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

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

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