The humble trilobite, a helmet-headed creature that swam the seas hundreds of millions of years ago, was hiding an extraordinary secret — a "hyper-eye" never seen before in the animal kingdom.

By poring over X-ray images,  researchers found that certain species of trilobite — extinct arthropods distantly related to horseshoe crabs — had "hyper compound eyes," complete with hundreds of lenses, their own neural network to process and send signals and multiple optic nerves, according to new research published Sept. 30 in the journal Scientific Reports. 

Related: Why did trilobites go extinct?

Today's arthropods, like dragonflies and mantis shrimp, are also known for their powerful compound eyes, which are composed of myriad eye facets called ommatidia, each equipped with its own lens, like a disco ball. 

But, according to the new findings, trilobites from the family Phacops had compound eyes that were far larger and more complex than their modern-day arthropod relatives. Each of their eyes (they had one on the left and one on the right) held hundreds of lenses. At nearly a millimeter across, these primary lenses were thousands of times larger than a typical arthropod's. Nestled beneath them like bulbs in a car headlight sat six (or more) faceted substructures akin to a typical compound eye. "So each of the big Phacopid eyes is a hyper compound eye with up to 200 compound eyes each," study lead author Brigitte Schoenemann, a paleontologist at the University of Cologne in Germany, told Live Science in an email.

Trilobites are creatures that lived from the early Cambrian period (521 million years ago) to the end of the Permian (252 million years ago) on ocean floors. Some may have been predators that hunted aquatic worms, though most were scavengers or plankton eaters. The remains are commonly found in limestone rock from the Cambrian period. But despite their ubiquity in the fossil record, scientists still have questions about their physiology and evolutionary history .

To answer some of those questions, the researchers used photo-enhancing techniques to examine dozens of archival photos, cross referencing them with recent findings. In the process, they also resolved a long-standing scientific debate: They confirmed that a mysterious series of "fibers" seen in X-ray images from more than 40 years ago were actually bundled optic nerves connected to the trilobites' eyes. 

"Inferring function in ancient, extinct organisms is always difficult," said Nigel Hughes, a trilobite expert at the University of California Riverside, who was not involved in the study. In fact, Hughes pointed out, even some oddball features on living creatures elude explanation — for example, there is still some debate about the function of narwhals' long, horn-like tooth, according to the Smithsonian Institution.

However, eyes are a bit easier to parse than teeth or horns, Hughes said, because optical systems have only one function: sight. "We know it's an eye from the structure," he said, and therefore it makes sense for the attached filaments to be nerves. "I think that that's pretty convincingly argued in the paper." Why a trilobite might need that much visual power remains a mystery.

The X-ray photos themselves were taken by Wilhelm Stürmer, a professional radiologist and amateur paleontologist from Siemens. In the 1970s, Stürmer mounted an X-ray probe inside his VW bus and created a novel method to study fossils: X-ray paleontology, which allowed him to peer through solid rock on site and take some of the most sophisticated fossil photos of his day.

Upon examining the Hunsrück Slate, a fossil quarry driving distance from his home in Munich, Germany, Stürmer uncovered a world of petrified creatures embedded in the rock. Remarkably, these specimens — including phacopid trilobites — were so well preserved that even their delicate soft tissues were visible. Stürmer and his collaborator Jan Bergström noted that the trilobites appeared to have fossilized "fibers" connected to their compound eyes, which they described in the June 1973 issue of the journal Paläontologische Zeitschrift.

Related: In images: A filter-feeding Cambrian creature

But when Stürmer brought these findings before other paleontologists, "his colleagues in the scientific world laughed at him," Schoenemann said. The prevailing wisdom at the time was that soft tissue, like nerves, simply did not fossilize. Stürmer must have mistaken gill filaments for optic nerve tissue, his critics argued, according to Schoenemann. The radiologist, however, remained firm in his convictions. 

"Stürmer believed his theory until he died, filled with bitterness in 1986," Schoenemann said. After nearly half a century, Schoenemann and her team feel they have finally vindicated his work.

Sadly, like Wilhelm Stürmer, phacopid trilobites are no longer with us — they went extinct about 358 million years ago at the end of the Devonian period, along with about 75% percent of all life on Earth, Schoenemann said. "But surely not because of their sophisticated, highly adapted eyes." 

Originally published on Live Science.

Photos of a bright pink manta ray have gone viral after the Pepto-Bismol-colored creature was spotted swimming near Australia’s Great Barrier Reef.

Photographer Kristian Laine, who snapped the photos while was freediving near Lady Elliot Island, initially thought that his camera was broken, National Geographic reported. Later, Laine learned that he had laid eyes on what may be the world's only pink manta ray — a fish comically named Inspector Clouseau, after the klutzy detective in the "The Pink Panther" movies.

Despite his stunning hue, the inspector has been seen fewer than 10 times since he was first spotted in 2015, National Geographic reported. (You can see a 2015 video of the inspector on The Guardian.)

Related: The pink and white album: Amazing albino animals

When biologists at Australia's Project Manta first learned about Inspector Clouseau, they suspected that the ray got its pink color from a skin infection or a strange meal, much like how a pink flamingo gets its rosy feathers from eating algae filled with beta carotene, a compound that contains a reddish-orange pigment.

But when the research group managed to collect a small skin biopsy from the pink ray in 2016, they learned the cause was something else entirely: the ray likely has a genetic mutation, Asia Haines, a research assistant at Project Manta, told National Geographic.  

Perhaps the manta ray has erythrism, a condition that causes animals to have a high amount of red pigment on their bodies, Solomon David, an aquatic ecologist at Louisiana's Nicholls State University, told National Geographic. 

Other animals with erythrism include this strawberry-blonde leopard and these bubble-gum-pink grasshoppers.

At the time of the the impromptu photo-op, Inspector Clouseau and several other male manta rays were courting a female. While other manta rays are all black, all white, or black and white, which help them evade predators and stalk prey, their pink comrade appeared to be doing just fine.

That's likely because at 11-foot-long (3.3 meters), the inspector is a big beast. As elephants clearly demonstrate, being large is a defense unto itself. 

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Originally published on Live Science.

Many millions or billions of years ago, a gargantuan star in the Sagittarius constellation named J1808 ran out of fuel, collapsed under its own weight and exploded. 

Blasts like this are common in the cosmos; scientists know they're part of a process that transforms mighty suns into shriveled neutron stars — the smallest and densest stars in the universe. What has astronomers intrigued about J1808 today, however, is the fact that it's still exploding, and apparently showering our galaxy with some of the most intense blasts of light ever detected.

On Aug. 20, 2019, a special neutron-star-watching telescope aboard the International Space Station (ISS) recorded a thermonuclear explosion on J1808 that blew all previously detected explosions away. The brief burst of X-ray light flickered for just 20 seconds, but released more energy in that time than Earth's sun releases in 10 days, according to a NASA news release. It was the single brightest flash of energy ever recorded by the telescope, which went online in 2017.

"This burst was outstanding," Peter Bult, an astrophysicist at NASA's Goddard Space Flight Center and lead author of a recent study on the explosion published in The Astrophysical Journal Letters, said in a statement. "We see a two-step change in brightness, which we think is caused by the ejection of separate layers from the [star's] surface, and other features that will help us decode the physics of these powerful events."

An unstable partnership

J1808 is a pulsar, or a neutron star that rotates extremely fast and emits powerful electromagnetic radiation from both of its pole. Stars like this spin so quickly (J1808 completes about 400 rotations every second) that the beams of energy at their poles appear to pulse like strobe lights every time they point toward Earth.

Similar to a black hole, the powerful gravity of a neutron star can steadily draw in huge amounts of surrounding matter that collect in a vast, swirling disk at the star's edge (this is called an "accretion disk"). According to the authors of the new study, J1808 appears to have spent a long time sucking in hydrogen gas from a mysterious celestial object that it shares a binary orbit with. This object, larger than a planet yet smaller than a star, earns the unflattering cosmological catch-all title "brown dwarf."

The massive explosion observed on Aug. 20 seems to be the result of a long, one-sided relationship between J1808 and its brown partner, the researchers wrote. The neutron star appears to have sucked up so much hydrogen from its neighbor over the past few years that the gas became a superhot, superdense "sea" that began to fall inward and coat the star's surface. Heat from the star warmed this sea so much that a nuclear reaction began to occur, causing hydrogen nuclei to fuse into helium nuclei. Over time, this newly formed helium created a second layer of gas around the star's surface that spanned several meters deep, the researchers wrote.

"Once the helium layer is a few meters deep, the conditions allow helium nuclei to fuse into carbon," study co-author Zaven Arzoumanian, also with NASA, said in the statement. "Then the helium erupts explosively and unleashes a thermonuclear fireball across the entire pulsar surface."

The researchers believe the Aug. 20 explosion occurred when such a fireball blew away both the hydrogen and helium layers surrounding the star in quick succession, causing a double flash of intensely bright X-ray energy to blast into space. (J1808 and its partner are located about 11,000 light-years from Earth, which is pretty close, cosmically speaking).

This interpretation of the explosion fits with the ISS observations, but leaves one important detail out. Following the first two spikes in X-ray energy, the pulsar released a third, slightly dimmer blast that was about 20% brighter than the star's normal flicker. It's not clear what sort of mechanism triggered this final blast of energy, the researchers said.

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Originally published on Live Science.

Astronomers, for the first time, have snapped an image of a cool, gassy ring swirling around the supermassive black hole at the center of our galaxy.

This ring is part of the so-called accretion disk — stars, dust and gases — that surround most black holes. These materials are held close by the black hole's strong gravitational grip and the far edge represents the outer limits of its gravitational reach. In the case of the Milky Way's black hole called Sagittarius A*, the disk extends out a few tenths of a light-year from the black hole's event horizon — the point at which even light can't escape the black hole's grasp. [9 Ideas About Black Holes That Will Blow Your Mind]

There are a few types of gases that make up parts of this accretion disk, and scientists previously have only imaged the very hot, glowing ones, according to a statement from the National Radio Astronomy Observatory. Because these gases are so hot — at about 18 million degrees Fahrenheit (10 million degrees Celsius) — they give off X-rays that researchers could easily detect.

But this accretion disk also has cooler hydrogen gas — 18,000 F (10,000 C) — though it hasn't been imaged before. The radiation in the area causes hydrogen atoms to constantly lose and gain their electrons, an activity that releases weak radio waves, according to the statement.

The team detected these radio waves using the Atacama Large Millimeter/submillimeter Array (ALMA) observatory in Chile, and stitched the measurements together into the new image.

The cool hydrogen ring is about a hundredth of a light-year away from the black hole's event horizon, and contains an amount of hydrogen equivalent to a tenth of the mass of Jupiter, according to the statement. What's more, because of the so-called "Doppler effect," which makes light from objects moving toward our planet look slightly "bluer" and light from objects moving away from our planet look slightly "redder," the researchers concluded that the gas is rotating around the black hole.

"We hope these new ALMA observations will help the black hole give up some of its secrets," lead author Elena Murchikova, an astrophysicist at the Institute for Advanced Study in Princeton, New Jersey, said in the statement.

The researchers reported their findings June 5 in the journal Nature.

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Originally published on Live Science.

NASA researchers have unveiled a new treasure map of the universe, and — thanks to a neutron-star-hunting telescope aboard the International Space Station — X-ray marks the spot.

The new all-sky map, uploaded May 30 to NASA's website, shows what the cosmos looks like in high-energy X-ray light. X-rays are among the most energetic forms of light in the universe; they're beamed into space by some of the most extreme objects in the cosmos, including powerful supernova explosions, gas-gobbling neutron stars, and supermassive black holes that suck matter into their maws at near-light-speed.

Humans can't see these arcing streams of light careening around the cosmos (our sight is limited to the much weaker, visible light chunk of the electromagnetic spectrum), but NASA's special X-ray observatory aboard the International Space Station can. Known as the Neutron Star Interior Composition Explorer (NICER), the telescope's primary mission is to study pulsars — fast-spinning, ultra-dense corpses of collapsed stars that pulse with high-energy light as they whirl.

Not only do researchers hope to figure out what, exactly, these stellar corpses are made of, but they also want to use them as waypoints that could help future satellites navigate on auto-pilot — sort of like a galactic GPS system, as a NASA statement put it.

While searching the full night sky for the nearest pulsars, NICER has also turned up some other powerful sources of X-ray light, including the afterglow of a relatively recent supernova (seen in the top left corner of this image).

"This image reveals the Cygnus Loop, a supernova remnant about 90 light-years across and thought to be 5,000 to 8,000 years old," Keith Gendreau, NICER's principal investigator at the Goddard Space Flight Center in Maryland, said in the statement. "We’re gradually building up a new X-ray image of the whole sky, and it’s possible NICER’s nighttime sweeps will uncover previously unknown sources."

Indeed, this map represents only the first 22 months of NICER's orbiting observations (it launched in June 2017), and has likely only scratched the surface of the many stellar mysteries hiding beyond our human sight.

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Originally published on Live Science.

When two stars love each other (and are sufficiently massive and sufficiently close in space), they might start going steady. Astronomers call these stellar partners binary star systems, because the smitten suns do everything together. They orbit around each other, pool their gases together and sometimes even come back from the dead together.

It's a beautiful thing — but it's not always good times. Sometimes, one member of a binary duo can be punished for its partner's toxic behavior. Take the 30-or-so binary star systems recently detected near a galaxy cluster 62 million light-years from Earth. According to a study published May 2 in The Astrophysical Journal, these lonesome pairs got kicked out of their home galaxies when one member of the partnership suddenly went off the rails, collapsed into a neutron star and created a blast so powerful that it sent both binary partners careening into interstellar space.

"It's like a guest that's asked to leave a party with a rowdy friend," lead study author Xiangyu Jin, of McGill University in Montreal, said in a statement. "The companion star in this situation is dragged out of the galaxy simply because it's in orbit with the star that went supernova." [15 Amazing Images of Stars]

Jin and his colleagues discovered these stellar exiles while studying 15 years of X-ray emission data collected by NASA's Chandra X-ray Observatory (a powerful X-ray telescope mounted on a satellite). The team zoomed in on the Fornax cluster, a group of more than 50 known galaxies located in the constellation Fornax (Latin for "furnace"). Certain emission patterns told the story of binary star systems where one partner had collapsed into a neutron star, sucked loads of gas and dust from its partner star into an orbiting disk and then superheated that disk, to tens of millions of degrees.

Those hot, hot disks were visible only in X-ray light, the researchers said, and about 30 of the X-ray signatures detected came from outside the bounds of any known galaxy. The team concluded that these glowing systems were most likely a pair of one neutron and one non-neutron star that had been catapulted out of their home galaxy when the neutron star went supernova and collapsed.

Thirty pairs of homeless stars might seem like a lot, but there are probably countless others just in the narrow patch of sky that the researchers were looking at, the team wrote. The researchers detected nearly 200 peculiar sources of X-ray emissions in Fornax, but many of them were just too far away to be resolved.

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Originally published on Live Science.

It's not the sound of a massive underwater earthquake, nor is it the sound of a pistol shrimp snapping its claws louder than a Pink Floyd concert. It is, in fact, the sound of a tiny water jet — about half the width of a human hair — being hit by an even thinner X-ray laser.

You can't actually hear this sound, because it was created in a vacuum chamber. That's probably for the best, considering that, at around 270 decibels, these rumbling pressure waves are even louder than NASA's loudest-ever rocket launch (which measured about 205 decibels). However, you can see the sound's microscopically devastating effects in action, thanks to a series of ultra-slow-motion videos recorded at the SLAC National Accelerator Laboratory in Menlo Park, California, as part of a new study. [Tiny Grandeur: Stunning Photos of the Very Small]

In the video above, which was filmed in about 40 nanoseconds (40 billionths of a second), the pulsing laser immediately splits the water jet in two, vaporizing the fluid that it touches while sending powerful pressure waves wobbling down either side of the jet. These waves create more waves and, by about 10 nanoseconds in, fizzing black clouds of collapsing bubbles form on each side of the cavity.

According to Claudiu Stan, a physicist at Rutgers University in Newark, New Jersey, and one of the study co-authors, these pressure waves likely represent the loudest possible underwater sound. If it were any louder, the sound "would actually boil the liquid," Stan told Live Science — and once the water boils, the sound has no medium to pass through.

Why try to discover a sound that rends apart its own medium? According to Stan, understanding the limits of underwater sound could help researchers design future experiments.

Scientists regularly suspend little bits of intriguing matter — say, a specific type of protein crystal, for example — in fluid jets and blast them with lasers to determine their chemical properties. If scientists know precisely how intense a laser pulse can be without accidentally destroying the liquid, that could improve the way these experiments are performed, Stan said.That’s particularly true for studies where scientists hit samples of material with high-powered beams to test the material’s structural integrity.

"This research can help us investigate in the future how microscopic samples would respond when they are vibrated severely by underwater sound," Stan said.

This is not the first time SLAC researchers have used this X-ray laser to test the limits of physics. In a 2017 study, researchers used the same laser to blast the electrons out of an atom, creating a "molecular black hole" that sucked in all the available electrons from nearby atoms. Taken in tandem, that study and the new one result in one unassailable conclusion: Lasers are really, really cool.

The new study was published April 10 in the journal Physical Review Fluids.

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Originally published on Live Science.

The first X-rays of an ancient Peruvian mummy — taken from the country about 100 years ago by an American railroad worker — recently uncovered long-hidden clues about its mysterious origins.

The mummy has been part of the collection at the Everhart Museum of Natural History, Science and Art in Scranton, Pennsylvania, for nearly a century. But very little was known about the mummy when the museum acquired it in the 1920s. Over the decades that followed, the mummy's fragile condition discouraged invasive examinations that could have revealed clues about its origins.

However, museum officials finally know a little more about this intriguing mummy. After X-raying it for the first time, they discovered that the mummified person was younger than they thought — a teen, rather than an adult male. And clues in its skeleton hinted that the boy may have suffered from health problems before his death, experts told Live Science. [Photos: Hundreds of Mummies Found in Peru]

The mummy's journey from Peru to Pennsylvania was both long and strange. In 1923, a Scranton dentist named Dr. G. E. Hill donated the mummy to the museum; Hill had received the mummy from his father, who brought it from Peru when he returned home after working on the railroads, Everhart Museum curator Francesca Saldan told Live Science.

"Other than that, we really have no documentation about how he acquired it or where in Peru it actually came from," Saldan said.

According to the museum's archives, curators at the time identified the mummy as belonging to the Paracas culture — one of the oldest in South America — which flourished from 800 B.C. to 100 B.C. When the museum acquired the mummy, it was in a fetal position; traditional Paracas burial practices usually swaddle mummies in fabric, but this mummy wasn't wrapped up. However, a textile imprint was pressed into one of the mummy's knees, suggesting that at one point it had a fabric cover that was then lost, Saldan said. 

Secrets of the bones

Computed X-ray tomography (CT) scans are typically used to examine preserved soft tissues. But the mummy had been kept in a large display case made of wood and glass since the 1950s. The unwieldy case was too big for a CT scanner, so the museum turned to Geisinger Radiology in Danville, Pennsylvania, to conventionally X-ray the mummy and learn what they could from its bones, Dr. Scott Sauerwine, medical director at Geisinger, told Live Science.

X-raying the mummy wasn't easy; its position inside the large case prevented the technicians from getting a clear view of the pelvis. But they were able to find good angles of the skull and other parts of the body.

"In some of the bones, the growth plates weren't fused, and we estimated the age to be in the late teens," Sauerwine said.

When the radiologists X-rayed the mummy's feet, they noted that several toes were missing. Amputations have been around for thousands of years, and it's possible that the teenager lost his toes to frostbite or infection, Sauerwine suggested. Then again, the toes may also have broken off after mummification due to rough handling, he added.

Other than the missing toes, there were no signs of trauma or healed fractures in the body, and there was no clear indication from the bones of what might have caused the teen's death. However, the radiologists did detect abnormal calcium deposits in the spine.

"We see spine abnormalities like this with aging — but this person was not old," Sauerwine said. In this particular case, the teenager likely suffered from a metabolic disorder such as pseudogout (a type of arthritis) or hypoparathyroidism (reduced production of parathyroid hormone).

Could those conditions have been severe enough to cause the teen's death? It's an interesting angle to consider, but it's impossible to say for sure, Sauerwine said.

The mummy is now on display at the Everhart Museum for the first time since the 1990s, as part of the exhibit "Preserved: Traditions of the Andes," open from March 9 to April 7.

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Originally published on Live Science.

A striking X-ray image shows the dark threads of arteries and veins carrying blood from wrist to fingertip — except in the index finger, which glows with a ghostly white hue.

The image is an angiogram — a type of medical imaging technique that reveals veins and arteries after they have been flooded with a special dye. If blood is flowing properly, it carries the dye through the branching networks of blood vessels, which show up as dark lines in the image.

The angiogram — which was taken back in 2005 but recently resurfaced on social media — revealed a lack of blood flow in the right index finger of David Schulte, aka Dazzling Dave, a profession yo-yo performer.

So, what led to that unusual image? At the beginning of 2005, Schulte sustained the injury while in North Dakota. He was performing demonstrations and giving lessons at schools, which called for near-constant yo-yo-ing for 8 to 12 hours at a stretch, he told Live Science.

He noticed that when his hands got cold, his index finger on his right hand started feeling cold sooner and took longer to warm up than his other fingers did. About a week after he returned to his home in Minnesota, the same finger started turning unusual colors — red, blue and dark purple — prompting Schulte to seek medical attention.

His doctor recommended an angiogram, "and then I got that really cool, interesting picture and it showed no blood getting past the second knuckle of the index finger," Schulte said. The diagnosis was not a blood clot, as his doctor first suspected. It was a vasospasm, a sudden constriction of the blood vessels, likely in response to Schulte's yo-yo repeatedly rebounding and hitting that finger for the past seven to 10 years, he wrote in a blog post that he published at the time.

"The hand specialist said, 'Show me how you do yo-yo tricks,' and I showed him one of my most-used tricks, which is a really hard, straight throw down," Schulte said. "And he said, 'Oh yeah, that could cause it.'"

The doctor prescribed blood thinners, which Schulte took for a month; his finger went back to its normal color, Schulte said.

Warm heart, cold hands

This type of condition — when blood stops flowing to extremities due to constricted blood vessels — is called Raynaud's syndrome, or simply Raynaud's, according to the National Heart, Lung and Blood Institute.

It's normal for blood vessels to constrict in the cold. But for people who have Raynaud's, the blood vessels clamp down too hard, constrict for too long and take longer than normal to relax. The result is that the affected extremities stay colder for longer and may change color, Dr. Elizabeth Ratchford, director of the Johns Hopkins Center for Vascular Medicine and an associate professor of medicine at the Johns Hopkins University School of Medicine in Maryland, told Live Science. Ratchford was not involved with Schulte's case.

In extreme cases, severely restricted blood flow can lead to nerve damage or even tissue loss, Ratchford told Live Science.

There are two types of Raynaud's: primary and secondary. Primary Raynaud's has no known cause, and secondary Raynaud's appears due to other circumstances, such as disease or an injury. For example, secondary Raynaud's may be the result of a medical condition, such as lupus, or could manifest as a side effect of certain medications, including beta blockers, Ratchford said. Smoking cigarettes can also raise the risk of developing Raynaud's.

Other risks include exposure to repetitive actions over time — such as using vibrating power tools like jackhammers or, in Schulte's case, yo-yo-ing — can also lead to Raynaud's, though what happened to Schulte is highly unusual, Ratchford told Live Science.

Luckily for Schulte, he suffered no lasting damage from his Raynaud's, and his yo-yo technique is pretty much the same as it was before — except when he performs outdoors in the extreme cold. During his winter shows, if outside, Schulte tends not to throw the yo-yo quite as hard as he would on a warm day, he said.

"It's such a fluke injury," Schulte said. "I literally don't know of any other yo-yo player who got it besides me."

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Originally published on Live Science.

In November 2016, astronomers watched a young star some 1,500 light-years away from Earth belch out an explosion of plasma and radiation that was roughly 10 billion times more powerful than any flare ever seen leaving Earth's sun. This sudden stellar eruption may be the most luminous known flare ever released by a young star — and it could help scientists better understand the still-murky process of star formation.

"Observing flares around the youngest stars is new territory and it is giving us key insights into the physical conditions of these systems," Steve Mairs, an astronomer and lead author of the study, said in a statement. [Aurora Photos: See Breathtaking Views of the Northern Lights]

Mairs and his colleagues detected the flare using the James Clerk Maxwell Telescope, perched atop Hawaii's dormant Mauna Kea volcano. The flare originated from a binary star system — a solar system where two big stars orbit around one another — located in the Orion Nebula, some 1,500 light-years away, researchers reported in the new study, which was published Jan. 23 in The Astrophysical Journal.

This nebula is the closest active star-forming region to Earth and is frequently studied by astronomers interested in the births of stars and planets. (You can actually see the nebula with the naked eye when you look for the Orion constellation; it's the middle "star" in Orion's sword, just south of his belt.)

Solar flares occur when a star's magnetic-field lines twist and tangle about each other until they snap, unleashing huge amounts of energy and charged particles. According to NASA, a typical solar flare from Earth's sun releases the energy equivalent of "millions of 100-megaton hydrogen bombs exploding at the same time." When this energy washes over Earth, it can temporarily knock out satellites and short-circuit technology around the world; one famous flare from 1859, known as the Carrington event, caused telegraph wires to shoot out sparks that caused offices to burst into flames.

So, how did the 2016 flare manage to burst billions of times stronger than our sun's worst solar storms? The researchers aren't sure, but it probably has something to do with the fact that the star in question is still very young and sucking up gargantuan amounts of nearby matter to fuel its growth.

Equally unknown are the effects that such massive energy expulsions have on young solar systems. The superhot, X-ray radiation emitted from flares like these could potentially change the chemistry of nearby bodies (like meteors) or possibly alter the atmospheres of young planets, the authors wrote.

Editor's Note: This story was updated to correct the date of the Carrington Event. It occurred in 1859, not 1895.

Originally published on Live Science

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It looks like someone drew a heart over a child's X-ray. But this cartoonish heart — which seemingly floats in the child's throat — is real, the result of a heart-shaped pendant that got stuck in the girl's esophagus.

The X-ray was taken when a 3-year-old girl was brought to the emergency room after she ingested the gold-colored pendant, according to a new report of the case, published today (Feb. 13) in The New England Journal of Medicine and appropriately titled "Heart of Gold."

The image confirmed there was a "heart-shaped foreign body" in the child's esophagus, the report said. [11 Weird Things People Have Swallowed]

Toddlers, of course, put all sorts of things in their mouths and sometimes swallow them. Potentially dangerous items, such as sharp objects and button batteries (which could tear or burn the esophagus), require immediate removal if swallowed, the report authors wrote. In addition, objects that have been stuck for more than 24 hours warrant removal.

But if a child swallows an item that doesn't appear to pose an immediate danger, the patient is observed for a limited period to "allow the foreign body to pass spontaneously," the report said. That was the case for this patient, who experienced no symptoms from the pendant.

In several more X-rays taken later, however, the pendant didn't appear to be budging from its location. So, doctors performed a nonsurgical procedure to remove the object. The child recovered well after the procedure and was sent home, the report said.

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Originally published on Live Science.

Scientists just blasted pottery from an ancient shipwreck with a "ray gun." Besides being totally sci-fi, the X-ray blaster revealed where the pottery came from.

The wreck was a trade ship dating to the 12th or 13th century that was thought to have departed from Quanzhou in southeastern China, with the Indonesian island of Java as its destination. However, it sank in the Java Sea near Java and Sumatra, taking its cargo to a watery grave. Discovered by local fishermen in the 1980s, the ship and its contents were recovered a decade later, and about 7,500 pieces of its cargo are currently in the collection of The Field Museum in Chicago.

In a new study, researchers addressed a long-standing mystery: where the pottery came from. The artifacts' shape and design suggested they originated in southeastern China — in fact, two boxes described in 2018 even included an identifying stamp. But pinpointing the precise locations where they were made was trickier, as kilns that produce this type of pottery are extremely common in the region, scientists wrote in the study. [In Photos: Ancient Shipwreck's Ceramics Traced to Kilns in China]

To find out, scientists looked at 60 pieces of the wreck’s pottery that were glazed with a blue-white coating called qingbai; that kind of porcelain is fired at such high temperatures that it is rendered almost glass-like, enabling it to spend centuries underwater without much degradation or damage, study co-author Lisa Niziolek, a research scientist in Asian anthropology at the Field Museum, told Live Science.

Lead study author Wenpeng Xu, a doctoral candidate in anthropology at the University of Illinois at Chicago, proposed noninvasive, nondestructive X-ray fluorescence to analyze the composition of the blue-white glaze and uncover the pottery's chemical secrets. Using a hand-held device, similar to a sci-fi ray gun, the researchers collected data from the Java Sea shipwreck pottery, and compared it with pottery debris gathered from four kiln complexes in China, with samples representing several kilns within each complex.

Variations in clay composition or in the ingredients that pottery-makers mix together create differences in finished vessels that can be detected with X-ray technology, by measuring and comparing their energy signatures, according to the study. By blasting the shipwreck ceramics and kiln debris with their ray gun device, the researchers were able to map the once-sunken pottery to the kilns where they were made centuries ago.

They divided the shipwreck pottery into groups and found matches among those groups to kiln complexes in Jingdezhen, Dehua, Shimuling, Huajiashan and Minqing, near the port of Fuzhou.

In fact, their findings suggest that the ship's port of departure was Fuzhou — where most of the shipwreck's pottery originated — and it likely later sailed to Quanzhou to take on porcelain from other kiln complexes, the scientists reported.

The number of kilns linked to the shipwreck's qingbai ceramics suggests that traders and merchants didn't rely on a single manufacturer to satisfy the demand for quality pottery, Xu said. And figuring out the locations where these ceramics came from adds tantalizing details about important trade routes dating to centuries ago.

"We're finding that the scale and complexity of exchange networks is greater than anticipated," Niziolek said. "For people educated to think that large-scale trade networks are only associated with modern Western capitalism, this shipwreck can really challenge those notions."

The findings were published online today (Feb. 8) in the Journal of Archaeological Science.

• Images: Amazing Artifacts from a Java Sea Shipwreck
• Shipwrecks Gallery: Secrets of the Deep
• In Photos: 700-Year-Old Shipwreck Discovered in China

Originally published on Live Science.

Scientists first proposed the existence of this invisible force two decades ago, to explain the surprising discovery that the universe's expansion is accelerating. (Surprising and incredibly important; the find netted three researchers the Nobel Prize in physics in 2011.)

The most-used astrophysical model of the universe's structure and evolution regards dark energy as a constant. Indeed, many astronomers believe it to be the cosmological constant, which Einstein posited in 1917 as part of his theory of general relativity. [The History & Structure of the Universe in Pictures]

But a new study of enormous, superbright black holes known as quasars suggests that dark energy could be miscast as the cosmological constant, or any kind of constant; the force may have varied since the universe's birth 13.8 billion years ago, research team members said.

"We observed quasars back to just a billion years after the Big Bang, and found that the universe's expansion rate up to the present day was faster than we expected," study lead author Guido Risaliti, of the University of Florence in Italy, said in a statement. "This could mean dark energy is getting stronger as the cosmos grows older."

Quasars are fast-growing supermassive black holes at the hearts of galaxies. Quasars' incredible luminosity — they're the brightest objects in the universe — originates in the disks of material that swirl around the black holes. These fast-spinning disks generate huge amounts of ultraviolet (UV) light, some of which slams into electrons in nearby clouds of hot gas. Such interactions can ramp up the UV radiation to X-ray levels, producing a powerful glow across multiple wavelengths of high-energy light.

The correlation between these two types of light can reveal the distance to a quasar, Risaliti and co-author Elisabetta Lusso, of Durham University in England, determined. In the new study, the duo examined this relationship for nearly 1,600 quasars. They used NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton spacecraft to observe the quasars' X-ray light, and the ground-based Sloan Digital Sky Survey to analyze the objects' UV output.

Risaliti and Lusso found many of the quasars to be incredibly distant. The most far-flung one, for example, was blasting out huge amounts of light into the cosmos just 1.1 billion years after the Big Bang.

Previous work on the universe's expansion rate — including the landmark late-1990s studies that introduced the concept of dark energy — have generally relied on observations of supernova explosions as "standard candles." Researchers determined the distances to these objects, whose intrinsic brightness is known, and figured out how fast they're moving relative to Earth by analyzing how much their light is "redshifted" (stretched to longer wavelengths).

Supernovas, while dramatic and powerful, are much less luminous than quasars and therefore cannot be observed from as far away. So, the new study gives researchers another standard candle, which can be used to assess the universe's expansion across a broader stretch of time.

But Risaliti and Lusso looked at some supernova measurements as well.

"Since this is a new technique, we took extra steps to show that this method gives us reliable results," Lusso said in the same statement. "We showed that results from our technique match up with those from supernova measurements over the last 9 billion years, giving us confidence that our results are reliable at even earlier times."

The new results are consistent with some earlier observations of relatively nearby supernovas. That previous work found an apparently accelerated expansion rate, compared to that of the early universe (as derived from measurements of the cosmic microwave background, the ancient light left over from the Big Bang).

"Some scientists suggested that new physics might be needed to explain this discrepancy, including the possibility that dark energy is growing in strength," Risaliti said. "Our new results agree with this suggestion."

The new study was published online Monday (Jan. 28) in the journal Nature Astronomy. You can read it for free at the online preprint site arXiv.org.

Mike Wall's book about the search for alien life, "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate) is out now. Follow him on Twitter @michaeldwall. Follow us @Spacedotcom or Facebook. Originally published on Space.com.

X-ray spectroscopy is a technique that detects and measures photons, or particles of light, that have wavelengths in the X-ray portion of the electromagnetic spectrum. It's used to help scientists understand the chemical and elemental properties of an object.

There are several different X-ray spectroscopy methods that are used in many disciplines of science and technology, including archaeology, astronomy and engineering. These methods can be used independently or together to create a more complete picture of the material or object being analyzed.

History

Wilhelm Conrad Röntgen, a German physicist, was awarded the first Nobel Prize in physics in 1901 for his discovery of X-rays in 1895. His new technology was quickly put to use by other scientists and physicians, according to the SLAC National Accelerator Laboratory.

Charles Barkla, a British physicist, conducted research between 1906 and 1908 that led to his discovery that X-rays could be characteristic of individual substances. His work also earned him a Nobel Prize in physics, but not until in 1917.

The use of X-ray spectroscopy actually began a bit earlier, in 1912, starting with a father-and-son team of British physicists, William Henry Bragg and William Lawrence Bragg. They used spectroscopy to study how X-ray radiation interacted with atoms within crystals. Their technique, called X-ray crystallography, was made the standard in the field by the following year and they won the Nobel Prize in physics in 1915.

How X-ray spectroscopy works

When an atom is unstable or is bombarded with high-energy particles, its electrons transition from one energy level to another. As the electrons adjust, the element absorbs and releases high-energy X-ray photons in a way that's characteristic of atoms that make up that particular chemical element. X-ray spectroscopy measures those changes in energy, which allows scientists to identify elements and understand how the atoms within various materials interact.

There are two main X-ray spectroscopy techniques: wavelength-dispersive X-ray spectroscopy (WDXS) and energy-dispersive X-ray spectroscopy (EDXS). WDXS measures the X-rays of a single wavelength that are diffracted by a crystal. EDXS measures the X-ray radiation emitted by electrons stimulated by a high-energy source of charged particles.

In both techniques, how the radiation is dispersed indicates the atomic structure of the material and therefore, the elements within the object being analyzed.

Multiple applications

Today, X-ray spectroscopy is used in many areas of science and technology, including archaeology, astronomy, engineering and health.

Anthropologists and archaeologists are able to discover hidden information about the ancient artifacts and remains they find by analyzing them with X-ray spectroscopy. For example, Lee Sharpe, associate professor of chemistry at Grinnell College in Iowa, and his colleagues, used a method called X-ray fluorescence (XRF) spectroscopy to identify the origin of obsidian arrowheads made by prehistoric people in the North American Southwest. The team published its results in October 2018 in the Journal of Archaeological Science: Reports.

X-ray spectroscopy also helps astrophysicists learn more about how objects in space work. For example, researchers from Washington University in St. Louis plan to observe X-rays that come from cosmic objects, such as black holes, to learn more about their characteristics. The team, led by Henric Krawczynski, an experimental and theoretical astrophysicist, plans to launch a type of X-ray spectrometer called an X-ray polarimeter. Beginning in December 2018, the instrument will be suspended in Earth's atmosphere by a long-duration, helium-filled balloon.

Yury Gogotsi, a chemist and materials engineer at Drexel University in Pennsylvania, creates spray-on antennas and water-desalination membranes with materials analyzed by X-ray spectroscopy.

The invisible spray-on antennas are only a few dozen nanometers thick but are able to transmit and direct radio waves. A technique called X-ray absorption spectroscopy (XAS) helps ensure that the composition of the incredibly thin material is correct and helps determine the conductivity. “High metallic conductivity is required for good performance of antennas, so we have to closely monitor the material,” Gogotsi said.

Gogotsi and his colleagues also use X-ray spectroscopy to analyze the surface chemistry of complex membranes that desalinate water by filtering out specific ions, such as sodium.

The use of X-ray spectroscopy can also be found in several areas of medical research and practice, such as in modern CT scan machines. Collecting X-ray absorption spectra during CT scans (via photon counting or spectral CT scanner) can provide more detailed information and contrast about what is going on inside the body, with lower radiation doses from the X-rays and less or no need for using contrast materials (dyes), according to Phuong-Anh T. Duong, director of CT at Emory University Department of Radiology and Imaging Sciences in Georgia.

Further reading:

• Read more about NASA's Imaging X-Ray Polarimetry Explorer.
• Learn more about X-ray and Energy-Loss Spectroscopy, from The National Renewable Energy Laboratory.
• Check out this series of lesson plans on the X-ray spectroscopy of stars, from NASA.

Whether you're visiting the emergency room after a rough spill from your mountain bike or visiting your health clinic for a routine cancer screening, it's likely that the doctor will request internal images to accurately assess your health.

One of the most common ways to capture internal body images is with a computed tomography (CT) scan.

CT scans, also called CAT scans, use a rotating X-ray machine to create cross-sectional, or 3D, images of any body part, according to the National Institute of Biomedical Imaging and Bioengineering (NIBIB). They provide a painless, noninvasive and fast way for doctors to examine bones, organs and other internal tissues.

How CT scans work

During a CT scan, the patient lies on a table that moves through a doughnut-like ring known as a gantry, according to the NIBIB. The gantry has an X-ray tube that rotates around the patient while shooting narrow beams of X-rays through the body. The X-rays are picked up by digital detectors directly opposite the source.

After the X-ray source completes a full rotation, a sophisticated computer creates a 2D image of that slice of the body, which typically ranges from 0.04 to 0.4 inches (1 to 10 millimeters) thick. The computer then combines several 2D slices to create a 3D image of the body, making it easier for a doctor to pinpoint where the patient's problem exists. The scan itself typically takes less than 15 minutes depending on the area of the body being imaged.

To make it easier to identify abnormalities, the patient may be given a contrast material. Solutions containing contrast materials, such as iodine or barium, are introduced into the body orally, rectally or injected directly into the bloodstream, depending on the target tissue. The materials in the solution work by temporarily altering how X-rays interact with certain body tissues, which makes those tissues appear different in the resulting image, according to the Radiological Society of North America. The contrast helps doctors distinguish between normal and abnormal tissue.

Why get a CT Scan

CT scan images help doctors diagnose and pinpoint infections, muscle disorders, bone fractures, cancer, tumors and other abnormalities.

In emergency situations, CT scans are life-saving tools that allow doctors to quickly determine the extent of internal injuries or internal bleeding, according to the Radiological Society of North America.

CT scans are also vital in cancer diagnosis, treatment and research, according to the National Cancer Institute.

Risks involved

While CT scans can be vital tools for assessing health, there are risks associated with the scan.

Depending on the area of the body being scanned, there may be risk of radiation exposure, according to the American College of Radiology Imaging Network (ACRIN). X-rays are a source of ionizing radiation, which can damage sensitive tissues such as lymphoid organs and blood. CT scans around the abdomen are not advised for pregnant women because of a chance the fetus would be exposed to harmful radiation.

More time in the CT scanner may lead to higher-quality images but also a higher radiation dose, which is often unnecessary, said Dr. Phuong-Anh Duong, director of computed tomography and associate professor at Emory University Department of Radiology and Imaging Sciences in Georgia. (A CT scan of just the chest area exposes the patient to about 70 times the amount of radiation as a traditional chest X-ray, according to Harvard Health Publishing.)

Duong said it's important to balance CT scan image quality with the amount of radiation exposure — a practice doctors call ALARA, or as low as reasonably achievable.

There are a few ways to reduce radiation exposure, Duong said. For example, image only when necessary and only the body part needed, and use lower-energy radiation and newer technology, such as more sensitive X-ray detectors.

Occasionally, patients might experience allergic reactions to the contrast materials, but major reactions are rare. If allergies are known ahead of time, medications may be given to reduce the effects of the contrast material, according to the Radiological Society of North America. People with asthma, hay fever, allergies, heart disease or kidney or thyroid problems seem to be more at risk of developing a reaction to the contrast material, although researchers are still unclear as to why.

Next-generation CT scanners

Artificial intelligence (AI) is being incorporated into CT scanners to create better images with less radiation, Duong told Live Science.

Earlier this year, researchers at the University of Central Florida incorporated AI into a CT scan system that was able to detect trace amounts of lung cancer.

In another advance this year, a group of researchers from the Icahn School of Medicine at Mount Sinai in New York City created an AI system that examines CT scan images of the brain. The system can detect problems, such as a stroke, in as little as 1.2 seconds. The team published its results in the journal Nature Medicine.

Another big leap forward in CT scan technology are photon-counting CT scanners. These scanners incorporate a detector that counts and tracks individual photons from the X-ray source and detects individual photon interactions. The result is a clearer image with improved resolution and contrast, as opposed to traditional CT scan images that use energy-integrating detectors to detect large numbers of photons at a time and simply measure intensity. The photon-counting CT scanners can lead to decreased X-ray doses, better tissue differentiation, sharper image quality and a reduced need for contrast material, Duong said.

CT scan machines are also becoming more specialized. CT machines specifically designed for scanning breast tissue provide information comparable to traditional mammograms, but without the need for breast compression, and with considerably less radiation exposure through the chest, according to the NIBIB.

Will CT scans ever evolve to the point of resembling a handheld diagnostic device like the "tricorders" from "Star Trek"? Not quite, although portable and mobile CT scanners do exist, Duong said, such as the mobile, van-mounted CT scanner used by Grady Health System at the Emory University School of Medicine. But the smaller machines aren't as efficient as traditional CT scanners, and it's difficult to protect bystanders from radiation exposure.

Further reading:

• How CT technology has evolved in the past 50 years, from the International Society for Computer Tomography.
• CT imaging versus X-rays, from the FDA.
• More information about CT scans, from the Mayo Clinic.

X-rays are types of electromagnetic radiation probably most well-known for their ability to see through a person's skin and reveal images of the bones beneath it. Advances in technology have led to more powerful and focused X-ray beams as well as ever greater applications of these light waves, from imaging teensy biological cells and structural components of materials like cement to killing cancer cells.  

X-rays are roughly classified into soft X-rays and hard X-rays. Soft X-rays have relatively short wavelengths of about 10 nanometers (a nanometer is one-billionth of a meter), and so they fall in the range of the electromagnetic (EM) spectrum between ultraviolet (UV) light and gamma-rays. Hard X-rays have wavelengths of about 100 picometers (a picometer is one-trillionth of a meter). These electromagnetic waves occupy the same region of the EM spectrum as gamma-rays. The only difference between them is their source: X-rays are produced by accelerating electrons, whereas gamma-rays are produced by atomic nuclei in one of four nuclear reactions. 

History of X-rays

X-rays were discovered in 1895 by Wilhelm Conrad Röentgen, a professor at Würzburg University in Germany. According to the Nondestructive Resource Center's "History of Radiography," Röentgen noticed crystals near a high-voltage cathode-ray tube exhibiting a fluorescent glow, even when he shielded them with dark paper. Some form of energy was being produced by the tube that was penetrating the paper and causing the crystals to glow. Röentgen called the unknown energy "X-radiation." Experiments showed that this radiation could penetrate soft tissues but not bone, and would produce shadow images on photographic plates. 

For this discovery, Röentgen was awarded the very first Nobel Prize in physics, in 1901.

X-ray sources and effects

X-rays can be produced on Earth by sending a high-energy beam of electrons smashing into an atom like copper or gallium, according to Kelly Gaffney, director of the Stanford Synchrotron Radiation Lightsource. When the beam hits the atom, the electrons in the inner shell, called the s-shell, get jostled, and sometimes flung out of their orbit. Without that electron, or electrons, the atom becomes unstable, and so for the atom to "relax" or go back to equilibrium, Gaffney said, an electron in the so-called 1p shell drops in to fill the gap. The result? An X-ray gets released.

"The problem with that is the fluorescence [or X-ray light given off] goes in all directions," Gaffney told Live Science. "They aren't directional and not focusable. It's not a very easy way to make a high-energy, bright source of X-rays."

Enter a synchrotron, a type of particle accelerator that accelerates charged particles like electrons inside a closed, circular path. Basic physics suggests that any time you accelerate a charged particle, it gives off light. The type of light depends on the energy of the electrons (or other charged particles) and the magnetic field that pushes them around the circle, Gaffney said.

Since the synchrotron electrons are pushed to near the speed of light, they give off enormous amounts of energy, particularly X-ray energy. And not just any X-rays, but a very powerful beam of focused X-ray light.

Synchrotron radiation was seen for the first time at General Electric in the United States in 1947, according to the European Synchrotron Radiation Facility. This radiation was considered a nuisance because it caused the particles to lose energy, but it was later recognized in the 1960s as light with exceptional properties that overcame the shortcomings of X-ray tubes. One interesting feature of synchrotron radiation is that it is polarized; that is, the electric and magnetic fields of the photons all oscillate in the same direction, which can be either linear or circular. 

"Because the electrons are relativistic [or moving at near light-speed], when they give off light, it ends up being focused in the forward direction," Gaffney said. "This means you get not just the right color of light X-rays and not just a lot of them because you have a lot of electrons stored, they're also preferentially emitted in the forward direction."

X-ray imaging

Due to their ability to penetrate certain materials, X-rays are used for several nondestructive evaluation and testing applications, particularly for identifying flaws or cracks in structural components. According to the NDT Resource Center, "Radiation is directed through a part and onto [a] film or other detector. The resulting shadowgraph shows the internal features" and whether the part is sound. This is the same technique used in doctors' and dentists' offices to create X-ray images of bones and teeth, respectively.[Images: Stunning Fish X-rays]

X-rays are also essential for transportation security inspections of cargo, luggage and passengers. Electronic imaging detectors allow for real-time visualization of the content of packages and other passenger items. 

The original use of X-rays was for imaging bones, which were easily distinguishable from soft tissues on the film that was available at that time. However, more accurate focusing systems and more sensitive detection methods, such as improved photographic films and electronic imaging sensors, have made it possible to distinguish increasingly fine detail and subtle differences in tissue density, while using much lower exposure levels.

Additionally, computed tomography (CT) combines multiple X-ray images into a 3D model of a region of interest.

Similar to CT, synchrotron tomography can reveal three-dimensional images of interior structures of objects like engineering components, according to the Helmholtz Center for Materials and Energy.

X-ray therapy

Radiation therapy uses high-energy radiation to kill cancer cells by damaging their DNA. Since the treatment can also damage normal cells, the National Cancer Institute recommends that treatment be carefully planned to minimize side effects. 

According to the U.S. Environmental Protection Agency, so-called ionizing radiation from X-rays zaps a focused area with enough energy to completely strip electrons from atoms and molecules, thus altering their properties. In sufficient doses, this can damage or destroy cells. While this cell damage can cause cancer, it can also be used to fight it. By directing X-rays at cancerous tumors, it can demolish those abnormal cells. 

X-ray astronomy

According to Robert Patterson, professor of astronomy at Missouri State University, celestial sources of X-rays include close binary systems containing black holes or neutron stars. In these systems, the more massive and compact stellar remnant can strip material from its companion star to form a disk of extremely hot X-ray-emitting gas as it spirals inward. Additionally, supermassive black holes at the centers of spiral galaxies can emit X-rays as they absorb stars and gas clouds that fall within their gravitational reach. 

X-ray telescopes use low-angle reflections to focus these high-energy photons (light) that would otherwise pass through normal telescope mirrors. Because Earth's atmosphere blocks most X-rays, observations are typically conducted using high-altitude balloons or orbiting telescopes. 

Additional resources

• To learn more, download this PDF from SLAC titled "Early History of X-Rays."
• The NDE/NDT Resource Center provides information about nondestructive evaluation/nondestructive testing. 
• NASA's mission page on the electromagnetic spectrum explains how astronomers use X-rays.

This page was updated on Oct. 5, 2018 by Live Science Managing Editor, Jeanna Bryner.

Space is filled with bizarre signals that we scramble to put meaning to — and now, researchers have detected yet another mysterious signal. This one emanated from near a neutron star, and for the first time, it's infrared.

So, what's nearby that could have created the weird signal? Scientists have a few ideas.

When a star reaches the end of its life, it typically undergoes a supernova explosion— the star collapses, and if it has enough mass, it will form a black hole. But if the star isn't massive enough, it will form a neutron star. [Supernova Photos: Great Images of Star Explosions]

Neutrons stars are very dense and, as their name suggests, are made up mostly of closely packed neutrons. Neutron stars can also be called "pulsars" if they are highly magnetized and rotate rapidly enough to emit electromagnetic waves, according to Space.com.

Typically, neutron stars emit radio waves or higher-energy waves such as X-rays, according a statement released by NASA yesterday (Sept. 17). But an international group of researchers from Penn State, the University of Arizona and Sabanci University in Turkey observed something interesting in NASA's Hubble Space Telescope data: a long signal of infrared light emitted near a neutron star, the researchers reported yesterday in The Astrophysical Journal.

This signal, they found, was about 800 light-years away and was "extended," meaning it was spread across a large stretch of space, unlike typical "point" signals from neutron stars that emit X-rays. Specifically, the signal stretched across 200 astronomical units (AU) of space, or 2.5 times the orbit of Pluto around the sun, according to a statement from Penn State. (One AU is the average distance from Earth to the sun — about 93 million miles, or 150 million kilometers.)

Such extended signals have been observed before, but never in the infrared, lead author Bettina Posselt, an associate research professor of astronomy and astrophysics at Penn State, told Live Science.

Based on previous data, the amount of infrared radiation is much more than the neutron star should be emitting, Posselt said. So "all of the emission in infrared we see is likely not coming from the neutron star itself," Posselt said. "There's something more."

The neutron star in question, RX J0806.4-4123, is one of the nearby X-ray pulsars collectively known as the Magnificent Seven. They are bizarre characters: They rotate much more slowly than typical neutron stars (it takes 11 seconds for one rotation of RX J0806.4-4123, whereas typical ones rotate in a fraction of a second), and they're much hotter than they should be based on when they formed.

In their study, the researchers proposed two possibilities for what could have snuggled up near RX J0806.4-4123 and emitted these mysterious signals: a disk of dust that surrounds the pulsar, or a "pulsar wind nebula."

A "fallback disk" — that could stretch 18 billion miles across — could have formed from the remnants of a resident star following a supernova explosion, Posselt said. Such disks that "have been long searched for, but not found" would most likely be made up mainly of dust particles, she added.

The inner part of such a disk would likely have enough energy to produce infrared light, Posselt said. This could also help explain why RX J0806.4-4123 is so hot and spins so slowly. "The disks in the past could have provided some extra heating," and also slowed down its rotation, Posselt said.

The second explanation is that perhaps the infrared signal is coming from a nearby pulsar wind nebula.

A pulsar wind can form when electrons from a neutron star are accelerated in an electric field produced by the neutron star's fast rotation and strong magnetic field, according to the NASA statement. As the neutron star moves through space, typically faster than the speed of sound, it crashes into the interstellar medium — those tiny bits of gas and dust that reside between large celestial objects. The interaction between the interstellar medium and the pulsar wind can produce the so-called pulsar wind nebula, which could give off infrared radiation, Posselt said.

Pulsar wind nebulas are typically seen emitting X-rays, so a pulsar wind nebula that radiates only in the infrared is "definitely interesting," Posselt said.

Originally published on Live Science.

Stunning new color X-ray images, from a company called Mars Bioimaging, in New Zealand, seem to make flesh and bone translucent and hyperreal.

The gif above shows one of the company's strange and fascinating images: a slice of human ankle, with off-white, rugged bones, bloody-looking muscle tissue and a pad of fat smeared protectively under the heel with a whipped-cream texture.

This image shows a wrist with more muscle, less visible bone, almost no fat and a clearly-articulated watch:

It's important to note that these aren't "true-color" X-ray scans as most people would commonly understand the term. As the inventors of the sensor that was used to make these images described in a 2015 paper in the journal IEEE Transactions on Medical Imaging and on the company's website, the colors in these images are applied based on the computer's detection of different wavelengths of X-rays passing through different substances. There are, however, no "true" red X-rays or "true" white X-rays; the device's programmers assign different colors to different detected body parts. (What human brains interpret as color comes from different wavelengths of light in the visual spectrum bouncing off objects. Visible light is also a form of electromagnetic radiation but is lower-energy than X-ray light.)

To successfully distinguish muscle, fat and bone, Mars Bioimaging developed sensors that could fit inside computed tomography (CT) scanners (circular X-ray devices that produce three-dimensional X-ray images) and produce very detailed information about the wavelengths of individual X-ray photons that pass through and bounce off human tissue. By sensing the wavelengths that disappear after passing through a particular bit of tissue, the device makes a judgement about what chemicals make up that tissue and uses that information to figure out what sort of tissue it was. The photon-counting technology, the company says in its marketing materials, was originally developed as part of its founders' work with CERN, the European Organization for Nuclear Research, which operates the world's largest atom smasher.

By matching those scans with details about how different chemical compounds interact with X-ray light, they were able to distinguish different compounds in X-ray scans, the researchers wrote in the 2015 study. To produce these new grody, gorgeous color images of living tissue, they simply tasked the computer with painting the different compounds of fat, bone and muscle different colors.

The benefit for researchers, the company claims in its marketing materials, isn't so much the fascinating visuals (though that's a plus) as it is the wealth of precise chemical data on objects in the scanner. The careful, multilayered tissue scans, they write, will enable new precision in medical research.

Originally published on Live Science.

It takes 512 years for a high-energy photon to travel from the nearest neutron star to Earth. Just a few of them make the trip. But they carry the information necessary to solve one of the toughest questions in astrophysics.

The photons shoot into space in an energetic rush. Hot beams of X-ray energy burst from the surface of the tiny, ultradense, spinning remnant of a supernova. The beams disperse over long centuries in transit. But every once in a while, a single dot of X-ray light that's traveled 157 parsecs (512 light-years) across space — 32 million times the distance between Earth and the sun — expends itself against the International Space Station's (ISS) X-ray telescope, nicknamed NICER. Then, down on Earth, a text file enters a new point of data: the photon's energy and its arrival time, measured with microsecond accuracy.

That data point, along with countless others like it collected over the course of months, will answer a basic question as soon as summer 2018: Just how wide is J0437-4715, Earth's nearest neutron-star neighbor?

If researchers can figure out the width of a neutron star, physicist Sharon Morsink told a crowd of scientists at the American Physical Society's (APS) April 2018 meeting, that information could point the way toward solving one of the great mysteries of particle physics: How does matter behave when pushed to its wildest extremes? [10 Futuristic Technologies 'Star Trek' Fans Would Love]

On Earth, given humanity's existing technology, there are some hard limits on how dense matter can get, even in extreme laboratories, and even harder limits on how long the densest matter scientists make can survive. That's meant that physicists haven't been able to figure out how particles behave at extreme densities. There just aren't many good experiments available.

"There's a number of different methodologies that people come up with to try to say how super-dense matter should behave, but they don't all agree," Morsink, a physicist at the University of Alberta and a member of a NASA working group focused on the width of neutron stars, told Live Science. "And the way that they don't all agree can actually be tested because each one of them makes a prediction for how large a neutron star can be."

In other words, the solution to the mystery of ultradense matter is locked away inside some of the universe's densest objects — neutron stars. And scientists can crack that mystery as soon as they measure precisely just how wide (and, therefore, dense) neutron stars really are.

Particle physics in deep space

"Neutron stars are the most outrageous objects that most people have never heard of," NASA scientist Zaven Arzoumanian told physicists at the meeting in Columbus, Ohio.

Arzoumanian is one of the heads of NASA's Neutron Star Interior Composition Explorer (NICER) project, which forms the technical basis for Morsink's work. NICER is a large, swiveling telescope mounted on the ISS; it monitors and precisely times the X-rays that arrive in the area of low Earth orbit from deep space.

A neutron star is the core left behind after a massive supernova explosion, but it's believed to be not much wider than a midsize city. Neutron stars can spin at high fractions of the speed of light, firing flickering beams of X-ray energy into space with more precise timing than the ticking of atomic clocks.

And most importantly for Morsink and her colleagues' purposes, neutron stars are the densest known objects in the universe that haven't collapsed into black holes — but unlike with black holes, it's possible for scientists to figure out what goes on inside them. Astronomers just need to know precisely how wide neutron stars really are, and NICER is the instrument that should finally answer that question.

Quark soup

Scientists don't know exactly how matter behaves in the extreme core of a neutron star, but they understand enough to know that it's very weird.

Daniel Watts, a particle physicist at the University of Edinburgh, told a separate audience at the APS conference that the interior of a neutron star is essentially a great big question mark.

Scientists have some excellent measurements of the masses of neutrons stars. The mass of J0437-4715, for example, is about 1.44 times that of the sun, despite being more or less the size of Lower Manhattan. That means, Morsink said, that J0437-4715 is far denser than the nucleus of an atom — by far the densest object that scientists encounter on Earth, where the vast majority of an atom's matter gathers in just a tiny speck in its center.

At that level of density, Watts explained, it's not at all clear how matter behaves. Quarks, the tiny particles that make up neutrons and protons, which make up atoms, can't exist freely on their own. But when matter reaches extreme densities, quarks could keep binding into particles similar to those on Earth, or form larger, more complex particles, or perhaps mush together entirely into a more generalized particle soup. [7 Strange Facts About Quarks]

What scientists do know, Watts told Live Science, is that the details of how matter behaves at extreme densities will determine just how wide neutron stars actually get. So if scientists can come up with precise measurements of neutron stars, they can narrow down the range of possibilities for how matter behaves under those extreme conditions.

And answering that question, Watts said, could unlock answers to all sorts of particle-physics mysteries that have nothing to do with neutron stars. For example, he said, it could help answer just how individual neutrons arrange themselves in the nuclei of very heavy atoms.

NICER measurements take time

Most neutron stars, Morsink said, are believed to be between about 12 and 17 miles (20 and 28 kilometers) wide, though they might be as narrow as 10 miles (16 km). That's a very narrow range in astronomy terms but not quite precise enough to answer the kinds of questions Morsink and her colleagues are interested in.

To press toward even more precise answers, Morsink and her colleagues study X-rays coming from rapidly spinning "hotspots" on neutron stars.

Though neutron stars are incredibly compact spheres, their magnetic fields cause the energy coming off of their surfaces to be fairly uneven. Bright patches form and mushroom on their surfaces, whipping around in circles as the stars turn many times a second.

That's where NICER comes in. NICER is a large, swiveling telescope mounted on the ISS that can time the light coming from those patches with incredible regularity.

That allows Morsink and her colleagues to study two things, both of which can help them figure out a neutron star's radius:

1. The speed of rotation: When the neutron star spins, Morsink said, the bright spot on its surface winks toward and away from Earth almost like the beam from a lighthouse turning circles. Morsink and her colleagues can carefully study NICER data to determine both exactly how many times the star is winking each moment and exactly how fast the bright spot is moving through space. And the speed of the bright spot's motion is a function of the star's rate of rotation and its radius. If researchers can figure out the rotation and speed, the radius is relatively easy to determine.

2. Light bending: Neutron stars are so dense that NICER can detect photons from the star's bright spot that fired into space while the spot was pointed away from Earth. A neutron star's gravity well can bend light so sharply that its photons turn toward and smack into NICER's sensor. The rate of light curvature is also a function of the star's radius and its mass. So, by carefully studying how much a star with a known mass curves light, Morsink and her colleagues can figure out the star's radius.

And the researchers are close to announcing their results, Morsink said. (Several physicists at her APS talk expressed some light disappointment that she hadn't announced a specific number, and excitement that it was coming.)

Morsink told Live Science that she wasn't trying to tease the upcoming announcement. NICER just hasn't collected enough photons yet for the team to offer up a good answer.

"It's like taking a cake out of the oven too early: You just end up with a mess," she said.

But the photons are arriving, one by one, during NICER's months of periodic study. And an answer is getting close. Right now, the team is looking at data from J0437-4715 and Earth's next-nearest neutron star, which is about twice as far away.

Morsink said she isn't sure which neutron star's radius she and her colleagues will publish first, but she added that both announcements will be coming within months.

"The aim is for this to happen later on this summer, where 'summer' is being used in a fairly broad sense," she said. "But I would say that by September, we ought to have something."

Originally published on Live Science.

Recently, researchers uncovered the adaptations that enable this superfast snapping in an elusive and little-studied genus of trap-jaw ants called Myrmoteras, using X-ray scans and high-speed video to analyze the ants' jaws in action — inside and out.

The scientists identified the latch, spring and trigger mechanisms for two Myrmoteras species, finding that their trap-jaw system operates in a manner unlike those in other groups of trap-jaw ants. [In Photos: Trap-Jaw Ant Babies Grow Up]

Myrmoteras ants are native to Southeast Asia and measure about 0.16 to 0.20 inches (4 to 5 millimeters) in length. They live and forage in leaf litter on the forest floor, which makes them difficult to find and capture while still alive, said study lead author Frederick Larabee, a postdoctoral research fellow with the Smithsonian AntLab at the Smithsonian National Museum of Natural History. It was previously unknown how fast the ants' jaws could snap closed and how exactly they worked, Larabee told Live Science.

When Myrmoteras' jaws are locked in the "open" position, as they are when the ant is hunting, they extend backward at a steep angle, pointing toward the ant's body. The Myrmoteras' ants' spiny, prey-catching mandibles are longer and more slender than those of their trap-jaw cousins, which suggests that Myrmoteras use these body parts to quickly stab and immobilize prey, rather than stunning them with a blow, the study authors wrote.

The scientists worked in the lab with several live colonies that had been previously collected, Larabee said. Footage shot at 50,000 frames per second revealed that the ants' jaws closed in about half a millisecond — not as quickly as ants in the trap-jaw genus Odontomachus, which snap their mandibles in one-tenth of a millisecond, according to the study.

But it was micro-CT scans — computed X-ray tomography — that enabled the researchers to detect and digitally model the inner workings of Myrmoteras' deadly strikes in 3D, the researchers said. 

"We wanted to be able to visualize all the internal structures — the muscles, the neurons, and the attachments between the muscles and the mandible itself," Larabee said.

Spring-loaded systems such as those found in trap-jaw ants have three main parts: a lock to hold the jaws open, a spring to store energy and a trigger to release the strike, transferring energy into the jaw to propel it closed at high speeds. Using CT scans, the researchers modeled the muscles responsible for opening and closing the jaws. Once the scientists knew what the muscles looked like, they could identify how they powered Myrmoteras' speedy bite, a process the researchers visualized in a video posted to YouTube.

The latch holding the jaws open was unlike any observed in other trap-jaw ants, resembling the locking mechanism in grasshopper legs, Larabee told Live Science.

Another unusual and unique structure that drew the scientists' attention was a strangely shaped lobe on the back of Myrmoteras ants' heads. The researchers noticed that it would compress immediately prior to a strike, hinting that the structure was part of the spring mechanism that released stored energy into the jaws.

"We're not entirely sure what the spring is, but we think it's the ligaments linking the muscle to the mandible," Larabee explained.

A spring-loaded jaw is a highly specialized feature, which makes it even more incredible that different ant lineages evolved such diverse structures to make these jaws work, Larabee said.

"All these ultrafast jaws, using different components or different body structures to serve this system — it's a great example of convergent evolution, where evolution has found different strategies for achieving the same behavioral goal," he said.    

The findings were published online Aug. 30 in the Journal of Experimental Biology.

Original article on Live Science.

Oops!

It's probably not a good idea to swallow anything that isn't food or medicine. Yet doctors have seen cases of people who've swallowed all sorts of weird objects, from household items like lighters to tech gadgets like an entire cellphone. One 10-year-old girl even swallowed a part of her fidget spinner. Take a look ...

Fidget spinner

It was only a matter of time … Fidget spinners sprouted up out of nowhere, reaching a frenzy of popularity in the spring of 2017. With so many little kids spinning these three-paddled toys on their fingers and elsewhere, someone was bound to get hurt, somehow. On May 13, 2017, in Texas, Kelly Rose Joniec's 10-year-old daughter accidentally swallowed part of her spinner. Joniec noticed her daughter was choking while driving home from a swim meet, Joniec wrote on her Facebook page. She immediately pulled over and got her daughter to urgent care; when the doctors there couldn't figure out the problem, an ambulance brought the Joniecs to Texas Children's Hospital in Houston. Apparently, her daughter had put part of the fidget spinner into her mouth to clean it. An X-ray taken at the hospital showed the spinner's bushing, or one of the metal disks that can pop out from the toy — lodged in her esophagus. A doctor performed endoscopic surgery and removed the object, Joniec wrote. [Fidget Spinners: What They Are, How They Work and Why the Controversy]

A lighter

A man in Croatia was found to have a lighter in his stomach, which had been there for 17 months. The man admitted to his doctors that he intentionally swallowed the lighter when he was at a police station, where he was being questioned about possibly smuggling drugs, according to a 2012 report of the case. The man had wrapped the lighter in cellophane, so he wasn't exposed to the toxic chemicals in the lighter, even after all that time. Doctors were able to successfully remove the lighter by using a snare-like medical tool, and pulled it out through the man's esophagus.

Cellphone

A 29-year-old prisoner in Ireland went to the emergency room after he swallowed a cellphone. An X-ray showed the phone was in the man's stomach. Since the phone didn't pass through the digestive system on its own, doctors tried to remove it using medical tools to pull the device up through the esophagus. However, they couldn't align the phone correctly to get it out of the stomach without potentially damaging the esophagus, according to a 2016 report of the case. Ultimately, the doctors needed to make a make a surgical incision into the man's stomach to get the phone out.

Doctors at the Dublin Incorporating the National Children's Hospital described the case in the International Journal of Surgery Case Reports in 2016.

SpongeBob

Doctors who treated a 16-month-old boy got a surprise when an X-ray of his throat revealed SpongeBob SquarePants looking back at them. It turned out that the child had swallowed a pendant featuring the cartoon character that belonged to his sister. The doctors were able to remove the pendant without any complications.

A toothbrush

An 18-year-old woman went to the doctors after she accidentally swallowed her toothbrush, according to a 2011 report of the case. The woman admitted she had been using the toothbrush to induce vomiting when she swallowed it, the report said. Doctors were able to successfully remove the 8-inch toothbrush using a snare-like medical tool. The women recovered and went home 6 hours later.

A fitness tracker

A 13-year-old girl in South Korea accidentally swallowed her Misfit Shine activity tracker after she put it in her mouth while swimming. After 30 hours of waiting for the device to pass on its own, it remained in the girl's stomach, and so doctors decided to try to remove it. They were able to use a snare-like tool to lasso the tracker, and take it out. The Shine still worked, and the girl recovered quickly.

Dentures

A 55-year-old man in India accidentally swallowed a part of his denture when he had a seizure while sleeping. But the man didn't realize what he had swallowed until he went to the doctor eight days later, after he experienced chest pain and difficulty swallowing. An X-ray showed that part of the denture was stuck in his esophagus. Removing the denture proved difficult, but doctors were eventually able to extricate it without needing to perform surgery.

Dental instrument

A 4-year-old boy in India was undergoing a root canal when he suddenly moved his head, and swallowed a sharp dental instrument called a pro taper file, which is used for root canals and looks like a small screwdriver. Initially, doctors weren't sure if the boy had inhaled the file or swallowed it, but an X-ray suggested the instrument was in his stomach. The boy wasn't in pain, and so doctors waited to see if the instrument would pass through the digestive tract on its own. X-rays taken later showed that the instrument was moving, and 41 hours later it passed, according to a 2015 report of the case.

Bobby pin

A bobby pin may seem benign enough, especially if you're a toddler who sees everything mouth-size as something to be, of course, put in your mouth. But for a 4-year-old boy in Saudi Arabia, swallowing a bobby pin meant a trip to the hospital, according to a case report published Nov. 5, 2015, in the journal BMJ Case Reports. The boy had apparently swallowed the hair accessory months before his hospital visit, long enough that the bobby pin had rusted and become sharp, the researchers said. The sharpened bobby pin had pierced through the first section of his small intestine and pierced his kidney, according to the report. Doctors surgically removed the bobby pin, and the boy recovered successfully, they said.

"Children actually start exploring the world using their mouth as soon as they are able to pick up objects," said co-author of the case report Dr. Yasmin Abdulaziz Yousef, of the department of surgery at KAMC-JD, National Guard Health Affairs in Jeddah, who treated the boy. However, such swallowed objects typically "pass through the gastrointestinal tract and end up in the diaper," she said in 2015.

Light-bulb moment

A 15-month-old girl who was brought to the ER at Queen Mary Hospital in Hong Kong in 2012 with breathing difficulty gave doctors a light-bulb moment, literally. After X-raying her chest, the doctors thought she had swallowed her grandmother's hairpin. But when the doctors had a closer look through a scope inserted into her nose, they realized a href="http://www.livescience.com/52151-led-light-bulb-toddler-cough.html">the girl had inhaled a light-emitting diode, or LED, bulb, intact, and it was lodged in her windpipe. Using forceps, the doctors removed the LED in pieces to minimize damage to the girl's airway, they reported online Aug. 26, 2015, in the journal BMJ Case Reports.

A Pen

After 25 years of lying in a woman's stomach, a felt-tip pen was still in working order. How did it get into her stomach? When the 76-year-old woman went to a doctor due to weight loss and diarrhea, an investigation with a scope and a computed tomography (CT) scan revealed the item. "She recalled unintentionally swallowing a pen 25 years earlier. While she was interrogating a spot on her tonsil with the pen she slipped, fell and swallowed the pen by mistake," the doctors wrote in 2011 in the journal BMJ Case Reports. "Her husband and general practitioner dismissed her story, and plain abdominal films done at the time were reported as normal." Though her symptoms resolved on their own and there was no stomach damage, the doctors decided to remove the felt-tip pen because of the possibility of future damage to her stomach.

For the first time, scientists have captured time-lapse video of a maggot transforming into an adult fly.

Researchers used X-ray imaging to peer at the developing insect as it nestled inside an opaque shell called a puparium. They watched as the larval structures melted away and mature body parts sprouted in their place.

The incredible footage offers an unprecedented glimpse of the larva's metamorphosis, showing the process in greater detail than was previously known. The video provides fresh insights into the stages that mark the dramatic physical transformation between larva and adult fly, the scientists said. [Maggots Metamorphosing Into Blowflies: X-Ray Time-Lapse Video]

A taste for decay

The bluebottle blowfly (Calliphora vicina) is known for its metallic blue color and its attraction to decomposing flesh. Females lay their eggs in decaying remains, and larva occupy their grisly homes through three instars, or developmental stages. They then become pupas, retreating into puparia and metamorphosing into their adult forms.

Blowflies are quick to detect the odor of decay and usually arrive and lay their eggs soon after death occurs, prior studies have shown. Because temperature plays an important role in how quickly the maggots and pupas develop, their presence on a human corpse — and their developmental stage — can help experts determine when the person died.

Forensic entomologists — scientists who study the relationship between insect life and decaying corpses to assist in crime-scene investigations — look closely at the flies, maggots and pupas on and near a body. These scientists are "essentially working out how old the oldest specimens feeding on the body (or that fed on the body) are — the ones laid there by the first-arriving adult flies," study co-author Martin J.R. Hall, a research entomologist at the Natural History Museum (NHM) in London, told Live Science in an email.

Blowflies develop from egg to adult after about 18 days. The insects spend more than 50 percent of that time — 10 days — inside a puparium, but it is the least-understood stage of their life cycle, Hall said. Scientists in previous investigations had applied mineral oil to puparium shells and blasted them with light to see the pupa inside, but the image resolution of those methods was poor, he explained.

Transformers — more than meets the eye

In a 2012 study, Hall and his colleagues peered inside puparia using CT scans, a method that worked well on preserved and stained specimens but couldn't be applied to living animals. For the new study, the researchers took a different approach, using low-energy X-rays that captured images at 1- to 2-minute intervals, revealing developmental changes happening in the living pupa.

The scientists saw thatafter about 6 hours inside the puparia, the pupa produced an air bubble that moved around inside the shell to create space as the insect transformed. Larval body structures melted away within the first 24 hours, then special cells began producing adult body parts: head, legs, thorax and wings. 

It took only about 1 hour and 15 minutes for the general shape of the adult body to emerge, the scientists said. The rest of the pupation — which lasted about nine days — was spent fine-tuning the development of all the insect's new parts, the researchers said.

"The videos were a wonderful tool to demonstrate the marvel of nature that is metamorphosis," Hall told Live Science.

Future investigations will use a new high-resolution micro-CT system at NHM to capture even more details in the blowfly's developmental changes, Hall said.

"We will especially focus on the brain and how it changes from larva to adult, to accommodate the different sensory inputs, especially from the eyes, which are not found in larvae," he added.

The findings were published online Jan. 24 in the journal Royal Society Open Science.

Original article on Live Science.

Swiss researchers may have solved the mystery over the identity of a 17th-century man who was buried face-down with a knife and purse filled with coins.

X-ray computer tomography of the coins has revealed the man was likely a merchant, but the reason for his prone burial continues to puzzle the archaeologists.

Unearthed in 2013 in the Bernese Lakeland region of Switzerland during the construction on a new underground garage, the skeleton was found along 342 bodies laid to rest between the 8th and 17th centuries. The individual was among the last 15 bodies to be buried at the ancient cemetery.

The face-down skeleton stood out from all the other graves.

"It is certainly a deviant burial, in the sense that the burial practices here seem to be very unusual for the time," Christian Weiss, a numismatic expert with the Archaeological Services of Canton Bern, told Discovery News. "The individual was facing to the ground; moreover, a knife and a purse were found within the burial where we normally don't find any grave goods in this time," Weiss said.

RELATED: Anti-Demonic Burial Found in Poland

Under the individual's chest, the archaeologists found what remained of a leather purse. Over time, the leather had decomposed and the coins it contained had corroded together to form a solid block of metal.

Unable to separate the coins, the researchers turned to a powerful X-ray computer tomograph, a new instrument called µDETECT. Used in conjunction with a high resolution detector, the µDETECT revealed the presence of 24 coins.

"The astonishing fact about these coins is that they belong to three different coin circulation areas, the Fribourg-Bern-Solothurn, Basel-Freiburg in Breisgau and Luzern-Schwyz regions," Weiss said.

The finding suggests the individual was moving in these three areas, which had their own coins in local circulation at that time.

"It is possible he was a traveling merchant," Weiss said.

With one exception, a heavily worn silver coin from France, all the coins in the purse are of rather low value.

"They are really just small change," Weiss said. "The most interesting to me isn't really one particular coin, but the ensemble all together. We rarely get such a big ensemble of small value coins from this time."

RELATED: Medieval 'Witch Girl' Suffered From Scurvy

The latest among the coins in the purse dates from 1629, indicating the man must have been buried after then. The reason behind the face-down burial remains a mystery.

Like other deviant burials, in which the dead were buried with a brick in the mouth, nailed or staked to the ground, the prone burial aimed to humiliate the dead and prevent the individual from rising from the grave, since it was believed that the soul left the body through the mouth.

Usually these rare burials were meant as an act of punishment and in extreme cases the victim was interred alive.

In the case of the Swiss merchant, there is no conclusive answer. 

"It is likely they buried the man intentionally facing downwards. Whether the burial was meant to prevent him from returning to the living, or to face him to hell is just speculation. There could be other, rather unspectacular reasons behind this," Weiss said.

Originally published on Discovery News.

Until recently, manta rays — which sail through tropical and temperate ocean waters, looking much like enormous kites — were thought to migrate great distances across ocean basins, as do many of the largest marine animals.

But a new study finds that these big fish have a much smaller range than scientists had thought.

Researchers investigated data gathered from tracking devices on the manta rays, as well as chemical and DNA analysis of the rays' muscle tissues. The scientists were surprised to find that these giants of the deep are not long-distance seasonal commuters at all. Rather, they spend their lives in much more localized areas, the researchers found. The discovery radically changes scientists' understanding of mantas' habits and carries dramatic implications for their conservation. [Watch 'Homebody' Manta Rays Get Tagged]

Now you see them, now you don't

With a "wingspan" that can extend more than 23 feet (7 meters), mantas are the largest rays and one of the ocean's biggest fishes. But tracking even very large animals in the open ocean can be extremely difficult, and mantas have always been especially so, according to lead study author Josh Stewart, a graduate student at the Scripps Institution of Oceanography in San Diego.

"They live in hard-to-reach places — and in a lot of these places, it's challenging to find them consistently. So for a long time, no one was tagging them," Stewart told Live Science.

Stewart, who is also the associate director of the nonprofit conservation organization Manta Trust, explained that individual mantas can be identified by unique patterns of spots on their bellies; photos of mantas captured by researchers, dive tours and citizen scientists were used to track mantas over time.

But sometimes, nearly two decades would elapse between sightings, Stewart said. And in some locations, researchers would see the mantas for a few weeks or months, but they wouldn't find any at all for the rest of the year. And because mantas are so big, it was thought that they were simply doing what large migratory ocean creatures such as whales, leatherback turtles and bluefin tuna do — following their food.

"If you look at every other big animal that lives in remote pelagic [open ocean] environments, they're making long, epic migrations," Stewart said. "So we thought the mantas were migratory, too. They're certainly big enough and capable enough."

The researchers set out to tag and sample manta-ray populations at four sites that were up to 8,000 miles (13,000 kilometers) apart, to find out how far the rays traveled.

"Well, that's interesting"

Tagging technology has been used by oceanographers for more than two decades, but recent innovations have made devices much more robust and reliable, with a recovery rate of 80 to 90 percent, Stewart said.

The tags were programmed to detach after six months and then float to the ocean surface, where scientists could retrieve them.

In the very first batch they collected, Stewart and his colleagues noticed something unexpected: The tags popped off within about 62 miles (100 km) from where they were originally attached, and when the scientists mapped the mantas' movements over months, they found that the tags remained in largely the same area.

Stewart said their initial reaction was, "Well, that's interesting," though they needed to collect more data to be sure. But every tag they deployed after that returned the same results over a six-month period. And their genetic analysis confirmed that mantas in the different sample sites were not, in fact, the same individuals traveling from place to place, but rather established groups that staked out their ranges and stayed put. [Marine Marvels: Spectacular Photos of Sea Creatures]

Flexible feeders

So why don't mantas seasonally roam the oceans as other massive predators do? Greater flexibility in their diet might be the answer, Stewart suggested.

"The tags also record where in the water column they are," he said. "Some months, they were close to the surface, and some months, they were much deeper, which correlates to where we think different types of food may have been available."

Mantas were known to feed primarily on tiny marine organisms called zooplankton, filtering them from seawater with specialized gill plates, but tissue analysis of the rays revealed that their diets are broader than scientists had expected.

"They can feed on everything from really tiny copepods that you can barely see to big shrimp, and even fishes," Stewart said. "We think they're able to shift what they're feeding on at different times of the year, which may allow them to stay put and not migrate."

Recognizing that mantas are local and affected by smaller groups of people could shift conservation efforts to local communities — which tend to be more effective, Stewart said.

On the other hand, he added, mantas that don't stray as far are more likely to be negatively affected by activities from local fisheries and poaching for the illegal wildlife trade.

"It's a double-edged sword," Stewart told Live Science. "It's good in terms of facilitating management. But it also means we have to act much more quickly, because these populations are more vulnerable due to their restricted ranges."

The findings were published online today (June 20) in the journal Biological Conservation.

Original article on Live Science.

Scientists have captured dramatic video footage of what happens to liquid droplets when they are hit with the beam of an X-ray laser. Spoiler alert: They explode.

These are the first movies of the microscopic realm showing water being vaporized by the world's brightest X-ray laser, taken at the Department of Energy's SLAC National Accelerator Laboratory. Data from this research could lead to better understanding and use of X-ray lasers in experiments, according to SLAC.

The footage shows the X-ray pulse ripping a drop of liquid apart, which creates a cloud of smaller particles and vapor. When the X-ray pulse hits a jet of liquid,it initially creates a hole in the stream. As the gap grows, the ends of the jet become an umbrella-like shape, eventually folding back to merge with the jet. [Gallery: Dreamy Images Reveal Beauty in Physics]

Scientists use X-ray lasers' extremely bright, fast flashes of light to take atomic-level snapshots of nature's speediest processes.

"Understanding the dynamics of these explosions will allow us to avoid their unwanted effects on samples," Claudiu Stan of the Stanford PULSE Institute, a joint institute of Stanford University in California and SLAC, said in a statement.

"It could also help us find new ways of using explosions caused by X-rays to trigger changes in samples and study matter under extreme conditions," he said. "These studies could help us better understand a wide range of phenomena in X-ray science and other applications."

Liquids are commonly used to bring samples into the X-ray beam's path for analysis. In only a tiny fraction of a second, samples can blow up from the power of an ultrabright X-ray, but researchers can, in most cases, take the data they need before damage sets in.

The new study, published online May 23, 2016, in the journal Nature Physics, shows, in microscopic detail, how these explosions unfold. The researchers took one image, timed from five-billionths of a second to one ten-thousandth of a second, for each X-ray pulse hitting the liquid. The images were then edited together into movies.

From the data gathered during these experiments and their resulting movies, the researchers developed mathematical models to describe the liquid explosions. These models could help researchers tune the lasers more precisely, and will eventually be used in experiments employing extremely high-powered X-ray lasers. That could include the European XFEL, a laser currently under construction in Germany that will fire thousands of times faster than those at SLAC.

"The jets in our study took up to several millionths of a second to recover from each explosion, so if X-ray pulses come in faster than that, we may not be able to make use of every single pulse for an experiment," Stan said. "Fortunately, our data show that we can already tune the most commonly used jets in a way that they recover quickly, and there are ways to make them recover even faster."

Follow Kacey Deamer @KaceyDeamer. Follow Live Science @livescience, on Facebook & Google+. Original article on Live Science.

There's more than meets the eye in artist Rembrandt van Rijn's famous 17th-century painting, "Susanna and the Elders," according to a new study.

To learn more about how the Dutch painter created his masterpiece, art historians and researchers recently compared two imaging techniques that revealed hidden layers in the nearly 400-year-old painting.

The oil painting, dated and signed in 1647, hangs in Gemäldegalerie, an art museum in Berlin, Germany. The painting illustrates the biblical story of Susanna, who is caught bathing by a group of elders and is blackmailed into coming with them. In the tale, Susanna refuses, and the elders are undone by their lies. [Gallery: Hidden Gems in Renaissance Art]

Using two imaging techniques, the researchers found that the painting has a "considerable number of overpainted features," they wrote in the study. For instance, Rembrandt redrew one of the Elder's arms from his original draft. They also identified a number of chemical elements used in the pigments, such as manganese and iron in the earth-colored pigments, white lead in the distinct whites and mercury in the painting's vermillion-red pigments.

But the researchers didn't choose to study "Susanna and the Elders" on a whim. Earlier research had already revealed that Rembrandt had labored over the painting, redrawing figures as he perfected the piece.

In the 1930s, researchers took an X-ray of the painting. The results showed that the work of art was replete with pentimenti, or changes the artist made to the painting as he carefully crafted the final scene. (Pentimenti comes from the Italian verb "pentire," which means "to repent.")

Researchers found even more concealed details in 1994, when they used neutron activation autoradiography. This technique involves using a nuclear research reactor to blast the painting with neutrons. By seeing how the neutrons interact with the painting, the researchers can determine what elements are present in the pigments, with the exception of lead-based pigments.

The painting was also small enough that the researchers of the new study could complete X-ray scans within a single day at the museum in Berlin. Then, they compared their findings with the previous scans of the painting, and tested which method provided the best results.

Interestingly, the elements identified from the X-ray scans were the easiest to interpret, the researchers said. This is likely because many of the individual elements are clearly separated in the results. This technique, known as macro X-ray fluorescence, can also be used to study a broader range of chemical elements compared to autoradiography, they said.

But macro X-ray fluorescence analysis isn't perfect. It can only detect bone black (a carbon-based black pigment) on a painting's surface, not on its underlayers, which means the scanning technique misses hidden, preliminary sketches, the researchers said.

In contrast, autoradiography is a good tool for detecting phosphorus (present in bone black) and pigments like umber (dark-yellow brown), copper-based greens and blues, smalt (blue) and vermilion. However, it's less adept at identifying calcium, iron and lead in pigments.

But, when combined with X-ray scanning, autoradiography can help detect single brush strokes — an important factor in learning about an artist's technique.

"Given the relatively short time and less effort required for investigations using X-ray fluorescence scans, this technique is expected to be applied more frequently in the future than autoradiography," study lead researcher Matthias Alfeld, a researcher at the University of Antwerp in Belgium, said in a statement.

However, Alfeld added that autoradiography is still a useful tool that can "visualize the distribution of certain elements through strongly absorbing covering layers — both methods ultimately provide complementary information. This is especially true for phosphorus, which was found present in the sketching of the painting investigated."

The study was published online Tuesday (April 14) in the journal Applied Physics A: Materials Science and Processing.

Follow Laura Geggel on Twitter @LauraGeggel. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

Two colliding galaxies are lit up like a Christmas tree in a dazzling new NASA photo.

The new image, which was released Thursday (Dec. 11), shows "ultra-luminous X-ray sources" (ULXs) studding the spiral galaxies NGC 2207 and IC 2163, which are grazing each other about 130 million light-years from Earth, in the constellation Canis Major.

The photo is a composite that combines data from three NASA spacecraft — the Chandra X-ray Observatory (X-ray light, colored pink); the Hubble Space Telescope (optical light, appearing as blue, white, brown and orange); and the Spitzer Space Telescope (infrared light, colored red), NASA officials said.

While the exact nature of ULXs isn't known for sure, astronomers think they're probably a special type of X-ray binary — a system in which a star circles either a super-dense stellar core called a neutron star or a stellar-mass black hole.

"The strong gravity of the neutron star or black hole pulls matter from the companion star.  As this matter falls toward the neutron star or black hole, it is heated to millions of degrees and generates X-rays," NASA officials wrote in a description of the new photo.

"The black holes in some ULXs may be heavier than stellar-mass black holes and could represent a hypothesized, but as yet unconfirmed, intermediate-mass category of black holes," they added.

NGC 2207 and IC 2163 are active and exciting targets for astronomers. To date, researchers have counted 28 ULXs in the two galaxies, which have also been home to three supernova explosions in the last 15 years.

Galaxy collisions are known to spawn intense bouts of star birth; shock waves generated during such interactions cause clouds of gas and dust to collapse, forming star clusters, researchers said. Indeed, NGC 2207 and IC 2163 are forming the equivalent of 24 new suns every year, compared to one to three suns per year in the Milky Way.

The ULXs in NGC 2207 and IC 2163 likely contain very young stars, perhaps just 10 million years old or so, researchers said. Earth's sun, in contrast, is 5 billion years old and is just about halfway through its life. 

A study detailing these results has been accepted for publication in The Astrophysical Journal.

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

The Chilean devil ray has always been considered a shallow-water swimmer, but new research shows that the species frequently dives to depths of more than 6,000 feet (1,800 meters), likely in search of food.

Prior to this research, marine biologists thought Chilean devil rays (Mobula tarapacana) did not descend below 3,280 feet (1,000 m). However, new satellite tracking data now shows that these rays are among the deepest-diving marine animals. Researchers think the rays spend most of their time in shallow water to warm themselves, and then dive down to extreme depths in search of small crustaceans and fish to eat.

"The fact that they were traveling so far horizontally was not necessarily surprising, but the diving behavior was very surprising," Simon Thorrold, a senior scientist at Woods Hole Oceanographic Institution in Woods Hole, Massachusetts, told Live Science. "What they're doing down there is the big unknown." [In Photos: The Wonders of the Deep Sea]

It's common for ocean predators to dive into the mesopelagic zone, a stretch of ocean water 656 to 3,280 feet (200 to 1,000 m) below the surface, to feast on squid and krill. But few predators make it deeper than the mesopelagic zone to the bathypelagic zone. The bathypelagic zone is a huge food resource, home to an estimated 10 billion tons of prey fish, but few ocean predators can withstand the extreme pressure, cold temperatures and low oxygen levels. 

In deep ocean zones, the water can be as cold as 37 degrees Fahrenheit (3 degrees Celsius). Deep-diving ocean predators must maintain a higher brain temperature than the surrounding water, so they are equipped with a special organ called the rete mirabile. The organ functions as a heat-exchange system that warms the animal's brain and helps it function better in the extreme cold. The organ also helps the animal see better when it's hunting in deep, dark waters.

Scientists were puzzled as to why Chilean devil rays, believed to be surface dwellers, had the organ. Researchers originally suggested that the rete mirabile helped to cool the brains of the rays living in the warm and shallow tropical waters.

Researchers tagged 15 Chilean devil rays off the coast of northern Africa and tracked them for nine months. The satellite data revealed that the rays can reach depths of around 6,560 feet (2,000 m), where temperatures can drop as low as 37 degrees Fahrenheit.

The rays typically hover just a few feet below the surface for about an hour, before descending deep into the cold water. Most of the dives followed the same pattern. The rays would first dive to the maximum depth, and then ascend slowly in a stair-step pattern. The researchers think this stair-step pattern allows the rays to hunt for prey that usually travel in layered clumps in the bathypelagic zone. The dives lasted between 60 and 90 minutes, and the rays usually only made one dive in a 24-hour period.

Thorrold and the researchers think the devil rays likely dive for food, because the rays exhibit the same quick-descent and slower-ascent diving behavior that other ocean predators (such as sharks) use when hunting. However, more research is needed to confirm this idea, the researchers said.

Most of the dives happened during the day. This is likely because the rays can warm up more during the day and because prey are easier to catch during the day, when they travel in clumps, rather than at night, when they are more spread out, Thorrold said.

This is the only species of Mobula rays that researchers have observed diving. The scientists hope that more research into these marine creatures' behavior will reveal insights about the relationship between marine animals and different ocean zones.

The details of the discovery are published today (July 1) in the journal Nature Communications.

Follow Kelly Dickerson on Twitter. Follow us @livescience, Facebook & Google+. Original article on Live Science.

An 8-year-old boy in Australia had high levels of lead, a toxic metal, in his blood for more than two years for unexplained reasons, until doctors found lead pellets in his body, trapped in an unlikely place, according to a new report of his case.

Doctors had tested the boy for toxins in looking for the cause of his unusually hyperactive behavior. They found levels of lead in his blood ranging from 17.4 to 27.4 microgram per deciliter, much higher than the level of 5 micrograms considered normal. But the source remained mysterious -- doctors couldn't find what the boy might have been touching, inhaling or eating, to have such high lead levels for months.

When the boy started to have a stomachache and was admitted to the hospital, the doctors did an x-ray, which revealed large numbers of small round objects in the boy's abdomen, according to the researchers, who published a case report in Aug. 8 issue of the New England Journal of Medicine. [9 Weird Ways Kids Can Get Hurt ]

The metallic-looking objects were in the lower right side of the boy’s abdomen, appearing to be inside the digestive tract. The doctors immediately gave the boy a bowel washout, which should have cleared any object within his digestive tract, but a second x-ray showed the objects had not moved.

The doctors suspected the unlikely scenario – the objects had to be in the boy's appendix.

In surgery, the doctors removed the boy’s appendix and cut it open, revealing 57 lead pellets trapped inside. "It's one of those things you only see once in a life time," Dr. Ibrahim Zardawi, the pathologist who examined the appendix, told LiveScience. "I've been in medicine for almost 40 years now, and had never seen anything like this."

The boy’s appendix weighed 5 times heavier than normal when containing the pellets, but other than few tissue scars, it was normal and wasn’t inflamed. [See the image of the appendix with the pellets inside ]

It is highly unlikely for external objects to end up in the appendix, Zardawi said. Sometimes small fruit seeds such as tomato seeds may find a way through, but it’s a puzzle as to how so many pellets entered and became stuck in the boy's appendix, he said. The pellets likely came from the geese the boy’s family regularly hunted and ate, they later told the doctors. The boy and his siblings said they had been eating the pellets as part of a game they played, to make the pellets disappear.

Lead is a heavy metal used in manufacturing batteries and plastics. It is strongly poisonous to humans when ingested or inhaled. Once in the body, lead circulates in the blood and small amounts can be excreted through urine or feces, but some can remain in the tissues, organs and bones. Symptoms of severe lead poisoning include confusion, seizures, coma and death.

"One important question to ask is, why not use copper pellets?" Zardawi said. The pellets used to kill the birds usually stay inside the animal, and the lead can be dangerous to other animals and to whoever eats the meat. The whole family had high levels of lead, he said.

Consuming just one lead pellet could have been enough to make the child seriously ill, Zardawi said.

In another case of lead poisoning from a mysterious source, a 4-year-old boy was brought to a hospital in Knoxville, Tenn., with symptoms of lead poisoning. As detailed in the report of his case, published in 1994 in the Journal Pediatric Surgery, it took the doctors several rounds of x-rays and bowel washouts to finally find a lead pellet trapped in his appendix.

Email Bahar Gholipour. Follow LiveScience @livescience, Facebook & Google+. Original article on LiveScience .

Dr. Helise Coopersmith is a musculoskeletal and body imaging radiologist for the North Shore-LIJ Health System, assistant professor of radiology at the Hofstra North Shore-LIJ School of Medicine and a member of the Hofstra medical school's admissions committee. She contributed this article to LiveScience's Expert Voices: Op-Ed & Insights.

I have worked as a musculoskeletal radiologist for many years and have seen a wide range of bone injuries. But recently, I found myself for the first time using my X-ray table to look at a 2,500-year-old bone and a piece of an ancient arrow.

The bone, discovered in Northern Greece, was brought to me by Anagnostis Agelarakis, a professor and chair of anthropology at Adelphi University. It was a section of the ulna bone, which is the inner of two forearm bones. 

My initial impression was surprise. Although the outer region of bone, the cortex, was thinned by time, and the inner region, the medullary cavity, had long since disintegrated, the girth and contours of the bone were quite similar to a human bone one would see today. [Images: Ancient Mural Tomb Discovered in China ]

But, most notably, there was a turquoise-colored object jutting out from the bone, and according to Agelarakis, this was one of four sides of a bronze arrowhead. He proposed that this piece of the arrowhead was never removed by the field surgeons of the time because a barbed component anchoring it into the bone would have damaged the superficial soft tissues if removal were attempted.

Beside my X-ray table, I had a photograph of the re-assembled skull that was found with the ulna bone and a sketch by scientific illustrator Argie Agelarakis (Anagnostis's wife) of what the soldier's face may have looked like around the time of his eventual death, presumably at about 58 to 62 years of age.

My team and I took three X-rays of the ulna bone, and we found that indeed the films confirmed what Anagnostis Agelarakis had suspected.

There was a barbed component to the arrowhead that could not be seen with the naked eye. The full extent of the remaining arrowhead could now be seen and was seated superficially within the bone, located only within the cortex, or outer shell. This supported Agelarakis's notion that the arrowhead could have been removed if not for its barbed component.

There was a large bony (osseous) spur adjacent to the arrowhead, which make sense as the human body can form extra bone material in response to trauma. Such spurs take many months to fully mature, which implies that the soldier lived for a long time after the injury. Also, there was no bony erosion adjacent to the arrowhead, confirming that the arrowhead did not cause life-threatening infection. [The 7 Biggest Mysteries of the Human Body]

We also noted that the arrowhead and the osseous spur were in the region of the flexor digitorum profundus muscle, which means the injury would have made it difficult for the soldier to flex his fingers and grasp objects.

There was a story behind the objects we were seeing, the story of an ancient Greek warrior who was an injured veteran, like many who are celebrated today and served by the hospital I work in.

It is amazing to think that the same X-ray technology that we use to diagnose conditions for our patients can answer age-old questions and help solve historical mysteries.

The views expressed are those of the author and do not necessarily reflect the views of the publisher. This article was originally published on LiveScience.com.

Black holes may have been abundant among the first stars in the universe, helping explain the origin of the supermassive monsters that lurk at the heart of galaxies today, researchers say.

An international team of astronomers has found that black holes likely contributed at least 20 percent of the infrared cosmic background, light emitted 400 million to 800 million years after the Big Bang that created our universe 13.8 billion years ago.

These early pioneers may have been the seeds that later grew into supermassive black holes, which contain millions to billions of times the mass of our sun, researchers said. [Gallery: Black Holes of the Universe]

"It's a relief to find a possible signature of these seeds," study co-author Guenther Hasinger, director of the Institute for Astronomy at the University of Hawaii in Honolulu, told SPACE.com.

The earliest black holes

Black holes possess gravitational fields so powerful that not even light can escape. They are generally believed to form after a star dies in a gigantic explosion known as a supernova, which crushes the remaining core into a tiny but incredibly dense volume.

It's unclear how black holes grow to supermassive proportions, but they can apparently do so quite rapidly. For example, some of them were apparently already well-established by 800 million years or so after the Big Bang.

To learn more about the earliest stars and the first black holes, the study team analyzed X-ray and infrared signals using NASA's Chandra X-ray Observatory and Spitzer Space Telescope, respectively.

The X-rays that Chandra saw likely came from matter that became superheated as it rushed into black holes, researchers said. The infrared rays Spitzer detected, on the other hand, make up the cosmic infrared background, the collective light from clusters of massive stars in the universe's first stellar generations after the Big Bang, as well as from black holes, which generate vast amounts of energy as they devour gas.

The investigators focused on a region known as the Extended Groth Strip, a well-analyzed slice of sky slightly larger than the full moon in the constellation Bootes. They concentrated on spots that shone powerfully in both infrared and X-ray light. Black holes are the only plausible sources that can produce both forms of light at the intensities they looked at, scientists said.

"This measurement took us some five years to complete and the results came as a great surprise to us," lead author Nico Cappelluti, an astronomer with the National Institute of Astrophysics in Bologna, Italy, and the University of Maryland, Baltimore County, said in a statement.

"Our results indicate black holes are responsible for at least 20 percent of the cosmic infrared background, which indicates intense activity from black holes feeding on gas during the epoch of the first stars," co- author Alexander Kashlinsky, of NASA's Goddard Space Flight Center in Greenbelt, Md., said in a statement.

How monsters grow

These early objects could help explain the origins of supermassive black holes, researchers said, and also shed light on another puzzle from the universe's youth — a stage known as reionization.

During this era between about 150 million to 800 million years after the Big Bang, radiation ionized the neutrally charged hydrogen pervading the universe to its constituent protons and electrons.

"It is currently thought generally, although not unanimously, that stars were responsible for reionization," Kashlinsky told SPACE.com. "Our result indicates that black holes were a significant, potentially dominant, contributor to that process."

It remains uncertain how massive these early black holes were. They could be mini-quasars containing a few tens of thousands of solar masses, born from the collapse of giant clouds of gas and dust. Or they could be micro-quasars a few hundred solar masses large spawned from massive dying stars.

Mini-quasars would be heavily obscured by clouds and thus likely would not factor into reionization very much, while micro-quasars could easily pump out enough radiation to make a key contribution, Hasinger said.

The Euclid mission from the European Space Agency and the eROSITA mission from Russia and Germany might be able to shed more light on these early black holes. In addition, NASA's upcoming James Webb Space Telescope might be able to see these objects individually, confirming whether they are mini-quasars or micro-quasars, Hasinger said.

This story was provided by SPACE.com, a sister site to LiveScience. Follow us @Spacedotcom, Facebook or Google+. Originally published on SPACE.com.

NASA will reveal new findings about black holes during a news conference Wednesday (Feb. 27).

The news conference, which starts at 1 p.m. EST (1800 GMT) Wednesday, will relay results based primarily on observations made by two X-ray space telescopes: NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) and the European Space Agency’s XMM-Newton observatory, NASA officials said.

The scientists participating in the briefing are:

• Fiona Harrison, NuSTAR principal investigator at Caltech in Pasadena
• Guido Risaliti, astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.
• Arvind Parmar, head of Astrophysics and Fundamental Physics Missions Division, European Space Agency

NASA will stream audio of the teleconference, along with participants' visual aids, live at http://www.ustream.tv/nasajpl2. SPACE.com will carry the NASA feed here.

The $165 million NuSTAR observatory launched in June 2012, kicking off a planned two-year mission to study the universe in high-energy X-ray light. The telescope's observations should help scientists better understand galaxy formation, black hole growth and other phenomena, mission team members have said.

XMM-Newton is a grizzled space veteran by comparison. The telescope launched in December 1999 and has been probing X-ray emissions around the universe ever since.

This story was provided by SPACE.com, a sister site to Live Science.  Follow SPACE.com senior writer Mike Wall on Twitter @michaeldwall or SPACE.com @Spacedotcom. We're also on Facebook and Google+.

This Behind the Scenes article was provided to LiveScience in partnership with the National Science Foundation.

Buried in ancient Chinese tombs, money trees are bronze sculptures believed to provide eternal prosperity in the afterlife.

One money tree was crafted in southwest China during the Eastern Han Dynasty (25-220 CE). Supported by a ceramic base, this rare piece of art stands 52 inches tall and spans 22 inches wide. Dragons and phoenixes — symbols of longevity — and coins decorate the tree's 16 bronze leaves.

The Portland Art Museum acquired the tree as a gift from a private collection. There was little information available about the tree and no documentation as to the time or place of its excavation. It was also unclear whether the tree had all of its original parts from the Han Dynasty or if replacement parts had been added. Nor were the artistic details fully visible, due to layers of corrosion.

The museum partnered with assistant professor of chemistry Tami Lasseter Clare and her team from Portland State University to learn more about the tree and its mysterious past.

Clare had several goals:  identify points of breakage in the tree and determine how to prevent breakage in the future;  identify the tree's material composition to see if it dated to the Han Dynasty;  identify the corrosion products and layers of materials that accumulated over time and, determine if all parts of the tree were original.

The benefits of this research are largely educational, Clare said. "Many major museums employ scientists who study similar issues; however, no museums in the Pacific Northwest do. This project was a rare opportunity to collaborate with the Portland Art Museum and to demonstrate what 'secrets' can be learned using scientific methods." Clare also explained that some of the research findings are featured in an exhibition at the Portland Art Museum, "which is an exciting outcome for this work."

Clare and her team used various techniques to "look beneath the surface" of the tree and determine the chemical composition. They used X-radiography, which is an imaging technique that uses X-rays to study an object or materials' structure and composition. The X-rays pass through different parts of the sample object or material and an image is recorded based on how the varying parts of the sample absorb radiation. The images are displayed in different tones depending on the intensity of the X-ray. This process is especially useful for examining metal objects, such as the tree, covered by corrosion, as well as paintings with multiple layers of paint, biological samples and other objects and materials with multiple layers.

Using this technique, the team identified weaknesses and cracks in the tree and areas that needed extra reinforcement and handling care. This information also helped determine areas of the tree that might be prone to future breakage.

In addition, the team used X-ray fluorescence spectroscopy and fourier transform infrared micro-spectroscopy to identify the tree's chemical composition and the encrustations, or what Clare explains are "the layers of material that adhered to its branches as a result of its presumed burial, often composed of sand, calcite and corrosion products." XRF is specifically used to find the elemental composition of solid materials using an X-ray beam, and FTIR is used to determine various types of infrared spectrums that can identify and study chemicals.

These techniques helped the team learn valuable information about the money tree and its history. They determined it was made using cast bronze, each piece of the tree produced via molten bronze set in a two-part mold.

They also learned that the tree was buried in the ground at some point. Clare observed "thin, almost hair-like roots" that grew within or on top of the encrustation layers of the tree. Some of the roots were covered in a crust of calcite, or calcium carbonate. Further evidence that the tree was buried included some of the corrosion products on the tree — azurite (a copper mineral) and malachite (a copper carbonate hydroxide mineral) — which are common minerals found on bronze objects buried in the ground.

Although encrustations and corrosion products helped prove that the tree spent time underground, they were covering artistic details of the tree. Using X-radiography, the team learned that encrustations covered the entire figures of two monkeys holding bananas, and also the outlines of dragon gills and eyes that form the "foliage" on the branches.

Encrustations were not the only additions that transformed the tree over time.

The team determined that the tree was repaired numerous times in the past with replacement parts that did not match the originals. The replacement parts were made with a different method, had a different chemical composition and lacked the design detail of the original.

"The numerous and distinct repair methods suggest that the [tree] may have changed hands several times, though the record of ownership is not known," said Clare.

Instead of bronze casting, the repairers manufactured replacement parts using mechanical cutting tools and abrasives. They attached the pieces to the original tree using lead-tin solder, a fusible metal alloy. Via X-ray fluorescence and infrared spectroscopy, the team also learned that the chemical composition of the replacement parts was different than the composition of the original. These tenons — pieces that fit into notches and attach branches to the trunk or one another — were more likely to break because they carried the weight of the branches.

While those who repaired the tree attempted to make the replacement parts blend in with the original, their efforts were ultimately in vain.

"Interestingly, the replaced parts had been painted to match the blues and greens of corroded bronze and the white color of the encrustation layers, showing that whoever made the replacements didn't want those pieces to be visibly different from the others, probably to increase the market value of the tree," said Clare.

Currently the money tree is at the Portland Art Museum as part of an exhibition, "Cornerstones of a Great Civilization," which features Chinese art masterpieces. The exhibition will run through Nov. 12, 2012.

Editor's Note: The researchers depicted in Behind the Scenes articles have been supported by the National Science Foundation, the federal agency charged with funding basic research and education across all fields of science and engineering. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation. See the Behind the Scenes Archive.

Scotch tape, that transparent, sticky hero of offices everywhere, could be a NASA superstar as well.

The rolled-up adhesive tape is the inspiration behind a novel idea for a completely new kind of X-ray mirror for big telescopes in space. The concept, dreamed up by NASA scientist Maxim Markevitch, is this: Instead of building an expensive telescope mirror to capture high-energy "hard" X-rays in space, why not create a mirror from tightly rolled plastic tape at a much lower cost?

"I remember looking at a roll of Scotch tape and thinking, 'Was it possible to use the same design for capturing hard X-rays?'" Markevitch explained in a NASA statement. "I talked with a few people, and to my surprise, they didn't see any principal reasons why it couldn't be done."

Markevitch and a team of other X-ray space optics experts at NASA's Goddard Space Flight Center in Greenbelt, Md., have begun testing materials that could be used to build a rolled mirror sensitive enough to collect hard X-rays from deep space. [Giant Space Telescopes of the Future (Infographic)]

Capturing 'hard' X-rays

Several space telescopes already scan the heavens for X-rays today, including NASA's Chandra X-ray Observatory and black hole-hunting NuSTAR instrument, as well as Japan's New X-ray Telescope (which is also known as Astro-H).

But Chandra is sensitive to lower-energy "soft" X-rays, and NuSTAR and Astro-H have limited collecting areas that allow them to only "graze the surface" of possible discoveries in the hard X-ray realm, Markevitch said.

To really do the job, scientists need an imaging X-ray telescope with a collecting area perhaps 30 times larger than that of NuSTAR, he added. If such a telescope could be built, it could study galactic cosmic rays, super-fast subatomic particles generated in deep space.

Scientists believe cosmic rays and the magnetic fields between galaxy clusters can alter the physics within clusters. A better understanding of these physics could reveal more about the birth and evolution of the universe, Markevitch said.

But a telescope capable of making such finds using current technology — which would require building a large number of individual mirror segments, coating them with reflective material and them nesting them precisely inside an optical assembly — doesn't appear to be coming along anytime soon.

"However, to our knowledge, nothing of the kind is planned or even proposed in the U.S. or elsewhere because of the cost something like this presents," Markevitch said.

Just a concept — for now

Markevitch and his team hope a new way of thinking could help push such a project along.

Their idea calls for coating plastic tape on one side with multiple layers of reflective material, then winding the tape into a roll to form a large number of densely packed nested shells. This process could theoretically create a mirror with a huge collecting area, Markevitch said.

While the team is currently testing candidate materials, the idea is still a long way from getting off the ground.

"Maxim's Scotch tape idea is in an early stage," said team member Will Zhang, also of NASA Goddard. "In the next year, we will know whether it has a chance of working." If the tape does indeed work, it could be "game-changing for hard X-ray astronomy," Markevitch said. "It could significantly reduce the cost of building large mirrors, bringing within reach the possibility of building a mirror with 10 to 30 times greater effective area than current X-ray telescopes."

This story was provided by SPACE.com, a sister site to LiveScience.  Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

People who've had frequent dental X-rays may have an increased risk of developing meningioma, a type of brain tumor, new research suggests.

People in the study with meningioma were twice as likely as tumor-free individuals to report ever having a "bitewing" exam, which requires a patient to bite down to hold an X-ray film in place while a device photographs a portion of the mouth.

While the study suggests an association between dental X-rays and risk of meningioma, it doesn't show the radiation actually causes brain tumors, researchers said. Moreover, the cancer remains rare — about 6,500 people are diagnosed with meningioma yearly in the U.S., according to the University of California, Los Angeles.

The researchers also pointed out that the study looked at X-rays performed in the past, when dental radiation exposure was greater than it is now, because of new guidelines and technology.

Still, "if there's a potential that extended exposure to dental X-rays is associated with meningioma risk, and this risk can be moderated by fewer screenings, then I think there's an important public health interest here," study lead author Dr. Elizabeth Claus, a professor of public health at Yale University, told MyHealthNewsDaily.

Meningioma risk

Meningioma is a noncancerous tumor in the protective linings of the brain and spinal cord that can cause blurry vision, seizures and loss of coordination.

The causes of meningioma are not well-understood, but the most consistently identified environmental risk factor is exposure to ionizing radiation, which includes radiation from atomic bombs and radiation therapy.

Dental X-rays are the most common artificial source of ionizing radiation, Claus explained, adding that previous research has suggested a link between the brain tumor and dental X-rays, but those studies were small, involving at most a few hundred participants.

In the new study, Claus and her colleagues interviewed 1,433 people who were diagnosed with meningioma between 2006 and 2011. They also spoke with 1,350 people who didn't have condition, but were similar to the meningioma patients in terms of age, sex and where they lived.

In a questionnaire, study participants reported how often they received bitewing, full-mouth and panorex films (which are taken from outside the mouth) during four periods of their lives: younger than 10 years old, between ages 10 and 19, between ages 20 and 49 and older than age 50.

"A fair number of people said they got X-rays every six months in the past; most commonly, they were getting it every year," Claus said. The American Dental Association guidelines suggest children get X-rays once every 1 to 2 years, teens every 1.5 to 3 years, and adults every 2 to 3 years. "It's clear that many people were not aware of the guidelines."

The researchers found that people who had bitewing exams done on a yearly basis or more often when they were younger than 10 years old were 1.4 times more likely to get meningioma than people who never had the exam during those years. This risk jumped to 1.9 for those getting the exams done yearly between ages 20 and 49.

They also found an elevated meningioma risk with panorex exams — patients who ever received such films when younger than 10 years old had a 4.9 times increased risk of the brain tumor compared with those who didn't get the x-rays. Fewer patients in the study reported receiving these exams, compared with those who reported receiving bitewing exams.  

Cost-benefit analysis

Dr. Keith Black, a neurosurgeon at the Cedars-Sinai Medical Center in California who was not involved in the research, said he was impressed with the breadth of the research and that the findings fit nicely with those of previous smaller studies. A lingering question, however, is "whether there's an increased risk in the pediatric population," he said. 

It may be the case that children have an increased risk of meningioma compared with teens and adults. "Children's tissues are thinner than adults," Black said. "Also, their cells are dividing more rapidly, and can be more easily damaged by X-rays." 

People should carefully weigh the risks with the benefits of getting dental X-rays, which can spot such issues as decay, gum disease and oral abscesses, said Black, who's declined getting routine dental X-rays for more than 20 years.

Claus said she is concerned that patients and maybe even some dentists don't know the dental X-ray guidelines.

"We need to just get the word out and make people aware of the guidelines and talk with their dentists about it," Claus said.

The study is published today (Apr. 10) in the journal Cancer.

Pass it on: Frequent past exposure to dental X-rays is associated with an increased risk of developing meningioma.

This story was provided by MyHealthNewsDaily, a sister site to LiveScience.

A massive supernova explosion that destroyed a faraway star apparently turned the left over stellar corpse inside out as well, scientists say.

Using NASA's Chandra X-ray Observatory spacecraft, a team of researchers mapped the distribution of elements in the supernova remnant Cassiopeia A (Cas A for short) in unprecedented detail. They found that Cas A — which is located about 11,000 light-years from Earth and exploded 300 years ago from our perspective — is wearing its guts on the outside.

Before it went supernova, the star Cas A likely had an iron-rich core that was surrounded by layers of sulfur and silicon, which were in turn overlaid by magnesium, neon and oxygen, researchers said.

Chandra's observations showed that, after the explosion, most of that iron has now migrated to Cas A's outer edges. Neither Chandra nor NASA's Spitzer Space Telescope, which is optimized to see in infrared wavelengths, has detected any iron near the supernova remnant's center, where the element was originally formed.

Further, much of the silicon, sulfur and magnesium are now found on the outside of the still-expanding debris shell. Neon distribution hasn't changed much, and not much can be said about the oxygen because its X-ray emissions are strongly absorbed along the line of sight to Cas A.

Overall, this distribution of elements suggests that an instability in the supernova explosion process somehow turned the star inside out, researchers said. These latest Chandra observations, which are based on more than 11 days of observing time, are the most detailed study ever made of X-ray-emitting debris in Cas A, or in any other supernova remnant, they added.

The researchers estimate that the total amount of X-ray emitting debris has a mass just over three times that of our sun. Researchers found clumps of almost pure iron, indicating that this material must have been produced by nuclear reactions near the center of the pre-supernova Cas A.

The study's findings are detailed in the February edition of the The Astrophysical Journal.

The Chandra X-ray Observatory launched aboard the space shuttle Columbia in 1999 and has been observing the heavens ever since. It's one of NASA's "Great Observatories," a class of space telescopes that also includes Spitzer and the iconic Hubble Space Telescope.

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Black holes, neutron stars and supernova remnants won't be able to hide in the fog of space for much longer.

NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) mission — which is due to launch sometime this spring, though the agency has yet to pin down a date — will pierce the dust and gas shrouding sources of high-energy X-rays, revealing many secrets they have long managed to conceal, scientists say.

Although telescopes such as NASA's Chandra X-ray Observatory have probed the skies with X-rays before, these other instruments have focused on lower-energy bands.

"NuSTAR is going to be the first focusing high-energy X-ray telescope," said mission principal investigator Fiona Harrison of the California Institute of Technology. [Photos: NuSTAR, NASA's Black-Hole-Hunting Space Telescope]

Extreme events

The NuSTAR mission's increased sensitivity will allow it to probe the hearts of other galaxies for some of their most violent and mysterious objects, such as black holes.

Black holes form when a dying star collapses in on itself. As the stellar remnant becomes smaller and more dense, its gravitational pull becomes so strong that not even light can escape.

But as dust and gas fall inward, friction and other forces heat the material to millions of degrees. The resulting X-rays, detectable to NuSTAR, should allow astronomers to calculate how fast black holes are spinning, and understand more about how they formed, researchers say.

Some material also shoots away from black holes in jets approaching the speed of light. The accelerated particles can vary in brightness over the course of time, and NuSTAR will be able to study how they change.

While NuSTAR will study some black holes in distant galaxies, it will also make observations closer to home. "There is a black hole that's four million times the mass of the sun at the heart of the Milky Way," Harrison told SPACE.com. "It doesn't emit a lot of radiation, for reasons that are somewhat mysterious."

Occasionally, black holes "burp" or "hiccup," giving off a burst of radiation for unknown reasons. Observing the black hole in the high-energy X-ray spectrum should provide more clues about how this local black hole works, researchers say.

Supernovas, too

Black holes aren't NuSTAR's only targets.

"We're also looking at the remnants of stars that have exploded," Harrison said.

Called supernova remnants, the leftover guts of stellar objects can reveal insights into the inner workings of massive stars before they blow.

"We can still see [the material] glowing with radioactivity," Harrison said.

The radioactive leftovers can tell scientists about how the star exploded, and how the materials inside them were formed. Since all elements other than hydrogen and helium were created inside stars and spread into space by supernova explosions, such insights can provide clues about the formation and evolution of the universe, researchers say.

A new technology

High energy X-rays are tough for scientists to work with because they are so difficult to measure, Harrison said.

"The energy range we're talking about for X-rays is the same energy range your doctor or dentist uses to image through skin and see your bones," she said. "High-energy X-rays — or X-rays in general — will only reflect off surfaces at very glancing angles."

Harrison compared this reflection to skipping a stone off the surface of a pond.

Instead of a flat surface, NuSTAR uses 133 nested shells in each of two telescopes. Like Russian dolls, the shells — which are each about as thick as a fingernail — lie inside of one another. As X-rays pass between the layers, they are guided down to the detector.

In comparison, Chandra has only four shells, and each one is approximately 1 centimeter thick.

The increased number of shells makes NuSTAR 10 times sharper and 100 times more sensitive than any previous high-energy X-ray telescope, all in a compact, 33-foot (10-meter) package.

"NuSTAR is going to be a tremendous breakthrough, but it's also done on NASA's smallest astrophysics platform, Small Explorers," Harrison said. "It shows you can still do unique and new things on small missions."

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The gigantic black hole at the heart of our Milky Way galaxy may be devouring asteroids on a daily basis, a new study suggests.

For several years, NASA's Chandra spacecraft has detected X-ray flares about once a day coming from our galaxy's central black hole, which is known as Sagittarius A* (Sgr A* for short). These flares may be caused by asteroids falling into the supermassive black hole's maw, according to the study.

"People have had doubts about whether asteroids could form at all in the harsh environment near a supermassive black hole," study lead author Kastytis Zubovas, of the University of Leicester in the United Kingdom, said in a statement. "It's exciting because our study suggests that a huge number of them are needed to produce these flares."

Asteroids circling a black hole

Zubovas and his colleagues suggest that a cloud around Sgr A* contains trillions of asteroids and comets that the black hole stripped from their parent stars.

Asteroids passing within about 100 million miles (160 million kilometers) of the black hole — roughly the distance between the Earth and the sun — are likely torn to pieces by Sgr A*'s gravity, according to the study. [Photos: Black Holes of the Universe]

These fragments would be vaporized by friction as they encounter the hot gas flowing onto the black hole, much as meteors are burned up by the gases in Earth's atmosphere. This vaporization likely spawns the X-ray flares, which last for a few hours and range in brightness from a few times to nearly 100 times that of the black hole's regular output, researchers said.

Sgr A* then swallows up what's left of the close-flying asteroid.

"An asteroid's orbit can change if it ventures too close to a star or planet near Sgr A*," said co-author Sergei Nayakshin, also of the University of Leicester. "If it's thrown toward the black hole, it's doomed."

It would take an asteroid at least 6 miles (10 km) wide to generate the flares seen by Chandra, the researchers estimate. The black hole may also be consuming smaller space rocks, but the resulting flares would likely be too faint to observe.

Trillions of asteroids

The new study is in rough agreement with previous modeling work, which has estimated that trillions of asteroids are likely to surround the Milky Way's central black hole.

"As a reality check, we worked out that a few trillion asteroids should have been removed by the black hole over the 10-billion-year lifetime of the galaxy," said co-author Sera Markoff of the University of Amsterdam in the Netherlands. "Only a small fraction of the total would have been consumed, so the supply of asteroids would hardly be depleted."

Sgr A* is probably also devouring planets that stray too close, causing much more powerful X-ray flares than those analyzed in the new study. Such dramatic events are likely rare, since planets are not nearly as common as asteroids, researchers said.

However, scientists may have observed the aftermath of the Milky Way's black hole gobbling up a planet. About 100 years ago, the X-ray output of Sgr A* brightened by a factor of a million. While this event happened before the existence of X-ray telescopes, Chandra and other instruments have seen evidence of an X-ray "echo" reflecting off nearby clouds, researchers said.

The researchers report their results in the Monthly Notices of the Royal Astronomical Society.

This article was provided by SPACE.com, a sister site to LiveScience. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

Viper Moray

A travelling Smithsonian exhibit set to debut in New Haven, Conn. in July reveals the insides of fish in a whole new light. This is a moray eel, a major predator on coral reefs. The image reveals a second set of "jaws" in the eel's throat. These are the gill arches, which support the eel's gills. All fish have gill arches.

Crisscross Prickleback

This crisscross prickleback was preserved in 1910, but the details of its skeleton are still precise 100 years later. These fish live in the Eastern Pacific in rocky intertidal areas, where they snack on crustaceans and mollusks.

Torrent Loach

Not a leech, but a loach: These fish cling to rocks with the crescent-shaped fins on their undersides, keeping them in place in their fast-moving stream habitat.

Wedge-tail Triggerfish

You can call it a wedge-tail triggerfish, or you can do as the Hawaiians do and call it "Humuhumunukunukuapua'a." This reef fish erects its doral spines when threatened, the smaller, shorter spine locking the first into place. When threatened, the fish wedges itself into reef rocks with this quick-deploy system.

Dhiho's Seahorse

This Japanese seahorse is just over one inch (2.5 cm) long. Its curly tail can anchor the seahorse to algae or coral.

Lookdown Fish

It's not hard to see where this fish gets its name. A sloped head makes the lookdown fish look like it's always, well, looking down. Lookdowns like shallow waters in the western Atlantic.

Long-spine Porcupine

Yeowch! When threatened, the long-spined porcupine fish pumps its body full of water, becoming a thoroughly unappetizing pincushion. When the fish relaxes, the spines lay flat against its body.

If you've always thought of fish bones as an annoying barrier to enjoying a salmon fillet, think again. An upcoming exhibit by the Smithsonian Institution reveals the diverse skeletal structures of marine animals from eels to seahorses in beautiful black-and-white.

The X-ray images, set to premiere at the Yale Peabody Museum of natural History in New Haven, Conn., on July 2, are part of the Smithsonian Institution's research on fish evolution. By peering inside the fish without cutting them open, scientists can study the animals' undisrupted skeletons. X-rays may also reveal other hidden details, including undigested food in a fish's stomach. [Slideshow: Fish in X-ray Vision]

The travelling exhibit features 40 dramatic X-rays, laid out from evolutionarily primitive jawless hagfish to complex, spiny-finned species like the striped bass. The exhibit will remain in New Haven until Jan. 8, 2012, when it will embark on a 10-city tour that will last until 2015.

You can follow LiveScience senior writer Stephanie Pappas on Twitter @sipappas. Follow LiveScience for the latest in science news and discoveries on Twitter @livescience and on Facebook.

This Behind the Scenes article was provided to LiveScience in partnership with the National Science Foundation.

Attic pottery is the iconic red and black figure-pottery produced in ancient Greece from the 6th to the 4th centuries B.C. Similar to the vessel shown above, such pottery required immense precision to produce, and the means by which craftsman created these vessels is still not completely understood.

Now, thanks to funding from the National Science Foundation Chemistry and Materials Research in Cultural Heritage Science program, a collaborative group of California scientists from the Getty Conservation Institute (GCI), The Aerospace Corporation, and the Department of Energy's SLAC National Accelerator Laboratory (SLAC) at Stanford is investigating the ancient technology used to create these works of art. From their study of the makeup of this iconic pottery, the researchers hope to further current conservation practice and future space travel.

What does the investigation of ancient ceramic pots have to do with cutting-edge research into future space travel? More than you'd think – it's hard to imagine a more dissimilar pairing, but the technology is actually quite transferrable.

Led by Karen Trentelman, a conservation scientist at the GCI, the grant team is working with conservators and curators from the J. Paul Getty Museum to attribute characteristic material "signatures" to known artists, which should aid the classification of unsigned works. The information will provide a deeper understanding of ancient pottery techniques and inform future conservation methods.

Of importance to aerospace industries, the effort will also create a deeper knowledge of iron-spinel chemistry, which is critical for advanced ceramics found in aerospace applications.

"Ceramic components are used all through space technology and space vehicles." says Mark Zurbuchen, a materials scientist with The Aerospace Corporation. "We need to continue to learn about interactions of components within these materials to help us better understand any real-world issues that may arise in actual space components."

One primary scientific technique the researchers are using is X-ray absorption near edge structure (XANES) spectroscopy, a tool for determining the iron oxidation states in the Attic pottery, which gives the pottery its iconic black and red coloring.

The researchers will also use X-ray absorption fine structure (EXAFS) analyses to provide information on the molecular structure of the iron minerals, and high resolution digital microscopy to study the surface of the works, among other analytical methods.

Aside from the technical aspects of the work, all of the scientists also are keenly interested in the sociological aspects of the work—that is, what impact did these potters have on their community?

For GCI scientist Marc Walton, who helped Trentelman develop the project, the effort is about understanding the society in which these pots were made.

"Using scientific methods, we want to look at the sociological context of ancient Greek workshops and potters and re-establish what we know about these workshops," said Walton.

At SLAC, which houses a high powered X-ray source driven by a particle accelerator called a synchrotron, staff scientist Apurva Mehta is working with the team to reveal nanoscale details across large regions of the pots. According to Mehta, the work will push the development of high-powered tools to probe many other materials, from biomaterials to the electrodes of lithium-ion batteries. His work will also help uncover answers to some important questions.

"There were several workshops making this pottery at the same time," says Mehta. "It's a fairly challenging technology—how was it invented? Did one workshop invent it and other workshops copy, modify and perfect it? Were they collaborating or competing with each other? I want to understand how technology really works in a society. How does a technology grow, how does it transfer from place to place, how does it change, what keeps it alive, why do some technologies eventually die away? Maybe this will help us understand how technologies are growing and changing today."

Using the information gleaned from the scientific studies of ancient vessels as a guide, the group also plans to reproduce the technology used by early artisans, ultimately firing small replicas.

The scientists hope to uncover whether works attributed to different artists used the same methods, or if techniques for creating the work differed amongst workshops producing pots at the same time. The researchers also hope to document how the process evolved over time.

The results are expected to impact a diverse range of fields in both art and science, including materials science, chemistry, archaeology, art history and art conservation.

"By partnering with SLAC and The Aerospace Corporation, we can look at the artwork in a new way," said Trentelman. "Scientific analysis gives us new insight into how and when the work was produced. In turn, our analysis can support hypotheses developed by art historians about ancient workshop practices, and also inform museum conservation efforts. Using nothing but clay dug from the ground, ancient craftsmen were able to create magnificent vessels with amazing detail. Something doesn't need to be complex to be sophisticated. If we can understand the technology with which these works of art were made, we can use the knowledge for a surprisingly wide variety of applications."

This research is funded by the National Science Foundation Chemistry and Materials Research in Cultural Heritage Science program, which supports collaborative research between academic, industrial and cultural heritage institutions. This program was developed out of a workshop jointly sponsored by the NSF and the Andrew W. Mellon Foundation.

Editor's Note: This research was supported by the National Science Foundation (NSF), the federal agency charged with funding basic research and education across all fields of science and engineering. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation.

Hobbits and orcs may exist only in fiction, but a real-life supermassive black hole has spawned a structure that looks strikingly like the evil "Eye of Sauron" from J.R.R. Tolkien's "Lord of the Rings" fantasy novels and the films inspired by them.

The black hole sits at the heart of a spiral galaxy called NGC 4151, which is 43 million light-years from Earth. This composite image stitches together data from several different telescopes, revealing a gigantic structure that astronomers say resembles the all-seeing eye of Tolkien's malevolent wizard Sauron.

In the eye's "pupil," X-rays (blue) from NASA's Chandra X-ray Observatory mix with visible-light data (yellow) from the Jacobus Kapteyn Telescope in the Canary Islands, which show emissions of positively charged hydrogen. The red around the pupil shows neutral hydrogen, detected by radio observations from the Very Large Array in New Mexico, researchers said.

The yellow blobs interspersed throughout the red rim are regions where star formation has recently occurred. [Images: Black Holes of the Universe]

A black hole outburst

The X-ray emission near the galaxy's heart was likely caused by an outburst powered by the supermassive black hole, researchers said. Scientists have proposed two different scenarios to explain the X-ray emission.

One possibility is that the central black hole was growing much more rapidly about 25,000 years ago (in Earth's time frame), researchers said. The radiation produced by material falling into the black hole was so bright back then, according to this theory, that it stripped electrons away from atoms in the gas in its path. X-rays were then emitted when electrons recombined with these ionized atoms. The second scenario posits that material spiraling into the black hole from an accretion disk spawned a vigorous outflow of gas from the surface of this disk. This outbound flow then heated the gas in its path to X-ray-emitting temperatures, researchers said. [Video: Black Holes: Warping Time and Space]

Both of these scenarios predict that an outburst has happened in the relatively recent past. They imply that periods of high activity are common, making up at least 1 percent of the black hole's lifetime, researchers said.

Learning from the Eye of Sauron NGC 4151 is one of the nearest galaxies that contains an actively growing black hole. Because of this proximity, it offers one of the best chances to study the interaction between an active supermassive black hole and the surrounding gas of its host galaxy, researchers said.

Such interaction, or "feedback," is known to play a key role in the growth of supermassive black holes and their host galaxies. If the X-ray emission in NGC 4151 originates from hot gas heated by the outflow from the central black hole, it would be strong evidence for feedback from active black holes to the surrounding gas on galactic scales, researchers said.

With the Eye of Sauron providing so much potentially useful information, perhaps astronomers will now scan the heavens for Gandalf's Staff, or the Mirror of Galadriel.

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This story was provided by SPACE.com, a sister site to LiveScience.

The ultradense core of an exploded star contains a bizarre form of superconducting matter called a superfluid, new studies suggest.

Two teams of researchers using NASA's Chandra X-ray Observatory detected a rapid dip in the temperature of Cassiopeia A (Cas A), which is a neutron star — the remnant left behind when a massive star ends its life in a supernova explosion. The huge temperature drop is solid evidence for the presence of a strange state of matter in the core of Cas A, researchers said.

"The rapid cooling in Cas A’s neutron star, seen with Chandra, is the first direct evidence that the cores of these neutron stars are, in fact, made of superfluid and superconducting material," Peter Shternin of the Ioffe Institute in St. Petersburg, Russia, said in a statement. He is leader of one of the teams.

Superfluids made of charged particles are also superconductors, which allow electric current to flow with no resistance.

A neutron star cools off

Cas A is the remnant of a huge star that exploded about 330 years ago. The neutron star is about 11,000 light-years away, in the constellation Cassiopeia.

Researchers in both of the new studies found that it has cooled by about 4 percent over a 10-year period.

"This drop in temperature, although it sounds small, was really dramatic and surprising to see," said Dany Page of the National Autonomous University in Mexico, leader of the other research team. "This means that something unusual is happening within this neutron star."

Neutron stars are some of the densest known objects. One teaspoon of neutron star stuff has a mass of 6 billion tons. [The Strangest Things in Space]

The pressure in the star’s core is so immense that most of the electrons there merge with protons, producing neutrons, researchers said.

Physicists have developed detailed models to predict how matter should behave at such high densities, including the possibility that superfluids may form.

Superfluidity is a friction-free state of matter, and superfluids created in labs here on Earth exhibit remarkable properties. It can climb upward, for example, and escape airtight containers, researchers said.

Superfluids in dead star's core

In their studies, both research groups found evidence that Cas A's rapid cooling is due to the formation of a neutron superfluid in the neutron star's core, and that this happened within the last 100 years or so.

The details of Shternin's study will appear in the journal Monthly Notices of the Royal Astronomical Society Letters. The reseach by Page and his team will appear in the journal Physical Review Letters.

Cas A's dropping temperatures are consistent with theory, which predicts that a neutron star should undergo a distinct cool-down during the transition to the superfluid state, researchers said.

During this time, nearly massless, weakly interacting particles called neutrinos form in huge numbers and then escape, taking energy with them. The cooling is expected to continue for another few decades before slowing down, researchers said.

On Earth, the appearance of superfluidity in materials occurs at extremely low temperatures, near absolute zero, about minus 273 degrees Celsius (minus 459.6 degrees Fahrenheit). But in neutron stars, it can take place at temperatures near 1 billion degrees F because interactions of particles occur via the strong nuclear force — the force that binds quarks together to make protons and neutrons, and protons and neutrons together to form atomic nuclei.

Until now, there was a very large uncertainty in estimates of this critical temperature. But the new research pins it down to between 900 million and 1.8 billion degrees F (500 million to 1 billion degrees C), researchers said. "It turns out that Cas A may be a gift from the universe because we would have to catch a very young neutron star at just the right point in time," said Page’s co-author Madappa Prakash, from Ohio University. "Sometimes a little good fortune can go a long way in science."

Helping shed light on neutron stars The researchers said their findings suggest that the Cas A supernova remnant can serve as a good test bed for studying how ultradense matter behaves at the atomic level.

These results are also important for understanding the diversity among neutron stars, including pulsation, magnetar outbursts and the evolution of powerful neutron star magnetic fields, researchers said. The new studies could also help scientists better understand small, sudden changes in highly magnetized, rotating neutron stars known as pulsars.

Past studies of the pulsar changes, known as glitches, have yielded evidence of superfluid neutrons in the crust of a neutron star, where densities are lower than in the core.

The new research on Cas A, however, provides the first direct evidence for superfluid neutrons and protons in the core of a neutron star, researchers said.

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This story was provided by SPACE.com, a sister site to LiveScience.

A space telescope has spotted a strange, distant galaxy cluster with a cosmic heart that is surprisingly cold.

NASA's Chandra X-ray Observatory snapped an image of the cluster, which is about 8 billion light-years from Earth. The cluster surrounds a bright object known as a quasar.  This particular quasar is called 3C 186, making it the farthest galaxy cluster with a quasar ever seen. [X-ray image of the cold quasar]

Quasars form at the central regions of some galaxies, where giant black holes gobble up matter so furiously that the remaining stuff around them generates tremendous energy transmissions that span the entire electromagnetic spectrum, including radio waves, light and X-rays. They are some of the brightest objects in the universe.

But the heart of the galaxy cluster studied by the Chandra observatory is only cold in astronomical terms.

The gas at the cluster's center is a mere 30 million degrees Fahrenheit (16.7 million degrees Celsius), while stuff at the outskirts tops out around 80 million degrees Fahrenheit (44.4 million Celsius). While that seems scorching hot to the average human, for quasars it's positively chilly, researchers said.

This drop in temperature occurs because intense X-ray emission from the gas nearer the core cools it down, the researchers added.

The galaxy cluster surrounding quasar 3C 186 is the most distant one ever found containing a quasar. It's also the most distant cluster ever observed with a cooling core. The faraway object could therefore provide insight into how quasars form and clusters grow, researchers said.

Because it took 8 billion years for the cluster's light to reach Chandra's instruments, researchers are seeing it as it appeared when the universe was still relatively young — less than half its current age of about 13.7 billion years.

Previous observations have revealed large numbers of clusters with strong cooling cores closer to Earth, less than about 6 billion light-years. But they appear to be more rare the farther away researchers look.

One reason for this may be that more distant galaxy clusters — which are younger, since astronomers are seeing them at an earlier point in the universe's history — merge more often with other clusters or galaxies, researchers said.

These mergers would destroy the cooling cores. When coupled with the fact that it takes cooling cores a long time to form, this would make them rare in the earlier stages of the universe.

This cluster was found fortuitously via a relatively modest Chandra survey. So it's possible that many other similar objects exist at large distances, researchers said.

The picture of the cluster surrounding quasar 3C 186 is a composite. It includes a new image from Chandra showing X-ray emissions from gas surrounding the point-like quasar near the center. Optical data from the Gemini telescope in Chile contribute views of nearby stars and galaxies.

The research is detailed in the Oct. 10 issue of the Astrophysical Journal.

• Top 10 Strangest Things in Space
• Video: The Black Hole That Made You Possible
• Video: Quasar Interaction

This article was provided by SPACE.com, a sister site of LiveScience.com.

Intro

The average American is exposed about 620 millirem (mrem) of radiation each year, according to the United States Nuclear Regulatory Commission. This radiation comes from both natural and man-made sources.

Half of our yearly dose comes from natural "background radiation" present in the environment. Most of this comes from radon (an odorless, colorless, gas naturally occurring in the air), and smaller amounts come from cosmic rays and the Earth itself, according to the USNRC.

The other half of person's radiation dose comes from man-made sources, which can be medical, commercial or industrial, but medical procedures typically account for 96 percent of a person's man-made radiation exposure, according to the USNRC.

"In general, a yearly dose of 620 millirem from all radiation sources has not been shown to cause humans any harm," according to the USNRC.

So just what around us is contributing to our yearly radiation dose?

Food

All plants and animals contain trace amounts of radioactive potassium-40 and radium-226. In fact, all water contains dissolved radioactive uranium and thorium, according to the USNRC.

However, these amounts are very small. All the food and drink a person ingests over a year add up to about 30 mrem.

The sun

While Earth's atmosphere does a good job of protecting us from the continuous stream of cosmic radiation striking the planet from the sun and stars, some radiation gets through.

Where a person lives determines the amount of cosmic radiation they are exposed to, as differences in elevation, atmospheric conditions and Earth's magnetic field can alter radiation dosage.

For example, a person living in mile-high Denver gets more than 50 mrem every year, compared with the 26 mrem that a resident of sea-level Key West, Fla., gets, according to the Centers for Disease Control and Prevention. Denver's higher altitude means thinner air, which makes it easier for the sun's UV rays to get through.

Air travel

High altitudes are also to blame for exposure to cosmic radiation during flights. How much radiation is absorbed during a flight depends on the plane's altitude and latitude, and on solar activity.

For a typical cross-country flight in a commercial airplane, a person receives 2 to 5 mrem, less than half the dose received during a chest X-ray (10 mrem), according to U.S Environmental Protection Agency.

In addition, a person receives about 0.002 mrem from airport security scans each way, according to the EPA.

Cell phones

Threats to health from cell phone radiation have been a persistent, though scientifically uncertain, concern for years now. Last June, San Francisco voted to become the first U.S. city in which retailers must display the radiation levels emitted by cell phones.

"We are not suggesting people abandon cell phones we certainly wouldn't but we suggest that people use cell phones differently by using headsets, and that they buy low-radiation cell phones," Olga Naidenko, a senior scientist at the Environmental Working Group (EWG), told TechNewsDaily, a sister site of Life's Little Mysteries.

Cell phones, as well as radio towers and Wi-Fi networks, emit radio frequency waves, which are absorbed by human tissue and measured using the Specific Absorption Rates (SARs) scale. [Read: Which Five Phones Have the Lowest Radiation Levels?]

Medical x-rays

Because medical procedures make up 96 percent of the average person's exposure to man-made radiation, people should limit the number and types of x-rays they receive. X-ray, mammography and CT (Computerized Axial Tomography or CAT Scan) machines all increase a person's dose.

A chest X-ray typically delivers a dose of about 10 mrem, while a full-body CT scan packs a 1,000-mrem punch, according to the USNRC. By comparison, a CT scan of the chest delivers 700 mrem, while a scan of the head gives 200 mrem. A dental x-ray gives 1.5 mrem, and an x-ray of a hand or foot delivers 0.5 mrem.

Airline passengers flying through storms might have more to worry about than a little turbulence. A new study suggests that if jets pass near lightning discharges or related phenomena known as terrestrial gamma-ray flashes, passengers and crew members could be exposed to harmful levels of radiation, a dose equal to that of 400 chest X-rays.

However, the likelihood of encountering these lightning events is very small, the researchers say. In addition, airline passengers are always exposed to slightly elevated radiation levels due to cosmic rays, which bombard Earth's upper atmosphere constantly but typically don't make it to the surface.

Airplane passengers would only be exposed to this high radiation dose if their airplane happens to be near the point of origin of a lightning discharge or a gamma-ray flash, and scientists aren't sure how often, if ever, such exposure occurs. The radiation bursts are extremely brief and extend over just a few hundred feet in the clouds. 

"We know that commercial airplanes are typically struck by lightning once or twice a year," said Joe Dwyer, professor of physics and space sciences at Florida Tech. "What we don't know is how often planes happen to be in just the right place or right time to receive a high radiation dose. We believe it is very rare, but more research is needed to answer the question definitively."

Lightning and other mysterious flashes

Scientists admit lightning is still mysterious. They don't really know why it produces X-rays or gamma rays (which are more intense than X-rays), or even how it gets from there to here.

The researchers did not measure high radiation doses directly with airplanes. Instead, they estimated radiation based on satellite and ground observations of X-rays and gamma rays.

With orbiting satellite data, they were able to study terrestrial gamma-ray flashes, or TGFs, mysterious phenomena that appear to originate at the same altitudes used by jet airliners and occur along with lightning. While scientists don't know what causes TGFs, they believe they are produced by electric fields above the thunderstorms.

The research team also included measurements of X-rays and gamma rays from natural lightning on the ground, as well as artificial lightning triggered with wire-trailing rockets fired into storm clouds.

They  then used computer models to estimate the amount of radiation that could be produced within, or very near, thunderclouds during lightning storms.

They concluded the radiation in a football field-sized space around these lightning events could reach "biologically significant levels," up to 10 rem (roentgen equivalent man), which is the dosage considered the maximum safe radiation exposure over a person's lifetime.

While the research raises obvious concerns, recent in-flight experiments suggest the incidents are rare, according to study scientist David Smith, an associate professor of physics at UC-Santa Cruz. Flying aboard an aircraft this past summer in Florida, Smith and several of the other researchers used a highly sophisticated instrument to measure gamma-ray flashes from thunderstorms. Over the course of several flights, they only detected one such flash, at a safe distance from the plane.

"These observations show that although thunderstorms do occasionally create intense gamma-ray flashes, the chance of accidently being directly hit by one is small," Smith said.

More inquiry needed

Martin Uman, another author and a professor of electrical and computer engineering at UF, noted that airline pilots typically seek to avoid flying through storms.

However, he said, the fact that commercial planes are struck once or twice a year suggests more inquiry is needed. He said he would recommend to the Federal Aviation Administration that it place detectors aboard planes capable of measuring the radiation bursts to determine how often they occur.

"We also need to spend more time looking at gamma and x-ray radiation from lightning and thunderstorms and trying to understand how it works," Uman said.

The research will be detailed in an upcoming issue of the Journal of Geophysical Research — Atmospheres.

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Passing kidney stones is often described as the worst pain people have ever experienced. Even worse, about half of kidney stone sufferers will get another stone within the following five years. Worse still, it's often the initial treatment that leads to the subsequent stones.

But scientists are working on a new technique that could help prevent reoccurring kidney stones and maybe even get rid of smaller fragments before they become large and painful.

The technique involves using ultrasound waves to gently nudge stones toward the kidney exit. Testing in live pigs, whose kidneys are similar to ours, has shown success.

"It just takes a flick, just a fraction of a second, we see the stone just jump in the kidney several centimeters, and sometimes it even bounces right out the door of the kidney," Michael R. Bailey from the University of Washington in Seattle. "We have always been able to move the stones in each animal."

What they are

Kidney stones are crystallized mineral deposits that form inside the kidneys. They form when the basic elements that make up urine (water, minerals and salts) are out of balance. This can happen when there is not enough liquid to dissolve the minerals and salts, or if there is an abundance of these crystal-forming materials.

People who are dehydrated or who have certain metabolic conditions are prone to kidney stones.

The stones become problematic when they get bigger than about 2 millimeters (about 1/16th of an inch) in diameter. The buildup happens over time, but the stones become painful when they begin to travel down the ureter, a small tube that connects kidneys to the bladder.

About 10 percent of people in the United States will have a kidney stone at some point in their lives, and about 10 percent to 15 percent of all cases require an interventional treatment.

Blasting vs. nudging

The main method used for treating large stones (up to 10 mm in diameter) is to blast them with high-intensity ultrasound pulses, known as "extracorporeal shock wave lithotripsy." However, this method can leave small pieces of stone that then can become the foundation for future stones, Bailey said.

The technique being developed by Bailey and his colleagues gently pushes small fragments toward the kidney exit so that they pass naturally. Their device uses a relatively low-intensity ultrasound beam (similar to what a doctor might use to look at a fetus) to both view the kidney stone and move it.

Their method is not intended to replace current treatments, but rather to supplement them. Since large stones cannot pass through the ureter they first must be broken into smaller bits. The device could help remove the small fragments that remain after lithotripsy treatment; or it could move large stones close to the kidney exit so that, when they are broken up, they are in the right place to pass naturally, said Bailey.

And if stones are detected when they are quite small, the device could help them pass without the patient ever needing the lithotripsy treatment, he said.

Other advantages

Avoiding multiple treatments with lithotripsy would be desirable, because each procedure comes with a risk of injury, such as bleeding in the kidneys.

The scientists think the imaging aspect of their technique may even be able to compete with the current method of diagnosing kidney stones – a spiral computed tomography (CT) scan. These scans use X-rays, and thus expose patients to ionizing radiation (too much radiation is thought to be a health hazard).

"We may just be able to have a portable ultrasound device in a doctor's office," Bailey said. "You come in, he or she can quickly put it on the body, see the stone, and see the size and location of the stone, and save you that trip to the spiral CT."

The pulses from the kidney stone-pushing device are longer than those used for a regular diagnostic ultrasound. And so if the device were used on humans, doctors would need to switch it off for a longer time period between pulses to avoid a heat injury.

Bailey hopes the method will be ready to test on humans in about two years. He and his colleagues will present their work at the 158th Meeting of the Acoustical Society of America on Oct. 27 in San Antonio, Texas.

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Using a 54 million-year-old skull, researchers have constructed the first-ever virtual model of a primitive primate brain.

"This is our first glimpse of what an ancestral primate would have looked like in terms of its brain," said Jonathan Bloch, a vertebrate paleontologist at the Florida Museum of Natural History who was part of the modeling team. "And that tells us quite a bit about its behavior and the evolution of things like certain aspects of intelligence."

To develop their model, the scientists took 1,200 ultra high resolution X-rays of a well- preserved 1.5-inch-long skull from a mammal belonging to the ancient primate group Plesiadapiforms. The two dimensional X-rays were then stacked up and "stitched" together to form a 3-D model, Bloch said. While this imaging technique has been used to examine primate brains from more recent fossils, no one has used it to study so-called "stem primates," mammals that existed 65 million to 55 million years ago and gave rise to today's primates, until now. The skull used for this model is a "late-occurring" stem primate, a member of a group that survived from the Paleocene (65 million to 55 million years ago) into the early Eocene (55 million to 33 million years ago), Bloch said, adding: "But likely [it] is very similar to what stem-primates would have looked like during the Paleocene."

Traditionally, scientists have used fossils called "endocasts" to study ancient primate brains. These casts form when rock sediments fill the skull's brain cavity. If the skull breaks away, what's left is a mold that provides a good picture of what the surface of the brain looked like. The problem is that endocasts are rare for stem primates. But the imaging technology used in this study has given scientists a new look at these old brains.

For example, the technology yielded a very precise measure of the animal's brain size.

"We could very accurately figure out brain volume from this endocast; there was a tiny bit of distortion, but very little," Bloch told LiveScience. "In the past, there have only been fragments of endocasts, so they would have to guess essentially how large the brain was."

What Bloch and his colleagues saw was that, contrary to some proposed ideas about early primate brains, the brain was not exceptionally small. "Actually, for animals of that time, it's really sort of a normal-sized brain," Bloch said. However, compared to today's primates, it is a small brain, he added.

Using the model, the researchers were also able to make some inferences about primate brain evolution. One unique feature of primates today is their large brains, and people have wondered when and how primate brains got so big. One idea is that primates "may have evolved large brains in coordination with increasing specializations for living in trees and eating fruits and leaves and these kinds of things," Bloch said.

Previous research by Bloch and his colleagues has shown that early primates were very well-adapted for living in trees and eating fruits and leaves, but the current research indicates that these primates had very small brains.

"So at the beginning, they were doing many of the same things that living [modern] primates do in terms of their behavior, but they did it with smaller brains," Bloch said. "So it's not likely that large brains evolved in coordination with a lifestyle that included living in trees and eating fruits and flowers and leaves, but in fact probably large brains evolved a bit later in primate evolution, corresponding with things like increasing visual specialization."

From their model, the researchers saw that the early primate had very large olfactory lobes, meaning that "it is a very smell-oriented animal," said Bloch. In contrast, it had small temporal lobes indicating it was not sight-oriented, he adds. "So we can see, with the first stages of primate evolution, primates had relatively small brains and were specialized for smelling rather than focused on visualizing."

The study was led by anthropologist Mary Silcox from the University of Winnipeg in Canada. The results from the study were published online in the June 22 issue of the journal Proceedings of the National Academy of Sciences. The research was funded by the National Science Foundation and the National Sciences and Engineering Research Council.

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New airport security scanners could become a popular alternative to body searches, but have also prompted some privacy concerns.

Whole-body imaging technologies can see through clothing to reveal metallic and non-metallic objects, including weapons or plastic explosives. They also reveal a person's silhouette and the outlines of underwear.

That hasn't stopped security officials from implementing them. The U.S. Transportation Security Agency (TSA) started using whole-body imaging at six airports this year, and plans are in the works to expand it to airports in several more U.S. cities later this year.

The TSA has tested two technologies, including "millimeter wave" (MMW) technology which bounces radio-frequency waves off people to construct a 3-D image within a few seconds. TSA also temporarily leased four "backscatter" units which use X-ray scanning, although the MMW method is currently faster.

Early this year, TSA began implementing MMW as a primary screening technology next to metal detectors at airports in San Francisco, Miami, Albuquerque, Tulsa, Salt Lake City and Las Vegas.

Airports in 20 U.S. cities, such as JFK in New York City and LAX in Los Angeles, have used or plan to use MMW tech this year. Other countries have also begun using or evaluating MMW for airport screening, including the UK, Netherlands, Japan and Thailand.

The MMW and backscatter scans intentionally blur facial features, and the security officer viewing images sits in a remote location where he or she cannot identify the passengers, said Lara Uselding, a TSA spokesperson. She added that the systems also delete scanned images after the viewings, and have "zero storage capability."

That has not stopped privacy advocates from asking how much passengers may unwittingly reveal in whole-body imaging.

"Body scanners produce graphic images of travelers' bodies and are an assault on their essential dignity," said Barry Steinhardt, director of the ACLU's Technology and Liberty Project. "The safeguards announced by the TSA do not convince us that the technology is acceptable, and we question the supposed voluntary nature of these scanners."

TSA pointed out that passengers can currently choose between the MMW screening and the more traditional body search conducted by a security officer with a wand. The new screening tech actually proved popular in testing conducted in January 2009.

"More than 99 percent of passengers selected for Millimeter Wave screening opted to use the technology instead of the traditional pat-down procedure at Los Angeles International Airport," Uselding said. "We saw the same percentage for use at JFK with MMW."

A body scan that leaves no record might be less invasive than background searches which look through computer records containing personal passenger information, said Bruce Schneier, chief security technology officer for British Telecommunications, who has published several books and testified on security issues for the U.S. Congress.

However, Schneier raised two main issues: whether security officials are doing the right thing to address security issues, and whether they're doing it right. His concern is that high-tech airport screening has become too focused on specific threats.

"I dislike security that requires us to guess a target and tactic," Schneier told LiveScience. He added that airport screening represents the last line of defense against potential threats, whereas spending more money on intelligence gathering has benefits whether terrorists are targeting an airport or shopping mall.

"Security is a tradeoff," Schneier said. "Every dollar we're spending on airport security is a dollar not spent someplace else."

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