Mar 24, 2012

Hoard of Roman Coins Found in England

One of the largest collections of Roman coins -- over 30,000 silver pieces -- has been recovered in England from the building site of a new hotel in Bath, just 450 feet from the historic Roman Baths.

Known as the Beau Street Hoard, from the street where they have been unearthed, the coins date to 270 A.D., a time of great upheaval when the western Roman empire was threatened by civil war and barbarian invasion.

Aware of the difficult times, the owner might have just decided to hide away the treasure.

"In the crisis of the third century, Rome had 25 emperors in 50 years. It was a time of great unrest especially on the continent as the Empire came near to collapse," Stephen Clews, manager of the Roman Baths and Pump Room, told Discovery News.

"Britain was part of a breakaway western empire and although it seems to have been relatively peaceful, this hoard may reflect events unfolding in those troubled times," Clews said.

The archaeologists found thousands of coins fused together in a large block. This makes identification and counting the exact number very difficult.

"Conservators at the British Museum are taking a whole year to do the work. There are believed to be more than 30,000 coins, making this one of the fifth largest hoards ever found in Britain and the largest from a Roman town," Clews said.

The coins are also the largest hoard ever found by a professional archaeologist -- Hazel O'Neill of Cotswold Archaeology.

Read more at Discovery News

Laser Hints at How Universe Got Its Magnetism

Scientists have used a laser to create magnetic fields similar to those thought to be involved in the formation of the first galaxies; findings that could help to solve the riddle of how the Universe got its magnetism.

Magnetic fields exist throughout galactic and intergalactic space, what is puzzling is how they were originally created and how they became so strong.

A team, led by Oxford University physicists, used a high-power laser to explode a rod of carbon, similar to pencil lead, in helium gas. The explosion was designed to mimic the cauldron of plasma -- an ionized gas containing free electrons and positive ions -- out of which the first galaxies formed.

The team found that within a microsecond of the explosion strong electron currents and magnetic fields formed around a shock wave. Astrophysicists took these results and scaled them through 22 orders-of-magnitude to find that their measurements matched the 'magnetic seeds' predicted by theoretical studies of galaxy formation.

A report of the research is published in a recent issue of the journal Nature.

'Our experiment recreates what was happening in the early Universe and shows how galactic magnetic fields might have first appeared,' said Dr Gianluca Gregori of Oxford University's Department of Physics, who led the work at Oxford. 'It opens up the exciting prospect that we will be able to explore the physics of the cosmos, stretching back billions of years, in a laser laboratory here on Earth.'

The results closely match theories which predict that tiny magnetic fields -- 'magnetic seeds' -- precede the formation of galaxies. These fields can be amplified by turbulent motions and can strongly affect the evolution of the galactic medium from its early stages.

Read more at Science Daily

Mar 23, 2012

Who Knew? Fruit Flies Get Kidney Stones Too

Research on kidney stones in fruit flies may hold the key to developing a treatment that could someday stop the formation of kidney stones in humans, a team from Mayo Clinic and the University of Glasgow found.

They recently presented their findings at the Genetics Society of America annual meeting.

"The kidney tubule of a fruit fly is easy to study because it is transparent and accessible," says physiologist Michael F. Romero, Ph.D., of Mayo Clinic in Rochester, Minn. He said researchers are now able to see new stones at the moment of formation.

"More important is that fruit flies are not bothered by the presence of kidney stones, so they are ideal subjects to study in order to better understand the condition in humans," Dr. Romero says.

For example, Dr. Romero's team has identified a gene that encodes a protein which transports oxalate into the fly kidney. When this gene is genetically modified, flies get fewer stones.

Dr. Romero and his colleagues are now using this gene as a target as they test gut, renal and crystal dissolving therapies in fruit flies for possible drug development.

Read more at Science Daily

Why Humans Began Walking Upright

Most of us walk and carry items in our hands every day. These are seemingly simple activities that the majority of us don't question. But an international team of researchers, including Brian Richmond at the George Washington University, have discovered that human bipedalism, or walking upright, may have originated millions of years ago as an adaptation to carrying scarce, high-quality resources. This latest research was published in this month's Current Biology.

The team of researchers from the U.S., England, Japan and Portugal investigated the behavior of modern-day chimpanzees as they competed for food resources, in an effort to understand what ecological settings would lead a large ape -- one that resembles the 6 million-year old ancestor we shared in common with living chimpanzees -- to walk on two legs.

"These chimpanzees provide a model of the ecological conditions under which our earliest ancestors might have begun walking on two legs," said Dr. Richmond, an author of the study and associate professor of anthropology at GW's Columbian College of Arts and Sciences. "Something as simple as carrying -- an activity we engage in every day -- may have, under the right conditions, led to upright walking and set our ancestors on a path apart from other apes that ultimately led to the origin of our kind."

The research findings suggest that chimpanzees switch to moving on two limbs instead of four in situations where they need to monopolize a resource, usually because it may not occur in plentiful supply in their habitat, making it hard for them to predict when they will see it again. Standing on two legs allows them to carry much more at one time because it frees up their hands. Over time, intense bursts of bipedal activity may have led to anatomical changes that in turn became the subject of natural selection where competition for food or other resources was strong.

Two studies were conducted by the team in Guinea. The first study was in Kyoto University's "outdoor laboratory" in a natural clearing in Bossou Forest. Researchers allowed the wild chimpanzees access to different combinations of two different types of nut -- the oil palm nut, which is naturally widely available, and the coula nut, which is not. The chimpanzees' behavior was monitored in three situations: (a) when only oil palm nuts were available, (b) when a small number of coula nuts was available, and (c) when coula nuts were the majority available resource.

When the rare coula nuts were available only in small numbers, the chimpanzees transported more at one time. Similarly, when coula nuts were the majority resource, the chimpanzees ignored the oil palm nuts altogether. The chimpanzees regarded the coula nuts as a more highly-prized resource and competed for them more intensely.

In such high-competition settings, the frequency of cases in which the chimpanzees started moving on two legs increased by a factor of four. Not only was it obvious that bipedal movement allowed them to carry more of this precious resource, but also that they were actively trying to move as much as they could in one go by using everything available -- even their mouths.

Read more at Science Daily

Why Magicians Are a Scientist’s Best Friend

A magician will instantly see the truth behind any colleague’s illusion. But we have a bit of an advantage: We know we are being fooled. Scientists are instinctive doubters who employ a rigorous method to zero in on the truth, but they aren’t necessarily trained to expect deception by subjects and collaborators.

We can’t make magicians out of scientists — we wouldn’t want to — but we can help scientists “think in the groove” — think like a magician. And we should.

For most of my life I’ve pecked away at a certain type of swindler: faith-healers, mystics, mind-readers. Those of a certain age may remember my appearances on The Tonight Show with Johnny Carson — a skilled amateur magician himself who introduced my exposure of flummery to a huge television audience.

Mine was a lonely voice back then, but I’m not alone anymore. The immensely talented and popular Penn & Teller long ago joined me as foes of harmful deception, along with other magicians; the president of my foundation, D.J. Grothe, has a background in magic, and many of our associates are professional magicians, as well. They all agree with me that the Society of American Magicians and the International Brotherhood of Magicians should re-establish their once very active investigations of the fakers who claim supernatural powers.

It’s not something that is generally done, or maybe at all – I’d love to see one funding grant that has a line item for the services of a magician, if somebody out there has one. But it is long overdue that my peers in the conjuring profession try to take a more active role in the elimination of nonsense science by joining forces with scientists, and that scientists be open to the proposition.

Please bear with me while I offer you a peek behind the curtain, a cursory glance at what we magicians are — and aren’t. First, we’re entertainers, actors, showbiz people who have as our primary objective the delight of our audiences. We’re deceivers, yes, taking on roles and characters to express our art, just as any actor does.

We are not scientists — with a few rare but important exceptions, like Ray Hyman and Richard Wiseman. But our highly specific expertise comes from knowledge of the ways in which our audiences can be led to quite false conclusions by calculated means — psychological, physical and especially sensory, visual being rather paramount since it has such a range of variety.

The fact that ours is a concealed art as well as one designed to confound persons of average and advanced thinking skills — our typical audience — makes it rather immune to ordinary analysis or solutions.

I’ve observed that scientists tend to think and perceive logically by using their training and observational skills — of course — and are thus often psychologically insulated from the possibility that there might be chicanery at work. This is where magicians can come in. No matter how well educated, or how basically intelligent, trained, or observant a scientist may be, s/he may be a poor judge of a methodology employed in deliberate deception.

I particularly like the way our associate, magician and skeptic Jamy Ian Swiss, has expressed this point:

    Any magician worth his salt will tell you that the smarter an audience, the more easily fooled they are. That’s a very counterintuitive idea. But it’s why scientists, for example, get in trouble with psychics and such types. Scientists aren’t trained to study something that’s deceptive. Did you ever hear of a sneaky amoeba? I don’t think so. You know, they don’t get together on the slide and go, “Hey, let’s fool the big guy.”

It’s not a novel notion to call in a trickster for advice. In England, famous magician John Nevil Maskelyne [1839-1917] appeared in a courtroom to demonstrate how spiritualist fakers were working their swindles on vulnerable victims, with great success. French illusionist Gérard Majax and Italy’s Massimo Polidoro have repeatedly exposed a variety of swindlers in throughout Europe.

Harry Houdini stood on the floor of the U.S. Congress and stridently denounced a variety of hoaxers, flaunting his cash prize for an example of a supernatural feat that would prove him wrong. Magicians like Penn & Teller and others have stepped forward to express their expert opinions concerning expensive and wasteful pursuits of chimeras.

What we need now is to formalize this. We magicians have to make it clear that the insights we need to be magicians can be leveraged in the scientific method, and that we are on call. And scientists have to be open to the idea that a magician just might be the most important research associate on the team when it comes to looking into anomalous claims.

Read more at Wired Science

Black Hole Punch Can Launch a Planet

Punched by the gravitational fist of Sagittarius A* (Sgr A*), the location of the supermassive black hole that lives at the center of our galaxy, a planet could be hurled through space at speeds of up to 30 million miles per hour (48 million kilometers per hour), the Harvard-Smithsonian Center for Astrophysics and Dartmouth College report this week.

"These warp-speed planets would be some of the fastest objects in our galaxy. If you lived on one of them, you'd be in for a wild ride," Harvard-Smithsonian's Avi Loeb said in a press release about the research.

The only known objects that move faster than these planets are subatomic particles, added Dartmouth's Idan Ginsburg.

Scientists got to thinking about runaway planets after colleagues discovered a star launching out of the Milky Way at 1.5 million miles per hour (2.4 million kilometers per hour).

Simulations showed the star -- known as a hypervelocity star -- must have been part of a double-star system that ended up in the wrong part of the Milky Way.

"A double-star system wanders too close to the supermassive black hole at the galactic center. Strong gravitational forces rip the stars from each other, sending one away at high speed while the other is captured into orbit around the black hole," writes Christine Pulliam, spokeswoman for the Harvard-Smithsonian Center for Astrophysics.

Turns out the same thing can happen to planets. Ginsburg, Loeb and Darthmouth’s Gary Wegner created computer models showing what would happen if each star had a planet or two orbiting nearby.

"They found that the star ejected outward could carry its planets along for the ride. The second star, as it's captured by the black hole, could have its planets torn away and flung into the icy blackness of interstellar space at tremendous speeds," Pulliam wrote.

A typical hypervelocity planet would slingshot outward at 7 to 10 million miles per hour, she added, noting that "a small fraction of them could gain much higher speeds under ideal conditions."

Because any tag-along planets would have to be in tight orbits around their parent stars, astronomers may be able to detect them by looking for a hypervelocity star that dims slightly as its planet passes across its face, relative to the view from Earth.

Read more at Discovery News

Mar 22, 2012

Mysterious Booms Plague Wisconsin Town

The small town of Clintonville, Wis., can hardly be called a boom town -- until recently.

On the evening of Sunday, March 18, five loud, mysterious booms thundered through the town at approximately two-hour intervals starting at around 8 p.m. They occurred again the following night, and, much to the sleepless residents' relief, finally stopped Tuesday night. The town thought it was over, but then it started again Wednesday night.

Police, after receiving nearly 100 concerned calls about the sounds, investigated and found nothing. There were no known gas or sewer explosions, no landslides. It was not a military exercise, nor mining explosions. Some think it might be related to sonic booms, groundwater, or earth settling -- though no earthquakes have been recorded.

Some thought it might be a clandestine meth house exploding -- at least the first time, probably not over and over again. Others suspect pranksters with powerful fireworks or dynamite.

Authorities have assured the town that they will continue to search for the source of the booms, though residents are frustrated at the lack of progress. In theory, it should not be difficult for well-equipped technicians to locate the source of a loud boom. After all, you just listen for the sound and go in the direction you hear it, right?

Investigating Sounds

Not so fast. We know from physics that sound travels in waves, and identifying the source of a sound can be very difficult in urban areas where concrete, glass, and buildings can reflect, change, and amplify sound waves.

Those nearest the sound will, in theory, hear it the loudest. However there are confounding factors; for example people farther away may hear it more loudly than people living closer but who have large buildings in between them and the source of the sound that dampen the volume.

Furthermore, without some objective measure of how loud the sound is, witnesses may have difficultly describing variation in volume: was it "loud" or "really loud?" (To most people awakened in their beds very early in the morning by the boom, the most likely response would be an annoyed "too damn loud.")

The first step to locating the source of the sounds would be to place a dozen or more carefully calibrated audio recorders on a grid system throughout (and surrounding) the town. The next time a mysterious boom is recorded, scientists can collect data from all the recorders, determine which microphones recorded the highest volume, and triangulate the location from that information.

Read more at Discovery News

Geologists Discover New Class of Landform -- On Mars

An odd, previously unseen landform could provide a window into the geological history of Mars, according to new research by University of Washington geologists.

They call the structures periodic bedrock ridges. The ridges look like sand dunes but, rather than being made from material piled up by the wind, the scientists say the ridges actually form from wind erosion of bedrock.

"These bedforms look for all the world like sand dunes but they are carved into hard rock by wind," said David Montgomery, a UW professor of Earth and space sciences. It is something there are not many analogs for on Earth."

He believes the ridges, while still bedrock, are composed of a softer, more erodible material than typical bedrock and were formed by an unusual form of wind erosion that occurs perpendicular to the prevailing wind rather than in the same direction.

He contrasts the ridges with another bedrock form called a yardang, which has been carved over time by headwinds. A yardang has a wide, blunt leading edge in the face of the wind, and its sides are tapered so that it resembles a teardrop.

In the case of periodic bedrock ridges, Montgomery believes high surface winds on Mars are deflected into the air by a land formation, and they erode the bedrock in the area where they settle back to the surface.

Spacing between ridges depends on how long it takes for the winds to come back to the surface, and that is determined by the strength of the wind, the size of the deflection and the density of the atmosphere, he said.

The discovery is important because if the ridges were actually created by wind depositing material into dunes, "you're not going to have information from any prior history of the material that is exposed at the surface," he said.

"But if it's cut into instead, and you're looking at the residual of a rock that has been eroded away, you can still get the history of what was happening long ago from that spot," Montgomery said.

"You could actually go back and look at some earlier eras in Martian history, and the wind would have done us the favor of exposing the layers that would have that history within it," he said. "There are some areas of the Martian surface, potentially large areas, that up until now we've thought you couldn't really get very far back into Mars history geologically."

Montgomery is the lead author of a paper documenting the discovery published online March 9 in the Journal of Geophysical Research, a journal of the American Geophysical Union. Coauthors are Joshua Bandfield, a UW research assistant professor of Earth and space sciences, and Scott Becker, who did the work as an undergraduate in Earth and space sciences and has received his degree. The work was funded in part by NASA.

There could be landforms on Earth that are somewhat similar to periodic bedrock ridges, Montgomery said, but to date there's nothing exactly like it, largely because there are not many bedrock landscapes on Earth in which wind is the main erosion agent.

Read more at Science Daily

New Understanding of Earth's Mantle Beneath the Pacific Ocean

Scientists have long speculated about why there is a large change in the strength of rocks that lie at the boundary between two layers immediately under Earth's crust: the lithosphere and underlying asthenosphere. Understanding this boundary is central to our knowledge of plate tectonics and thus the formation and evolution of our planet as we know it today. A new technique for observing this transition, particularly in the portion of Earth's mantle that lies beneath the Pacific Ocean basin, has led Carnegie and NASA Goddard scientist Nick Schmerr to new insight on the origins of the lithosphere and asthenosphere.

His work is published March 23 in Science.

The lithosphere-asthenosphere boundary, or LAB, represents the transition from hot, convecting mantle asthenosphere to overlying cold and rigid lithosphere. The oceanic lithosphere thickens as it cools over time, and eventually sinks back into the mantle at Earth's so-called subduction zones. Studies of seismic waves traveling across the LAB show higher wave speeds in the lithosphere and lower speeds in the asthenosphere. In some regions, seismic waves indicate an abrupt 5 to 10% decrease in wave speeds between 35 and 120 km depth, forming a boundary known as the Gutenberg discontinuity. In many cases, the depth of the Gutenberg discontinuity is roughly coincident with the expected depth of the LAB, leading to the suggestion that the two boundaries are closely inter-related.

However, temperature alone cannot fully explain the abrupt change in the mechanical and seismic properties that have been observed at the Gutenberg discontinuity. This has led many scientists to suggest that other factors--such as the presence of molten rock, water, and/or a decrease in the grain size of minerals--may also play important roles.

Older techniques made imaging seismic discontinuities shallower than 100 kilometers quite difficult, and regions beneath the oceans could only be accessed where seismic stations were installed on ocean islands or by deploying ocean bottom seismometers, giving an incomplete picture of where the Gutenberg occurs beneath the Pacific Ocean.

But an innovative observation technique -- one that incorporates seismic waves that sample beneath remote regions of Earth at higher frequencies, and new signal processing techniques--enabled Schmerr to hone in on the Gutenberg discontinuity.

He discovered that the seismic discontinuity is not a Pacific-wide phenomenon, but rather only detectable beneath regions with recent surface volcanism. He also found the Gutenberg appears to become deeper beneath older crust, confirming the discontinuity is, indeed, related to the LAB.

Schmerr proposes that the Gutenberg is formed by partially molten rock produced in the asthenosphere that collects and ponds at the base of the lithosphere. Decompression of hot rock at small-scale upwellings or hot mantle plumes is responsible for generating the melt. Plumes will thermally reheat the lithosphere, making it shallower than would be expected underneath older crust.

Read more at Science Daily

Did Belief in Gods Lead to Mayan Demise?

A dread of malevolent spirits haunting forsaken areas could, along with environmental catastrophes, help to explain why some areas in the ancient Mayan world proved less resilient than others when their civilization disintegrated, researchers suggest.

The ancient Maya once claimed an area about the size of Texas, with cities and fields that occupied what is now southern Mexico and northern Central America, including the countries of Guatemala, Belize, El Salvador and Honduras. The height of the Mayan civilization, known as the Classic period, extended from approximately A.D. 250 to at least 900.

For unknown reasons, the Classic Mayan civilization then collapsed. The population declined catastrophically to a fraction of its former size, and many of their great cities were left mostly abandoned for the jungle to reclaim.

Scientists have long drawn connections between the decline of the ancient Maya and environmental catastrophes, especially drought. Deforestation linked with farming could also have triggered disaster — for instance, reduced tree cover of the ground would have led to loss of fertile topsoil by erosion, as well as greater evaporation of water by sunlight, exacerbating drought.

However, while some locales remain abandoned for long periods, others recovered more quickly. This patchwork pattern of recovery might argue against environmental catastrophes being the sole determining factor behind the collapse of the Classic Mayan civilization — if they were, one might expect such catastrophes to affect all areas equally.

Moreover, archaeologists have pointed out that ancient Mayan societies may have been vulnerable to collapse by their very nature. They apparently funneled wealth to a small ruling elite topped by hereditary divine kings, who had virtually unlimited power but whose subjects expected generosity — a string of military defeats or seasonal droughts could greatly damage their credibility. The stability of this system was further threatened by polygamy among rulers, spawning numerous lineages that warred against each other, overall generating conditions ripe for collapse.

To learn more about the reasons behind the patchy apocalypse and recovery, scientists focused on social declines seen in the terminal part of the Classic period in the Mayan lowlands, ranging from A.D. 750 to 950. They also looked at downturns from A.D. 100 to 250, the terminal part of the "Pre-Classic" period.

Available data suggested the elevated parts of the Mayan lowlands, which include much of today's Yucatan Peninsula, were significantly more vulnerable to collapse and less likely to recover than lower-lying areas. Sites within this elevated region lacked perennial water sources and were more dependent solely on what rainwater they could capture and store, leaving them vulnerable to shifts in climate. In contrast, neighboring lower-lying areas had access to springs, perennial streams and sinkholes known as cenotes that were often filled with water.

Reoccupying elevated interior areas with large numbers of people would require intense labor to re-establish water management systems, helping to explain why they were left abandoned, the researchers noted. In contrast, dwelling in the neighboring, low-lying areas was less challenging, and evidence suggests that sites there were typically occupied continuously even when the major political and economic networks they were linked with collapsed.

At the same time, the Classic Maya would have implicated gods and their "divine" rulers for the collapse. In that way, their abandoned territories became thought of as chaotic, haunted places, and reclaiming any lands from the forest was at best done with great care and ritual. Survivors in outlying sites may often not have bothered. "Reoccupation called for a reordering of a most profound kind," the researchers write in the March 6 issue of the journal Proceedings of the National Academy of Sciences.

"I have little doubt that droughts and environmental degradation — for example, soil erosion or declining soil fertility — played roles in the collapse, defined here as a substantial and prolonged decline in population, of some sites or regions," said researcher Nicholas Dunning, a geographer at the University of Cincinnati. "There is also the important role played by the environmental setting of sites — for example, sites in the elevated interior region were significantly more vulnerable to drought cycles than those in surrounding lower-elevation areas where water was more abundant."

Read more at Discovery News

Mar 21, 2012

Seeing Movement: Why the World in Our Head Stays Still When We Move Our Eyes

When observing a fly buzzing around the room, we should have the impression that it is not the fly, but rather the space that lies behind it that is moving. After all, the fly is always fixed in our central point of view. But how does the brain convey the impression of a fly in motion in a motionless field? With the help of functional magnetic resonance imaging (fMRI) scientists from the Werner Reichardt Centre for Integrative Neuroscience and the Max Planck Institute for Biological Cybernetics in Tübingen have identified two areas of the brain that compare the movements of the eye with the visual movements cast onto the retina so as to correctly perceive objects in motion.

The two areas of the brain that are particularly good at reacting to external movements, even during eye movements, are known as V3A and V6. They are located in the upper half in the posterior part of the brain. Area V3A shows a high degree of integration: it reacts to movements around us regardless of whether or not we follow the moving object with our eyes. But the area does not react to visual movements on the retina when eye movements produce them. Area V6 has similar characteristics. In addition, it can perform these functions when we are moving forwards. The calculations the brain has to perform are more complicated in this case: the three-dimensional, expanding forward movement is superimposed onto the two-dimensional lateral movements that are caused by eye movements.

The scientists Elvira Fischer and Andreas Bartels from the Werner Reichardt Centre for Integrative Neuroscience and the Max Planck Institute for Biological Cybernetics have investigated these areas with the help of functional magnetic resonance imaging (fMRI). fMRI is a procedure that can measure brain activity based on local changes in blood flow and oxygen consumption. Participants in the study were shown various visual scenarios whilst undergoing fMRI scanning. For example, they had to follow a small dot with their eyes while it moved across a screen from one side to the other. The patterned background was either stationary or moved at varying speeds, sometimes slower, faster or at the same speed as the dot. Sometimes the dot was stationary while only the background moved. In a total of six experiments the scientists measured brain activity in more than a dozen different scenarios. From this they have been able to discover that V3A and V6, unlike other visual areas in the brain, have a pronounced ability to compare eye movements with the visual signals on the retina. "I am especially fascinated by V3A because it reacts so strongly and selectively to movements in our surroundings. It sounds trivial, but it is an astonishing capability of the brain," explains Andreas Bartels, project leader of the study.

Whether it is ourselves who move or something else in our surroundings is a problem about which we seldom think, since at the subconscious level our brain constantly calculates and corrects our visual impression. Indeed, patients who have lost this ability to integrate movements in their surroundings with their eye movements can no longer recognize what it is that ultimately is moving: the surroundings or themselves. Every time they move their eyes these patients feel dizzy. Studies such as this bring us one step closer to an understanding of the causes of such illnesses.

Read more at Science Daily

Albert Einstein, Up Close and Personal, Now Online

The Hebrew University of Jerusalem this week began posting its extensive collection of private letters, postcards and research notes written by famed physicist Albert Einstein, a project that ultimately will include about 80,000 documents.

The items at include a rare manuscript wth the formula Einstein proposed in 1905 to explain the theory of relativity, E=mc2, where E (energy) equals mass (m) times the speed of light in a vacuum (c) squared.

The collection also includes Einstein's love letters to his mistress, who later became his second wife, and a proposal for bringing about peace in the Middle East.

"This is going to be not only something to satisfy the curiosity of the curious,” former Hebrew University president and archive overseer Hanoch Gutfreund said during a press conference. "It also will be a great education and research tool for academics."

Einstein was one of Hebrew University's founders. He bequeated his papers and the rights to the use of his image to the school upon his death in 1955.

Initially, the Einstein Archives Online website includes about 2,000 documents, or 7,000 pages, covering Einstein’s personal and professional life through 1921. The rest of the collection, which includes 14 notebooks with research notes, fanmail and private correspondences with his lovers, will be posted over the coming years.

Along with scans of the original documents, the bulk of which are in Einstein's native German, the university will publish English translations and notes.

The project is part of an initiative with Princeton University and the California Institute of Technology to publish annotated scholarly work on all of Einstein's papers.

The Polonsky Foundation UK is backing the digital archive, a follow-on to a similar initiative to digitize Sir Isaac Newton's writings. That project, undertaken by the University of Cambridge, attracted 29 million hits in its first 24 hours.

Read more at Discovery News

Mercury Makes Precise Measurement of the Sun

In what sounds like an astronomical "David and Goliath" tale, the smallest planet in the solar system (no, not Pluto, the other one) has helped astronomers precisely measure the width of the largest thing in the solar system -- the sun.

Wait. I hear you cry. Do astronomers have nothing better than to measure the girth of our nearest star? Besides, we should know that already... shouldn't we?

In the sage words of Bad Astronomer Phil Plait: "Sometimes the simplest things can be the hardest, I suppose." And he'd be right.

When we hear about incredible observations of black holes guzzling dinky asteroids, tiny worlds being detected around distant stars and the age of the Universe being measured to a precision of 0.8 percent, it sounds absurd that we don't know the size of the sun. You know, that thing I can see out of my window. Every day! Come on, it can't be that hard. Can it?

Yes, yes it can. And as planet-dwelling creatures, our atmosphere really doesn't help.

As announced by scientists at the lovely University of Hawaii Institute for Astronomy (IfA) in Honolulu plus collaborators from Brazil and Stanford University on Wednesday, the sun's radius was measured by carefully timing two transits of the tiny planet Mercury. A transit is when a planet orbits in front of the sun, from the observer's perspective.

Mercury transits occur 12-13 times per century, and in recent years the joint NASA/ESA Solar and Heliospheric Observatory (SoHO) was able to observe two transits -- once in 2003 and once in 2006.

Already, you may have realized that SoHO has a distinct advantage. Not only does the observatory have an uninterrupted view of our nearest star -- hovering around the Earth-sun L1 point, 1.5 million miles from our planet in the direction of the sun -- it doesn't suffer the obscuring effects of the Earth's atmosphere.

Our atmosphere bends, distorts, refracts and reflects incoming light, and although the sun may seem very bright and easy to observe, making precision measurements of its size have proven difficult for ground based observatories. As noted by the researchers, "the true solar radius is still a matter of debate" and that the solar radius as noted by other studies vary as much as 500 kilometers (310 miles). Their publication, accepted for publication in the Astrophysical Journal, can be read in its entirety online (PDF).

 But using space-based observations of Mercury transits, the time taken for Mercury to complete its dash across the disk of the sun could be accurately measured to an accuracy of a couple of seconds. As the orbital period of Mercury is very well known, and after using a little trigonometry, the little planet had become a very useful (and very accurate) tape measure.

So, what's the sun's waistline measurement?

The sun's radius is 696,342 (plus or minus 65) kilometers -- that's 432,687 (plus or minus 40) miles.

Therefore, the sun's diameter is 1,392,684 +/- 65 kilometers or 865,374 +/- 40 miles.

But what I really want to draw attention to is the "+/-" number. This represents the error in the measurements made. "Error" doesn't mean the astronomers made a mistake; it means that once all the systematic aberrations in the instrumentation, any distortions by looking through the sun's atmosphere and any slight transit time uncertainties have been considered, this is the precision that the astronomers can be confident their observations achieved.

Read more at Discovery News

Ocean Expedition Gets Rare Glimpse of Earth's Guts

Oceanographers recently returned from an expedition to an unusual seafloor mountain, where they conducted what may be the first-ever on-site study of a type of rock that makes up a huge amount of our planet, but is largely out of reach.

Researchers aboard the research vessel JOIDES Resolution sent instruments to the Atlantis Massif, a seamount that lies near the Mid-Atlantic Ridge, a long volcanic rift bisecting the Atlantic Ocean, where two tectonic plates are being slowly shoved apart and fresh oceanic crust is created. (Seamounts are essentially a mountain that doesn't rise above the ocean's surface.)

Unlike most seamounts, which are typically made of volcanic rock, geological forces essentially yanked the Atlantis Massif from the Earth's gabbroic layer — the deepest layer of the Earth's crust, which rests directly on the planet's ever-shifting mantle.

Even though the dense, greenish rock constitutes the greatest volume of the ocean's crust, it has rarely been studied because it's so difficult to reach.

However, the Atlantis Massif has thrust the elusive rock within reach of drill-equipped ships, and the recent expedition simply used existing boreholes in the seamount to make their measurements.

A team of researchers lowered instruments to depths between 2,600 and 4,600 feet (800 and 1,400 meters) below the seafloor, and took data on temperature and the way that seismic waves — essentially, sound waves — move through two different types of gabbroic rock.

Getting an up-close portrait of the rocks' properties will allow scientists to better understand what they see when looking at data from future seismic surveys of geological structures buried deep below the seafloor.

"This is exciting because it means that we may be able to use seismic survey data to infer the pattern of seawater circulation within the deeper crust," co-chief scientist Donna Blackman, of the Scripps Institution of Oceanography in La Jolla, Calif., said in a statement.

Read more at Discovery News

Mar 20, 2012

Beer and Bling in Iron Age Europe

If you wanted to get ahead in Iron-Age Central Europe you would use a strategy that still works today -- dress to impress and throw parties with free alcohol.

Pre-Roman Celtic people practiced what archaeologist Bettina Arnold calls "competitive feasting," in which people vying for social and political status tried to outdo one another through power partying.

Artifacts recovered from two 2,600-year-old Celtic burial mounds in southwest Germany, including items for personal adornment and vessels for alcohol, offer a glimpse of how these people lived in a time before written records were kept.

That was the aim of the more than 10-year research project, says Arnold, anthropology professor at the University of Wisconsin-Milwaukee and co-director of a field excavation at the Heuneburg hillfort in German state of Baden-Wurttemberg. The work was partially funded by the National Geographic Society and Arnold collaborated with the State Monuments Office in Tübingen, Germany.

In fact, based on the drinking vessels found in graves near the hillfort settlement and other imported objects, archaeologists have concluded the central European Celts were trading with people from around the Mediterranean.

Braü or mead?

"Beer was the barbarian's beverage, while wine was more for the elite, especially if you lived near a trade route," says Kevin Cullen, an archaeology project associate at Discovery World in Milwaukee and a former graduate student of Arnold's.

Since grapes had not yet been introduced to central Europe, imported grape wine would indicated the most social status. The Celts also made their own honey-based wine, or mead, flavored with herbs and flowers, that would have been more expensive than beer, but less so than grape wine.

They also made a wheat or barley ale without hops that could be mixed with mead or consumed on its own, but that had to be consumed very soon after being made. "Keltenbräu," is an example of such an ale. It would have been a dark, roasted ale with a smoky flavor.

To the upper-class, the quantity of alcohol consumed was as important as the quality. Arnold excavated at least one fully intact cauldron used for serving alcoholic beverages in one of the graves at Heuneburg. But it's hard to top the recovery of nine drinking horns -- including one that held 10 pints -- at a single chieftain's grave in nearby Hochdorf in the 1970s.

Dapper dudes and biker chicks

In addition to their fondness for alcohol, Celtic populations from this period were said by the Greeks and Romans to favor flashy ornament and brightly striped and checked fabrics, says Arnold. The claim has always been difficult to confirm, however, since cloth and leather are perishable.

The Heuneburg mounds yielded evidence of both, even though no bones remain due to acidic soil. But the team of archaeologists were able to reconstruct elements of dress and ornamentation using new technology.

Rather than attempt to excavate fragile metal remains, such as hairpins, jewelry, weapons and clothing fasteners, Arnold and her colleagues encased blocks of earth containing the objects in plaster, then put the sealed bundles through a computerized tomography, or CT, scanner.

"We found fabulous leather belts in some of the high-status women's graves, with thousands of tiny bronze staples attached to the leather that would have taken hours to make," she says. "I call them the Iron-Age Harley-Davidson biker chicks." Images show such fine detail, the archaeologists theorize that some of the items were not just for fashion.

"You could tell whether someone was male, female, a child, married, occupied a certain role in society and much more from what they were wearing."

The pins that secured a veil to a woman's head, for example, also appear to symbolize marital status and perhaps motherhood. Other adornment was gender-specific -- bracelets worn on the left arm were found in men's graves, but bracelets worn on both arms and neck rings were found only in graves of women.

Read more at Science Daily

Super-Earth Unlikely Able to Transfer Life to Other Planets

While scientists believe conditions suitable for life might exist on the so-called "super-Earth" in the Gliese 581 system, it's unlikely to be transferred to other planets within that solar system.

"One of the big scientific questions is how did life get started and how did it spread through the universe," said Jay Melosh, distinguished professor of earth and atmospheric sciences. "That question used to be limited to just the Earth, but we now know in our solar system there is a lot of exchange that takes place, and it's quite possible life started on Mars and came to Earth. There's also been a great deal of discussion about the possible spread of life in the universe from star to star."

Moon rocks and Mars meteorites have been found on Earth, which led Melosh to previously suggest living microbes could be exchanged among planets in a similar manner.

A Purdue research team has found that, in contrast to our own solar system, the exchange of living microbes between "super-Earth" and planets in that solar system is not likely to occur.

Laci Brock, a student studying interdisciplinary physics and planetary science, and Melosh will present those findings March 20 at the 43rd Lunar and Planetary Science Conference in The Woodlands, Texas.

Brock examined the Gliese 581 planetary system because Planet d, known as super-Earth, falls in a "habitable zone" where liquid water could possibly exist.

"Laci has found the somewhat surprising result that it is very difficult for materials to spread throughout that system in the same way it could take place in our solar system," Melosh said.

All four planets found in Gliese 581 are within close proximity to their central star, which results in large orbital velocities, Brock said. However, the initial velocity of material leaving Planet d is not enough to allow exchanges among planets.

"Planet d would have a very small chance of transferring material to the other planets in the Gliese system and, thus, is far more isolated, biologically, than the inner planets of our own solar system," Brock said. "It really shows us how unique our solar system is."

Melosh said a more extended solar system would be needed for exchange of materials among planets.

"None of the solar systems that have been found so far would have opportunities for exchange of life among the different planets like what our own solar system offers," he said.

The Opik-Arnold method was used to simulate 10,000 particles being ejected from Planet e and super-Earth. The velocity ranges of the particles were scaled from each of the planet's orbital velocities, which is very high by solar system standards due to the close proximity to their central star.

"Ejections from Planet d have a low probability of impact on any other planet than itself, and most ejected particles would enter an initial hyperbolic orbit and be ejected from the planetary system," Brock said.

Several members of Purdue's planetary sciences department are attending the 43rd Lunar and Planetary Science Conference, presenting research on possible biologic contamination of Mars' moon Phobos by microbes from the surface of Mars; the formation of jets on comets; and gravity anomalies around large lunar craters.

Read more at Science Daily

Satellite Views Reveal Early Human Settlements

Scientists have unveiled a new technique for mapping early human settlements in Mesopotamia, the so-called "cradle of civilization" comprised of modern-day Iraq, northeast Syria, southeast Turkey and southwest Iran.

A pair of Harvard University anthropologists developed a way to measure mounds of athrosol, a type of soil formed by long-term human activity, in multi-wavelength satellite images.

Anthrosols are finer, lighter-colored, and richer in organic material than surrounding soil.

"Soil discoloration is one of the characteristics of archaeological sites in this part of the world (alongside surface artifact density and mounding)," Harvard University anthropologist Jason Ur wrote in an email to Discovery News.

Scientists have been using anthrosols to locate settlement sites for 10 years, but were limited to ground observations and declassified black-and-white spy satellite imagery.

"Multi-spectral imagery opens up new possibilities for identifying ancient places because now we can look for these distinctive soil discolorations not only in the visible part of the spectrum (what the human eye seems as red, green, and blue) but also beyond the abilities of our eyes (the near-infrared and even larger wavelengths)," Ur said.

"The mounds that we find are entirely artificial creations on an otherwise relatively flat plain," he added.

Until the development of cement, building material was limited to mud bricks, which don't last forever.

Eventually, the structures become unstable and must be leveled and rebuilt.

"If this process continues for centuries or millennia, settlements grow vertically," Ur said, leading to massive buildups of decayed mud brick.

For example, the largest site, Tell Brak in northern Syria, contains about 8 million cubic meters of decayed mud brick and rises about 40 meters (131 feet) above ground.

"The sites are essentially large piles of anthrosols," Ur said.

He and colleague Bjoern Menze, a computer scientist by training, used imagery from a sensor on NASA's Terra satellite to detect the telltale sediments and a global digital terrain map made from radar imagery taken during a 2000 space shuttle mission to model the height and volume of mounded sites.

In all, the scientists mapped more than 14,000 sites, spanning 8,000 years of human settlement in northeast Syria. Some 9,500 of those sites showed significant elevations, a mass accumulation of 700 million cubic meters of collapsed architecture and settlement debris.

Read more at Discovery News

Wounded Black Bears Sleep It Off

Injured black bears emerge from hibernation with barely a scratch.

Although their body temperatures and heart rates drop dramatically and blood circulation slows, black bears heal while hibernating without infections and little scaring, reported zoologists in the journal Integrative Zoology. What's more, the sleeping bears heal without eating, drinking, or relieving themselves.

But the benefits aren't just for bears. Understanding the healing hibernating bruins could bear fruit for doctors.

“Further research as to the underlying mechanisms of wound healing during hibernation could have applications in human medicine,” said the zoologists in the abstract to the paper.

Humans and most other mammals don't heal well when their body temperatures are even slightly below normal or they have poor circulation.

“Unique approaches may be found to improve healing for malnourished, hypothermic, diabetic and elderly patients or to reduce scarring associated with burns and traumatic injuries,” wrote the zoologists.

To test the healing ability of the bears, the zoologists proved they were willing to risk it all in the name of science. They gave small cuts to the skin of a group of wild bears they were observing just as the bears were preparing for hibernation. Then they backed off and let them hibernate for two to three months. As the bears were reaching the natural time in the season when they wake up, the brave bear researchers checked the wounds.

Not only had every bear healed itself, the skin had sealed up with little visible damage and even started growing new fur.

Read more at Discovery News

Mar 19, 2012

Are Some Brains Better at Learning Languages?

In his spare time, an otherwise ordinary 16-year old boy from New York taught himself Hebrew, Arabic, Russian, Swahili, and a dozen other languages, the New York Times reported last week.

And even though it's not entirely clear how close to fluent Timothy Doner is in any of his studied languages, the high school sophomore -- along with other polyglots like him -- are certainly different from most Americans, who speak one or maybe two languages.

That raises the question: Is there something unique about certain brains, which allows some people to speak and understand so many more languages than the rest of us?

The answer, experts say, seems to be yes, no and it's complicated. For some people, genes may prime the brain to be good at language learning, according to some new research. And studies are just starting to pinpoint a few brain regions that are extra-large or extra-efficient in people who excel at languages.

For others, though, it's more a matter of being determined and motivated enough to put in the hours and hard work necessary to learn new ways of communicating.

"Kids do well in what they like," said Michael Paradis, a neurolinguist at McGill University in Montreal, who compared language learning to piano, sports or anything else that requires discipline. "Kids who love math do well in math. He loves languages and is doing well in languages."

"This is just an extreme case of a general principle," he added. "If you practice and have a great deal of motivation for a particular domain, you're going to be able to improve in that domain beyond normal limits."

Very young children are remarkably good at learning multiple languages simultaneously. They can develop native-sounding accents in each tongue. And into adulthood, all reinforced languages hold their own in the brain without interfering with the others -- unlike later learners who may have trouble remembering a second language when they begin to learn a third.

With age, though, it not only becomes tougher to learn new languages, there may even be developmental stages beyond which certain nuances of language simply become inaccessible. By the age of 9 to 12 months, for example, babies begin to lose the ability to distinguish between sounds that are not used in their native language, said Loraine Obler, a neurolinguist at the CUNY Graduate Center in New York.

After about age 4, most people will never gain a truly deep grasp on a second language's morphology, which refers to the rules that govern how words are formed from linguistic units. After age 7 or so, the brain begins to pay more attention to what it's learning, Paradis said, which affects the type of memory kids use to pick up languages.

And beyond puberty, it becomes unlikely that someone will be able to speak a new language without a foreign accent, though Doner is unique in how impressive his accent sounds, which may reflect a late-to-mature brain. (There seems to be no cut-off point for learning vocabulary).

For more than a century, scientists have known that there are key areas on the exterior cortex of the brain's left hemisphere, known as Broca's area and Wernicke's area, that are critical for learning to speak and understanding speech, Obler said. There are also many other areas throughout the brain that process language.

Genes, neurotransmitters and brain regions involved in long-term memory play roles as well, Paradis said. And a number of different structures probably come into play when people speak a second language compared to when they speak their first.

That would explain why brain damage from Parkinson's, Alzheimer's or other disorders that affect specific areas of the brain can knock out just a native language -- or just a language that was learned later in life, leaving the other one intact. Aging can also bring out an accent that was once unnoticeable.

Read more at Discovery News

Success! LHC Sets New Energy Record

Over the weekend, physicists and engineers at the Large Hadron Collider (LHC) nudged proton beam energies to a new record: 4 Tera-electron volts (TeV). This record comes shortly after CERN announced last month they'd be cranking up the juice through 2012.

    "Record-breaking 4 TeV beams in the #LHC over the weekend (22h40 CET on Friday to be precise). First collisions at 4 TeV planned for April." -- CERN (Twitter)

Now their goal of 4 TeV has been achieved, CERN aims to collide the first protons at this energy in April. As the LHC collides protons head-on, the counter-circulating protons speeding around the 11-mile ring of supercooled electromagnets under the France-Swiss border will have an effective collision energy of 8 TeV (double the beam energy).

Although these collision energies are impressive, the LHC still isn't operating at its designed maximum. In 2014, after the facility's routine 20-month shutdown, physicists hope that they will be ready to push beam energies to 7 TeV -- culminating in collision energies of 14 TeV.

With larger collision energies comes the promise of uncovering new physics. But first on the list of "Cosmic Mysteries to Solve" is to discover the Higgs boson -- the long-theorized (and much-hyped) subatomic particle believed to endow all matter in the Universe with mass. Tantalizing hints of the Higgs are beginning to show in the huge quantity of data being spewed by the LHC and the vast archive of data from the recently retired U.S. Tevatron particle accelerator.

Read more at Discovery News

Viking Mice Live On

Fierce Viking raiders spread out from Scandinavia during the late eighth to mid-10th centuries. They spread terror, destruction ... and mice ... wherever they went.

House mice (Mus musculus domesticus) accompanied the Norse in their longships and colonized the same lands. Genetic studies of mice in lands visited by ancient Scandinavians showed that the mice lived on in Iceland along with their Norse hosts but died out on Greenland and Newfoundland, just like the Vikings.

"Human settlement history over the last 1,000 years is reflected in the genetic sequence of mouse mitochondrial DNA. We can match the pattern of human populations to that of the house mice," said one of the scientists involved in the study, Eleanor Jones of the University of York and Uppsala University, in Sweden, in a press release.

DNA samples from nine sites in Iceland, Narsaq in Greenland and four sites near the Viking archaeological site, L'Anse aux Meadows, in Newfoundland, formed the modern set of mouse genetics. Mouse remains from the Eastern and Western settlements in Greenland and four archaeological sites in Iceland provided ancient samples of mouse DNA.

Icelandic mice still contained the genetic fingerprint of their seafaring ancestors, but mice on Greenland had been replaced by Danish mice (Mus musculus musculus), brought over by a more recent wave of European colonizers.

Read more at Discovery News

Early Earth Hazy One Day, Clear the Next

A new study of ancient South African rocks indicates Earth may have experienced huge swings in the composition of its early atmosphere.

The study in the journal Nature Geoscience indicates Earth's atmosphere transitioned between an oxygen-rich environment and a thick methane hydrocarbon haze similar to what is now seen on the Saturnian moon Titan.

The work by scientists including Dr Aubrey Zerkle from the University of Newcastle in the United Kingdom, analyzed marine sediments deposited in the Campbellrand-Malmani carbonate platform in South Africa's Ghaap Group.

The platform is one of the oldest on Earth with rocks dating back to between 2.65 and 2.5 billion years ago.

The analyses allowed Zerkle and colleagues to reconstruct the ocean and atmospheric chemistry of the period, finding evidence of oxygen production by microbes.

They also found carbon and sulfur isotopes indicating the oxygen was made in a reduced atmosphere that was periodically rich in methane.

Zerkle and colleagues believe the findings are consistent with previous theories of Earth's early atmosphere having a thick organic haze similar to that on Titan.

However their simulations suggests Earth's atmosphere repeatedly transitioned between two main atmospheric states, one haze free, the other thick in hydrocarbons.

Zerkle and colleagues attribute the transitions to changes in the rate of methane production by microbes.

They say the hydrocarbon haze didn't permanently retreat until the oxygenation of the atmosphere some 100 million years later.

Professor Malcolm Walter from the Australian Center for astro-biology at the University of New South Wales says the paper confirms a very large change in the chemistry of the Earth's surface about 2.65 billion years ago.

Read more at Discovery News

Mar 18, 2012

Ultracold Experiments Heat Up Quantum Research

University of Chicago physicists have experimentally demonstrated for the first time that atoms chilled to temperatures near absolute zero may behave like seemingly unrelated natural systems of vastly different scales, offering potential insights into links between the atomic realm and deep questions of cosmology.

This ultracold state, called "quantum criticality," hints at similarities between such diverse phenomena as the gravitational dynamics of black holes or the exotic conditions that prevailed at the birth of the universe, said Cheng Chin, associate professor in physics at UChicago. The results could even point to ways of simulating cosmological phenomena of the early universe by studying systems of atoms in states of quantum criticality.

"Quantum criticality is the entry point for us to make connections between our observations and other systems in nature," said Chin, whose team is the first to observe quantum criticality in ultracold atoms in optical lattices, a regular array of cells formed by multiple laser beams that capture and localize individual atoms.

UChicago graduate student Xibo Zhang and two co-authors published their observations online Feb. 16 in Science Express and in the March 2 issue of Science.

Quantum criticality emerges only in the vicinity of a quantum phase transition. In the physics of everyday life, rather mundane phase transitions occur when, for example, water freezes into ice in response to a drop in temperature. The far more elusive and exotic quantum phase transitions occur only at ultracold temperatures under the influence of magnetism, pressure or other factors.

"This is a very important step in having a complete test of the theory of quantum criticality in a system that you can characterize and measure extremely well," said Harvard University physics professor Subir Sachdev about the UChicago study.

Physicists have extensively investigated quantum criticality in crystals, superconductors and magnetic materials, especially as it pertains to the motions of electrons. "Those efforts are impeded by the fact that we can't go in and really look at what every electron is doing and all the various properties at will," Sachdev said.

Sachdev's theoretical work has revealed a deep mathematical connection between how subatomic particles behave near a quantum critical point and the gravitational dynamics of black holes. A few years hence, offshoots of the Chicago experiments could provide a testing ground for such ideas, he said.

There are two types of critical points, which separate one phase from another. The Chicago paper deals with the simpler of the two types, an important milestone to tackling the more complex version, Sachdev said. "I imagine that's going to happen in the next year or two and that's what we're all looking forward to now," he said.

Critical Experiments

Other teams at UChicago and elsewhere have observed quantum criticality under completely different experimental conditions. In 2010, for example, a team led by Thomas Rosenbaum, the John T. Wilson Distinguished Service Professor in Physics at UChicago, observed quantum criticality in a sample of pure chromium when it was subjected to ultrahigh pressures.

Zhang, who will receive his doctorate this month, invested nearly two and a half years of work in the latest findings from Chin's laboratory. Co-authoring the study with Zhang and Chin were Chen-Lung Hung, PhD'11, now a postdoctoral scientist at the California Institute of Technology, and UChicago postdoctoral scientist Shih-Kuang Tung.

In their tabletop experiments, the Chicago scientists use sets of crossed laser beams to trap and cool up to 20,000 cesium atoms in a horizontal plane contained within an eight-inch cylindrical vacuum chamber. The process transforms the atoms from a hot gas to a superfluid, an exotic form of matter that exists only at temperatures hundreds of degrees below zero.

"The whole experiment takes six to seven seconds and we can repeat the experiment again and again," Zhang said.

The experimental apparatus includes a CCD camera sensitive enough to image the distribution of atoms in a state of quantum criticality. The CCD camera records the intensity of laser light as it enters that vacuum chamber containing thousands of specially configured ultracold atoms.

"What we record on the camera is essentially a shadow cast by the atoms," Chin explained.

The UChicago scientists first looked for signs of quantum criticality in experiments performed at ultracold temperatures from 30 to 12 nano-Kelvin, but failed to see convincing evidence. Last year they were able to push the temperatures down to 5.8 nano-Kelvin, just billionths of a degree above absolute zero (minus 459 degrees Fahrenehit). "It turns out that you need to go below 10 nano-Kelvin in order to see this phenomenon in our system," Chin said.

Read more at Science Daily

T. Rex's Killer Smile Revealed

One of the most prominent features of life-size models of Tyrannosaurus rex is its fearsome array of flesh-ripping, bone-crushing teeth.

Until recently, most researchers who studied the carnivore's smile only noted the varying sizes of its teeth. But University of Alberta paleontologist Miriam Reichel discovered that beyond the obvious size difference in each tooth family in T. rex's gaping jaw, there is considerable variation in the serrated edges of the teeth.

"The varying edges, or keels, not only enabled T. rex's very strong teeth to cut through flesh and bone," says Reichel, "the placement and angle of the teeth also directed food into its mouth."

Reichel analyzed the teeth of the entire tyrannosaurid family of meat-eating dinosaurs and found T. rex had the greatest variation in tooth morphology or structure. The dental specialization was a great benefit for a dinosaur whose preoccupation was ripping other dinosaurs apart.

Reichel's research shows that the T. rex's front teeth gripped and pulled, while the teeth along the side of the jaw punctured and tore flesh. The teeth at the back of the mouth did double duty: not only could they slice and dice chunks of prey, they forced food to the back of the throat.

Reichel says her findings add strength to the classification of tyrannosaurids as heterodont animals, which are animals with teeth adapted for different functions depending on their position in the mouth.

One surprising aspect of T. rex teeth, common to all tyrannosaurid's, is that they weren't sharp and dagger-like. "They were fairly dull and wide, almost like bananas," said Reichel. "If the teeth were flat, knife-like and sharp, they could have snapped if the prey struggled violently when T. rex's jaws first clamped down."

Read more at Science Daily