Flying Snakes, Caught on Camera

Five related species of tree-dwelling snakes found in Southeast and South Asia may just be the worst nightmares of ophidiophobes (people who have abnormal fears of snakes). Not only are they snakes, but they can "fly" -- flinging themselves off their perches, flattening their bodies, and gliding from tree to tree or to the ground.
To Virginia Tech biologist Jake Socha, these curious reptiles are something of a biomechanical wonder. In order to understand how they do what they do, Socha and his colleagues recently studied Chrysopelea paradisi snakes as they launched themselves off a branch at the top of a 15-meter-tall tower.

Four cameras recorded the curious snakes as they glided. This allowed them to create and analyze 3-D reconstructions of the animals' body positions during flight -- work that Socha recently presented at the American Physical Society Division of Fluid Dynamics (DFD) meeting in Long Beach, CA.

The reconstructions were coupled with an analytical model of gliding dynamics and the forces acting on the snakes' bodies. The analyses revealed that the reptiles, despite traveling up to 24 meters from the launch platform, never achieved an "equilibrium gliding" state -- one in which the forces generated by their undulating bodies exactly counteract the force pulling the animals down, causing them to move with constant velocity, at a constant angle from the horizon. Nor did the snakes simply drop to the ground.

Instead, Socha says, "the snake is pushed upward -- even though it is moving downward -- because the upward component of the aerodynamic force is greater than the snake's weight."

"Hypothetically, this means that if the snake continued on like this, it would eventually be moving upward in the air -- quite an impressive feat for a snake," he says. But our modeling suggests that the effect is only temporary, and eventually "the snake hits the ground to end the glide."

The presentation, "Gliding flight in snakes: non-equilibrium trajectory dynamics and kinematics" was given on November 22, 2010

This research is being published in the journal Bioinspiration and Biomimetics.

Early Universe Was a Liquid, Nuclei Collisions at the Large Hadron Collider Show

In an experiment to collide lead nuclei together at CERN's Large Hadron Collider physicists from the ALICE detector team including researchers from the University of Birmingham have discovered that the very early Universe was not only very hot and dense but behaved like a hot liquid.
By accelerating and smashing together lead nuclei at the highest possible energies, the ALICE experiment has generated incredibly hot and dense sub-atomic fireballs, recreating the conditions that existed in the first few microseconds after the Big Bang. Scientists claim that these mini big bangs create temperatures of over ten trillion degrees.

At these temperatures normal matter is expected to melt into an exotic, primordial 'soup' known as quark-gluon plasma. These first results from lead collisions have already ruled out a number of theoretical physics models, including ones predicting that the quark-gluon plasma created at these energies would behave like a gas.

Although previous research in the USA at lower energies, indicated that the hot fire balls produced in nuclei collisions behaved like a liquid, many expected the quark-gluon plasma to behave like a gas at these much higher energies.

Scientists from the University of Birmingham's School of Physics and Astronomy are playing a key role in this new phase of the LHC's programme which comes after seven months of successfully colliding protons at high energies. Dr David Evans, from the University of Birmingham's School of Physics and Astronomy, and UK lead investigator at ALICE experiment, said: "Although it is very early days we are already learning more about the early Universe."

He continues: "These first results would seem to suggest that the Universe would have behaved like a super-hot liquid immediately after the Big Bang."

The team has also discovered that more sub-atomic particles are produced in these head-on collisions than some theoretical models previously suggested. The fireballs resulting from the collision only lasts a short time, but when the 'soup' cools down, the researchers are able to see thousands of particles radiating out from the fireball. It is in this debris that they are able to draw conclusions about the soup's behaviour.

Two papers detailing this research have been submitted for publication and posted on: http://xxx.lanl.gov/abs/1011.3914| and http://xxx.lanl.gov/abs/1011.3916|.

Making Stars: How Cosmic Dust and Gas Shape Galaxy Evolution

Astronomers find cosmic dust annoying when it blocks their view of the heavens, but without it the universe would be devoid of stars. Cosmic dust is the indispensable ingredient for making stars and for understanding how primordial diffuse gas clouds assemble themselves into full-blown galaxies.
"Formation of galaxies is one of the biggest remaining questions in astrophysics," said Andrey Kravtsov, associate professor in astronomy & astrophysics at the University of Chicago.

Astrophysicists are moving closer to answering that question, thanks to a combination of new observations and supercomputer simulations, including those conducted by Kravtsov and Nick Gnedin, a physicist at Fermi National Accelerator Laboratory.

Gnedin and Kravtsov published new results based on their simulations in the May 1, 2010 issue of The Astrophysical Journal, explaining why stars formed more slowly in the early history of the universe than they did much later. The paper quickly came to the attention of Robert C. Kennicutt Jr., director of the University of Cambridge's Institute of Astronomy and co-discoverer of one of the key observational findings about star formation in galaxies, known as the Kennicutt-Schmidt relation.

In the June 3, 2010 issue of Nature, Kennicutt noted that the recent spate of observations and theoretical simulations bodes well for the future of astrophysics. In their Astrophysical Journal paper, Kennicutt wrote, "Gnedin and Kravtsov take a significant step in unifying these observations and simulations, and provide a prime illustration of the recent progress in the subject as a whole."

Star-formation law

Kennicutt's star-formation law relates the amount of gas in galaxies in a given area to the rate at which it turns into stars over the same area. The relation has been quite useful when applied to galaxies observed late in the history of the universe, but recent observations by Arthur Wolfe of the University of California, San Diego, and Hsiao-Wen Chen, assistant professor in astronomy and astrophysics at UChicago, indicate that the relation fails for galaxies observed during the first two billion years following the big bang.

Gnedin and Kravtsov's work successfully explains why. "What it shows is that at early stages of evolution, galaxies were much less efficient in converting their gas into stars," Kravtsov said.

Stellar evolution leads to increasing abundance of dust, as stars produce elements heavier than helium, including carbon, oxygen, and iron, which are key elements in dust particles.

"Early on, galaxies didn't have enough time to produce a lot of dust, and without dust it's very difficult to form these stellar nurseries," Kravtsov said. "They don't convert the gas as efficiently as galaxies today, which are already quite dusty."

The star-formation process begins when interstellar gas clouds become increasingly dense. At some point the hydrogen and helium atoms start combining to form molecules in certain cold regions of these clouds. A hydrogen molecule forms when two hydrogen atoms join. They do so inefficiently in empty space, but find each other more readily on the surface of a cosmic dust particle.

"The biggest particles of cosmic dust are like the smallest particles of sand on good beaches in Hawaii," Gnedin said.

These hydrogen molecules are fragile and easily destroyed by the intense ultraviolet light emitted from massive young stars. But in some galactic regions dark clouds, so-called because of the dust they contain, form a protective layer that protects the hydrogen molecules from the destructive light of other stars.

Stellar nurseries

"I like to think about stars as being very bad parents, because they provide a bad environment for the next generation," Gnedin joked. The dust therefore provides a protective environment for stellar nurseries, Kravtsov noted.

"There is a simple connection between the presence of dust in this diffuse gas and its ability to form stars, and that's something that we modeled for the first time in these galaxy-formation simulations," Kravtsov said. "It's very plausible, but we don't know for sure that that's exactly what's happening."

The Gnedin-Kravtsov model also provides a natural explanation for why spiral galaxies predominately fill the sky today, and why small galaxies form stars slowly and inefficiently.

"We usually see very thin disks, and those types of systems are very difficult to form in galaxy-formation simulations," Kravtsov said.

That's because astrophysicists have assumed that galaxies formed gradually through a series of collisions. The problem: simulations show that when galaxies merge, they form spheroidal structures that look more elliptical than spiral.

But early in the history of the universe, cosmic gas clouds were inefficient at making stars, so they collided before star formation occurred. "Those types of mergers can create a thin disk," Kravtsov said.

As for small galaxies, their lack of dust production could account for their inefficient star formation. "All of these separate pieces of evidence that existed somehow all fell into one place," Gnedin observed. "That's what I like as a physicist because physics, in general, is an attempt to understand unifying principles behind different phenomena."

More work remains to be done, however, with input from newly arrived postdoctoral fellows at UChicago and more simulations to be performed on even more powerful supercomputers. "That's the next step," Gnedin said.

Researchers Kick-Start Ancient DNA

Binghamton University researchers recently revived ancient bacteria trapped for thousands of years in water droplets embedded in salt crystals.
For decades, geologists have looked at these water droplets -- called fluid inclusions -- and wondered whether microbes could be extracted from them. Fluid inclusions have been found inside salt crystals ranging in age from thousands to hundreds of millions years old.

But there has always been a question about whether the organisms cultured from salt crystals are genuinely ancient material or whether they are modern-day contaminants, said Tim Lowenstein, professor of geological sciences and environmental studies at Binghamton.

Lowenstein and Binghamton colleague J. Koji Lum, professor of anthropology and of biological sciences, believe they have resolved this doubt. And they've received $400,000 from the National Science Foundation to support further research on the topic.

Lowenstein's team, which has been pursuing this problem for years, began by examining the fluid inclusions under a microscope. "Not only did we find bacteria, we found several types of algae as well," he said. "The algae actually may be the food on which the bacteria survive for tens of thousands of years."

When Lum got involved, the researchers began to wonder about the DNA of the organisms they were finding.

"You have a little trapped ecosystem," Lum said. "Some of these guys are feeding on other ones trapped in this space. The things that aren't alive in there, their DNA is still preserved."

Lum's graduate student Krithivas Sankaranarayanan reviewed existing literature on ancient DNA and helped to develop a protocol for use with Lowenstein's samples.

"We have these samples going back from the present to over 100,000 years in one exact location," Lum said. "So Tim can look at the salinity and reconstruct ancient climates. Now we're looking at the DNA from bacteria, the algae, the fungi and what was living in those waters and how those things changed over time. We have a view of all the different organisms that were in the lakes at the time these inclusions were formed."

The researchers sequence the DNA and culture the bacteria they find. Then it's time to think big. Lum's most optimistic view of the project goes like this: "It's possible that we can observe organisms evolving and see how they're reacting to climate change over geologic time."

The samples Lowenstein works with are drawn from Death Valley and Saline Valley in California as well as from sites in Michigan, Kansas and Italy.

Temperatures at these locations may have reached 130 degrees Fahrenheit in the past, and the pockets of water trapped inside the rocks are generally very salty.

The environment may sound harsh -- in fact, it's among the most extreme on Earth -- but the creatures that survive there are tough.

"These are some of the hardiest beasts on the planet," Lum said. And the conditions inside these water droplets are ideally suited to preserving DNA.

"They're like time capsules," Lowenstein agreed.

Evolution May Go Wild on Violent Exoplanets

In the coming decades we will begin to characterize planets in the habitable zones around nearby stars. The problem is that just because they are habitable we will still be hard-pressed to understand if the chemistry of their atmospheres comes only from microorganisms, or six-legged giraffes, or even sentient beings.

A huge influence on planet's ability to evolve complex life is not just location, location, location, but rather environment, environment environment. The difference? Some planetary systems may have gas giant planets that accelerate the rate of comet or asteroid impacts on the surface of their terrestrial siblings.
garbage

Other Earth-like worlds might orbit petulant young red dwarf stars that spit out searing flares that pound the planets.

But Earth history has shown that one species’ Armageddon may be another species’ Genesis. Take the devastating asteroid impact that triggered a mass extinction 65 million years ago, toppling the mightiest predators that ever-walked Earth, the dinosaurs. Surviving dinosaurs evolved to take to the air and mammals rose from the shadows to dominate our planet.

Even more dramatically, a biological arms race -- the Cambrian Explosion -– took place on the cusp of Earth’s near-death experience as a "snowball Earth" about 500 million years ago.

Based on these discoveries, the emerging view is that long periods of ecological stability are punctuated by catastrophes, both Earth-made and extraterrestrial. It seems that when all hell is breaking loose on a Earth major evolutionary changes happen rapidly.

Aside from our new view of the devastating threats from space debris, this kind of "kick in the pants" model for evolution is not new.

Last year was the 150th anniversary of Darwin's landmark publication, On the Origin of the Species, which laid the foundation for modern biology.

Darwin's idea was that most evolution was accomplished very gradually by competition between organisms that became better adapted to relatively stable environment. But 28 years earlier than Darwin's publication the Scottish horticulturalist Patrick Matthew published his own ideas about the process of natural selection:

"There is a natural law universal in nature, tending to render every reproductive being the best possibly suited to its condition . . . it is only the hardier, more robust, better suited to circumstance individuals, who are able to struggle forward to maturity, . . . from the strict ordeal by which Nature tests their adaptation to her standard of perfection and fitness to continue their kind by reproduction.'

In other words, Matthew thought that it took no less than global catastrophes to shock evolution out of a laid-back state and spur diversity and competition among organisms. When the going gets tough only the tough get going -- to borrow the phrase from Billy Ocean's 1985 pop song.

Matthew’s musings were simply published in the appendix to his 1831 book with the utterly forgettable title: Naval Timber and Arboriculture.

Writing in a recent issue of Historical Biology, New York University geologist Michael Rampino concludes: "Others have said that Matthew's thesis was published in too obscure a place to be noticed by the scientific community, or that the idea was so far ahead of its time that it could not be connected to generally accepted knowledge. As a result, his discovery was consigned to the dustbin of premature and unappreciated scientific ideas."

Oh, only if the Internet existed in 1831, Matthew could have blogged away on his ideas.


But this is a very salient idea today as it applies to the rough-and-tumble planetary systems we are finding. Those terrestrial planets though to undergo intense periods of bombardments might be a hotbed of evolution gone wild. Or perhaps there is a "catastrophe rate limit" beyond which life suffers arrested development.

Age of the Exoplanet

This is one of the biggest motivations I can image for undertaking a many-centuries-long program of understanding the evolutionary history of nearby Earth-like planets. This would require extraordinarily sophisticated survey robots that would scrutinize a planet’s biosphere. Other robots would have to probe a planet’s geologic past, and the architecture of the home planetary system.

Therefore, simply finding circumstantial evidence of microbial activity on other worlds will become intellectually dissatisfying to future scientists.

Perhaps on the millennial celebration of Darwin’s work -- or instead Matthew’s work -- our distance descendants will have a truly universal concept of how life evolves in a range of planetary environments.

This is a monumental task only dreamt of in science fiction stories. But little might Matthew have imagined that his ideas would be potentially be applicable to worlds whirling around the distant stars.

Newly Discovered Planet Adopted by Milky Way

* The first planet of extra-galactic origin in the Milky Way has been found.
* The planet is located about 2,000 light-years from Earth in the constellation Fornax.
* The finding also challenges theories of planet formation, which hold that stars need more than hydrogen and helium to produce planets.

HIP 13044b is the first planet of any origin found around a star lacking resources beyond hydrogen and helium. Click to enlarge this image.
ESO/L. Calçada

Between six billion and nine billion years ago, the Milky Way and another smaller galaxy found themselves at approximately the same place at approximately the same time.

Our galaxy emerged the victor, taking with it some spoils of war -- stars and material from the crushed galaxy -- which even to this day remain not quite meshed into the Milky Way's overall churn and flow. Scientists now discover there was a tag-along as well: a Jupiter-like planet known as HIP 13044b.

Like most of the 500 or so planets that have been discovered beyond our solar system, not much is know about the adoptee, which was found by measuring the slight gravitational tugs it exerts on its parent star.

But astronomers suspect it's a survivor. Not only did HIP 13044b successfully migrate from its galaxy of origin to ours, the planet also apparently survived the brutal ballooning of its parent, which has transitioned from a hydrogen-burning middle-aged star into a helium-fueled senior citizen known as a red giant.

Our own sun will undergo a similar change of life in another five billion years or so.

HIP 13044b's existence is bit of a mystery too, since it is the first planet of any origin found around a star lacking resources beyond hydrogen and helium. Such so-called "metal-poor" stars weren't believed to have the right stuff to produce planets.

"More statistics are needed to really find out how likely it is for metal-poor stars to form planets," study co-author Rainer Klement, with the Max-Planck-Institut für Astronomie, told Discovery News. "I think this will be the biggest impact of the research."

"They did an extremely careful job," added exoplanet-hunter Sara Seager, with the Massachusetts Institute of Technology. "They seemed to have gone through the scenarios very carefully."

The transplanted planet, which is at least 1.25 times the mass of Jupiter, lies about 2000 light-years from Earth in the southern constellation of Fornax, also known as the Furnance.

Lead researcher Johny Setiawan, also from Max Planck, and colleagues remain on the hunt for any HIP 13044b sibling planets -- those that are still around anyway. From the spin rate of the parent star, which is faster than it should be, scientists think the red giant already has consumed some of HIP 13044b's sisters.

Weird Ringed Nebula Glows in Infrared

NASA’s WISE infrared space telescope is losing its refrigeration, but its backlog of data is still yielding cool images such this one of an odd, blobby, jellyfish-like nebula.

“I just happened to look up one of my favorite objects in our WISE catalogue and was shocked to see these odd rings,” said Michael Ressler, a member of the WISE science team at NASA’s Jet Propulsion Lab, in a press release.

The object, called the “Crystal Ball” nebula or NGC1514, is a planetary nebula located 800 light-years away in the constellation Taurus. Planetary nebulas form when a dying star puffs off its outer layers of material and illuminates the gaseous cloud from within. They’re called “planetary” because the first such objects discovered were roughly spherical, like a planet, although nebulas with lopsided wings are now known to be common.

In visible light (left image), NGC 1514 looked a lot like any other asymmetrical nebula. But WISE’s infrared image (right) shows loopy rings surrounding NGC 1514 that are unlike anything astronomers had seen before.

“This object has been studied for more than 200 years, but WISE shows us it still has surprises,” Ressler said. The observations are reported Nov. 9 in the Astronomical Journal.

The rings could be dust ejected from a pair of dying stars at the nebula’s center, one a giant star heavier and hotter than the sun, the other a dense white dwarf. The giant star sheds some outer layers as it ages to form a bubble around the two stars. Jets of material from the white dwarf are thought to have smashed into the bubble, forming the rings that glow orange in the WISE image.

The green cloud is an inner shell of previously shed material, which shows up in light blue in the visible image.

The rings went undetected until WISE because their dust is heated and glows with the infrared light that WISE can detect. In this image, infrared light with a wavelength of 3.4 micrometers is blue; 4.6-micrometer light is turquoise; 12-micrometer light is green and 22-micrometer light is red. In visible-light images, the rings are washed out by the bright clouds of gas.

Many more surprises lurk in the piles of data WISE collected between January and October of this year. The first batch of data will be released to the astronomical community in spring 2011. Meanwhile, WISE — which ran out of coolant in late September and is now too warm for two of its infrared cameras to function — is continuing on as NEOWISE, searching for near-Earth objects like asteroids and comets.