Here at Nobel Intent, we applaud any effort that gets the public interested or enthused about the scientific endeavor. From time to time, we get made aware of a program designed to do so, but the past few weeks have brought a number of excellent to my attention, so I'm going to share them all in a quick rundown.

Northrop Grumman puts teachers in the vomit comet: The vomit comet is the semi-affectionate nickname for a jet that performs a series of climbs and dives in order to simulate a gravity-free environment, generally for astronaut training. But Northrop Grumman is putting teachers on board, giving them a chance to experience the flights, and bring a bit of the experience (and a bit of the sense of fun) back to the classroom, as the teachers get to videotape experiments and demonstrations while on the plane. Surveys of the teachers afterward say it works—the teachers say their enthusiasm is infectious, and students are more likely to be considering science and engineering studies post-vomit comet.

NASA wants you to name the next Mars rover: Right now, the Mars Science Laboratory is being constructed at the Jet Propulsion Laboratory. The rover is significantly larger than Spirit and Opportunity, and will be using the heat of radioactive decay to power itself through the Martian winter instead of simply riding it out. When it gets to the red planet, though, it is going to have a catchier name, as NASA is running an essay contest for students in grades K-12, with the winner getting to name the hardware.

Toshiba USA sponsors public school science projects: The Japanese electronics giant's US division funds the Toshiba America Foundation, which provides grants that support teachers trying to add some math and science projects to their classrooms. In conjunction with the National Science Teacher's Association, it also sponsors the ExploraVision contest; entries for that are now being accepted. Students can compete for up to $240,000 in savings bonds.

The National Academies wants to help Hollywood do better: The National Academies of Science have created a Science and Entertainment Exchange, designed to help connect people in the media with experts in the scientific fields that are the subjects of scripts. It's easy to groan when movies and TV tackle a scientific topic, but it's hard for people who don't actually know science to get it right without bogging down a plot line. Hopefully, the the existence of this group can at least help those in the entertainment business get a bit more of it right.

Dance your PhD: Now an annual event, AAAS and Science just announced the winners of their dance contest, where entrants translate their PhD into fancy footwork. This year's winning entrants included a number on the role of vitamin D in beta cells, a comparison of PET scans, hemoglobin getting down in the bloodstream, and DNA being measured. You can watch the winners, and the other entrants, to get some inspiration for next year.

Wildfires are an enormous problem, as anyone in California will confirm. Large swathes of forest or tussock can be destroyed in a very short time. Meanwhile, it is often difficult to predict where, and how fast a fire will move. Consequently it is difficult to figure out where best to deploy firefighting resources. At present, local knowledge combined with weather conditions and satellite imagery are used to decide where to deploy, but it would be nice to have a model that could make predictions on speed and direction as well.

This is exactly what a group of French researchers have described in the latest issue of Applied Physics Letters. To predict wildfire behavior, they break the problem into several parts. First, the terrain is broken up into a lattice with fuel at some sites but not at others, and there is direct connectivity between nearest neighbors—a fire in one lattice can travel to the next lattice sites, provided that there is fuel. The weather then plays a role by strengthening or weakening the connectivity, depending on the wind direction and strength. Finally, the fire itself can modify connectivity between two lattice locations through heating. Although the terrain itself does not allow for remote connections between lattice locations, the wind and fire do create longer range connections.

The researchers found that their model provides the same statistical behavior observed in real wildfires. With super-percolation (fast moving flow in an otherwise diffusive medium), site jumping, and ballistic movement, each of which begins to occur at critical weather and fire temperature conditions. The burn patterns under windy conditions are fractal, with the same fractal dimension as observed in nature. Of course, this is not surprising, as super-percolating systems all have the same fractal dimension.

All this is very nice, but it doesn't really help unless it can actually be used to predict the spread of a fire. They tested this in a lab, on an artificial terrain, sloped at 30 degrees. Their model predicted the fire's extent as a function of time quite accurately. They also tested it against a real fire that occurred near Lancon in Provence, France. In this case, they compared their predictions with GPS-recorded data taken during the fire.

The model was accurate in the first 2 hours of the fire. However, firefighters arrived at hour three, making the predictions for the next two hours less accurate—the authors decided not to include the effects of firefighting because they didn't know how the firefighters were deployed. Actually, from the lines, one can clearly see where the firefighters were effective because the fire began to burn along a very straight front at one boundary.

This will not replace local knowledge, because the model requires details about the amount of fuel and terrain before it can be used. On the other hand, the few firefighters I know are usually quite grateful for any technology that can help them predict where a fire will go and how fast. I imagine that it is too late to test this in the coming southern hemisphere fire season, but it could well be tested in Europe next summer—being a French development might slow its deployment in the US, though (I kid, I kid).

Applied Physics Letters, 2008, DOI: 10.1063/1.3030980

In an earlier opinion piece, I discussed how impact factor, scientific quality, and writing ability came together in a cycle that did not necessarily select for the best science. In this piece, we'll look at how some commercial publishing houses (Elsevier, in this particular case) are bringing disrepute to the scientific enterprise.

The practice of subscription bundling is used to make it more economic to buy access to all of a publisher's journals than it is to buy a substantial subset. We'll look at how bunding combines with the publication of pseudoscientific journals and having pseudoscientists edit respectable journals to create a situation where junk science shows up in real research institutes. That, in turn has an impact on the credibility of science, as well as its cost of science.

The example at hand, Elsevier publishes some 930 odd journals—most of them are low impact so, if you had any results worth a damn, you would probably publish them elsewhere. Elsevier could charge a premium for journals with very high quality science in them, but that doesn't appear to be what Elsevier does. Its charges are such that, in at least one case, Elsevier journals constitute two percent of a library's subscription catalog, but 20 percent of its subscription fees. This policy is designed to encourage bundling.

Bundling is Elsevier's practice of offering steep per-journal subscription discounts if you take the lot. The numbers quoted above are from Cornell's bundled subscription deal, so one can only imagine what the per-journal subscription fees must be. Now, bundling wouldn't be so bad if Elsevier were flexible about it. But they don't seem to be. Don't have a Mathematics department? Tough, you get Applied Numerical Mathematics or you pay per-journal.

This practice is not just designed to increase Elsevier's bottom line, it is also designed to make Elsevier appear larger than it actually is. That is because Elsevier publishes many specialized journals that very few people actually want. These journals are nearly worthless to Elsevier in every respect except two. They enable Elsevier to say that it has the largest single library of peer reviewed journals, and it can advertise about how all these libraries subscribe to their journals—the Journal of Podunk Economics must be important if Harvard takes it.

This practice suggests to me that Elsevier primarily regards science as a vehicle for making money, with quality a distant second concern. For those of you thinking that this is a "well, duh" moment, Nature publishing group places a much higher value on quality and still maintains profitability, so the two are not incompatible. Furthermore, Nature has taken the opposite tack by creating the impression that publishing in its journals are the height of scientific achievement.

Elsevier's practice of expensive bundled subscription policies actually has serious consequences for the amount of research performed at universities. The money to pay for subscriptions typically comes from the agencies that provide research grant money. When calculating the budget for a research grant, researchers must include overhead costs, which are used to pay for things like janitorial services, computer network infrastructure, and journal subscriptions. Now, contrary to what many people think, scientists are usually very cost conscious: we want to give and get value for money. We accept that instruments may be very expensive because of the limited market. We accept that graduate students and post-docs must be paid. Experimental work, even if it doesn't directly use such services, should contribute to the maintenance of a mechanical workshop.

Every dollar that goes into these overhead costs is a dollar that doesn't go into science.

In general, university overheads are high, and the library constitutes a significant proportion of that cost. Elsevier has, in effect, an umbilical cord attached to just about every granting agency on Earth. Forcing Elsevier to change its prices will not remove the umbilical cord, but could see the umbilical cord reduced in diameter.

The argument that Elsevier would make is that it publishes valuable specialist journals, where the small number of subscriptions warrant high prices. Several factors appear to undercut this claim. Electronic distribution, which is now the main delivery vehicle for science journals, means the subscriber number is far less relevant. In fact, fewer subscribers means fewer downloads, which means reduced hosting costs for those journals—especially when you consider that there's a single database and front end common to all Elsevier journals. They also use the same format for nearly all their journals, meaning that type setting costs are widely distributed. In fact the only place where they can claim increased cost is editorial staff. Except that most journals are voluntarily edited by academics. There doesn't seem to be a valid economic justification for Elsevier's pricing structure, other than the inherent value of their journals.

So, are they worth it? Lets take a look at some examples. Exhibit A must be the Journal of Homeopathy. Homeopathy is not science. The journal has a negative scientific value because it does not distribute scientific knowledge, but rather disseminates wishful thinking about reality. It is the very essence of anti-science. Yet, here it is, a peer-reviewed "scientific" publication being foisted upon universities through subscription bundling. A wedge, if you will, of pseudoscientific thinking right in the heart of science.

Exhibit B is Chaos, Fractals, and Solitons, a real mathematical journal that was once a respectable vehicle for scientific communication. Now, however, the Editor-in-Chief is one M. S. El Naschie, who has managed to publish 300 peer-reviewed papers in his own journal. By itself, this would be an abuse of position, but it's actually worse than that. El Naschie is apparently a numerologist. Yes, that's right, the idiots who spend time looking for mystical significance in integers.

No matter where you look, numerical coincidences occur. But coincidences are not the subject of science—in fact, much of science involves demonstrating that data isn't the result of coincidence. El Naschie would never have a voice on an adequately edited scientific journal, and any journal that was inadequately edited enough to allow numerology in would normally be shunned by the scientific community. It is only Elsevier's drive to profit, even at the expense of their own credibility, that lets this sort situation occur.

It's not clear that Chaos, Fractals, and Solitons can be rescued. It doesn't even deserve to be rescued—mathematicians are publishing in other journals now. Even if that journal were to recover, that wouldn't solve the more general problem posed by bundling. Only if Elsevier charged a reasonable per-journal subscription fee for each journal, one that reflected not just its cost but also its significance, would the journal be compelled to improve or fold.

This approach could generally solve the problem of poor content and poor editorial choices. If the quality of a journal falls, or is filled with pseudoscientific garbage, subscriptions will be cancelled. In this case, libraries will need to start analyzing usage patterns more carefully. Has anyone downloaded a paper from Chaos, Fractals, and Solitons since it turned into a journal of numerology? If the mathematics department at your local university knew about its content, would they still want it in the university? These are questions that should be subjected to regular review, but the bundling practice makes asking them useless. Universities should have the power to cancel these subscriptions without looking forward to a huge increase in subscription fees.

It would be nice to think that Elsevier will listen to scientist, but I suspect that this will not happen until scientists start getting a little more strident. If you are scientist, publish your work in society journals rather than Elsevier journals. Try to avoid citing work published in Elsevier journals. Elsevier lives by a combination of pricing and impact factor, and scientists have direct control over only one of these—impact factor. Librarian could start looking at Elsevier journal usage patterns; perhaps they can follow Cornell's example, and subscribe to just a few Elsevier journals.

I don't often use Ars Technica as a podium, but Elsevier's practices cut to the very heart of science as a profession: they reduce the ability to perform research, and they reduce the credibility of the profession.

A large part of the Division for Planetary Science conference's second day (back on October 11^th) was devoted to studies of the largest satellite of Saturn, Titan. For this report, I am going to focus on the studies of the features that have been interpreted as hydrocarbon lakes. They were originally discovered through the Cassini orbiter's synthetic aperture radar observations. The features reflected the radar signals extremely poorly and, as a result, appeared as dark patches in those radar images. 

This sort of signature indicates that the surface being observed is extremely flat, consistent with a calm liquid surface. The outlines of these areas are also very reminiscent of shore lines—some are even accompanied by what appear to be drainage channels—and the climatic conditions at their sites allow the presence of liquid methane and ethane. Thus, the radar-dark features near the north pole have been interpreted as liquid-filled depressions, similar to what we call "lakes" on Earth.

However, a calm liquid surface is not the only possible scenario that fits the radar image of the features. For example, depressions filled with fine loose particles (which we would call sand on Earth) could appear dark in radar signature. Although the climatology of the polar region makes this scenario unlikely, there has been no direct confirmation that these radar-dark patches are indeed filled with liquid, and researchers continue to study the properties of the features we have been calling the "lakes" to see what they really are.

Specifically, Titan researchers have been searching for signs of specular reflections of sunlight off of the lakes' surface, which would constitute undisputable evidence that those features are indeed filled with liquid. So far, however, no such reflections have been observed. Even if the lakes are actually filled with liquid, the absence of specular reflections is not particularly surprising because Titan's atmosphere contains a very thick layer of haze, which blocks most direct sunlight. Scientists have been looking for reflections in the spectral windows of Titan's atmosphere, where some wavelengths of light penetrate down to the surface, but they still have not spotted anything. This could be either because we have not observed the lakes from the right angle to see the reflections, or perhaps because the lakes are not filled with liquid.

Specular Reflection on Earth, seen on my way home from the conference. Specular reflection is a very powerful effect—notice that the bright reflected sun dominates the image even though water covers a very small portion of it.  The image also illustrates the importance of the viewing angle; the river spans the entire width of the image but only a small section shows specular reflection.

The latest results presented at the conference drew a very mixed picture.

First, Roger Clark of US Geological Survey presented an analysis that indicated the lakes must be, at most, several millimeters deep to be consistent with the spectrum obtained using Cassini's Visual and Infrared Mapping Spectrometer (VIMS) instrument. He used the spectral characteristics of liquid hydrocarbons to show that VIMS spectral coverage can measure the depth of lakes up to tens of centimeters before things get too deep; the liquid hydrocarbon at the sites of the "lakes" seem to be much shallower. 

While Clark hinted that this result makes the feature more similar to mudflats or playas on Earth, he also pointed out there could be something floating on the surface of the lakes that could mask any deep layer of liquid underneath. As the density of liquid hydrocarbons is very low, it is unclear what can float on a liquid body of this sort.

Next, Jason Barnes of the University of Idaho pointed out that the lakes appear the same regardless of the direction of sunlight or the angle of observation. This is a bit of a puzzle, since the spectrum of light scattered by any material usually appear different depending on the geometry of the illumination and the observation. 

Barnes explained this by proposing that the uniform appearance of the lakes is the product of Titan's atmosphere. Since Titan is completely covered by a thick layer of haze that scatters sunlight, the surface is illuminated evenly from all angles. We experience the same effect when it is cloudy on Earth; even though there is plenty of light during the day, there are no shadows cast on the ground because the clouds scatter sunlight and create a uniform illumination. Thus, if the light given off from the surface of Titan's lakes is a reflection of the hazy sky, it will appear the same regardless of the observation geometry. Barnes also presented many images that show geological features around the lakes that suggest that the depth of lakes has varied in the recent past, perhaps indicating seasonal changes in their levels.

Another presentation by Jason Soderblom of the University of Arizona showed that the lakes' surfaces are extremely poor reflectors of light when observed in the 5-micron spectral window using the VIMS instrument. His observations indicate that the lakes' surfaces reflect no detectable light—he places an upper limit of one percent reflectivity based on the sensitivity of the data. His observations also detect no scattering or specular reflection of sunlight.  Soderblom argues that this is consistent with an extremely smooth surface, like that of quiescent liquid, in which sunlight reflects only in one direction and the specular reflection can be seen only from a very narrow range of observation angles.

In short, one analysis says there is almost no liquid on the surface of those lakes, another shows the depth of the lakes has varied recently and suggests that the hazy sky is reflected on the lake surfaces, while another says there is no light reflecting from the lakes' surfaces. It is unclear whether there is a scenario that consistently explains all existing observational data, including those presented at the meeting. 

This situation nicely illustrates a real scientific process, directed towards understanding what makes things appear and behave the way they do. As scientists, we focus on things we cannot explain and try to draw a picture that's consistent with everything we know—in fact, even though the three studies presented above may seem to contradict each other, the three presenters are co-authors on each other's studies. 

To be sure, the prevailing interpretation in the field remains that those "lakes" are indeed liquid-filled depressions on the ground; there remain some things that still need to be explained before we draw any final conclusions. The scientific process is still very much ongoing, so stay tuned for future updates!

DNA. 

DNA, an essential part of all known living organisms, has many functions that are useful outside of genetics. Its structural properties are ideal for nanotechnology, and its interactions with multiple environmental components make it a potential scavenger of harmful chemicals. DNA can bind heavy metal ions and intercalate harmful compounds. Normally when your DNA intercalates mutagenic chemicals like ethidium bromide, it's bad news. However, when this happens outside of living organisms, it can be used to isolate the mutagens.

Several research groups have already used materials containing DNA to gather toxic chemicals that have a planar structure, including polychlorobiphenyl (PCB) and dioxin derivatives. Unfortunately, many biologically and environmentally damaging chemicals have nonplanar structures. Masanori Yamada and Kazuki Hashimoto at Okayama University proposed that a composite material of DNA and β-cylcodextrin, a seven-membered sugar ring, would be able to accumulate both planar and nonplanar chemicals.

Cyclodextrin is known to encapsulate nonplanar, harmful chemicals like bisphenol A, which disrupts the endocrine system, in its intramolecular cavity. It's also commonly used in foods, drugs, and cosmetics, where it helps solubilize the components and stabilize sensitive compounds. Yamada and Hashimoto hypothesized that, by combining cylcodextrin with DNA, they would make a material that could retain the absorbing properties of both constituents.

β-cylcodextrin. 

To make the composite material, the authors mixed DNA and β-cylcodextrin-immobilized poly(allylamine) in a ratio of 8:2 at pH 8. They had to add poly(allylamine) to β-cylcodextrin to obtain a solid that wasn't soluble in water. A material made out of DNA and plain β-cylcodextrin would dissolve in water, and so would be ineffective in pulling contaminants out of aqueous environments—it's better to have a solid material that can be removed easily after it has soaked up harmful chemicals.

Their DNA and β-cylcodextrin-immobilized poly(allylamine) material is stable in aqueous environments, and doesn't degrade even after a month immersed in water. The material had properties of both DNA and β-cylcodextrin—it could intercalate like DNA and encapsulate like β-cylcodextrin. Thus, it could absorb a large range of environmentally and biologically damaging compounds regardless of whether they are planar or nonplanar.

Yamada and Hashimoto see a number of applications for their novel DNA and cylcodextrin composite material. It could purify drinking water or industrial drainage without being too costly, as DNA can be obtained from waste like salmon milts and shellfish gonads, and β-cylcodextrin is easily synthesized.

Biomacromolecules, 2008. DOI: 10.1021/bm800984p

Atmospheric CO₂ is an important driver of the global climate system and, as such, understanding the global carbon cycle is important to predicting future climate change. While we have a good handle on the amount of CO₂ we are emitting, the net ecosystem fluxes are less well quantified.

In general, the natural fluxes of carbon between the atmosphere and the land or ocean are far greater than our own emissions. Indeed, CO₂ released by soils is about 10 times greater than anthropogenic emissions. Because the natural input and output fluxes are roughly balanced, our own emissions have a large impact on the net flux. However, if future climate change causes the natural CO₂ fluxes to go out of balance, they could easily become more larger sources of CO₂ than our own emissions. A recent paper in Nature Geoscience examines how climate change can cause potential changes in soil carbon emissions.

It is generally accepted that increasing temperatures lead to CO₂ being transfered from soils to the atmosphere. However, Johannes Lehmann and colleagues suggest that current models may overestimate this increase. The study, released Sunday, showed that a model of soil carbon over-predicted the amount of labile, or unstable, carbon in soils. By looking at almost 1,900 measurements of soil carbon across Australia, they showed that, on average, 20 percent of soil carbon in these samples is in the form of black carbon, or soot.

Black carbon is important because it has a much longer residence time in soils—1,300 to 2,600 years—compared to more labile carbon pools, which range from 10-100 years. The authors estimate that this can lead some current models to over-predict the amount of climate change induced carbon release by 20-40%.

While this study is interesting because it highlights an area of the carbon cycle that needs further attention, it is far from definitive. For one thing, all of the soils they measured came from Australia, which is suspected of having undergone major biomass burning in the past, albeit longer ago than the mean residence time of soot.

In addition to a limited data set, the paper only tested a single model. Biogeochemical cycle models are plentiful, with the CENTURY model and the Biome-BGC model being two of the more commonly used ones. Biome-BGC is the basis for the biogeochemical cycle in the Community Land Model, which is part of a model used in IPCC projections. While these models may not do any better than the RothC model tested here, the authors make no mention of whether the other models handle soot better.

Nature Geoscience, 2008. DOI: 10.1038/ngeo358

We're used to seeing wings, spoilers, and other aerodynamic appendages on racing cars. Ever since Colin Chapman stuck what looked like a door on the back of a Formula One car, aerodynamics took on a new importance in keeping cars stuck to the road. Soon, spoilers might be coming to a minivan or SUV near you, according to a paper published in the International Journal of Vehicle Design.

Wings, spoilers, and diffusers can be used by vehicle designers for a number of tasks, mainly revolving around decreasing lift (increasing downforce), decreasing drag (and therefore increasing fuel efficiency), but they can also manage things like limiting wind noise.

The spoiler design presented in this paper has been developed specifically for the shape found on minivans and SUVs, which is characterized by a cliff-like dropoff at the rear. Using a novel shape mounted just behind the trailing edge of the roof, the spoiler acts as a diffuser (which one would normally see under the rear bumper) to increase air pressure on the back of the vehicle. At 67 mph, the authors calculate that a vehicle equipped with this new design would exhibit five percent less drag and 100 percent less lift (more downforce) than an otherwise identical vehicle.

With Detroit's pressing need to do something about the fuel economy of their products, it seems that this wing design might provide some of what they're looking for. Not only does it cut drag and therefore increase efficiency, the increase in downforce means the vehicle would stick to the road better; good news for the driver, bad news for the tow truck industry.

Int J. Vehicle Design, 2008. DOI: 10.1504/IJVD.2008.021155

I am currently attending a meeting called photonics4Life, which is an EU-funded network. This is one of the things that I believe EU science funding has gotten right. The meeting is not what would be described as high impact, but it serves a different purpose: to establish cross-disciplinary collaborations.

Let me elaborate. I am a physicist, and I know a lot about optics. However, if told by a funding agency that the future of optics will involve designing optical techniques for biology, I simply would not know where to start. What are important questions in biology? What are the practical considerations in making measurements that might answer those questions? This sort of cross-discipline ignorance can be more subtle, as well. A biophysicist may be using optical tweezers to play with DNA and yet be at a loss when asked how to apply that capability to more biologically relevant situations.

The over-specialization endemic to science is both necessary and a curse. I could not do the things that I can do without the level of specialization that I possess. On the other hand, my focus on optics means that I know very little about disciplines outside of optics.

Photonics4Life is one of a series of networks that seeks to generate cross-discipline contacts. The idea is to start a continuing dialog among scientists from different disciplines, which should enable them to find common ground for new research projects. For most of us, no light bulbs will light up, and we will go home. However, I have also been there when the light bulb lit up very brightly—we started a very successful collaboration that continues to this day. As a result, I have high hopes for this meeting, as well.

An important aspect of these meetings is alcohol. This is not really a joke. We are scientists, and we can be shy—we are certainly terrified of being wrong. Alcohol relaxes you enough to ask stupid questions, which are a necessary prerequisite to forming a solid cross-disciplinary collaboration. A side effect of these meetings is that the speakers must present their data in a much more accessible way. I have found it very interesting to see how successful (and unsuccessful) many researchers have been.

Who knows what ideas will pop out—you may yet find me reporting on Laser guided Neuron growth tomorrow.

The availability of sufficient water is a limiting factor for agriculture in a variety of major growing areas, including much of the US west. Given its scarcity and annual variations in the supply, a lot of emphasis has been placed on efficient use of water supplies, and many governments have considered providing subsidies to increase the uptake of efficient irrigation systems. A new study, however, suggests that these policies may interact in unexpected ways with economics and water rights to undermine some of the programs' goals.

The researchers involved focused on the upper Rio Grande Basin in New Mexico. They built a linked water-agriculture model of the entire basin and explored how several subsidies and usage patterns could influence the water dynamics in the area. Although they drew some economic conclusions based on the impact of subsidies (they were minor), what was more striking was the effect that efficient irrigation had on the watershed.

Most of the issues seem to arise from the fact that agriculture in the area is already water-limited, with agriculture already having a set water allotment. When more efficient irrigation is brought in, there was no reason to view the water saved in existing plots as anything more than a free resource. In many cases, it made excellent economic sense to switch to more water-intensive crops or bring unused land under cultivation. In short, efficient irrigation didn't mean more unused water in the watershed.

In fact, it appeared to make matters worse. Based on their model, inefficient irrigation methods, through runoff and seepage, actually return water into the watershed. By largely eliminating these factors, the amount of water exiting via the Rio Grande actually appeared to drop.

There are a lot of assumptions in the model, and it would be great to see it backed up with more real-world data. But it nicely emphasizes how policy changes, such as pushing for new irrigation patterns, can't be pursued in isolation, but need to be integrated into larger initiatives that take things like the agricultural markets and water rights into account.

The paper will be made available by PNAS sometime this week.

PNAS, 2008. DOI: 10.1073/pnas.0805554105

Human pelvises are unique in that they have evolved to support walking upright and, in the case of females, the ability to give birth to large-brained offspring. Understanding of the morphology of the pelvises of human ancestors' remains minimal due to the fact that the majority of fossil remains that are found are pieces of skulls and teeth. Finds of bones from the neck down are relatively rare, and confirmed discoveries of female bones are rarer still. A recent find from the Busidima Formation of Gona, Afar, Ethiopia included a relatively intact female pelvis that is changing what anthropologists know about early hominid evolution during the Pleistocene.

Image Credit: Scott W. Simpson,
Case Western Reserve University

Previous knowledge about the neonatal brain size of H. Erectus has come from a 1.53 million year old juvenile male skeleton found in Kenya. The dimensions of an adult female's pelvis and birth canal were estimated based on measurements of this young boy's pelvis—it was estimated that the maximum neonatal brain size would be approximately 230 mL. This lead to the hypothesis that H. Erectus offspring would be born developmentally immature and would then undergo a rapid postnatal brain growth period—one that would require a high degree of maternal care.

The new pelvis, unearthed in 2001 and fully excavated in 2003, is dated to 0.9 to 1.4 million years old. In a publication in last week's edition of Science, researchers from a number of institutions reported on measurements of the fossil; they found that the birth canal was 30 percent larger than had been previously estimated. The shape of the pelvis implies that its owner was shorter and had a broader body, something more often seen in specimens from more temperate climates.

This single discovery revealed a great deal about the morphology of H. Erectus and other early humans. The authors conclude the article by stating that "the H. erectus pelvis retained many elements of its australopithecine heritage, although substantially modified by the demands of birthing large-brained offspring."

Science, 2008. DOI: 10.1126/science.1163592

When chemists try to synthesize a chemical compound, we normally do it in a very systematic and linear fashion, combining a set number of compounds that react under specific conditions to make our desired product. Biological organisms, on the other hand, synthesize compounds with far more complexity, using multiple enzymes, interconnected signaling networks, checkpoints, feedback loops, and a plethora of other mechanisms. How did this intricate metabolism develop?

Many scientists hypothesize that self-replication of simple organic molecules came before metabolism. Billions of years ago, some organic molecules could have created a primitive metabolism where they autocatalyzed chemical reactions, operating in a pool of many chemicals to synthesize more of themselves. This would lead to molecular evolution, which could further develop into a full biological metabolism.

Experimentally and conceptually, evidence that this is possible has been difficult to obtain. Chemists must come up with a dynamic pool of chemicals that produces a particular molecule that than goes on to exploit other components of this pool to self-replicate. Jan Sadownik and Douglas Philp from the University of St. Andrews overcame many of the difficulties involved and identified a mixture of chemicals from which a single synthetic molecule emerged by amplifying its own formation. Their demonstration that organic molecules can self-replicate appears in an advanced article of Angewandte Chemie.

Dynamic reaction system. 

In a pool of nitrones and imines, reversible exchange reactions occur freely. This "exchange pool" can also produce products nonreversibly when they react with a maleimide (red). One of the products, trans-7 (blue), is a replicator. It creates a catalytic complex with the maleimide and one of the other compounds in the exchange pool, accelerating further synthesis of itself. Trans-7 ends up dominating the reactions, becoming the major product at the expense of the other ones.

Sadownik and Philp showed that it is possible to have a primitive metabolism with just organic chemicals. Thus, they support the hypothesis that molecular evolution, stemming from the self-replication of organic molecules, was a precursor to biological metabolism.

Angewandte Chemie Int. Ed., 2008. DOI: 10.1002/anie.200804223

One of the coolest astronomical objects is the neutron star. A normal star can pretty much be described by classical physics: the pressure of heat and light balancing the force of gravity. The heat and light is, of course, from fusion, which is an inherently quantum process. Most stellar models don't worry too much about getting the details of fusion right, and they still do a remarkably good job of predicting stellar behavior. Neutron stars and pulsars are altogether different beasts, requiring a quantum mechanical description from start to finish, with the exception of the input from gravity.

But—and here is the tricky part—once you add quantum mechanics to the picture at these immense pressures, can you say for sure what the contents of the star actually are? How would you tell different star compositions apart? A recent Physical Review Letter has tried to answer the second question.

Let us begin with a short primer on neutron stars and pulsars, which I will refer to interchangeably. At the end of a sufficiently large star's life, it will explode in a fiery death. The remnants of that explosion collapse and, if the mass is in the right range, a neutron star will be born. This isn't quite as simple as it looks, because most of the material collapsing in to form the star is hydrogen—one proton, one electron, neutrons need not apply. The process begins when the inrushing mixture of electrons and protons gets crushed together by gravity. If the pressure is high enough, the electron and the proton combine to form a neutron, emitting a neutrino in the process. The neutrino flies off, but the neutrons are captured by the gravitational field and held together in a dense mass.

Neutrons are fermions though, meaning that when they are close to each other, they interact in a way such that each has a slightly different state—they might, for instance, differ only by their angular momentum, but there must be some difference. This holds them apart, preventing further collapse. This is the theory, and it seems pretty good, as the behavior of neutron stars we've observed is well described by it. Nevertheless, there is a tiny seed of doubt here: can neutrons exist over the entire range of pressures predicted?

At the upper end of the pressure range, it may well be possible that the neutrons turn into strange quarks, creating a strange star. For the most part, both star types are expected to have nearly identical properties, which makes it very difficult to figure out if either or both actually exist. Furthermore, the properties of strange quarks are less well known than those of neutrons, making it difficult to model a star made of them. So, even though we expect them to be the same, we can't be sure. There is, however, one property of the strange quark that can be modeled accurately: the mass. This latest study, from researchers in China, has used this fact to look at the gravity waves emitted by neutron stars and strange stars, and found that the two are very different.

The researchers are really interested in the few seconds just after the birth of the star, when everything is still sloshing about vigorously. During these moments, both neutron and strange stars will emit a strong pulse of gravitational waves, but it appears that the neutron star's pulse should contain much higher frequencies of gravitational waves. It turns out that the relativistic nature of the strange quark—they are all moving at very high speeds within the star—reduces the oscillation frequency of the star. Neutron stars, as they form, are made up of relativistic leptons (electrons) and non relativistic neutrons, providing greater rigidity and allowing higher frequency vibrations.

Currently, LIGO and other gravity wave sensors are not sufficiently sensitive to detect the formation of neutron stars. Nevertheless, improvements to LIGO are continuing at pace, and we should start seeing positive gravity wave detection events in the next few years. After that, we may be adding a new star type to our catalogs.

Physical Review Letters, 2008, DOI: 10.1103/PhysRevLett.101.181102

Coming from a research background in the UK, I'm all too aware of the problems caused by animal rights extremists. Despite (or perhaps because of) that country's stringent laws regarding the use of animals in research, researchers have to worry about retribution from a violent minority that has targeted them with tactics such as beatings, fire bombings, and even grave robbery. Here in the US, the laws governing the use of animals in research are far more lax and, until recently, the issue of animal rights extremists was mostly limited to activists trashing labs. But this past summer has seen these groups escalate their tactics, with several firebombings in California.

In an effort to raise awareness of the issue, the Federation of American Societies of Experimental Biology has launched a new website, animalrightsextremism.org. It hosts a lot of information on the problem, along with news reports and policy statements. According to Carrie Wolinetz, FASEB's Director of Scientific Affairs and PR, "we wanted researchers who have been targeted by these groups to have centralized access to the resources available to assist them. Scientists need to know that the research community supports them and they are not alone."

Unfortunately, we still don't have the tools and experimental models to abandon animal research, contrary to the claims of some animal rights groups. As long as the use of research animals is a necessity (and federally mandated in the case of drug development), scientists have a responsibility to educate the public as to why this is the case. This site from FASEB is a great tool for that effort.

Graphene has shown the great potential in the short time that it has been at the forefront of materials research. It's essentially an unrolled carbon nanotube, so graphene shares many of the unique electrical and physical properties that have made carbon nanotubes the poster child of materials research in the last decade. Production of graphene is still decidedly archaic, though.

Nobel Intent covered a decomposition technique that allowed for more accurate deposition. At the time, this was a "high volume" technique, but it provided nothing close to the volume needed for any industrial application or larger scale research effort. Recent research, published in Nature Nanomaterials, demonstrated a solution-based technique that has the promise of both large-scale production and bigger samples, which should open the door for more extensive characterization efforts.

When graphene was first discovered, the best method available for making it was simply taking graphite and peeling it apart with cellophane tape until you had a monolayer of graphene that you could transfer to a substrate (science at its finest, my friends). The arduous part came in determining just what exactly you had produced—scanning electron microscopy, which uses electrons instead of photons to resolve an image, would reveal candidate graphene sites, while atomic force microscopy (think of it as a record player that reads individual atoms instead of your worn out copy of Led Zeppelin III) would confirm a that it was, in fact, a perfectly flat single layer of carbon. To say that this method doesn't lend itself to large-scale production, or even large-scale laboratory work, would be an understatement.

Decomposition methods involving baking silicon carbide, which are also used to produce carbon nanotubes, often yield misshapen, mutant sheets of graphene, and demands high temperatures that rule out any sort of in-line processing with traditional electronics manufacturing equipment. It often yields materials that are less than a square micron, which rules out several characterization techniques that require a larger mass of material.

Researchers have continued working with hydrazine (a well-known rocket propellant), using it as a solvent for graphite oxide that can also strip off the oxygen, preparing the graphene for deposition. The resulting process could be controlled to make samples of graphene as large as 40 microns square, as well as smaller samples if required. The graphene was reasonably high quality, although testing revealed a lack of n-type semiconductor behavior might have resulted from residual hydroxyl groups left by the hydrazine.

Hydrazine processing eliminates several problems associated with using water as a solvent, such as agglomerations of graphene during drying. The dissolved graphene oxide could also be transferred to a less toxic solvent for deposition.

A truly bulk process, such as the solution process demonstrated in this research, is a big step towards making graphene devices a reality. A chemical process like this, although incredibly toxic, is much cheaper for a research institution to deal with than tying up expensive and specialized lithography equipment, which represented the previous state of the art for graphene production. Keep checking Nobel Intent, and we will continue to bring you news on studies of graphene's unique properties, and the efforts to produce it en masse.

Nature Nanomaterials, 2008. DOI: 10.1038/nnano.2008.329

As the local physics dude, I am always banging on my keyboard, writing about entanglement. It is a necessary component of both quantum computers and quantum key distribution, but no one really understands it, in part because entanglement predicts some very weird results for certain experiments. Although these experiments have been performed on numerous occasions, a recent Physical Review A paper provides yet another, particularly elegant demonstration.

Let us take a look at entanglement and what makes it so special. At its simplest, entanglement is a correlation between two objects. We can use that dreaded tool, analogy. I have a green ball and a red ball, which I juggle for a bit, then give you one ball. You go somewhere far away and take a look at the ball. It's green. You now know that my ball is red. If this were all there was to the story, the laws of physics would have turned up, in person, and closed the show—place your research grants in the circular basket on your way out, please.

When looking at the quantum version of this analogy, however, things get a bit weirder. We have done the ball juggling thing, and you have walked away with one of the balls. While you are walking away, I drop my ball in a bucket of paint with an unknown color; the ball could come out blue or yellow. When you examine your ball, you discover (much to your surprise) that it is yellow—it is also slightly damp and has a lingering turpentine odor. My act of painting the ball has also painted your ball.

But wait, there's more. We are doing the juggling trick again, but this time with red and green blocks that are square and triangular in shape. You get one of the blocks and wander off. Now, you can either see the color of the ball, or feel the shape, but you can't do both at the same time. You take a peek and see that it is red—I must have the green block. Next, you cop a feel and know that it is triangular. I have a square green block, right?

Not necessarily. These two properties might not be knowable at the same time. After checking the shape, if you take a second peek at the color, you once again have a 50/50 chance of getting a green block. The act of measuring the shape of one block makes the color unknown for both blocks, while the act of observing the color of one block makes the shape unknown for both blocks.

Although these experiments are easy to arrange on paper, they have been incredibly difficult to observe in the lab. But the development of quantum optics for fundamental research, quantum key distribution, and quantum computing, has turned these measurements into a routine tool. Nevertheless, elegant demonstrations are always welcome. A group of researchers at the University of Science and Technology of China have done just that. In particular, they wanted to show that orbital angular momentum (OAM)—think of these as beams of light with little vortices in their profile—is entangled in a particular process called four wave mixing

The experiment consists of shining two lasers on a metal vapor. One strong laser triggers atoms in an excited state to emit a photon and fall to the ground state in a process called anti-Stokes emission (the new photon is bluer than the exciting laser light). Meanwhile a second, weaker laser excites atoms from the ground state into an excited state, releasing a Stokes photon in the process (this photon is redder than the exciting laser). The two lasers couple together through the medium, releasing nearly simultaneous Stokes and anti-Stokes photons as the weak laser provides excited atom for the strong laser. These two photons should be entangled and emitted in opposite directions.

The two beams from the lasers used by the researchers had no OAM, so the total OAM of the photon pair must be zero. But that fact says nothing about the OAM of the individual photons. If the researchers had simply made measurements of the OAM, they would, with a very very high probability, measure zero for both photons. But this is not what they did.

Instead, they inserted a computer-generated hologram into the path of both the Stokes and anti-Stokes beams. When positioned correctly, the hologram adds OAM to a photon; when positioned elsewhere, there is only a certain probability of adding OAM, meaning that, until that photon is measured, it would be in more than one OAM state simultaneously. The experimental process used one hologram to modify the OAM state of one photon, while a second hologram was scanned across the other photon beam, measuring the OAM state of the second photon. The first photon was measured after its state was modified, so the experimenters have complete knowledge.

Their experiment showed that if, the researchers modified the OAM state of the first photon, then the second photon's state was also modified—even though the two are were separated and could not interact. The researchers suspect that the medium the photons were in was in an entangled state as well, but have no data to support that claim.

I should note that there is nothing excitingly new here. But most of these experiments are so difficult to describe that the physics is hidden behind experimental complexities. These complexities make me feel like I am describing a shell-game as something Earth shattering. Here, everything is quite clear: the covers have been taken off the shells so to speak, to reveal that, underneath, reality is still weird.

Physical review A, 2008, DOI: 10.1103/PhysRevA.78.053810

Mucus, while slimy and a bit unpleasant, forms a protective barrier for the surfaces of our eyes, respiratory tracts, gastrointestinal systems, and other vital parts. In preventing the penetration of various toxins, fine particles, and pathogens, mucus also blocks potentially therapeutic nanoparticles, making it very difficult to deliver drugs and gene therapy through mucosal surfaces. Viruses, on the other hand, have little trouble passing right through due to their outer coating. Scientists have tried to mimic this slippery coating by covering nanoparticles with PEG (poly(ethylene glycol)), a commonly used polymer that can vary in molecular weight depending on the length of its chain.

Cervical mucus. 

PEG makes nanoparticle surfaces more hydrophilic and less electrostatic, which should improve mucus penetration. However, it has experienced mixed reviews in the scientific community. A large number of research groups report that PEG-coated nanoparticles failed to go through mucus. Instead, it got stuck as a result of either hydrogen bonding interactions or entaglement of the PEG polymer chains with the mucus mesh.

Other researchers report that PEG-covered surfaces vastly improved the penetration of nanoparticles. To understand these conflicting results, Justin Hanes led researchers from Johns Hopkins University in an attempt to correlate PEG-coating performance with physicochemical properties, specifically, the molecular weight of the PEG and the extent of surface coverage.

In testing the effect of PEG's molecular weight, the authors densely coated nanoparticles with 2 kDa, 5 kDa, or 10 kDa PEGs. They discovered that going from 2 kDa to 10 kDa, which is just a five-fold increase in weight, produced a 1000-fold decrease in the average displacement of the nanoparticles in mucus. Hanes proposed that the longer chains of heavier PEGs become entangled with the mucus network, so lighter PEGs work better.

To test the importance of PEG density at the surface, the researchers compared the penetration of 69 percent coated nanoparticles to ones that had 42 percent surface coverage. The 40 percent reduction in coating density caused a 700-fold decrease in the average rate of nanoparticle transport through mucus. Thus, it's important to have a densely PEG-packed surface in order to overcome adhesive interactions.

Hanes and his colleagues have shown that there is a simple rule to follow in coating nanoparticles with PEG for mucus penetration: a dense layer of low molecular weight PEG is ideal. They hope that their design principle will "facilitate the widespread development of biodegradable drug- and gene- loaded mucus-penetrating particles for the treatment of various mucosal diseases, including cancer and inflammation in the respiratory, gastrointestinal, and female reproductive tracts."

Angewandte Chemie Int. Ed., 2008. DOI: 10.1002/anie.200803526

Considering the problems inherent to fossil fuel energy production and the increasing saturation of mobile electronic devices, one would think that we could waste less of the energy that we produce and carry with us. However, it turns out that we lose a huge fraction of our energy as excess heat and vibration. While some of the lost energy is impossible to recover (in this journal, we follow the laws of thermodynamics!), most waste heat and vibration can be captured and converted back into useable energy.  

Piezoelectricity has been seen as the key to harnessing waste vibrations in mechanical devices.  Piezoelectricity is a material property that is a characteristic of many ceramics with noncentrosymmetric crystal structures. When these materials are strained, they develop an electric field. Straining the material causes positive and negative ions in each unit cell to displace in different directions. This produces a small electrical field but, when it's summed over moles of unit cells, it can be quite substantial. To convert vibrations into energy, piezoelectric materials must be packaged into a device so that the vibrations cause strain that can be extracted through a connection to an appropriate electrical circuit.

As with most engineering problems today, nanotubes and nanowires are being tested for their piezoelectric potential. Nanowire mechanical energy harvesting devices place piezoelectric ZnO nanowires vertically on a flat substrate, and contact them with a zig-zag shaped electrode. As the device vibrates, the free-moving, zig-zag electrode flexes the nanowires, generating an electrical potential. While these devices can produce substantial fields and do not require control over the placement of the nanowires, the design leads to mechanical breakdown of the nanowires and short service lifetimes. Sealing difficulties also make this design prone to environmental attack. 

Top (A): SEM image of ZnO nanowires

Middle (B): Schematic of a flexural based measurement system that is similar to "zig-zag" designs

Bottom (C): Plot of electrical response versus position showing the fields generated by discrete ZnO nanorods (credit for all three images: Georgia Institute of Technology through nsf.gov)

In this week's Nature Nanotechnology, researchers from Georgia Institute of Technology have modified the zig-zag design to increase its durability while maintaining efficiency. Their method was brilliantly simple—just lay the nanowires down to produce a laterally-packaged piezoelectric generator. In this system, ZnO nanowires were placed on a flexible polyimide film with both ends attached to a circuit. The researchers found that, when the film was flexed, a single nanowire could generate a 50 mV field with 6.8% efficiency. Clearly, the efficiency needs to be improved, but the device solves all of the major problems inherent to the previous design: the nanowires are not exposed to breaking stresses and the laterally packaged device is easily sealed.

The key to the design (and the real insight of the paper) is that at least one end of the nanowire must be electrically connected by a Shottkey contact rather than a simple ohmic contact. Ohmic contacts are characterized by a change in resistance at the junction, but Shottkey contacts create an electrical potential barrier that limits electron conduction. Non-stoichiometric defects at the wire ends perturb the band structure, resulting in a potential barrier in ZnO nanowires. 

In laterally packaged piezoelectric systems, ohmic contacts allow electrical conduction that immediately negates the piezoelectric field, thus rendering the system useless. However, by incorporating Shottkey barriers on at least one end of the ZnO wire, electron conduction is severely limited because the piezoelectric field generated cannot overcome the Shottkey potential barrier. This causes electrons to pile up at the Shottkey barrier when the device is flexed; a discharge occurs when the strain is relieved. The result is an alternating field and current that can be easily harnessed for storage or used to drive an electrical device.

The device described in this study is a clear incremental step over the current zig-zag nanowire designs, but it is by no means a revolution—the efficiency is far too low and the fabrication has substantial scaling issues. However, with future research, both of these problems should be overcome and the substantial engineering advantages of this system could lay the groundwork for future functional devices.

Nature Nanotechnology DOI:10.1038/nnano.2008.314

It was always expected to end like this. If there's anything much going on with the water currently on Mars, chances are good it's happening at the poles, so NASA directed its latest lander, the Phoenix, to that region of the planet. Unfortunately, that inevitably meant that the lander would run short on sunlight to power its solar panels once the long, cold Martian winter set in.

About an hour ago, Phoenix's Twitter page broke the news: "From Phoenix mission ops: Phoenix is no longer communicating with Earth. We'll continue to listen, but it's likely its mission has ended." Power for the lander had been getting short, and it was taking longer to recharge its batteries; the loss of contact was a sign that the batteries had fully run down. There was never really a chance that the lander would run long past its expiration date (unlike the rovers, which operate in sunnier climes), but the exact date of its demise had been anyone's guess.

In its time on the red planet, Phoenix had a good view of the polar weather, but its work focused on the chemistry of the polar regions. Right off the bat, the lander's robotic scoop appeared to hit solid ice just below the surface, and scientists were rewarded with time-lapse images of ice subliming into the thin Martian atmosphere from one of the trenches it dug.

Images: NASA/JPL-Caltech/University of Arizona/Texas A&M University

We'll have a better sense of what precisely Phoenix has found when the scientific papers start coming out, but the lander had already made one key discovery: the public's really interested in the prospect of life on Mars. Back in August, rumors about a major discovery with implications for life on Mars became so intense that NASA had to hold a press conference to dispel them. It turns out they'd discovered lots of a compound that contains chlorine but, as of last check, they were still unsure what it was.

Phoenix is one of those rare cases where NASA got exactly what it had planned on: spotless operation in precisely the place they intended to land it. Unfortunately that location ensured that, no matter how well-engineered the hardware was, the winter would bring its operation to an end.

There is bad news for patients with pacemakers who like listening to music on their iPods. According to data presented at the current American Heart Association meeting in New Orleans, personal music devices such as iPods might not represent a risk to patients with implanted pacemakers or defibrillators, but the headphones used to listen to those devices might.

At issue are the magnets that drive the little speakers in the headphones. Implanted pacemakers and defibrillators are rather sensitive to magnetic fields, and clinicians use magnets to calibrate and test the devices under controlled conditions. After measuring the magnetic field strength of eight different brands of MP3 player headphones, researchers at Beth Israel Medical Center in Boston discovered that all of them were an order of magnitude stronger than needed to influence an implanted pacemaker of defibrillator.

They then confirmed this effect by testing it with patients, where they found that 15 percent of the pacemaker patients and 30 percent of the defibrillator patients carried devices that responded to the magnets.

Luckily, the problem doesn't occur when the headphones are used to actually listen to music, as the distance between the ears and the implanted device is too great. However, if the headphones are closer than 3 cm to the skin around the heart, the potential for interference is there.

This might not seem such a massive deal but, since the magnets cause this effect regardless of whether the device is on or even plugged in, it means that a patient who had their headphones draped over their neck or in a breast pocket could be at risk. Dr. Willam Maisel, lead author of the study, cautions patients that, regardless of the brand, they should always ensure that their headphones remain at least 3 cm (1.5 inches) away from the site of their devices.

One of the coolest things about the European Journal of Physics is that it publishes examples of physics that can be used as problems and/or examples for teaching classroom physics. Although I will discuss why that is important later, what caught my eye—and now you can suffer through it, too—was an article on the flight of the Albatross.

Fluid mechanics, and in particular, aerodynamics are very challenging subjects to teach because any example that can be solved by the students is likely to be quite trivial. All the interesting stuff is way too hard to study quantitatively—though you can bet that students get to explore them qualitatively. Computers have been a real boon to teaching these subjects because students can explore computer models of more complicated systems and gain a better understanding of the topic without the distraction of learning how to numerically solve sets of coupled nonlinear differential equations. Nevertheless, real-world examples with relatively simple physics are still appealing and, it turns out, the gliding behavior of the albatross is pretty useful.

For those of you who didn't pay attention in ornithology, the albatross is a sea bird that traverses vast expanses of the windy southern oceans on nothing more than an occasional squid meal. During the summer, these birds fly in great circles (think 10,000km in 10 days) munching anything with ten arms that it happens to spot. It then gives most of the food to an enormous parasite chick ensconced in a hollow on a rocky promontory. After leaving the nest, a maturing albatross may not set foot on land for up to 10 years.

To do all of this, albatrosses spend a lot of time gliding, and, over time, have evolved a number of adaptions to help them survive the southern oceans. An albatross can lock its wings in an outstretched position, meaning that a glide is almost as good as a rest. They have an enormous wing-span, clocking in at 3.5m, which gives them the highest lift-to-drag ratio of any bird. Their main adaption, however, is the way they fly, which is called dynamic soaring.

The idea is that the albatross enters a shallow dive with the wind at its back. This enables it to pick up speed both from the loss of altitude and the wind pushing it along. A few meters off the tops of the waves, it levels out and begins a long, curving, flat flight that is pretty much perpendicular to the wind. During this phase of the flight, the bird hunts for food. It benefits substantially from its very low drag because it can travel for quite a long distance before its speed drops too low.

Once the speed reaches a critical point, the albatross turns into the wind. The increased wind-speed over the wings provides increased lift, allowing it to gain height as it slowly loses speed. Interestingly enough, when considered from a stationary position on the ocean top, the albatross expends more energy on the flat part of the flight and expends almost nothing climbing back up to altitude—kinetic energy is converted into potential energy with an additional boost from the wind.

That basic flight trajectory, excluding a wheeling turn at the end, is described by some very simple mathematics, and provides an excellent illustration of dynamic soaring and the flow of energy between the wind, the albatross' potential energy, and its kinetic energy. The wheeling turn, which connects the climbing flight to the diving flight, was not included because it is a very difficult thing to describe mathematically. In addition to the flow of energy, the model described in the paper also shows that the velocity profile of the albatross' flight is unstable, indicating that it requires constant small corrections.

As befits a teaching model, there are a number of simplifications that, when summed up, mean that the researchers have described the minimum performance of an albatross. If one were to include the ground effect, the wheeling turn, and the lift acquired from the wave action of the sea, then the model would show that the albatross' performance is substantially better.

I love these articles, and love the European Journal of Physics for publishing them, for two reasons. First, academics get very little credit for developing teaching resources. By allowing them a space to publish particularly good ones, researchers get to include them in their list of publications. They then get credit in the same way that they would for publishing a piece of original research—it's in a research journal, so bureaucrats who monitor this sort of thing aren't going to know the difference. More importantly, it encourages researchers to develop teaching examples based on their own research, bringing the classroom closer to the cutting edge of scientific research.

European Journal of Physics, 2008, DOI: 10.1088/0143-0807/30/1/008