if it weren't for those meddling demons. As Gene and his (soon to be ex-) girlfriend are suspended in their private bubble, the demons remove the safeguards, and the bubble starts to spread outward, freezing everything it engulfs in its path -- until Angel managed to shut down the system in the nick of time. The bubble collapses back in on itself, and time resumes for everyone.

There's a lot to criticize in the science of this episode if one is inclined to nitpick. In some ways, it's typical "Hollywood science": a smattering of nifty-sounding physics concepts and buzzwords that, when parsed, don't seem to make much sense. In this case, you've got the notion of carving time into infinitesimal pieces --something (if memory serves) mentioned in Brian Greene's The Fabric of the Cosmos. You've got elements of tabletop plasma wakefield accelerators and laser trapping in Gene's fictional experimental apparatus. And you've got elements of relativity and black hole physics. At one point, Gene compares the effect of his temporal experiment to "a tiny event horizon."

This doesn't mean that his premise is feasible by any "real world" standard in physics. He says that if a single drop of mercury is dropped into the field created by his tabletop accelerator, and if the particles that make up the laser beams are moving at just the right velocity (the speed of light, one assumes), the mercury would be accelerated completely out of our space-time. Accelerating something to exactly the speed of light would, indeed, cause time to contract to nothing from the perspective of that object, per Special Relativity. The catch is that no object with mass can ever reach the speed of light, even tiny subatomic particles. The LHC and other accelerators can speed up particles to within 99.999% of the speed of light, but no matter how much additional power they feed into the machine, because there is a corresponding increase in mass, the particles never quite reach light speed. It would require an infinite amount of energy.

Extreme gravity -- such as that of a black hole -- might do the trick, at least, as Gene points out, from the perspective of an outside observer. Your basic black hole physics states that as an object gets closer and closer to the event horizon, someone watching its approach would see it moving more slowly the closer it gets, until it stops entirely just before crossing the event horizon, on the verge of falling in for all eternity. (From the perspective of the object itself, of course, it would continue falling into the black hole and be "spaghettified" -- Kip Thorne's colorful phrasing -- by extreme gravity along the way.) Does creating a black hole in a lab the size of Gene's seem a bit far-fetched? Sure, especially when the episode first aired. But science presses forward, and the March 2008 issue of the IEEE Spectrum magazine has a fascinating article on how scientists at the University of St. Andrews in Scotland have created an "artificial black hole" using optical fiber -- or at least something with the telltale properties of an event horizon. Maybe Gene was just really cutting edge.

The theoretical possibility of the LHC creating "mini-black-holes" is one of the Doomsday scenarios causing the current brouhaha, so this notion isn't 100% far-fetched. But here, again, there is a catch: Hawking radiation, which causes a black hole to gradually evaporate over time, proportional to its size. The bigger the black hole, the longer it takes to evaporate, and the smaller the black hole, the less time it takes to evaporate. If the LHC does, indeed, create mini-black holes -- and this is still a matter of hot debate among theorists -- they would be roughly the size of a subatomic particle and would evaporate in fractions of a second -- long before they could pose any risk to the world's continued existence. The same would hold true for Gene's temporal experiment.

I personally found it impressive that Angel's writers even attempted to build an episode around something so complicated and esoteric. They get points in my book for their cutting-edge science flair, even if everything is stitched together rather awkwardly. (A Season 4  Angel episode entitled "Supersymmetry" does a better job in this regard, cleverly drawing on the notion of string compactification in string theory as a possible mechanism for the creation of portals to other worlds in the Buffyverse -- and using all the associated jargon correctly in the process.) It's an entertaining premise, even if it's wildly unlikely. The Buffyverse is a fictional world, after all, and is therefore not necessarily constrained by the laws of physics as we understand them. It only has to be consistent with its own laws.

The same cannot be said for Wagner's contentions about the LHC. Honestly, based on what I've heard from every single physicist I've spoken with about the issues over the years, the "risks" he cites are almost as wildly unlikely as the premise of "Happy Anniversary"'s temporal physics experiment gone haywire. And Wagner doesn't have the excuse of a fictional universe to fall back on. A whole string of unlikely events  -- each with an infinitesimally small probability on its own -- would have to all come together perfectly, at just the right time, and in just the right order, to bring about the end of the world as we know it.  Wagner might as well file a lawsuit saying the LHC should be postponed until we've established that a fanatical demon sect from a parallel universe won't over-ride the accelerator's safeguards to trigger his Doomsday scenario.

survival of the fittest

On March 5, 2007, the New York Times ran an obituary marking the passing of former US senator Thomas F. Eagleton. To most post-Baby Boomers like myself, the name meant very little. But to anyone eligible to vote in the 1972 presidential election, Eagleton was the infamous Running Mate for 18 Days. Democratic candidate George McGovern picked him as his running mate, only to discover one week later that Eagleton had struggled with clinical depression, had been hospitalized three times, and subjected to electroshock therapy. They initially tried to spin it as "nervous exhaustion," but the press had a field day (plus ca change...) with the revelations, and Eagleton eventually bowed to political pressure and stepped down, at McGovern's urging, for the sake of "party unity." Fat lot of good it did, in retrospect: McGovern suffered a crushing defeat in favor of Richard Nixon. But chances are, that would have happened anyway.

Those are the political breaks: it's not an arena you want to enter if you have secret vulnerabilities, like poor Eagleton, who was, by most accounts, an honorable man despite his all-too-human foibles. We've come a long way in our attitudes towards clinical depression; it's no longer the stigma it once was, and there are far more treatment options available (albeit with unpleasant side effects accompanying the most common drug therapies). Even McGovern, the year before Eagleton died, said publicly that he regretted asking for Eagleton's resignation as his running mate: "If I had it to do over again, I'd have kept him," he said. "I didn't know anything about mental illness. Nobody did." In fact, he listed Eagleton as being among the "10 or 12 best senators" with whom he had served.

We know much more about mental illness and depression in part because of advances made in neuroscience: specifically, in the case of depression (as well as bipolar disorder, Huntington's Disease, and schizophrenia), in our understanding of the role played by a family of proteins known as neurotrophins. This was the subject of a talk here at KITP last week by Moses Chao of New York University, who focused mostly on one neurotrophin in particular: brain-derived neurotrophic factor (BDNF). There have been several studies purporting to link low BDNF levels with depression or bipolar disorder, according to Chao, and while many of those have yet to be verified, one study by Pamela Sklar  of Harvard Medical School appears to be pretty solid, and Chao's own research with lab mice genetically altered to have low BDNF levels seems to support a link as well. Apparently antidepressants help boost BDNF expression, among other effects.

To really understand why Chao and others suspect a link between BDNF levels and depression, bipolar and Huntington's, it's helpful to have a bit of background. After Chao's talk, I did what I always do when I'm intrigued by a topic: I turned to Google. Fortunately for me, there's a wealth of useful information on neurotrophins available online, and much of it is reasonably accessible to the curious non-scientist.

Nerve growth factors are secreted proteins that induce the survival of neurons. They were discovered in the 1950s by an Italian developmental biologist named Rita Levi-Montalcini. She has a compelling personal story of conducting science under siege:  after overcoming her family's objections to a woman engaging in a professional career, she graduated from med school in 1936 with highest honors and devoted herself to the study of neurology and psychiatry. But that was the same year Mussolini issued his infamous manifesto barring academic and professional careers to non-Aryan Italian citizens (notably, those of Jewish descent, like Levi-Montalcini). She fled home to Turin in 1940, as the German army was poised to invade Belgium. The family opted not to emigrate to the US, but to hide out instead. Levi-Montalcini built a small research lab in her bedroom (and, when the bombing of Turin became too intense, in the attic of the country cottage to which her family fled), where she conducted experiments on chick embryos. That, my friends, is scientific grace under extreme pressure.

Once the war ended, she returned to Turin and resumed her academic positions, moving in 1947 to St. Louis to work with Viktor Hamburger, whose research had inspired her own wartime experiments on chick embryos. She ended up staying there through retirement, dividing her time between St. Louis and Rome. In 1952, Levi-Montalcini experimentally demonstrated that when tumors from mice were transplanted to chick embryos, they induced "potent growth of the chick embryo nervous system," specifically the sensory and sympathetic nerves. But there was no direct contact between the tumor and the embryo, leading her to conclude that there had to be a nerve-growth-promoting chemical that was released to cause such a response. She was the first to successfully extract and identify nerve growth factor. And it was very potent indeed! A mere few minutes after the addition of one billionth part of a gram of NGF (per milliliter of culture medium) caused nerve fibers to grow explosively out from the ganglion. After just one day, the ganglion looked like a sun surrounded by rays (see image above). She shared the 1986 Nobel Prize in Physiology or Medicine for this work, with Stanley Cohen (who discovered epidermal growth factor).

Differentiation among cells is critical to human development, not just the brain. We all start from a single cell containing the genetic material that determines our individual characteristics. As cells divide, and divide some more, they start to differentiate -- i.e., exhibit different characteristics, play specific roles or functions, and so forth. Scientists have linked growth factor chemicals with the regulation of cell growth and differentiation. In the case of nerve growth factors like neurotrophins, they activate the process by attaching to neuron cell receptors -- molecules that act like tiny antennas, sitting on the surfaces of cells like neurons. A good analogy is the lock and key. The receptors are the lock, and can only be opened by certain protein "keys" (known as ligands), and once opened, the receptors send a series of internal signals ricocheting through the nervous system.

Neurotrophins are keys that fit the locks of specific neuronal receptors in the brain. There are four related types of neurotrophins: BDNF, nerve growth factor (NGF), neurotrophin-3 (NT-3), and neurotrophin 4 (NT-4). Each of these correspond to a specific family of three receptors (A, B and C), known as Tyrokinase (Trk) receptors. NGF binds to TrkA; NT-3 binds to YrkC; and BDNF and NT-4 bind to Trk-B. There is a second class of receptor called p75 to which all the neurotrophins can bind, just with lower affinities. And p75 seems to play a critical role in triggering programmed cell death.

Once those "locks" have been opened, they trigger nerve growth, survival, and differentiation via a complex signaling pathway (so complex that the underlying mechanism is still not completely understood by neuroscientists). As such, they seem to play a vital role in behavior, learning and memory. BDNF acts specifically on certain neurons in the central nervous system and the peripheral nervous system (i.e., the lower spinal cord) to support the survival of existing neurons and encourage the growth and differentiation of new neurons and synapses. It isn't just found in the brain: BDNF is also expressed in the retina, motor neurons, the kidneys, and the prostate. Stress, or exposure to the stress hormone corticosterone, has been shown to decrease the expression of BDNF in laboratory rats, and if the exposure persists, and BDNF levels continue to drop, the entire hippocampus can atrophy. Similar atrophy has been shown in people suffering from clinical depression -- hence, the suspicion that there may be a critical link between that condition and low levels of BDNF.

The process is fairly complicated in the central nervous system, where there isn't as heavy a dependency on BDNF for survival, per Chao. But in the peripheral nervous system, sympathetic sensory neurons will undergo programmed cell death (a.k.a., apoptosis) when deprived of nerve growth factor. And since there are twice as many neurons competing for a limited number of neurotrophic factors, this is the primary mechanism by which neurons self-select and differentiate. Chao's group is seeking to identify "the biochemical steps that provide specificity in nerve growth factor signaling." Thus far, we know that nerve growth factors are responsible for neuronal cell survival and death via the activation of the TrkA tyrosine kinase (for survival) and the p75 neurotrophin receptor (for programmed cell death).

Chao and his colleagues have experimentally observed the effects of low BDNF levels in the lab. First, they bred mice with a mutation in the BDNF gene to eliminate the presence of the factor entirely, but per Chao, "This proved disastrous." The mice developed normally, but died within a few weeks from cardiovascular problems, before the researchers had time to train them to engage in experimental tasks. So next, they genetically engineered the mice to have 50% less BDNF. The mice survived this time, but showed signs of elevated anxiety, learning deficits, a tendency towards obesity, and among the males, there was more aggression and hyperactivity, particularly toward other male mice. Treating those mice with Prozac, intriguingly, reversed the aggressive behavior, as did increasing the amount of exercise.

This has some interesting implications for the development and evolution of the human brain, according to Chao. BDNF levels are generally low at birth and increase dramatically in the ensuing weeks in many different parts of the brain, with the strongest expression in the forebrain and cortical regions. The prefrontal cortex develops relatively late in life, sometimes not reaching full maturity until the mid 20s -- which might explain, in part, why certain mental conditions such as schizophrenia and bipolar disorder don't fully manifest until then. There seems to be a strong correlation between increased survival and growth of neurons in the hippocampus, and higher BDNF levels. As for Huntington's Disease, this tends to develop between ages 30 and 50, with associated loss of striatal neurons -- and since these depend on BDNF for survival, lowered BDNF levels (or complete absence thereof) could be a factor in the loss of those neurons.

I was especially struck by a comment made during the Q&A by Columbia University's Stuart Firestein, another of the KITP "Brainiacs" (he specializes in olfactory receptors): "There are no switches, everything's a dial." In other words, it's not like the brain throws a switch and someone suddenly develops bipolar disorder. It's all about levels of crucial chemicals, of which BDNF seems to be one of the most critical. These chemicals are "good at the right level, bad at too low levels," and even though bipolar or schizophrenia might seem to have sudden onsets, it's more likely that levels have been falling for quite some time, and finally passed a critical threshold. Or something like that. Nobody's 100% sure. I suspect we'll have to wait for further research results before we can make a definitive call one way or the other.

What does this mean for future treatment options for those suffering from these diseases? It's a bit premature, since Chao's research is more of a fundamental variety, but certainly improving our understanding of how neurons develop (and die) in the brain, and the factors that influence their survival (or death), has important implications for the development of better drug therapies. Chao has been struggling with the challenge  of exploiting the signal transduction mechanisms of neurotrophins to treat neurodegenerative and psychiatric disorders. Apparently, even though nerve growth factors serve to protect neurons, the brain is resistant to treatments that use them. Chao attributes the failure of prior attempts to "problems with delivery and numerous side effects" in clinical trials. "Nerve growth factors are large, sticky proteins that do not diffuse very well," he said.

Chao and his colleagues have demonstrated that neurotrophin receptors in damaged motor neurons in mice, for example, can nonetheless be activated through a different, entirely unrelated receptor system (in this case, G protein-coupled receptors) through a kind of "cross-talk." Since G protein-coupled receptors are the target of many therapeutic drugs, Chao is hopeful that one day we might be able to use the "cross-talk" phenomenon to bypass the blood-brain barrier -- a major stumbling block when it comes to delivering drugs to affected areas in the brain -- without the usual side effects. However, "Ideally, we would like to treat not just the BDNF deficiency, but to be able to eliminate the mutant protein that causes those levels in the first place."

tools of the brain trade

The Brainiacs have landed at KITP! Last week was the start of a new program on the anatomy, development and evolution of the brain, which means the halls of KITP are now filled not just with particle physicists and cosmologists, but also scientists engaged in various aspects of neuroscience research. Ergo, I call them Brainiacs. That's one of the great things about the KITP: it's so very interdisciplinary in its scope, one never knows what sort of scientist one is likely to encounter on any given day, or what topics will be featured in the various scheduled talks. Today, for example, I can learn about gene networks in animal development, or mass determinations in decay chains with missing energy -- or both, if I'm feeling especially curious. Good times!

Neuroscience isn't a subject I cover much, beyond the occasional physics-based imaging technique (functional magnetic resonance imaging, anyone?). So why not have an unofficial "Brainiac Week" here at the cocktail party? We'll start with a post about the foundations of modern neuroscience. Last week I heard a talk by Winfried Denk of the Max-Planck Institute in Heidelberg, Germany, which was technically about brain circuit reconstruction using sectioning electron microscopy. My magpie mind (ooh! shiny!) got sidetracked early on, however, by the fact that most of major breakthroughs in early neuroscience came about because of the development of two critical technologies: histological staining techniques, and photomicroscopy.

We have Camillo Golgi to thank for the first one. In the late 19th century, he discovered that treating brain tissue with a silver chromate solution caused a small number of neurons to become darkly stained, revealing their detailed structure. (I've also seen the technique described as using a weak solution of silver nitrate to stain individual nerve and cell structures, in a so-called "black reaction.") Golgi's method revolutionized the field, so he can be forgiven for misinterpreting the structural organization of the central nervous system. He thought that nervous tissue was made up an intricate web of interconnected cells (the rete nervosa diffusa, or diffuse neural network), much like the human circulatory system. As scientific hypotheses go, it seemed a perfectly respectable working model, and was accepted as such by the scientific community, until a rapscallion upstart named Santiago Ramon y Cajal proffered a competing view based on his own experiments using a modified version of Golgi's staining technique.

Even today, Cajal is lauded as one of the key founders of modern neuroscience; Denk declared him the "most accomplished anatomist in neuroscience history." He was perhaps destined to turn science on its ear, since he was a notorious trouble-making hothead in his youth in Aragon, Spain. He was kicked out from numerous schools for his "poor behavior and anti-authoritarian attitude," and even landed in jail at the tender age of 11 "for destroying a town gate with a homemade cannon." I'm sure it was just a science experiment gone awry, a worthy price to pay for fostering natural inquisitiveness and scientific inquiry. (Rocket pioneer Werner von Braun got into trouble with authorities as a young boy, too, when he strapped a homemade rocket to a toy wagon and sent it speeding through the town square.)

Cajal had a sensitive, less pugnacious side as well: he was an avid painter, and very much wanted to be an artist. His father, a professor of applied anatomy in the University of Saragossa, nixed that idea, however, in favor of a more practical bent. The young Cajal was apprenticed first to a barber, then to a cobbler, before embarking on medical studies, graduating fro the medical school of Zaragoza in 1873. But he never really abandoned art: his gift for draughtsmanship would end up serving him very well in his medical and scientific career. (At right is Cajal's drawing of the neural circuitry of the rodent hippocampus, published in his Histologie du System Nerveux de l'Homme et des Vertebrates in 1911. That opus provided the foundation of modern neuroanatomy.)

His early career unfolded fairly predictably, Fresh out of med school, Cajal served as a medical officer in the Spanish Army, stationed for a year in Cuba, where he handily contracted both malaria and tuberculosis. He bounced back, though, got married, produced seven offspring, and became a professor at Valencia in 1881. A few years earlier, he used "every peseta saved from the service in Cuba" to purchase a rickety old microscope, which he used to study the structure of muscle fibers, among other things. And thus began what would become a most illustrious scientific career.

In 1887, at the age of 35, Cajal made a fateful trip to Madrid to meet with Luis Simarro Lacabra, a psychiatrist with an interest in histological research, who had himself just returned from Paris bearing brain tissue specimens stained with Golgi's method (developed some 14 years earlier). Cajal was writing a book on histological techniques, and collecting illustrations to accompany the text. Even though he'd only been studying the nervous system for about a year, he realized that the ordinary methods for studying nervous tissue were woefully inadequate. So the specimens Lacabra showed him proved to be a revelation. In his autobiography, years later, Cajal described his reactions on seeing nerve cells "coloured brownish black even to their finest branchlets, standing out with unsurpassable clarity upon a transparent yellow background. All was sharp as a sketch with Chinese ink."

The experience changed the course of Cajal's research, as he worked vigorously to apply the Golgi stain to tissues of the retina, the cerebellum and spinal cord. "As new facts appeared in my preparations, ideas boiled up and jostled each other in my mind. A fever for publication devoured me." And publish he did; his works and articles numbered more than 100 by the time he died in Madrid in 1934, not just on the fine structure of the nervous system, but also on muscles, tissues and other more general areas of pathology. (He also has an asteroid named after him -- an honor he now shares, apparently, with bloggers Bad Astronomer Phil Plait, fire-breathing atheist PZ Myers, and SkepChick Rebecca Watson. And I'll bet Cajal totally would have had a blog had the technology been available to him.)

More importantly, he arrived at very different conclusions than Golgi about the structure of the central nervous system. Recall that Golgi advocated the view that nervous tissue was a continuous web of interconnected cells. Cajal advanced the notion that the nervous system is comprised of billions of separate neurons, communicating with each other via highly specialized junctions (called "synapses" for the first time in 1897). This became known as the "neuron doctrine," which concludes that the basic units of the nervous system are individual cellular elements. Cajal also advanced the "law of dynamic polarization," concluding that nerve cells are polarized, receiving information on their dendrites and conducting information to distant locations through axons -- now a fundamental principle of neural connections.

Back then, it was a controversial view, since it contradicted Golgi's own model, but Cajal defended it fiercely, and later studies with electron microscopy bore him out by revealing that each neuron was enclosed within a plasma membrane. The two men ended up sharing the 1906 Nobel Prize in Physiology or Medicine. It seems fair. After all, Golgi invented the staining technique used by Cajal to form his hypothesis, and used it to produce the first descriptions of the different types of neurons, and the structure of glial cells, as well as the branches given off by the axon. Also, there are those in the field who argue that if you take into account the later discovery of electrical synapses, Golgi was at least partially correct that the central nervous system is a vast interconnected network -- it's just not the cells themselves that are connected.

It made for an interesting pair of Nobel lectures, though: the two men contradicted each other in their talks, each espousing his own theory of the organization of the central nervous system. For all the intensity of their scientific disagreement, the two men nonetheless respected each other's work. Writing about his Nobel honor, Cajal observed: "The other half was very justly adjudicated to the illustrious professor of Pavia, Camillo Golgi, the originator of the method with which I accomplished my most striking discoveries."

In addition to staining techniques, imaging techniques proved equally important to the development of neuroscience -- particularly the micrograph, a photo taken through a microscope to produce a magnified image of the sample. It's sometimes called a photomicrograph, and Wikipedia credits a Canadian inventor named Reginald Aubrey Fessenden with its invention, although he's best known for his pioneering breakthroughs in radio broadcast technology (as well as holding a 1926 patent for an "infuser," apparently a device for making tea). It's easy enough, in concept, to build a rudimentary photomicrograph: just attach a camera to the microscope in place of the eyepiece, place a specimen under the microscope as usual, and take as many pictures as you like.

It's a standard tool in forensics to examine trace evidence, and in biology (and neuroscience) to take magnified photos of cells and proteins -- and, if you happen to be Roman Vishniac, of insect eyes. Vishniac was a pioneer in the field, known for his photographs of living creatures in full motion, and -- more weirdly -- for taking a series of revolutionary photographs from the inside of a firefly's eye (the image at left is his daughter, Maria, seen through a firefly's 4600 tiny ommatidia). He also took pictures of the circulating blood inside a hamster's cheek pouch, and invented a method of colorization in the 1960s and early 1970s that used polarized light to penetrate cell structure in greater detail in an image.

The issue of better penetration turns out to be a critical one in modern efforts to image the brain, at least from what I gleaned from Denk's talk last week. Whereas pioneers like Cajal laid the foundations for modern neuroscience by imaging thin slices of dead brain tissue cells, researchers like Denk are coming up with inventive new ways to image living tissue -- or rather, combining lots of different optically-based techniques to see the previously "un-seeable."

For example, modern neurobiologists are combining things like multi-photon microscopy (Denk pioneered two-photon microscopy, in fact, which allows imaging of living tissue to a depth of about 1 millimeter), various types of scanning electron microscopy, fiberscopes, voltage sensitive dyes, and adaptive optics, among other tools, to engage in a kind of reverse engineering of the brain in action. The latter proved especially important because brain tissue can be tough to penetrate optically: the light scatters, and the wavefront distorts. Applying adaptive optics unscrambles the wavefront, so to speak, producing a clearer image. It's used quite a bit in astronomy to remove the effects of atmospheric distortion, compensating for any distorted wavefronts via deformable mirrors (or, less commonly, by employing materials with varying refractive properties).

Just to give you an idea of how daunting a task it can be to map out neurons and neuronal assemblies, Denk cited a seminal 1984 paper that laid out the "map" for the humble nematode (C elegans), a simple creature with a complex neurosystem model featuring 502 neurons. It took the scientists 10 years to complete the analysis, and the paper is a whopping 340 pages. It would take even longer to map out the neurosystem of a fruitfly brain, or a mouse brain, never mind the human brain.

Sure, Denk et al are using cutting-edge tools not previously possible before the advent of the modern computing age (among other advances), but ultimately, they're still doing optical imaging. Maybe that's why Denk's home page describes his work as a kind of "return of the light microscope to the front lines of biological research." By making the most of the tools available to them, and coming up with new approaches and combinations, Denk and his ilk are very much the intellectual descendants of Golgi and Cajal.

into the infrared

It's a lazy Easter Sunday, with no plans other than to lounge around the loft with the Spousal Unit and resident cat, surfing the InterTubes for amusing items -- like this wonderful site detailing fiendish experiments on Peeps -- perhaps pausing now and then to reflect on Life With a Capital "L." Among other things, I was shocked to realize that I am more than halfway through my three-month fellowship at KITP, with only four more "Journal Club" sessions to go. It's been a lot of fun: we've had sessions on "The Art of the Book Deal"; a rousing panel discussion on ongoing tensions between scientists and the media (which the Spousal Unit describes at length here); a brainstorming session on scientists in Hollywood, in which we devised the framework for a physics-centric (or at least science-centric) TV series; and of course, a session on Science Blogging 101, in which I set up a blog for our cat, Clio, on Blogger just to illustrate how easy it is. (If Chad at Uncertain Principles can write a book about conversations with his dog about quantum mechanics, Clio can have her own blog.)

My musings reminded me that I've been meaning to write a post about the infrared photography of Caltech's Tom Prince, who's currently at KITP on sabbatical before heading back to Pasadena to take the helm of the newly funded Keck Institute for Space Studies. We hope it will be abbreviated KISS, making it possibly the best science acronym ever. As a handful of shyer souls beat a hasty exit when I asked if anyone wanted to participate in a practice press conference, Tom graciously volunteered to be the guinea pig during the session on Press Conference Protocol. (I have since learned to give people advance notice and ferret out volunteers beforehand.) He spoke for 10 minutes or so about his hobby -- complete with sample photographs of KITP in the infrared -- and took a few questions from the audience afterward. The photographs are truly stunning. Check this out:

And here's another that captures the nearby beach and big blue sky:

It's tough to pinpoint at first what makes these photographs so striking, but it's related to the properties of near-infrared light -- i.e., light just beyond the visible spectrum (wavelengths between 700 nm to 1200 nm, usually falling around 900 nm). Infrared photography records what the human eye cannot see. Many materials reflect and transmit IR light in a different manner than visible light. So there are elements in IR images that resemble photographic negatives (although these pix are clearly not negatives). Blues, browns and dark greens in shadow appear dark, while reds, whites and greens in sunlight appear light. Take a portrait of your loved one and the skin will have a chalky appearance in the IR image, red lips will be pale, and the eyes will show up as dark spots. Vegetation comes out very bright in IR photographs, while a clear sky appears dark, apart from the occasional white cloud.

Andrew Davidhazy of the Imaging and Photographic Technology Department at the Rochester Institute of Technology explains on his Website that this last effect occurs because of "the high near-infrared transmission characteristics of green chlorophyll and high infrared reflectance of the underlying cellulosic structure of these subjects." Among other things, this can be used in aerial surveys and reconnaissance to distinguish trees and grass from diseased or dead trees or burned grass, since those appear dark in IR photographs. (You do need to use a special filter for IR photography, and special IR film if you're using a traditional camera, since otherwise the infrared effect is masked by the exposure to visible light. And  note that this is not the same thing as thermal imaging: IR photography uses radiation reflected from the subject to form images, whereas thermography uses IR radiation naturally emitted by objects, and requires special IR sensors.)

Ideally, the photographer takes all these effects into consideration when composing a scene or choosing topics. Tom said that he tries to take his photographs on bright sunny days -- very common in Santa Barbara -- because there is more IR light when the sun is bright, making the high-contrast effects that much stronger, although he's gotten some interesting, moodier effects in photographs taken on cloudy days. Other suggestions from IR photographers include taking pictures in a graveyard, because the grass will come out almost completely white, with the dark tombstone seeming to almost float eerily in space. Stone buildings covered in ivy or other creeping vegetation also yield striking, high-contrast IR images. And apparently, if you photograph people wearing sunglasses, it's sometimes possible to see the eyes behind the opaque shades in an IR photograph, because the filters used in the sunglasses don't have any effect on IR light.

Tom is just one among thousands of IR photography enthusiasts around the world, as I discovered when I Googled the term after his talk. My research yielded a rich lode of fascinating details. I already knew that infrared light was discovered by Sir Frederick William Herschel, best known for building killer telescopes in the 18th century and discovering the planet Uranus. In 1800, Herschel took some time away from his telescopic observations to fiddle with a different kind of experiment: passing sunlight through different colored filters. The different colors seemed to pass different amounts of heat, so he took things one step further, and passed sunlight through a glass prism to create the telltale rainbow spectrum of visible light. Then he measured the temperature of each bulb.

Herschel found that not only were all the measured temperatures higher than the controls, but those temperatures increased with each color from the violet to the red part of the spectrum. And when he decided, just for curiosity's sake, to measure the temperature just beyond the red portion of the visible spectrum, it had the highest temperature of all. Herschel attributed the effect to "calorific rays," and subsequent experiments demonstrated that they behaved just like visible light -- not surprising, since what he'd discovered was infrared radiation. It was the first demonstration that there were types of light beyond the visible spectrum.

Infrared radiation spawned not only a host of practical applications, but also an entire field of astronomy. Infrared telescopes can see past the huge amounts of interstellar dust in the cosmos into the very hearts of galaxies. People had figured out how to take infrared photographs as recently as the 19th century, but it wasn't easy. In the early 20th century, however, scientists developed special infrared dye sensitizers to create infrared films, and the use quickly spread from the laboratory into more practical applications. In the late 1920s, for instance, John Logie Baird developed the first working infrared videosystem, Noctovision, which, among other things, made it possible to film nighttime scenes during the day (a technique known as "day for night," or, as Jen-Luc Piquant prefers to phrase it, La Nuit Americaine). Just underexpose the shot a little bit; then a dark sky with bright moon-lit clouds and deep shadows looks pretty much how we'd expect a nighttime scene to appear.

Today, IR photography has found application in the study of plant diseases, revealing changes in pigment or cellular material; in paleobotany; to enhance details of deeply pigmented tissues in photomicrography in the biological sciences; and by the textile industry to detect irregularities in fibers. It is also used quite often in criminal investigations to examine and identify cloth, fibers and hair, and it's become a standard laboratory tool for imaging faded, damaged or altered documents. It makes clear the differentiation between pigments, dyes and inks, so if something has been overwritten, you can sometimes figure out the underlying text using IR imaging techniques. This proved handy in the 1930s, for example, when people wanted to see what lay underneath the blacked-out portions of documents vetted through censors.

Davidhazy has a terrific example of this infrared luminescence (or fluorescence in the infrared) on his Website. Twenty years earlier, a mother had placed a letter to her children in a homemade time capsule and buried it near the cornerstone of their house, intending it to be unearthed and read 20 years into the future. Unfortunately, when he now-grown children did so, much of the ink had washed away because water had seeped into the box. There was residual ink, however, albeit not visible to the human eye. When the letter was illminated with light devoid of IR wavelengths, the residual inks fluoresced in the infrared, and when filtered through an IR transmitting filter placed over the lens of a camera, those emissions were captured on Kodak high-speed infrared film. And the children were able to read their mother's words after all.

The rise of the digital camera is beginning to eclipse the use of actual IR film and traditional cameras. No longer is there any need to fuss with all those chemical and mechanical processes. Instead of focusing reflected incoming light onto a piece of film, a digital camera focuses that light onto a semiconductor device -- either a charge coupled device (CCD) or complementary metal oxide semiconductor (CMOS) technology -- that records light electronically, converting that light into electrical charges.

The CCD and CMOS chips used in digital cameras are already very sensitive to near infrared, not just visible light, which is why these cameras come equipped with filters to remove the infrared. Tom Prince simply adapted his standard digital camera with an opaque filter that cuts out the visible light and enhances the infrared, for a cost of roughly $250. (He doesn't recommend doing so yourself unless you have easy access to a clean room, as it requires opening the camera and exposing the delicate electronic innards to particles in the environment.) Using such a filter, you can't see the shot through the viewfinder. Tom (and, I assume, other IR photographers) have to compose the shot with the filter off, steady the camera in place, put the filter back on, adjust the focus, and then take the shot. It's a little hit and miss, but as the images featured in this post attest, you can get some genuine stunners.

So what happens when you take a color photograph using an infrared filter? Tom has tried that, too, and it is possible to do so. It's just a bit more work, since you need to take two pictures: one with the IR filter, and immediately after, another regular photograph. They need to be in alignment, too, so most IR hobbyists recommend using a sturdy tripod to hold the camera in place. And don't forget to take both photos with the same aperture settings to ensure consistent depth of field. The two photos can then be merged in Photoshop, where one can modify the color channels directly. Any color image can be broken down into the red, green, and blue channels (which is how color images are created); IR light in that context is just another "channel." Here's one of Tom's color IR photographs:

The overall effect isn't quite so much of an eerie contrast, although one still gets the sense of something being "different" about the photograph. Here's the same scene in standard IR black-and-white, for comparison:

You can see many other examples of infrared photography by several different photographers by browsing this gallery of links, and several examples comparing and contrasting color and B&W IR photographs here. Why not browse a little bit and savor a novel way of looking at the world? It's way cooler than rose-colored glasses.

virulent ramblings

Since we're all in mourning this week for the loss of Arthur C. Clarke, I thought I'd put in a good word for one of my other favorite sci-fi authors: Connie Willis. There are many reasons I love Willis' work, not least of which is her ability to mix funky, cutting-edge science (time travel, chaos theory, neuroscience) with literary and historical references (Lincoln's Dreams), witty dialogue (Bellwether), colorful characters, elements of farce and slapstick (To Say Nothing of the Dog), and somehow also manage to break your heart (Passages) -- usually all in the same book.

Her big breakthrough novel was the Hugo-Award-winning The Doomsday Book, in which a young idealistic medieval historian in futuristic Oxford, England, travels back in time to the Middle Ages and finds herself trapped in a small village just as the Black Plague reaches the area. Spoiler alert! Everybody dies. Duh. Every sci-fi fan knows about the "Grandfather paradox," and savvy writers like Willis tend to adhere to the trope that time travelers can't change the course of history. And it's a matter of historical record that most villages saw 80%-100% mortality rates. Most of the European population was wiped out during the Plague Years. The fact that people panicked and fled only helped spread the disease faster.

Panic reactions and the spread of global disease was actually the subject of a session at the recent APS March meeting in New Orleans by researchers from the Max Planck Institute for Dynamics and Self-Organization. Recognizing that human beings will "change their dispersal characteristics" in response to local infections -- i.e., panic and flee to avoid becoming infected themselves. Not surprisingly (to me, anyway), they found that "the individual rationale of avoiding an epidemic wave... actually facilitates epidemic spread" -- at least in one of their models. A more fully developed dynamical model apparently showed the same effect, but also "an increased extinction probability of the epidemic as a function of increasing dispersal response." In other words, sure, the hypothetical "epidemic" spread faster as individuals dispersed broadly to avoid infection, but this also increased the likelihood that the epidemic would die out -- hopefully before everybody fell victim to the disease.

Epidemiological models of the dynamics of epidemics are tough nuts to crack precisely because there are so many unpredictable variables: not just irrational (or even rational) human behavior, but the behavior of whatever is the cause of the disease itself, whether it be a bacteria or a virus (or a virus that targets bacteria), whether it's vector-borne, or otherwise disseminated. Viruses can mutate into many different strains, for starters, and in some of these multistrain cases -- dengue fever, the Ebola virus --  the antibodies produced by the human immune system to ward off the primary infection can actually increase one's vulnerability to acquiring a secondary infection with a different strain.

So naturally, scientists would like to have a clearer picture of human mobility patterns -- preferably one that can be universally applied. There's good news on that front! Researchers at Northeastern University and Notre Dame University have analyzed cell phone usage to demonstrate that human mobility can be described by the same universal pattern, regardless of what our individual travel habits may be. It's been tough to model this sort of thing in the past, because scientists just haven't had the tools required to monitor the movements of a large number of people in real time. The ubiquitousness of the cell phone in modern society has changed all that: now it's possible to track people's movements by following the cell phone trail.

These patterns could be useful in urban planning, traffic forecasting, and of course, the spread of diseases and viruses. The latter would include the possibility of cell phone software viruses, in which malevolent code could be transmitted either via text messaging or through Bluetooth connections between devices. Each transmission pathway would require different countermeasures, according to Pu Wang of Northeastern (one of the speakers at a March Meeting session), since text message viruses, like email, would spread through social networks rather than the physical location of the actual cell phones, whereas a Bluetooth-specific virus would spread among cell phones in close proximity.

Some primer notes: The technical definition of a virus is "a sub-microscopic infectious agent that is unable to grow or reproduce outside a host cell." (I'm sure there's a more complicated definition than that, because otherwise, most reproductive processes would fall into this category.) They cause everything from the common cold, to rabies, yellow fever, smallpox, and the flu, and they don't respond to antibiotics, although some antiviral drugs have been successfully developed to treat a few critical types of infection, and vaccines can also prevent infection in the first place (polio has almost been eradicated, although rare cases still pop up now and then).

There are various historical records dating back to the 10th century indicating that folks understood something about the infectious nature of smallpox and measles, but I was intrigued to learn that a physician named Ibn Khatima discovered in the 14th century that the bubonic plague (Black Death) and other infectious diseases were caused by micro-organisms entering the human body. And of course, by the late 18th century, Edward Jenner had figured out that a milkmaid who had caught cowpox proved immune to smallpox (a related virus), and used it to develop the first smallpox vaccine. (Smallpox has been eradicated, per the pronouncement of the World Health Organization in 1979.)

There are countless strains of any one virus, and different types of viruses beyond that, which makes one wish there existed something like a periodic table of viruses just to keep everything straight. But we did learn the difference between simple viruses like the cowpea chlorotic mottle virus (CCMV), and bacterial viruses (those that attack bacteria): CCMV has a more easily compressed single-stranded RNA center, while bacterial viruses contain double-stranded DNA. That's noteworthy because a DNA strand typically measures some 17 microns in length, whereas a viral protein capsid is 60 nanometers -- 1000 times smaller than the length of the DNA. So the DNA has to fold up and squeeze into a very tiny space. That means the bacterial virus's capsid must be strong enough to contain the immense internal pressure of roughly 50 atmospheres. (Yowza!) Another difference is that unlike CCMV, bacterial viruses bind to receptor points on bacteria, and then the DNA comes shooting out, just like the cork of a just-opened bottle of champagne.

Bogdan Dragnea of Indiana University in Bloomington is one of a growing number of researchers interested in the physics of viral protein cages, or capsids. They're intriguing because they self-assemble to contain nucleic acid (RNA or DNA), and Dragnea is among those toying with constructing artificial viruses containing nanoparticles, droplets, drugs, or other elements besides nucleic acids. Among other things, he's embedded negatively charged gold nanoparticles inside viral capsids by exploiting their attraction to the positively charged proteins lining the capsids. This mimics the interaction between "anionic genetic contents" (RNA and DNA) and those same positively charged proteins in real viruses.

He's also encased fluorescent quantum dots of cadmium selenide crystals in a shell of zinc sulfide, which he then used to track how long it took for a particular virus to travel across a cell membrane (because the dots glow for extended periods). Dragnea's artificial viruses aren't "infectious" the way a natural virus might be, but he does believe it may one day be possible to replace vaccines -- made from actual viruses -- with completely artificial versions, thereby avoiding the risk of causing an outbreak of the very disease one is trying to prevent.

It's all part and parcel of an exciting new field called physical virology, which is getting its very first Gordon Conference next February (Dragnea is one of the organizers). Dragnea's early work focused on the Brome mosaic virus. The March Meeting session featured new research using CCMV which specifically infects the cowpea plant, more commonly known as the black-eyed pea.  Just imagine the poor little cowpea, innocently hanging out in a field, photosynthesizing to its heart's content, only to fall victim to a tiny invader that causes yellow spots to form on the cowpea's pretty leaves. It's unsightly, and and ultimately fatal to the plant. Next time there's a shortage of black-eyed peas, blame CCMV.

CCMV is a favorite choice for physical virologists because it's so easy to replicate and use -- it's like the hydrogen atom of viruses. That's because it's so evolutionarily designed for self-assembly that, according to UCLA's Charles Knobler, you can literally break them into their constituent parts, put them into a test tube with some sort of solution, shake them up a bit, and get fresh virus out. Under the right conditions, its purified coat protein mixed together in vitro with its genetic material will spontaneously assemble into infectious particles.

Wow. That's like the T-1000 in Terminator 2: Judgment Day literally reassembling itself after being frozen solid with liquid nitrogen, blown into tiny bits, then having the bits melt back into liquid form and "find" each other. The cowpea population could be doomed. (Jen-Luc Piquant isn't that fond of black-eyed peas anyway, but the plant leaves are so pretty.)

Knobler is investigating what determines the size of a virus. The answer appears to be some combination of polymer length, molecular weight, and capsid size, in an intricate self-assembling interplay. It is possible to manipulate the length of protein building blocks in the CCMV and the size of the capsid in such a way as to use virus proteins not only to make nonbiological particles that contain foreign molecules, but also that conform to a specific intended structure.

Building on the spontaneous re-assembly that occurs when purified viral RNA and capsid proteins are mixed in a solution at just the right pH and ionic strength, Knobler tweaked the parameters a bit, changing the solution conditions to cause the formation of empty capsids, multishell structures, tubes and sheets. He also examined the self-assembly process with different molecular weights, and noted that two distinct capsid sizes seemed to be preferred: 22 nanometers for lower molecular weights, and 27 nanometers at higher molecular weights. (I'm admittedly a bit fuzzy on the significance of that, but it's nice to have things narrowed down so specifically.)

Adam Zlotnick and his colleagues at the University of Oklahoma Health Sciences Center can manipulate the CCMV coat protein in such a way as to redirect its self-assembly to produce tubular structures. They didn't rely simply on static models based solely on the structure of the CCMV virus, which Zlotnick believes can lead to false predictions, namely, that CCMV capsids are extremely stable, and the assembly relies critically on hexamer (6 linked molecules) formation. That turns out not to be the case. "Experimentally, we have found that capsids are based on a network of extremely weak pairwise interactions and that pentamer (five linked molecules) formation is the critical step in assembly kinetics," he said. Far from being static structures, viruses are "very dynamic molecule machines based on weak energy interactions."

Furthermore, because those interactions are weak, it is possible to interrupt the assembly process to generate, say, tubular structures in addition to spheres -- or even keep the virus from forming completely in the first place. (Low pH seems to be one way to do the trick.) His kinetic models more closely match those experimental observations. And the fact that it's possible to disrupt and manipulate the process bodes well for the bottom-up production of manmade nanostructures via self-assembly for any number of applications, including the development of new antiviral drugs.

Per Zlotnick: "Knowing the structure of a virus gives us a snapshot, but add the knowledge about the kinetic process of assembly, and we have a much more complete picture" of how a virus works. And the more we know, the more we can manipulate and control. Perhaps one day, we could even defeat the common cold. But let's start with the saving the humble cowpea.

Sir Arthur C. Clarke, 1917-2008

"Sometimes I think we're alone in the universe, and sometimes I think we're not. In either case the idea is quite staggering." -Sir Arthur C. Clarke

Arthur C. Clarke, one of the Golden Age science fiction writers who fired the imagination of would-be space explorers everywhere, died today in his home in Sri Lanka. Clarke's 2001: A Space Odyssey was probably one of the most influential novels in the genre, along with the Stanley Kubrick movie made from it. His creation Hal  was an early model (good and bad) for AI constructs, along with Asimov's Three Laws of Robotics. From his first novel, Prelude to Space, which foreshadowed the Apollo missions to the moon, to The Fountains of Paradise, in which he described the construction of a space elevator now in the planning stages, Clarke, an engineer, was a practical visionary whose predictions had a habit of coming true. In 1945, he sketched out in a published paper the utility of geosynchronous satellites for communications purposes almost ten years before the folks at Bell Labs launched the Telstar and Echo satellites. Though he was by no means the originator of the idea, he was certainly a popularizer and active proponent of it, as he was of technology in general, and space exploration in particular.

Though his characters could be two-dimensional, his science was generally impeccable and inspiring. No one in my childhood reading made space or the possibility of "slip[ping] the surly bonds of earth" seem so real to me, not even Star Trek. It was Clarke who taught me what geosynchronous orbit and LaGrange points are, proving that a spoonful of fiction helps the mathematics go down, at least to people like me. That inspiration wasn't confined to interesting kids in science fiction. “I’m rather proud of the fact that I know several astronauts who became astronauts through reading my books,” Clarke once said. I can only imagine how many engineers and other space scientists he inspired.

Aside from his novels, Clarke was best known for his three laws of science and technology:

1. "When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong."
2. "The only way of discovering the limits of the possible is to venture a little way past them into the impossible."
3. "Any sufficiently advanced technology is indistinguishable from magic."

While the first two are important for egging on inventions and new discoveries, it will be useful to remember the third law should we ever meet an intelligent extraterrestrial civilization face to face, since far too many of us are prone to worship what we don't understand, as Clarke also illustrated in his Rama books. Generally dismissive of religion, Clarke was still painfully aware of the necessity of some kind of guiding morality. "As our own species is in the process of proving, one cannot have superior science and inferior morals. The combination is unstable and self-destroying," Clarke said in 1967. It's still a timely message.

Thanks for years and volumes of inspiration and great Saturday afternoons. RIP.

[Don't blame Jennifer for this. It's one of Lee Kottner's insidiuos posts, cross-posted from Spawn of Blogorrhea with Jennifer's consent.]

cut and run

Is anyone else tempted to take all their money out of their respective bank accounts and IRAs and just hide everything under the mattress, so we'll have ready cash after the apocalypse? That's how I'm feeling at the moment, after watching one of the nation's most venerable financial institutions, Bear Stearns, crash and burn in the space of just a few days. A few weeks ago, their shares were valued at around $170. By last week, that had dropped to $70. And this morning, I awoke to read that, thanks to a bailout by the feds, J.P. Morgan will be buying Bear Stearns for the rock-bottom price of $2 a share. The entire Bear Stearns headquarters building in Manhattan is worth more than that! Maybe they'll throw in a set of Ginzu knives with the purchase. ("Now how much would you pay?")

How art the mighty fallen. It wasn't that long ago that Bear Stearns was listed as one of the most admired financial institutions. Turns it out it was all an elaborate house of cards, much like the Enron meltdown of a few years ago, except this time it's worse, because stocks are tumbling globally, not just in the US. That's what happens when a company (or a nation) over-extends itself and takes on far too much debt. I'm sure James Cayne, the former CEO, feels just terrible -- maybe even badly enough to pause for reflection while rolling in the great wads of cash he raked in during his tenure: $232 million in compensation from 1993 to 2006. Personally, I think he should be forced to give some of it back to help bail out the company he helped drive into the ground. Call it a return to the traditional conservative values of accepting responsibility for financial imprudence.

No doubt Bush and Cronies will dismiss this as one of those statistical outliers, a "rare event" in the financial markets, instead of something that could have been avoided had management been a bit more prudent. I find myself wondering what Eugene Stanley of Boston University would have to say about the mess. He's one of the pioneers of econophysics, and was on hand at the APS March Meeting in New Orleans to talk about his latest research: namely, that these so-called "outlier" rare events actually occur in regular patterns, and thus should be incorporated into economic theories, which to date have dismissed them as "anomalies."

Stanley can make this statement with some degree of confidence because he's just completed analysis (with the help of numerous grad students and post docs) of an enormous amount of financial data -- 200 million transactions on the New York Stock Exchange spanning a two-year period. That's far more than has ever been included in such analyses before (10<8> data points, compared to 10<4> data points). "Classic economic theories not only fail for a few outliers, but there occur similar outliers of every possible size," he said. "So ignoring them is not a responsible option." He's applying the tools of physics to figure out if there are underlying unifying principles (equivalent to physical "laws") that dominate the NYSE and other financial bodies and institutions -- i.e., whether there is "an identical set of laws hat hold across diverse markets, and over diverse time periods."

Econophysics is a relatively new field, emerging in the mid-1990s thanks to the work of several physicists who decided to apply the tools of statistical mechanics to the complex problems posed by financial markets in particular. It was the right time for this to happen: not only did huge amounts of data suddenly become available in the 1980s, but there were an increasing number of PhD physicists fleeing the stagnant job markets in their fields for Wall Street, finding work as "quants" -- basically, sophisticated financial analysts. At the same time, according to Wikipedia, "It became apparent that traditional methods of analysis were insufficient. Standard economic methods dealt with homogenous agents and equilibrium, while many of the more interesting phenomena in financial markets fundamentally depended on heterogenous agents and far-from-equilibrium situations."

Lots of different physics models have been applied to financial systems, including percolation models, diffusion theory (the famed Black-Scholes equation garnered a Nobel Prize in Economics), models with self-organizing criticality of complexity, models developed for earthquake prediction, even chaotic models originally developed to study cardiac arrest. That was the topic of another paper at the March Meeting, in fact. Nothing that fractal analyses of cardiac rhythms suggest that healthy people have complex cardiac behavior -- compared to the rhythms of unhealthy people, which are more random or periodic in behavior -- researchers at Brigham Young University are looking into whether similar complexity might be an indication of a healthy company. The title of their paper: "Fractal Hearts are Healthy Hearts -- Are Fractal Companies Healthy Companies?" (If so, I'd bet Bear Stearns would have failed any test devised along those lines.)

Stanley has used a spin glass model to describe stock market fluctuations. I've heard of biophysicists adopting a similar approach to, say, mutations of the flu virus. Apparently spin glass models are pretty generic in their applicability. They can be used whenever you have a complex system made up of lots of units: eg, stock market traders who all have different opinions, interact with each other, and make decisions based on the relative strengths of those interactions. The stronger the interaction -- or the more trustworthy a trader deems a colleague -- the more influence that interaction has. But the strength of those interactions can change with time, for example, if a trader loses confidence in a colleague. (Jen-Luc Piquant gives a rousing vote of "no confidence" to James Cayne, just for the record.)

Of course, treating human beings as if they were mere particles has its limitations; human behavior is inherently unpredictable. And no model is likely to ever enable analysts to predict a specific event in the stock market, any more than one can precisely pinpoint the time, location, and severity of an earthquake. Stanley was unequivocal about this, calling the stock market "a very complex system and probably insoluble," emphasizing, "There is absolutely no way anyone has been, or will be able to predict the future.

One of the prevailing economic theories is the random walk hypothesis for stock market prices, which basically says the prices can't be predicted due to the lack of correlation of past and present. Just because a stock rises one day, there's no guarantee it will rise again the next. Here's an interesting anecdote: Princeton economics professor Burton Malkiel -- author of A Random Walk Down Wall Street -- conducted an experiment with some of his students, giving them a hypothetical stock worth $50 at the outset.

Each day, he would flip a coin to determine the closing stock price for the day: heads, the stock closed half a point higher; tails, it would close half a point lower. So it was pretty much a 50/50 chance. Malkiel mapped out the cycles and trends in a chart and graph form, then took it to what's known in the financial industry as a "chartist" -- a person whose job it is to predict how the stock market will behave in the future based on past patterns. The chartist, not knowing Malkiel's data was based on a coin toss, immediately wanted to buy the stock, and was disappointed when the truth was revealed. Probably a bit depressed, too, since if the market and stocks are indeed as random as flipping a coin, he's pretty much out of a job. (You can create your own random walk with this spiffy online game involving virtual turtles.)

There are naysayers to the random walk hypothesis, most notably Martin Weber, who specialized in behavioral finance. He observed the stock market over 10 years, analyzing market prices for any signs of trends. He concluded that stocks with high price increases in the first five years tend to under-perform in the following five years. In a different study, he found that stocks with an upward revision for earnings tend to outperform other stocks in the next six months, giving investors a bit of an edge when deciding which stocks to pull out of the market and which ones to leave in (the ones with the upward revision -- at least for the next six months). Other naysayers include MIT's Andrew Lo and Craig MacKinley, who argue in A Non-Random Walk Down Wall Street (1999) that "even the casual observer can look at the many stock and index charts generated over the years and see the trends. if the market were random... there would never be the many long rises and declines so clearly evident in those charts." They believe the stock market is predictable.

Hmmm. I'm no economist, but I have some doubts about those "trends." First, human beings are kind of designed to see patterns, so it's easy to see something that isn't really there, and make a lucky guess based on the perceived trend, causing confirmation bias to kick in. I think this is a particular risk when you're working with a limited data set. That's why Stanley's work is noteworthy -- he's working with an order of magnitude more data. And while he definitely sees patterns, he appears to be looking less for short-term trends, and more for universal principles of economics. I guess we'll just have to let the proponents of the various models fight it out in the Economics Octagon until there's One Model Standing.

[Jen-Luc is rooting for the Relativistic Economic Model, which seeks to incorporate relativistic effects into economic analysis (h/t: Arjendu of Confused At a Higher Level). You know, deposit a small amount of money in a bank account, then rocket off into space at the speed of light, returning to find hardly any time has passed for you, but your meager deposit has accrued tons of interest, and you are rich, my friend -- stinking rich! Until you find, as Woody Allen's hapless time traveler did in Sleeper, that $1 billion doesn't go very far when a phone call from a public payphone costs a couple million. Inflation is such a buzzkill for the nouveau pseudo-riche.]

Apparent trends there may be, but to date, it's still impossible to predict the stock market with 100% precision (although Doyne Farmer and Norm Packard of Prediction Company are no doubt still trying, continually refining their methods). But we can continue to analyze probabilities to reduce risk, and better models translate into better risk management. That's something everyone at Bear Stearns should be able to get behind, along with the rest of Wall Street. Ironically, many economists have resisted the encroachment of physicists onto their academic territory; econophysics has had the greatest impact on models for price fluctuations in financial markets, with less of an impact on general principles of economics. Considering how those prevailing principles seem to be faring, maybe they should at least consider giving physicists like Eugene Stanley a try. Still, I doubt anyone could have predicted Bear Stearn's demise -- that's gotta be the outlier of outliers.

a coupla physicists sittin' around talkin'

Oh, frabjous day! We have so much to celebrate this March 14th. It's Pi Day, of course, and also the very first Talk Like a Physicist Day -- we have been employing physics-speak off and on in honor of the occasion: see some suggestions here and here. And as an amuse-bouche of sorts to this post, we offer this classic scene from 3rd Rock from the Sun, the very first hit sitcom to feature a physics professor (John Lithgow, playing an alien in disguise) as the main character, in which he explains to his students his method of grading on a transient loop. And it's also Albert Einstein's birthday. That's why we picked March 14th for Talk Like a Physicist Day, in fact. Besides, holding these sorts of whimsical Internet "holidays" on the same day keeps the calendar just a wee bit tidier. Perhaps some other, more major holidays could be combined in the future.

Anyway, this post might have possibly more typos and wrong links than usual, because (a) I had to prepare my usual talk for this Friday's KITP workshop -- all about the Art of the Book Deal, audio and PowerPoint are posted here  -- and (b) I'm getting sick again, having picked up some kind of virus while in New Orleans. This would be an excellent segue into a planned post on "designer viruses," the topic of an APS March Meeting session. But frankly, I'm not feeling up to it. Instead, this post will be a paean to all things Einstein, in honor of the venerable man's entrance onto the great stage of life.

What does it take to make a singular genius like Einstein, or an Isaac Newton for that matter (beyond the usual biological processes)? Hard to say. Little Al was the sort of kid who, by age 5, could be enthralled by the movement of the needle in a magnetic compass -- something he later said convinced him that there had to be "something behind things, something deeply hidden." I don't know about you, but even though I could read by 5, and was highly verbal, I doubt I was capable of that kind of insight at such a young age. Mostly, I was concerned about when we got to have milk and cookies before naptime in my kindergarten class.

So Einstein was a prodigy. Of sorts. He actually didn't do that well in school. (There's a nice little NPR bit from 2005 by David Kestenbaum, entitled "How Smart Was Einstein?") For years, his own parents thought he might be a bit "slow" because he spoke rather hesitantly, and didn't have the top grades one would expect a bona fide prodigy to earn. But really, Einstein was just bored to tears by the rigidly structured teaching methods of his formal education -- rote memorization and blind obedience weren't really his style. He most preferred to study on his own, reading books on math, physics and philosophy, among other topics. One of my favorite quotes of Einstein about his early education, made many years later, is this: "It's almost a miracle that modern teaching methods have not yet entirely strangled the holy curiosity of inquiry. For what this delicate little plant needs more than anything, besides stimulation, is freedom."

Einstein even failed the entrance exam for the prestigious Swiss Federal Institute of Technology, and ended up attending a local school in Aarau instead. This turned out to be a very good thing, because that learning environment was much more suited to his temperament, and intellectual gifts. His teachers gave him the freedom and latitude to pursue his own ideas. This is where he first encountered James Clerk Maxwell's theories of electromagnetism -- Maxwell's equations of light -- something that wasn't actually part of the standard curriculum at most schools at that time. (Nowadays, of course, it's absolutely required of physics students.)

He eventually wound up at the Institute of Technology in Zurich, where he graduated with a distinct lack of honors. That's how he ended up working as a patent clerk, doing theoretical physics on the side. He did assemble a small group of physicist pals, who called themselves the "Olympia Academy," and met periodically to discuss books, science and so forth. He wasn't without intellectual stimulation. And in 1905, all that prep work came to fruition. As Einstein later described it, "A storm broke loose in my mind" -- a storm on a par with, say, Hurricane Katrina. That was his so-called Annus Mirabilis (Miracle Year), in which he published not one, not two, not three, but FOUR seminal physics papers that influenced the field of physics of decades to come -- in fact, they changed the field forever.

To commemorate these achievements in 2005 (the World Year of Physics, and the 100th anniversary of Einstein's spectacular output), my pal James Riordon (a.k.a, blogger Buzz Skyline) wrote a charming poem about it, in the style of Dr. Seuss (illustrated by cartoonist Paul Dlugokencky, who also did the illustrations for The Physics of the Buffyverse). You can find it here, complete with hyperlinks for more information about the science. Here's my favorite lines:

He thought and he thought and he thought a bit more,

He thought 'til the thoughts made his thinking parts sore.

With a little deduction and persistence galore,

He thought of an answer, not thought of before.

Clever, no? Read the whole thing. The American Physical Society ended up publishing it as a little booklet, and also put together an award-winning 15-minute film on Einstein's Miracle Year. And of course, a couple of years later NOVA weighed in with its own documentary. Actually, Einstein gets quite a bit of play, all the time. He's probably the most instantly recognizable physicist in history, with his telltale mustache and wildly rumpled white hair.

Why the big deal over his 1905 papers? Not only were they seminal, offering novel solutions to problems physicists had been pondering for quite some time, but they ranged across a broad range of research areas. It's not like he was specializing on one particular flavor of quark, for example. This was a different, less highly specialized era, and Einstein was definitely a bit of a "Renaissance Man" in that context.

He wrote his first paper on the photoelectric effect: first observed in 1887 by Heinrich Hertz, who noticed that that shining a beam of ultraviolet light onto a metal plate would cause it to shoot sparks. Einstein explained that this happens because light is a beam of energy-carrying particles (which we know call photons), and when that beam is directed at a metal, the photons collide. This was an extension of Max Planck's work five years earlier proposing "quanta" and it's the work for which Einstein won the Nobel Prize in Physics in 1921. This paper was followed soon after by one contemplating Brownian motion (first postulated by a scientist/clergyman named Browne), concluding that if grains of pollen jiggled in a mud puddle, it wasn't because they were "alive," but because of the presence of molecules bumping into each other. In September, Einstein published his seminal paper on special relativity, outlining the principles of time dilation and length contraction, among other Big Ideas. And finally, he published the work for which he is most famous: E=mc<2>, or the equivalence of mass and energy. That principle forms the basis for, among other things, nuclear energy, and the nuclear bomb.

We haven't even mentioned General Relativity, which he developed subsequently, and which was confirmed to great fanfare in 1919. So I hope readers will join me in wishing Einstein a very happy birthday, wherever he may be. And, if they choose, they can also celebrate (as they see fit) Pi Day and Talk Like a Physicist Day as well. As for me, I've done my part. Now I'm going to go lie down. Look for more reports on the New Orleans meeting next week, when I'm feeling better.

reality bites

We're in the Big Easy, baby! And we're just a wee bit frazzled because there's simply too much to do and see, both in and around Nawlins, and at the APS March Meeting. They were handing out Mardi Gras beads in the press room (minus the usual requirement of flashing one's chest), where conversations covered everything from Eliot Spitzer's disgrace and the future of science publishing, to which one of the myriad competing parallel sessions one should attend. Should one go hear about block copolymer thin films or pyrochlores (rare earth metals)? Graphene transport or silicon photonics? Locomotion in complex fluids, or biological networks?

Or should one simply blow off an afternoon and take in the local sites and sounds? It's tough to resist the temptation in an iconic city like New Orleans -- one of the few towns (along with Montreal) where folks can pronounce my last name. Mostly, I have been working, although I did stop off at the legendary Cafe Du Monde for chicory-flavored cafe au lait and fresh beignets, and last night I indulged in a scrumptious dinner at Commander's Palace (in the Garden District) with Physics of NASCAR author Diandra Leslie-Pelecky -- gumbo to die for, and we both heartily recommend the bread pudding souffle for dessert. Alas, my shellfish allergy is severely limiting my dining options around these parts, where crawfish, crab and other crustaceans appear in some form in virtually every dish. But we can deal. At least I'm not allergic to beignets, which would be tragic indeed.

Perhaps in some future virtual world, I will be able to savor all the forbidden shellfish-based delicacies with no ill effects, and it will be almost like the real thing, because, according to University of Illinois physicist Alfred Hubler, I will inhabit a "mixed reality" state where there is no clear boundary between the real system and the virtual system: "The line blurs between what's real and what isn't."  Really, he said that. In a charming Teutonic accent, no less. It reminded me of a scene in The Matrix, where that despicable turncoat Cypher is dining with the Agents and observes that even though he knows the meal isn't technically "real," it feels and tastes just like it's real, and if it's good enough to fool the human brain, it's good enough for him after all those years struggling aboard the rebel ship Nebuchadnezzar. "Ignorance is bliss!"

Personally, I prefer the real world, with all its imperfections, but it's tough to deny the appeal of virtual worlds like Second Life. Not only can you have cafe au lait and beignets in a virtual New Orleans, but your avatar can literally make like Neo and fly there, with no need for cramped, overcrowded airplanes and the indignities routinely inflicted at airport security checkpoints by the TSA, just because they can. Oh yes -- we can all be The One, and wreak appropriate revenge on that over-zealous TSA employee in the Philly airport who confiscated the Spousal Unit's contact lens solution and my favorite lip gloss. Not that I'm bitter....

*ahem* Anyway, Hubler's just completed an experiment (the link is to his blog -- how cool is Hubler?) that he believes supports the existence of mixed reality states, using a real system -- in this case, a standard mechanical pendulum -- coupled with a virtual system (a virtual pendulum) that was programmed to follow the well-known equations of motion. He and his  colleagues sent data about the real pendulum to the virtual one, while sending information about the virtual pendulum to a motor that influenced the motion of the real pendulum. They found that when the two pendulums were of different lengths, they remained in a "dual reality state" in which their motion was uncorrelated, and thus not synchronized.

That in itself is not especially enlightening. But then they discovered that when the pendulum lengths were similar, they reached a critical transition point and became correlated, or, in Hubler's words, "They suddenly noticed each other, synchronized their motions, and danced together indefinitely." It's a lot like a typical phase transition, in fact: the critical temperature/pressure point wherein matter moves from one state (gas) to another (liquid). In this case, the phase transition occurs when the boundary between reality and virtual reality disappears.

This is the "mixed reality" state, where a real pendulum and a virtual pendulum move together as one. The trick is real-time feedback. Scientists have coupled mechanical pendulums with springs to create correlated motion, but without the staggering computational speed now achievable, coupling pendulums with a virtual system simply hadn't been possible. Per Hubler: "Computers are now fast enough that we can detect the position of the real pendulum, compute the dynamics of the virtual pendulum, and compute appropriate feedback to the real pendulum, all in real time." [That's the quote from the press release, but he said almost exactly the same thing in yesterday morning's press conference.]

As flight simulations, immersive VR, and online virtual games and worlds become increasingly accurate in their depictions of the real world, Hubler believes such "mixed reality" states via such "bidirectional coupling" will become more common. They could be very useful. Lasers, for example, are useful because of the synchronization of molecular motion. Laser light is "coherent," and thus all the molecules "help each other." Hubler thinks his lab-induced mixed reality states could be used to better understand real complex systems with a large number of parameters, by coupling a real system to a virtual one until their constant interactions result in a mixed reality state -- for instance, modeling neurons by coupling a real neuron with a virtual one.

Of course, Hubler admits that while there are benefits to be realized from such an effect, it could present problems. As an example, he pointed to the infamous wobbling of London's celebrated Millennium Bridge when it opened to much fanfare in June 2000. Thousands of pedestrians started walking across the bridge, and at first, nothing happened. Then, the bridge began to sway slightly until, quite suddenly, the wobble intensified to such an extent that people started walking in near-perfect unison without meaning to: left, right, left, right -- an enforced Sherman's March or something. The people began exhibiting the same coherent behavior as the molecules in laser light when the number and density of pedestrians on the bridge reached a critical threshold, resulting in the sudden transition to synchronized motion. This, in turn, exacerbated the bridge's wobble even more. The city was forced to shut down the $32 million bridge immediately (although it reopened in 2002 after being outfitted with strategic dampers, at an added cost of $8.9 million).

Similarly, while the human brain can be tricked, in The Matrix, into thinking one is consuming actual haute cuisine in a virtual environment because that environment so closely depicts "reality," there is also a downside. Remember what Morpheus told Neo after he failed to make that first virtual jump in the simulator, and, finding he was bleeding from the impact with the virtual pavement, said, "I thought it wasn't reality." Saith Morpheus: "The mind makes it real." You die in the Matrix, you die in the real world, because "The body cannot live without the mind."

Sure, it's just a sci-fi movie, but Hubler mentioned a series of recent experiments in what he unfortunately termed "out-of-body" experiences. He didn't mean anything mystical by it. He was just describing the effects when study participants were outfitted with 3D goggles that allowed them to see themselves from behind, via real-time video feedback. Then someone poked the participant from behind with a stick, making sure the "virtual" version of said participant was also poked. Eventually, they were able to only poke the virtual participant, yet the "meat world" version would see the action and immediately react as if he/she had actually been poked. The line between the real and virtual worlds had blurred to the point that study participants inhabited a "mixed reality" state, according to Hubler.

To me, this says that future generations of Second Life and other online games could become very exciting indeed, and almost indistinguishable from "reality." We're not there yet, if anyone finds this worrying. (As someone noted during the press conference, imagine if economic transactions in Second Life became so strongly coupled to, say, the real New York Stock Exchange that it caused a major market meltdown and folks didn't just lose their virtual shirts, but were bankrupted in the Real World as well.) Instantaneous interaction is a critical requirement and while we can manage this in the lab with real and virtual pendulums, expanding that to an entire virtual world will require even faster computers, as well as far better probes and actuators and other supporting device technologies. We've got a decade or so to prepare before The Matrix becomes "real" - or whatever "real" is going to mean by then.

a thousand paper cuts

It's a rare occasion when I go off on a bona fide rant, but I feel I must say something to the physics community, solely out of love (which means some of you won't want to hear it): what's with all the sour grapes of late, people? Maybe it was just an unfortunate coincidence, but almost everywhere I turned this past week, I was confronted with the grumpy toxic outpourings of various nattering nabobs of negativity. Even Jen-Luc Piquant lost patience with all the sniping, and she's faux-French, and thus naturally elitist, as well as a skilled connoisseur of the artfully disdainful put-down. Seriously, she can make other avatars cry with just a raised eyebrow and a dismissive shrug of her perpetually black-clad shoulders.

It wasn't constructive criticism either, just pointless griping about petty stuff. People were bitching about how physics students clearly have too much time on their hands if they're making silly YouTube videos; how dumb the ATLAS videos employing a Star Wars motif were (personally, I found them amusing and informative); and about how frivolous events like next week's Physics Singalong at the APS March Meeting in New Orleans, or Talk Like a Physicist Day, are silly and pointless and why are we celebrating scientific jargon anyway? And also? The Big Bang Theory sitcom will singlehandedly rot your brain and destroy science because of all the negative stereotypes. Just so you know. (I'm leaving out a few other instances because the above should be enough to make the point.)

I'm not suggesting we all become perky little Pollyanna cheerleaders -- ick, how horrid would that be? -- and frankly, one or two instances like those cited above in any given week would have little effect on my mood. No biggie. Let My People Bitch. But cumulatively, all in one week? It felt like the slow lingering death of my soul from a thousand paper cuts. Clearly I didn't get the memo about the approaching dark cloud of gloomy pessimism with scattered showers of snide disdain. Silly me, always out of the loop. I guess it made me a little hyper-aware of how prevalent these attitudes can become, very quickly -- and we give very little thought to how this might be perceived by those on the outside looking in.

You know, it's a really big playground out there, folks, and nobody is forcing you to play in any particular sandbox. Just politely opt out and find another sandbox more to your liking. It's as simple as that. What I just don't get is the compulsion to piss all over someone else's sandbox and spoil their fun, because you don't happen to like what they're doing, or had a particularly bad day. What, you don't like something, so nobody else should either? Get over it already.

I care deeply about the science community, and the field of physics in particular: it's filled with incredibly smart, altruistic, hard-working and good-hearted folks of great substance and depth, who also have a sense of humor and like to have fun on occasion. (*gasp* Haul out the smelling salts!) A big part of what I try to do, both here at the cocktail party and in the Real World (TM), is to convince those outside of physics that this is a community worth knowing, even embracing -- whether or not someone wants to become a professional scientist or not. It's very disheartening when there is a sudden wave of collective sourness that reinforces the (false) stereotype of physicists as dour, humorless buzzkills. This sort of thing does far more to damage the public perception of physicists than The Big Bang Theory, Talk Like a Physicist Day, silly YouTube videos, or March Meeting physics singalongs combined ever could.

Of course, it would be a shame to waste all that accumulated bile, so why not find a more productive outlet, and more deserving targets, for all that negative energy? For instance, vent your spleen over the latest round of devastating budget cuts by dashing off angry letters and emails to your government representatives -- or even your local newspaper -- whenever a foul mood strikes you. The American Physical Society, for starters, has a whole suite of advocacy tools, enabling you to write to Congress, join a science coalition, and even organize grassroots efforts on behalf of science locally. There are all kinds of groups and individuals working tirelessly behind the scenes to improve the situation, but a continuing collective outcry couldn't hurt, too.

In addition to the Department of Energy's ongoing woes, the uncertain fate of major projects like LISA, and the plight of Arecibo (just to name a few), news broke on Thursday that the UK is closing down Jodrell Bank, a venerable radio astronomy observatory in England. I'm sure other countries also have serious funding woes. Frankly, if things continue on the current draconian path in the US, there won't be much of a meaningful physics enterprise left in a few decades or so. A nostalgic physics singalong might seem just the ticket when PhD physicists find themselves forced to work in the local Tastee-Freez because all the major research facilities have been closed down for lack of funding. So channel your discontent and rage in such a way as to effect meaningful change if you feel the urge to vent.

Once you've got that out of your system, consider more positive efforts to effect change. That'll help keep more disgruntled bile from building up inside you, necessitating another outburst to clear the air. If you're in the Bay Area, maybe you could volunteer to help a local grade schooler participate in this year's Tech Challenge at the Tech Museum of Innovation, which centers on finding imaginative solutions to provide safe drinking water, especially in developing countries. Or consider reaching out to your local schools to help students appreciate the glories of science.

Opportunities to make a difference abound! Why, just last Monday, Neil Turok, cosmologist extraordinaire and this year's recipient of the TED award gave a blackboard lunch talk here at KITP describing a particularly intriguing project. In 2003, Turok founded the African Institute for Mathematical Science in Wuizenberg (AIMS). It's "a post-graduate education center supporting the development of mathematics and science across the African continent." (There have been articles about it in all the major science mags by now, and even a few major newspapers.) Turok was born in South Africa. His parents were jailed for opposing apartheid when he was just a kid, and the family lived for a time in abject poverty in Kenya and Tanzania, respectively. Not that he's bitter: he loved the astonishing landscape, and it was a bit of a blow when the family moved to "gray, depressing England," although his educational opportunities were far superior.

Turok has made the most of those opportunities and risen to dizzying professional heights. But he hasn't forgotten where he came from -- in fact, he's still in touch with his childhood math teacher. AIMS is his attempt to give something back to Africa, a continent where the educational system is "truly Victorian" and more than a little divorced from reality -- in part because there's no money to do actual experiments. Yet there is a vast amount of untapped intellectual talent.

Turok told of how he spent a stretch living in a mining town at 17 before heading off to college, where inhabitants lived "a brutal life, with almost no prospects." But the kids were bright and highly motivated. For instance, when he asked students to estimate the height of a building, one boy solved the problem by measuring a single brick, counting the number of bricks to the top, and multiplying to get the answer. Turok's "wish" -- a tradition granted to TED award recipients, plus you get to make your wish "in a room full of billionaires" -- is that "the next Einstein will come from Africa." And he maintains that while Africa needs physics, "Physics also needs Africa" -- precisely because of all that untapped talent.

Frustrated at the lack of any measurable impact from the traditional aid-giving models on Africa's plight, Turok found a new model. He bought an old hotel for $100K practically on the beach, and refurbished it. (He could always consider a career as a real estate mogul should this physics thing not pan out. The town is now a major tourist destination, and thus prime real estate; the value of the building has skyrocketed.) Now 50 or so students -- college graduates, the best and the brightest from all over the continent -- live in for nine months each year for what amounts to "a 24-hour learning environment." Some students have dubbed it "the house of no sleep." This isn't obligatory, mind you: the students are just so fired about about what they're learning, and the instructors so thrilled to find such hyper-motivated students, that nobody wants to waste precious hours doing much of anything else.

Turok invites the best minds, and best lecturers, in the world in math and physics to serve three-week stints (also living in) as instructors, supplemented by more permanent tutors to ensure some continuity. The emphasis is on interactive teaching and learning, with constant feedback within the classroom, and on problem-solving rather than grades and exams. (Apparently the invited lecturers often find their teaching styles completely transformed once they return home.) After their stint at AIMS, the students go on to earn master's or PhD degrees in their chosen fields, ideally returning to Africa after they're done to help others like them in turn -- which means building up a solid scientific enterprise and infrastructure in those countries, so these promising young minds can make a living. That's why Turok wants to expand his model to add a "wealth building" component through things like entrepreneurial partnerships, and also by establishing similar centers in other African countries.

The first group of students should be finishing up their degrees in the next year or so. It will be interesting to see where they all end up. Now Turok is trying to replicate the AIMS model throughout Africa. He and his partners have been investigating prospective new sites, and settled on sites in Nigeria, Uganda, Ghana, Madagascar, and the Sudan. (He admits the latter is a controversial choice, and negotiations are being handled delicately to avoid official association of the planned center with the draconian Sudanese government). Turok is working hard to raise the requisite $10 million endowments to provide $10K scholarships for students at each center, with each country's government ideally paying for operating costs (except for Sudan), thereby giving them a sense of local ownership and involvement.

He has no shortage of volunteers willing to spend three weeks at an African tourist resort town teaching math and physics; there's currently a waiting list of 400 or so, and competition for the three-week slots is pretty fierce. What he's really looking for are physicists willing to make a major time commitment and spend a year living at one of the new centers, helping to get things up and running.  As Turok put it, the idea is to dream big, shoot for the stars, and while you probably won't reach those unrealistic targets, you might just hit the moon.

We need more visionaries like Turok in physics. I'm guessing anyone who volunteers for such a year-long stint will have a life-changing experience, and when they return, they won't even notice silly things like physics sitcoms or YouTube videos made by overworked physics majors, much less feel compelled to sneer at them. (They might even decide -- correctly, in my opinion -- they're just harmless fun: a way of dissipating tension or blowing off steam after a lot of very hard work.) That's really the point of this post. Instead of a thousand tiny paper cuts tearing each other down, let's shoot for a thousand small individual efforts to collectively make a difference in our communities -- wherever they may be.