The research aims to produce valid information and must use reliable instruments that guarantee accurate and make it quantifiable and possible reproducibility. Allowing the exclusion or at least control prejudice of personal insights and trends that may distort the results.
jueves, 30 de abril de 2009
Mercury More Exciting Than Mars
Mercury was once seen as a cold, dead little world, spinning around the sun unchanged for the past 4 billion years.
No longer: Observations from the Messenger spacecraft say it’s anything but.
NASA’s orbiter is sending back evidence of massive volcanism, strange impact craters and magnetic tornadoes that funnel plasma directly from the sun to the planet’s surface.
“It’s definitely not this picture of an ancient world where everything that happened to it happened billions of years ago and nothing happened since then,” said Tom Watters of the Smithsonian Institution in Washington, DC. “We’re seeing a very dynamic planet that has a lot going on today.”
A slew of papers in Science report what Messenger (MErcury Surface, Space ENvironment, GEochemistry and Ranging) saw on its Oct. 6 flyby of the small rocky planet. The spacecraft (whose admittedly contrived name was chosen because Mercury was the messenger to the gods in Roman mythology) launched in 2004, and will fly by Mercury a total of three times before settling into orbit in 2011.
us_satellite_rembrandt_basin_cropCombined with mapping by Mariner 10 in the ’70s, we now know what 90 percent of the surface looks like.
And it looks weird. Superficially, Mercury looks a lot like the moon: small, grayish-brown and pockmarked with craters. Some scientists assumed that Mercury’s surface formed the same way the moon’s did, with lighter rocks rising to the surface of a magma ocean and congealing into a brittle crust early on. But the new observations reveal that 40 percent of the surface was formed by volcanoes.
“Up until before Messenger’s arrival, we weren’t even sure that volcanism existed on Mercury,” said Brett Denevi of Arizona State University, lead author on a paper describing the evolution of Mercury’s crust. “Now we’re seeing it’s very widespread across the surface.”
Most were probably effusive volcanoes, in which molten muck bubbles up from cracks in the surface and spreads, filling in crater basins and smoothing the landscape. But a few were explosive volcanoes, what Denevi described as “big fire fountains of magma” whose ejected material turned to glass before hitting the ground.
Messenger also spotted an impact basin that is “unlike anything I have ever seen anywhere in the solar system,” said Watters, the lead author on a paper focusing on this funny feature. The basin, dubbed Rembrandt, is one of the biggest and youngest craters on Mercury. If it were on Earth, its edges would extend from Boston to Washington, D.C. But for Rembrandt, size doesn’t matter. It’s what’s inside that counts.
Most impact basins — craters more than 186 miles in diameter — are formed by impacts so forceful that they crack the planet’s crust all the way to a liquid or molten layer underneath. The molten rock oozes into the basin and fills it up. The basin sags under the weight of all this extra material, and deforms the ground around it. The interior of the basin crinkles up into ridges, and the edges stretch into troughs.
Rembrandt is only partially filled with volcanic material. Even stranger is its pattern of ridges and troughs, which lie side by side in a radial pattern from the center, rather than being confined to either the rim or the middle.
“That pattern is like nothing we’ve ever seen before,” Watters said. “We’re going to have to go back and rethink the way that we generate these stresses in these basins.”
Observations from Messenger might help solve a few mysteries, in addition to creating new ones. Scientists wondered if Mercury had a stable magnetic field fueled by a liquid core like Earth, or a ghostly magnetic field left over from a once-liquid core that’s since frozen, like Mars. The Messenger flyby clinched it in favor of an active magnetic field — and though it’s weak, it’s really active.
Earth has an atmosphere and a strong magnetic field to protect it from the constant stream of ions ejected from the sun at supersonic speeds known as the solar wind. Mercury is not so lucky. Its magnetic field is just 1 percent the strength of Earth’s, and it has no atmosphere to speak of. What atmosphere it has is tenuous and extremely variable, made up mostly of sodium one day and mostly calcium the next.
This leaves its surface vulnerable to being ravaged by the solar wind at the best of times. Messenger flew by at a particularly bad moment, and ran right through a magnetic tornado.
Magnetic tornadoes form when the magnetic field in the solar wind links up to the field generated by a planet, a process called magnetic reconnection. Bundles of magnetic field lines connect the surface of the planet directly to the surface of the sun, and as the solar wind pushes them away from the sun, they twist and whirl like cyclones. On Earth, these cyclones (technically called “flux transfer events”) dance on the ionosphere, creating the Northern Lights and messing up GPS systems.
On Mercury, though, the twisters were 10 times as strong as any magnetic cyclones observed on Earth. With so little atmosphere to interfere, Mercury’s magnetic tornadoes are great spinning chutes that ionized gas can slide down.
“They act as magnetic channels or open windows that allow solar wind plasma from the sun, very fast and very hot, to come right down those field lines and impacts the surface,” said Jim Slavin of NASA Goddard Spaceflight Center. When the gas hits the surface, it knocks off neutrally-charged atoms and sends them on a loop high into the sky.
Slavin thinks that could explain Mercury’s inconsistent atmosphere. “People had hypothesized that it was because of day-to-day changes in the solar wind, and how much is able to reach the surface and sputter off neutral atoms,” he said. “We may have discovered the answer to that longstanding question, why is the atmosphere so variable: Because reconnection, when it occurs, is just so intense.”
Publicado por Nathaniel en 12:39 No hay comentarios:
Liaohe River Valley: Cradle of Chinese Dragon Culture
There is an old Chinese proverb that says, "The dragon raises its head on the second day of the second [lunar] month." It means the Heavenly Dragon King, who is in charge of clouds and rain, will awake from his winter sleep and begin sending rain to earth. In some parts of China, this day -- which fell on February 21 this year -- is known as the Spring Dragon Festival.
For millennia, the dragon has been a vital part of Chinese culture, and the people themselves have long been known as the "descendants of the dragon." The origins of dragon culture remained unclear, however, until recently. Archaeologists have now concluded that the dragon culture originated in the Liaohe River Valley of northeast China.
Although bronzeware decorated with dragon images dating back to the Shang Dynasty (c. 1600- 1100 BC) have been unearthed, they are no longer the oldest dragon icons in China. The artifact now being credited with "senior dragon" status was discovered in the Liaohe River Valley.
In late 2003, Chinese archaeologists found a jade dragon in the Hongshan ruins at Niuheliang, Liaoning Province. It was the fourth to be found at the site, but it proved to be the oldest.
The dragon-shaped jade carving is 26 cm high, with closed mouth and long muzzle. The dragon's two prominent nostrils are uptilted. Its neck sports a long mane and its tail curls up. The shape is very similar to the ancient pictographic character "long" ("dragon") found on oracle bones. Professor Su Bingqi, an archaeologist from Peking University, says it is the oldest jade dragon ever found.
The Hongshan tribes lived in the Liaohe River Valley some 5,000 to 6,000 years ago. Since the jade dragons were unearthed here, others have been found at the Zhaobaogou and Zhahai archeological sites. Although the carved dragons found at these places are not as old as the Hongshan jades, the ruins themselves are 6,000 and 8,000 years old, respectively. Archaeologists feel confident that the dragon culture of the Liaohe River Valley dates back at least 5,000 years.
Guo Dashun, a renowned archaeologist specializing in the Liaohe River Valley, says, "In addition to being very old, the dragon-related articles found in this area also feature diverse forms and clear continuity in development."
The early dragons excavated in the Liaohe River Valley can be divided into eight groups based on age and style. From oldest to newest, they are: placement of stones or other objects to create images; relief, woodcarving, engraving, colored pottery, clay sculpture, jade sculpture and color painting.
The jade dragon excavated in the Liaohe River Valley shows that the concept of the dragon is actually a combination of various animals: pig, deer, bear and bird have been identified. The image of the dragon as we know it today is the result of thousands of years of artistic interpretation.
The Liaohe River flows through northeastern Liaoning and Jilin provinces, eastern Inner Mongolia Autonomous Region and northern Hebei Province. The valley covers a total area of 345,000 sq km.
The dragon stands as a symbol of auspiciousness and wisdom. In mythology, it was a messenger between humans and gods and a bearer of blessings from heaven to earth. The dragon was endowed with magical abilities to control the wind and rain, to fly through the air and live beneath the sea. Eventually, it became a symbol of the country's seat of power: the imperial throne.
Publicado por Nathaniel en 9:15 No hay comentarios:
Hundreds Of Rogue Black Holes May Roam The Milky Way, Swallowing Anything That Gets Too Close
It sounds like the plot of a sci-fi movie: rogue black holes roaming our galaxy, threatening to swallow anything that gets too close. In fact, new calculations by Ryan O'Leary and Avi Loeb (Harvard-Smithsonian Center for Astrophysics) suggest that hundreds of massive black holes, left over from the galaxy-building days of the early universe, may wander the Milky Way.
Good news, however: Earth is safe. The closest rogue black hole should reside thousands of light-years away. Astronomers are eager to locate them, though, for the clues they will provide to the formation of the Milky Way.
"These black holes are relics of the Milky Way's past," said Loeb. "You could say that we are archaeologists studying those relics to learn about our galaxy's history and the formation history of black holes in the early universe."
According to theory, rogue black holes originally lurked at the centers of tiny, low-mass galaxies. Over billions of years, those dwarf galaxies smashed together to form full-sized galaxies like the Milky Way.
Each time two proto-galaxies with central black holes collided, their black holes merged to form a single, "relic" black hole. During the merger, directional emission of gravitational radiation would cause the black hole to recoil. A typical kick would send the black hole speeding outward fast enough to escape its host dwarf galaxy, but not fast enough to leave the galactic neighborhood completely. As a result, such black holes would still be around today in the outer reaches of the Milky Way halo.
Hundreds of rogue black holes should be traveling the Milky Way's outskirts, each containing the mass of 1,000 to 100,000 suns. They would be difficult to spot on their own because a black hole is visible only when it is swallowing, or accreting, matter.
One telltale sign could mark a rogue black hole: a surrounding cluster of stars yanked from the dwarf galaxy when the black hole escaped. Only the stars closest to the black hole would be tugged along, so the cluster would be very compact.
Due to the cluster's small size on the sky, appearing to be a single star, astronomers would have to look for more subtle clues to its existence and origin. For example, its spectrum would show that multiple stars were present, together producing broad spectral lines. The stars in the cluster would be moving rapidly, their paths influenced by the gravity of the black hole.
"The surrounding star cluster acts much like a lighthouse that pinpoints a dangerous reef," explained O'Leary. "Without the shining stars to guide our way, the black holes would be all but impossible to find."
The number of rogue black holes in our galaxy depends on how many of the proto-galactic building blocks contained black holes at their cores, and how those proto-galaxies merged to form the Milky Way. Finding and studying them will provide new clues about the history of our galaxy.
Locating the star cluster signposts may turn out to be relatively straightforward.
"Until now, astronomers were not searching for such a population of highly compact star clusters in the Milky Way's halo," said Loeb. "Now that we know what to expect, we can examine existing sky surveys for this new class of objects."
Loeb and O'Leary's journal paper will be published in the Monthly Notices of the Royal Astronomical Society.
Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.
Publicado por Nathaniel en 9:08 No hay comentarios:
Ancient Egypt Brought To Life With Virtual Model Of Historic Temple Complex
Digital recreation shows what Karnak probably looked like in ancient times. (Credit: UCLA/ETC)
Ancient Egypt Brought To Life With Virtual Model Of Historic Temple Complex
ScienceDaily (Apr. 30, 2009) — For the past two years, a team of UCLA Egyptologists, digital modelers, web designers, staff and students has been building a three-dimensional virtual-reality model of the ancient Egyptian religious site known as Karnak, one of the largest temple complexes ever constructed.
The result is Digital Karnak, a high-tech model that runs in real time and allows users to navigate 2,000 years of history at the popular ancient Egyptian tourist site near modern-day Luxor, where generations of pharaohs constructed temples, chapels, obelisks, sphinxes, shrines and other sacred structures beginning in the 20th century B.C.
Developed by UCLA's Experiential Technologies Center — which has helped pioneer the digital reconstruction of historical sites, including the innovative Rome Reborn, released in 2006 — the Karnak model and a host of additional digital resources are now available for educators, students, scholars and the public to explore for free at http://dlib.etc.ucla.edu/projects/Karnak.
The website features videos from the 3-D model, instructional resources for educators, a Google Earth version of the model and pages detailing the chronology and construction of individual structures at the temple complex. The collective resources offer a window onto the incredibly rich architectural, religious, economic, social and political history of ancient Egypt.
"The Digital Karnak project builds upon UCLA's expertise merging research and multidimensional technologies to inform and preserve knowledge about historic sites," said project director Diane Favro, a professor in the architecture and urban design department at the UCLA School of the Arts and Architecture. "This learning platform allows educators and researchers to geo-temporally situate information and thus visualize and interrogate the evolution of Karnak over 2,000 years."
In recent years, scientists, historians and archaeologists around the world have embraced the 3-D modeling of cultural heritage sites. Information technology has permitted them to recreate buildings and monuments that no longer exist or to digitally restore sites that have been damaged by the passage of time. The results can be used both in research, to test new theories, and in teaching, to take students on virtual tours of historical sites they are studying.
The Experiential Technologies Center (ETC) at UCLA, which promotes the critical incorporation of new technologies into research and teaching, has been a leader in this cutting-edge movement, having digitally reconstructed a wide variety of sites of historical and cultural importance in Europe, the Middle East, South America and the Caribbean.
Favro, who directs the ETC, brings her expertise as an architectural and urban historian to these digital cultural-mapping projects, as well as her familiarity with the challenges and impact of large-scale interdisciplinary projects.
Digital Karnak co-director Willeke Wendrich is an associate professor of Egyptian archaeology in the UCLA Department of Near Eastern Languages and Cultures and director of the Egyptian Lab at the UCLA Cotsen Institute of Archaeology. She is the editor-in-chief of the UCLA Encyclopedia of Egyptology, an award-winning digital encyclopedia that has been supported by the National Endowment for the Humanities since 2005. She is also a member of the Science Board of Digital Antiquity.
The Digital Karnak project is funded and supported by the National Endowment for the Humanities and the Steinmetz Family of Los Angeles.
Publicado por Nathaniel en 9:06 No hay comentarios:
Unique Roman Glass Dish Discovered At London Grave
Archeologists have discovered an exquisite Roman polychrome millefiori dish in East London, U.K. It has been painstakingly reassembled by Museum of London Archaeology conservator Liz Goodman. (Credit: Image courtesy of Museum Of London)
Archeologists have discovered an exquisite Roman polychrome millefiori dish in East London, U.K. The dish is made up of hundreds of indented glass petals (the term millefiori means simply “a thousand flowers”) in an intricate repeated pattern and was found during excavations in Prescot Street, Aldgate, by L – P : Archaeology. It was highly fragmented but miraculously held together by nothing more than the earth around it. It has been painstakingly reassembled by Museum of London Archaeology conservator Liz Goodman.
The dish is extremely rare and an unprecedented find, not only from London but from across the Western Roman empire. Originally the blue translucent petals, bordered with white, would have been embedded in a bright red opaque glass matrix. The hue was still present when the dish was uncovered, with the vermillion appearance diminishing as the water-saturated glass dried out. The red colouring can be seen around the rim. The complexity of its manufacture indicates that the dish was a highly-prized and valuable item. Beautifully crafted vessels like this were particularly in vogue in the 1st and early 2nd centuries. Dating is underway to establish the precise period of the find.
The dish formed part of the grave goods of a Roman Londoner whose cremated remains were uncovered, probably buried in a wooden container, in a cemetery in Londinium’s Eastern quarter. A number of other ceramic and glass vessels were also ranged along the sides of the casket, suggesting a rich and unusual burial.
The excavations at Prescot Street have continued the process of the recording of the extensive eastern cemetery of Roman London which, by law, lay outside the city wall. This and previous excavations have found both cremations and inhumations (burial of the body) that spanned over 400 years of Roman occupation from the late 1st to early 5th century. This burial came from an area of intense burials at the eastern end of the site where there was also a stone mausoleum, a possible funerary structure and a series of burial groups which perhaps indicate the on-going use of cemetery plots. Indeed, this particular burial had, at a later date, had another cremation burial interred on the same spot which may point to a family connection.
Liz Goodman, Museum of London Archaeology conservator said ““Piecing together and conserving such a complete artefact offered a rare and thrilling challenge. We occasionally get tiny fragments of millefiori, but the opportunity to work on a whole artefact of this nature is extraordinary. The dish is extremely fragile but the glasswork is intact and illuminates beautifully nearly two millennia after being crafted.”
Guy Hunt, Director, L – P : Archaeology said “The dig at Prescot Street produced an amazing range of Roman cemetery archaeology; it is fantastic for us that one of the many finds is such an exciting and beautiful object. It is great to be able to put an object such as this into context and to get a first hand impression of a rather wealthy east Londoner.”
About Milleflore Glass
Millefiore is a glass-working technique created from glass rods with multi coloured patterns that are only visible at the cut ends – like a stick of rock with the writing only visible once cut. These rods are created by heating and melding lengths of different coloured glass to create an individual pattern. Here, a solid red cane is set at the core with blue and white canes set around it to produce the petal effect. The small cross sections of glass rod are then used to create bigger pieces. It is a very labour intensive – and hence very exclusive – craft.
Publicado por Nathaniel en 9:04 No hay comentarios:
Publicado por Nathaniel en 8:55 No hay comentarios:
Publicado por Nathaniel en 8:50 No hay comentarios:
"Dark Age" Temple Found in Turkey
The remains of a temple (above) in southwestern Turkey may cast new light on the "dark age" that was thought to have engulfed the region from 1200 to 900 B.C., researchers announced in April 2009.
Ornate decorations and stone slabs carved with hieroglyphs suggest that, despite the written record, the time period might not have been marked only by cultural collapse, famine, and violence.
An ancient temple in Turkey has been found filled with broken metal, ivory carvings, and stone slabs engraved with a dead language.
The find is casting new light on the "dark age" that was thought to have engulfed the region from 1200 to 900 B.C.
Written sources from the era—including the Old Testament of the Bible, Greek Homeric epics, and texts from Egyptian pharaoh Ramses III—record the transition from the Bronze Age to the Iron Age as a turbulent period of cultural collapse, famine, and violence.
But the newfound temple suggests that may not have been the case, say archaeologists from the University of Toronto's Tayinat Archaeological Project, led by Timothy Harrison.
"We're beginning to find new archaeological evidence that there was a continuation of writing traditions, as well as cultural and political continuity from the Bronze Age into this Iron Age period," Harrison said.
"We are filling in a cultural and a political history of this era."
Harrison and colleagues found the temple in 2008 at the Tell Ta'yinat site, an archaeological settlement on the Plain of Antioch in southeastern Turkey.
The site, near the present-day Syrian border, served as a major cultural crossroads for thousands of years.
The temple appears to have been built during the time of King Solomon, between the 10th and 9th centuries B.C. It was likely destroyed with the rest of Tell Ta'yinat during the 8th century B.C.
Researchers initially examined the remains of the temple's southern entrance, which includes a stone-paved courtyard, a wide staircase, and a doorway once supported by an ornately carved column.
The team also found the smashed remains of massive stelae—commemorative stone slabs—carved with hieroglyphs in Luwian, an extinct language once spoken throughout what is now Turkey.
The temple's main room was long ago damaged by fire, but it was found littered with the remains of bronze and ivory wall or furniture fittings, along with gold and silver foil and the carved eye inlay from a human figurine.
Although excavations have yet to reach the earliest parts of the temple, researchers plan to continue digging this summer in the hopes of finding the temple's inner sanctuary.
Harrison believes the Tayinat temple might provide scholars with new evidence to help them understand similarly constructed temples from the same time period, as well as the temple rituals of the day.
"The textual record has very much informed our perception of the past," noted Gunnar Lehmann, an archaeologist with Ben-Gurion University of the Negev in Israel, who was not involved in the find.
"But there is now increasing archaeological evidence for a complex scenario of considerable cultural and political continuation and innovations during this [dark age] period."
Publicado por Nathaniel en 8:46 No hay comentarios:
Reader Picks of NASA Shots
Atafu Atoll, Tokelau, Southern Pacific Ocean (April 6, 2009)
A tiny atoll, part of a New Zealand territory, is seen as photographed from the International Space Station by an astronaut.
The Atafu Atoll is one of four atolls and islands that are part of the Tokelau Islands. Geology suggests that a volcanic island created the atoll. Coral reefs likely formed around the volcano, which then eroded beneath the water, leaving a ring of sand and reefs.
Atafu's main village can be seen to the left as a collection of small grey dots. Around 500 people responded to a 2006 census of the atoll.
Extratropical Cyclones Near Iceland (January 2, 2007)
One cyclone's bad enough. But the Terra imaging satellite managed to find double trouble--two of the spiraling storms, formed simultaneously above Iceland and Scotland.
Though cyclones are usually thought of as tropical events, they do often form at higher latitudes. Cyclones of this type drive much of Earth's weather.
Iceland can be seen at the top-center of the above image, showing through milder skies. Scotland is in the bottom right-hand corner, close to the larger and perhaps stronger cyclone.
STEREO's First View of the Sun (January 3, 2007)
Loops of highly charged particles shoot out from the sun's roiling surface, as seen in ultraviolet by the twin STEREO spacecraft.
The sun's surface regularly pumps out these coronal mass ejections--explosions caused by magnetic stress in the sun's atmosphere, which is shown above at roughly a million Kelvin (1.8 million degrees Fahrenheit). Solar flares surge into space with each eruption, causing auroras on Earth and disrupting communications and radio systems.
The active region at the base of each blast can be seen from Earth as sunspots, but the ultraviolet loops can only be observed from space.
The Southern Lights (January 25, 2006)
The aurora australis, or southern lights, glimmer green over Antarctica in the picture above.
Four days after a massive solar flare, NASA researchers obtained readings from the now-defunct IMAGE satellite, which monitored Earth's magnetic field.
Overlaying the data onto a "Blue Marble" satellite photograph of Earth resulted in both the image above and an animation of the solar storm's effects on Earth's atmosphere.
Ocean Sand, Bahamas (September 13, 2002)
Though viewers would be forgiven for thinking the above picture a work of abstract art, the image is actually a photograph captured by the Earth-orbiting Landsat 7 satellite.
Ocean currents in the Bahamas made the sand-and-seaweed sculpture in much the same way that winds create sand dunes in the Sahara.
Publicado por Nathaniel en 8:41 No hay comentarios:
Waving Hello to a New Subatomic Theory
1926: Nuclear physicist Erwin Schrödinger writes a letter to Albert Einstein, introducing a new term: wave mechanics. Things are getting particularly interesting. If they are things. Well, probably.
Schrödinger was home-schooled in Austria until age 11. After attending school with other youngsters, he enrolled at the University of Vienna, earning a Ph.D. in physics. As an artillery officer in the Austrian army in World War I, he served on the Italian front. He might have bombarded the young ambulance driver Ernest Hemingway. Or he might not have.
After the war, academic opportunities in the remnants of the Austro-Hungarian Empire were not what they used to be. Schrödinger oscillated from job to job before settling into a professorship at the University of Zurich, Switzerland.
A footnote in a paper by Albert Einstein inspired Schrödinger to model the motion of an electron around a nucleus as a wave rather than an orbiting particle. He began a correspondence with Einstein (then in Berlin) and proposed the term Wellenmechanik, or wave mechanics.
1926 was an astonishingly fertile year for Schrödinger, much like Einstein’s own 1905 annus mirabilis or Isaac Newton’s before that. Schrödinger published four papers, elucidating wave mechanics, expressing the new formulation in a precise equation, showing how it confirmed Niels Bohr’s atomic model, and demonstrating how the Schrödinger theory paralleled — rather than contradicted — Werner Heisenberg’s matrix mechanics.
Schrödinger moved in 1931 to the University of Berlin to succeed Max Planck. When the Nazis took power in 1933, Schrödinger — a nominal Catholic with an interest in Vedanta and other Eastern philosophies — was disturbed by the dismissal and flight of his Jewish colleagues. He left Germany and took a position at Oxford.
During his first week at Oxford, Schrödinger won the 1933 Nobel Prize in Physics (shared with Paul Dirac). Unfortunately, Oxford did not take to its new Nobel laureate: The dons seemed to mind that Schrödinger was living with two women.
He returned to the University of Graz in Austria in 1936, but was dismissed from the faculty after Germany annexed that nation in 1938. He lived and taught in Ireland until 1956, when he returned to his homeland for the final five years of his life.
Did Schrödinger, at any time, have a cat? He might have.Source: PBS
Publicado por Nathaniel en 8:38 No hay comentarios:
The Next Climate Change Battleground
t’s easy, from my yuppified Brooklyn perch among the Times-reading tattooed gentry, to see the climate change policy debate as over:
across the land, states are passing greenhouse gas laws, energy companies are calling for climate change legislation, the color of the moment is decidedly green. America, it seems, is finally catching up to the rest of the civilized world.
But warning signs are out there. A recent Newsweek poll found that more than half of Americans don’t think the greenhouse effect is felt today.
Some two-fifths still believe there is "’a lot of disagreement among climate scientists" on the basic question of whether the planet is warming.’" Even Democrats have been too wimpy to merely hold a vote on whether carmakers ought to improve gas mileage.
The Newsweek poll came as part of their soup-to-nuts investigation into industry-funded global warming denialism. They spend the first five-sixths of the article rehashing old, well-known history — at least, it ought to be well-known history; maybe I shouldn’t be such a snob, given the poll results — before getting to the new stuff. The picture’s not pretty.
The response to the international climate panel’s latest report, in
February, showed that greenhouse doubters have a lot of fight left in them. In addition to offering $10,000 to scientists willing to attack the report, which so angered Boxer, they are emphasizing a new theme.
Even if the world is warming now, and even if that warming is due in part to the greenhouse gases emitted by burning fossil fuels, there’s nothing to worry about. As Lindzen wrote in a guest editorial in
NEWSWEEK International in April, "There is no compelling evidence that the warming trend we’ve seen will amount to anything close to catastrophe."
This is important because it will influence the next stage of the debate. With John McCain, who has all the political capital of a John
Birch Society newsletter distributor, the last prominent GOP holdout against California-style federal emissions cuts, climate change legislation is coming. The battle will be over
what Americans are willing to pay and do to stave off the worst of global warming. So far the answer seems to be, not much. The NEWSWEEK
Poll finds less than half in favor of requiring high-mileage cars or energy-efficient appliances and buildings. No amount of white papers, reports and studies is likely to change that. If anything can, it will be the climate itself. This summer, Texas was hit by exactly the kind of downpours and flooding expected in a greenhouse world, and Las Vegas and other cities broiled in record triple-digit temperatures. Just last week the most accurate study to date concluded that the length of heat waves in Europe has doubled, and their frequency nearly tripled, in the past century. The frequency of Atlantic hurricanes has already doubled in the last century. Snowpack whose water is crucial to both cities and farms is diminishing. It’s enough to make you wish that climate change were a hoax, rather than the reality it is.
So the responsibility of climate change fighters is obvious: make clear to the denialists that climate change is a dangerous, uncomfortable, destablizing, economically disastrous phenomenon. And as Amory Lovins — described by Wired in this article on his supercar — has shown, cleaning up our act can be a money-making business proposition.
Publicado por Nathaniel en 8:36 No hay comentarios:
miércoles, 29 de abril de 2009
A Sex Chip? Targeting the Brain's Pleasure Center with Electrodes
A fundamental goal of neuroscience has always been to deduce the brain systems that underlie such basic drives as hunger, thirst and sex. In 1956 the well-known physiologist James Olds wrote an article for Scientific American, called “Pleasure Centers in the Brain,” that described how a rat kept without food for a day was lured down a platform by a tasty meal. En route to dinner, it received a pleasurable electric shock. The rat never showed up for mealtime, instead choosing to delight in the arousal. With the optimism characteristic of that era, Olds concluded that stimulation experiments would lead to an understanding of neural functioning that would allow “one drug that will raise or lower thresholds in the hunger system, another for the sex-drive system, and so forth.”
Fifty years later the promise of Olds’s vision has yet to fully materialize. Better drugs are needed to suppress appetite and spark sexual desire. But fascination has grown in recent years with taking Olds’s more direct route of stimulating the central nervous system.
So far no one has created anything like the Orgasmatron, first seen in Woody Allen’s 1973 comedy Sleeper. Undaunted, one clinician—who has trademarked the name Orgasmatron—ran a small, FDA-reviewed pilot trial to test the possibility of applying electric current to the spine to reverse sexual dysfunction. Stuart Meloy, a North Carolina physician who specializes in implanting spinal electrodes to alleviate pain, found by chance that a slightly off-kilter placement in the lower spine caused one woman to exclaim: “You’re going to have to teach my husband to do that.”
In 2006 Meloy reported that 10 of 11 women who stopped having or never had orgasms experienced sexual arousal with the temporary implant and, of that group, four had their ability to experience orgasm restored. Meloy is seeking a medical device manufacturer to bring the costs down to $12,000 for a permanent implant, about the charge for breast enlargement.
Neural electrodes may eventually move up the spinal cord to what is often characterized as the body’s primary erogenous zone. Deep-brain stimulation, the placing of electrodes at strategic spots far underneath the skull, now treats a variety of ailments, including Parkinson’s disease and dystonia (uncontrollable twisting of a body part caused by involuntary muscle contractions). An occasional side effect is spontaneous sexual stimulation.
Tipu Aziz, a neurosurgeon at the University of Oxford, speculates that better knowledge of the brain’s pleasure centers—combined with improved surgical procedures and control of electrical pulses—may make a sex chip in the brain a reality. “Lack of sexual pleasure is a huge loss in one’s life, and if one could restore that, that would enhance someone’s quality of life enormously,” Aziz remarks.
Some neuroscientists are not so sure. Morten L. Kringelbach, a researcher at Oxford who sometimes collaborates with Aziz and wrote the book The Pleasure Center (Oxford University Press, 2008), cautions that hedonic experience may consist of an impulse corresponding to “wanting” and another that represents “liking.” To succeed as a therapy, a sex chip would have to address the challenge of switching on neural circuits that activate both impulses. In a 2008 paper in Psychopharmacology with University of Michigan at Ann Arbor psychologist Kent Berridge, Kringelbach illustrated the distinction between the two by citing an infamous case from the 1960s, in which psychiatrist Robert Heath placed “pleasure electrodes” in the brain of a gay man code-named B-19, in part, as an attempt to “cure” his homosexuality.
The patient pressed a button compulsively to turn on an electrode that induced a desire for sex, but whether he actually enjoyed the sensation was unclear. The stimulation alone did not induce orgasm, and B-19 never expressed any real contentment while hitting the button. Kringelbach warns against similar misuses of contemporary deep-brain stimulation. “It’s important that we not get carried away by this technology,” he says. “It’s important that we not end up in another era of psychosurgeries,” referring to the mid-20th century popularity of lobotomies to treat psychiatric disorders.In the end, a sex chip may serve as a prop for moviemakers, but turning on the current may never become a truly practical means of adding the buzz back in your love life.
This story was originally published with the title "Turn It Up, Dear"
Publicado por Nathaniel en 10:38 No hay comentarios:
Hackers Weigh In: 8 Big Things to Do with a Mini Server
MINI SERVER Marvell Technology's SheevaPlug is a two-inch by four-inch (five- by 10-centimeter) box that plugs into any wall outlet and is almost indistinguishable from an oversize power supply.
We weren't sure what to do with a SheevaPlug, a cheap and powerful home server stuffed into a package the size of a power brick, so we asked a bunch of uber-geeks at M.I.T.--Here's what they said:
Tiny computers are everywhere—our cell phones, handheld gaming devices and set-top boxes, to name a few—so it should be no surprise that Marvell Technology in Santa Clara, Calif., one of the companies that makes the chips that go into such devices, managed to cram an entire home server into the SheevaPlug, a two-inch by four-inch (five- by 10-centimeter) box that plugs into any wall outlet and is almost indistinguishable from an oversize power supply.
Sheevaplug is designed to deliver storage capacity and processing power for technophiles looking to string together every network-capable device in their house so they can share movies, music, photos and other files, hook up surveillance cameras or create a mini data center that fits in the palms of their hands. Although much of this can be accomplished today using a standard computer server or even a PC costing anywhere from $500 to several thousand dollars, Sheevaplug's diminutive size, low price ($100) and minimal power consumption (less than five watts) make it an intriguing option.
Knowing that its current audience consists of tech-savvy tinkerers interested in experimenting with new computing platforms, Marvell designed the Sheevaplug to run on the Linux operating system, whose source code is freely available for anyone to use. Marvell also documented the device's hardware on its Web site so the curious could see how it works. "What we want is for developers to get this kit and come up with nifty applications for it," says Raja Mukhopadhyay, Marvell's product marketing manager.
ScientificAmerican.com found some adventurous alpha geeks at the Massachusetts Institute of Technology's (M.I.T.) Computer Science and Artificial Intelligence Laboratory (CSAIL), Carnegie Mellon University, Intel and elsewhere and asked them what kind of uses they could come up with for the SheevaPlug. We came away with eight different ideas:
1. Home automation:
"I would hook it up to a Web camera and track myself in the house," says Nikolaus Correll, an M.I.T. CSAIL postdoctoral associate. "The system could react to my presence by simple motion detection and then turn heating and lighting on and off. It could also detect my activities such as studying, dining and watching TV, and match them to a preset set of [automated] actions. Eventually it could even create a statistical profile of my activities that helps me optimize energy consumption."
2. Desktop computer replacement:
Sheevaplug features a 1.2 gigahertz processor made by Cambridge, England–based ARM, Ltd., 512 megabytes of RAM and 512 megabytes of flash storage—all comparable with what is found on low-end PCs. "Small-scale computing is catching up with the amount of [computer processing power] people need to do meaningful interactive tasks: Web browsing, e-mail, listening to music, and even—if not now, soon—watching movies or TV," says Dave Andersen, an assistant professor of computer science at Carnegie Mellon University and a former CSAIL PhD student. Andersen, whose research demands that he use small clusters of low-power processors to tackle larger computing tasks, sees a lot of potential in using SheevaPlug's processor, memory and storage capacity to make a low-cost computer server.
3. Data-center replacement (with a power strip full of plug-in computers):
In order to keep up with the demands of computer users, data center administrators often must link together large numbers of computers. These clusters are used for large computing tasks like simulating the weather or serving up the billions of Web pages visited daily. These "server farms" collectively draw a large amount of power. (A 2007 report by the U.S. Environmental Protection Agency estimated that power used by data centers in the U.S. had doubled between 2000 and 2006 and is set to double again by 2014.) "If these things would replace the cores of a virtualized farm of servers I'd be interested," says Eric Schwartz, a CSAIL system administrator. "If these things can compare with [server farms']…computational throughput at a fraction of the power consumption, that's intoxicating."
This trend toward low-power computing is on the rise. Microsoft recently announced that it is testing servers powered by Intel's tiny Atom processor, the chief competitor to the ARM processor that powers the SheevaPlug. The hope is that, although these servers may require more processors to do the same job as more powerful computers, they will, on the whole, draw less electricity.
4. Data availability:
San Francisco-based Cloud Engines Inc., the first company to license Marvell's SheevaPlug, sells a device called the Pogoplug based on the technology that computer users can connect to their hard drive (via a USB port) to make the entire contents of that drive available via the Internet. With a Pogoplug attached to the hard drive storing your information at home, you could access that information even if you are sitting in a Starbucks a thousand miles away, says Daniel Putterman, CEO of Cloud Engines.
5. Data mining:
Once servers are cheap and ubiquitous enough, they allow for interesting monitoring tasks of all sorts of devices, like vending machines. "Back in the day, some hackers hooked it up to the network, and anyone could connect to it and check the selection and supply levels of the sodas," says Jason Biddle, a first-year master's student in the M.I.T. Computation for Design and Optimization program. The soda machine is no longer connected to the net but, Biddle says, "we tossed around the idea of finding a small Web server [like the SheevaPlug] to bring the soda machine back to its former glory. I'm sure someone out there could use the data to find an unknown trend among soda drinkers." With low-cost and low-power servers, it is no longer prohibitive to start connecting devices to the Net, he adds. "Information from those devices could then be aggregated and mashed up with other streams to lend new insight."
6. Life filter:
SheevaPlug could be used to monitor incoming e-mail and other information, presorting it before you open your in-box. "I think it's important to view this as not only an always-on storage resource but an always-on processing resource," says Luke Hutchison, a fourth-year PhD candidate in CSAIL. "The device has enough power to run a decent machine-learning algorithm. It could sit there logged into my e-mail account and be learning from my reading and categorizing habits and would try to tag or star messages before I get to them based on what it thinks I would be most likely to want to read immediately or classify a certain way."
Video security could also be a SheevaPlug strength. "We're in discussions with service providers about remote service capability," Mukhopadhyay says. "A lot of people have cheap USB [digital] cameras in their home. With SheevaPlug you can plug in a camera, and with the right software, you can get a surveillance camera. These retail for $700 to $800, so you can imagine service providers trying to sell this as remote surveillance."
8. You name it:
Because SheevaPlug uses the Linux operating system and open-source software (both of which can be downloaded for free), it could be a cheap Web server, a source-code repository, a backup server or countless other things. "In general," M.I.T.'s Hutchinson says, "it would be possible to host a lot of different types of services on such a box."
Publicado por Nathaniel en 10:33 No hay comentarios:
Evidence Of The 'Lost World': Did Dinosaurs Survive The End Cretaceous Extinctions?
View eastward from divide between Ojo Alamo and Barrel Spring arroyos, Kirtland shale in foreground. Conical butte capped with lower part of Ojo Alamo sandstone. Butte at left consists of Kirtland shale at base, overlain by conglomeratic sandstone of Ojo Alamo, and that in turn by the middle or shale member of the same formation, with pebbles from the disintegrated upper conglomeratic member scattered over the top. San Juan County, New Mexico. Circa 1915. (Credit: Plate 71-A in U.S. Geological Survey / Bauer, C.M. 25
he Lost World, Sir Arthur Conan Doyle's account of an isolated community of dinosaurs that survived the catastrophic extinction event 65 million years ago, has no less appeal now than it did when it was written a century ago. Various Hollywood versions have tried to recreate the lost world of dinosaurs, but today the fiction seems just a little closer to reality.
New scientific evidence suggests that dinosaur bones from the Ojo Alamo Sandstone in the San Juan Basin, USA, date from after the extinction, and that dinosaurs may have survived in a remote area of what is now New Mexico and Colorado for up to half a million years. This controversial new research, published today in the journal Palaeontologia Electronica, is based on detailed chemical investigations of the dinosaur bones, and evidence for the age of the rocks in which they are found.
"The great difficulty with this hypothesis -- that these are the remains of dinosaurs that survived -- is ruling out the possibility that the bones date from before the extinction," says Jim Fassett, author of the research.
"After being killed and deposited in sands and muds, it is possible for bones to be exhumed by rivers and then incorporated into younger rocks" he explains. This is not the usual way in which fossil deposits of this kind form, but it has been shown to explain some other post-extinction dinosaur bones. Fassett has amassed a range of evidence that indicates that these fossils from the Ojo Alamo Sandstone were not exhumed and redeposited and that these dinosaurs really did live after the end Cretaceous extinction event.
The first step must be to demonstrate that the rocks containing the bones are younger than the extinction event. Fassett has analysed the magnetic polarity of the rocks, and the pollen grains they contain, different approaches to finding the age of rocks which, he concludes "independently indicate that they do indeed post-date the extinction".
Fassett also found that "the dinosaur bones from the Ojo Alamo Sandstone have distinctly different concentrations of rare earth metal elements to the bones in the underlying Cretaceous rocks" and this, he argues, "makes it very unlikely that the post-extinction bones were exhumed from the underlying sediments." This is supported by a find of 34 hadrosaur bones together -- "these are not literally an articulated skeleton, but the bones are doubtless from a single animal" -- if the bones had been exhumed by a river, they would have been scattered.
So does this provide conclusive proof that dinosaurs survived the Cretaceous extinctions? According to David Polly, one of the editors of the journal in which the research is published, "this is a controversial conclusion, and many palaeontologists will remain sceptical", but we already know that flying theropod dinosaurs (more generally referred to as birds) and crocodiles survived, so the possibility of pockets of survivors of other types of dinosaur is not quite as far fetched as it might sound.
Finding conclusive evidence, however, is a difficult matter when the crime scene is 65 million years old. "One thing is certain," continues Polly, "if dinosaurs did survive, they were not as widespread as they were before the end of the Cretaceous and did not persist for long." The 'Lost World scenario' of humans and dinosaurs existing at the same time, still belongs firmly in the realms of pure fantasy.
Publicado por Nathaniel en 10:29 No hay comentarios:
Did Comets Contain Key Ingredients For Life On Earth?
Comet Hale Bopp. Comets have always fascinated us. A mysterious appearance could symbolize God's displeasure or mean a sure failure in battle, at least for one side. Now new research justifies our fascination -- comets might have provided the elements for the emergence of life on our planet. (Credit: iStockphoto/Michael Puerzer)
Comets have always fascinated us. In early cultures, a mysterious appearance of a comet could symbolize a deity's displeasure with humankind or mean a sure failure in battle, at least for one side. Now Tel Aviv University research adds a new twist to that fascination: comets might have provided the elements for the emergence of life on our planet.
While investigating the chemical make-up of comets, Prof. Akiva Bar-Nun of the Department of Geophysics and Planetary Sciences at Tel Aviv University found they were the source of missing ingredients needed for life in Earth's ancient primordial soup. "When comets slammed into the Earth through the atmosphere about four billion years ago, they delivered a payload of organic materials to the young Earth, adding materials that combined with Earth's own large reservoir of organics and led to the emergence of life," says Prof. Bar-Nun.
It was the chemical composition of comets, Prof. Bar-Nun believes, that allowed them to kickstart life. He has published his theory widely in scientific journals, including recently in the journal Icarus.
A Pinch of Argon, A Dash of Xenon
Using a one-of-a-kind machine built at Tel Aviv University, researchers were able to simulate comet ice, and found that comets contain ingredients necessary for providing the basic nutrients of life.
Specifically, Prof. Bar-Nun looked at the noble gases Argon, Krypton and Xenon, because they do not interact with any other elements and are not destroyed by Earth's oxygen. These elements have maintained stable proportions in the Earth's atmosphere throughout the lifetime of the planet, he explains.
"Now if we look at these elements in the atmosphere of the Earth and in meteorites, we see that neither is identical to the ratio in the sun's composition. Moreover, the ratios in the atmosphere are vastly different than the ratios in meteorites which make up the bulk of the Earth. So we need another source of noble gases which, when added to these meteorites or asteroid influx, could change the ratio. And this came from comets.
Solving the Otherworldly Puzzle
Comets are essentially large chunks of ice, whose temperature ranges from -200 to -250 degrees centigrade. Formed in the early days of the solar system far away from the sun, water vapor condensed directly into ice, making little grains. These grains came together to form the comets, which are less than 2/3 of a mile in diameter, explains Prof. Bar-Nun.
During the comets' formation, the porous ice trapped gases and organic chemicals that were present in outer space. "The pattern of trapping of noble gases in the ice gives a certain ratio of Argon to Krypton to Xenon, and this ratio — together with the ratio of gases that come from rocky bodies — gives us the ratio that we observe in the atmosphere of the Earth."
Thus, the arrival on Earth of comets and asteroids led to the necessary ratio of materials for organic life, "which eventually were dissolved in the ocean and started the long process leading to the emergence of life on Earth," says Prof. Bar-Nun.
Asteroid Showers and Thunderstorms
The story started between 4.6 and 3.8 billion years ago, when both the moon and the Earth were bombarded by a flux of asteroids and comets. "On the Earth, most of the craters were obliterated by continental movement and by weathering winds and water erosion. On the moon, they remained as they were," says Prof. Bar-Nun, who adds that no life could thrive during this period of bombardment.
But the Earth recovered, and three to four hundred million years later, fragile forms of life emerged after the comet-delivered elements precipitated into the ocean. "There was another chemical development of these molecules in water, which became more and more complex," says Prof. Bar-Nun, leading to the origin of life on Earth.
Publicado por Nathaniel en 10:27 No hay comentarios:
New Details About Mysterious Giant Virus Uncovered
The N-terminal and C-terminal jelly-roll domains are colored green and red, respectively. Top left is a ribbon diagram of the adenovirus capsid protein. Diagrammatic representation of the arrangement of the β strands (arrows) within each jelly-roll are given for adenovirus, PBCV1, and Mimivirus at the top right, bottom left, and bottom right, respectively. The β strands within each domain are labelled A to H. This gives rise to the two opposing BIDG and CHEF β sheets in each jelly-roll as indicated in the ribbon diagram. (Credit: Structural Studies of the Giant Mimivirus Xiao C, Kuznetsov YG, Sun S, Hafenstein SL, Kostyuchenko VA, et al. PLoS Biology Vol. 7, No. 4, e92 doi:10.1371/journal.pbio.1000092)
An international team of researchers has determined key structural features of the largest known virus, findings that could help scientists studying how the simplest life evolved and whether the unusual virus causes any human diseases.
The mimivirus has been called a possible "missing link" between viruses and living cells. It was discovered accidentally by French scientists in 1992 but wasn't confirmed to be a virus until 2003.
The virus infects amoebas, but it is thought to possibly be a human pathogen because antibodies to the virus have been discovered in pneumonia patients. However, many details about the virus remain unknown, said Michael Rossmann, Purdue University's Hanley Distinguished Professor of Biological Sciences.
Now a team of researchers from Purdue, the University of California at Irvine and the University of the Mediterranean in Marseilles, France, have thrown more light on the mimivirus' makeup.
The scientists have determined the basic design of the virus' outer shell, or capsid, and also of the hundreds of smaller units called capsomeres making up this outer shell. Findings also confirmed the existence of a starfish-shaped structure that covers a "special vertex," an opening in the capsid where genetic material leaves the virus to infect its host, and an indentation in the virus's genetic material itself is positioned opposite this opening, Rossmann said.
"The findings are important in terms of studying the evolution of cells, bacteria and viruses," said Siyang Sun, a postdoctoral research associate working in Rossmann's lab. "The mimivirus is like an intermediate between a cell and a virus. We usually think of cells as being alive and a virus is thought of as being dead because it needs a host cell to complete its life cycle. The mimivirus straddles a middle ground between viruses and living cells, perhaps redefining what a virus is.”
The virus approaches the size of bacteria and is about half of a micron in diameter, more than 10 times larger than the virus that causes the common cold and large enough to be seen with a light microscope. Other viruses are too small to be seen with conventional light microscopes.
The findings are detailed in a research paper that will appear online April 28 in the journal PLoS Biology, published by the Public Library of Science, a nonprofit organization of scientists and physicians. The paper's lead author was Chuan Xiao, a former Purdue postdoctoral research associate and now an assistant professor in the Department of Chemistry at the University of Texas at El Paso.
Researchers had previously been unable to determine the virus's structure because they had assumed that, like many other viruses, it's capsid possessed a design known as icosahedral symmetry.
Xiao discovered the true structure when he decided to try reconstructing the virus assuming it possessed not standard icosahedral symmetry but another configuration called five-fold symmetry.
"If you start out thinking the object has icosahedral symmetry, then you assume there are 60 identical pieces, and that influences how you reconstruct the virus's structure," Rossmann said.
Researchers took images of the virus using an atomic force microscope, revealing a pattern of holes regularly spaced throughout the virus's outer shell.
"The capsids of most other large, pseudo icosahedral viruses do not contain such holes, and their function is unknown," Rossmann said.
The researchers used a method called cryo-electron microscopy reconstruction to determine the structure details. The reconstruction method enables researchers to produce three-dimensional structures by combining two-dimensional pictures, much like a complete architectural drawing of a house can be assembled with two-dimensional drawings of the sides, the roof and other elements.
Using five-fold symmetry revealed that one side of the virus's capsid is slightly different than the others, whereas all sides are the same in a regular icosahedron.
An icosahegron has a roughly spherical shape containing 20 triangular facets and 60 identical subunits. Like an icosahedron, the mimivirus capsid also has 20 facets. However, unlike an icosohedron, five facets of the capsid are slightly different than the others and surround the special vertex. Icosohedra contain 12 similar vertices, whereas the mimivirus contains eleven such vertices, with the 12th being different than the others.
The new reconstructed picture of the virus matched features seen using the atomic force microscope picture, Rossmann said.
The starfish-shaped feature apparently opens up like a blooming flower when the virus is ready to infect its host amoeba, enabling the virus to eject its DNA for insertion into the host, Rossmann said.
"In addition, we think the indentation of the genetic material has something to do with how the genome comes out of the virus," he said. "There is a relationship between the shape of the genome and the special vertex."
The research, which is funded by the National Institutes of Health, is ongoing, with future work probing additional properties of the virus, particularly the structure of the starfish-shaped feature and how it functions.
The paper was written by Xiao; microscope expert Yurii G. Kuznetsov in the Department of Molecular Biology and Biochemistry at UC Irvine; Sun; postdoctoral research associates Susan L. Hafenstein and Victor A. Kostyuchenko and electron microscopist Paul R. Chipman, from Purdue; research scientist Marie Suzan-Monti and Didier Raoult, a professor of microbiology, both from the University of the Mediterranean; Alexander McPherson, a professor of molecular biology and biochemistry at UC Irvine; and Rossmann.
Publicado por Nathaniel en 10:26 No hay comentarios:
Bigfoot Hoax: "Body" Is Rubber Suit
Two men claiming in August 2008 to have found the corpse of a Bigfoot—a legendary apelike creature said to roam North America—offered meager evidence, including this allegedly phony photograph.
Now the "body" has been exposed as this rubber ape costume.
As far as Bigfoot hoaxes go, it was short-lived one.
Only days after Georgia residents Matt Whitton and Rick Dyer told reporters at a press conference on Friday that they had a dead Bigfoot body, their evidence has been exposed as a rubber ape costume.
The deception was made public by the very company Whitton and Dyer teamed up with to announce their supposed find.
In a statement posted on the Web site of Searching for Bigfoot Inc., "Sasquatch Detective" Steve Kulls said he realized the Bigfoot "corpse" was a fake when the frozen body began to thaw—after the press conference had already taken place.
Kulls wrote that he and a colleague plucked a few hairs from the defrosting body and burned them for analysis, but became suspicious when they "melted into a ball uncharacteristic of hair."
More ominous signs emerged as the ice encasing the body began to melt away.
"Within the next hour of thaw, a break appeared up near the feet area," Kulls wrote. "As the team and I began examining this area near the feet, I observed the foot, which looked unnatural, reached in and confirmed it was a rubber foot."
Kulls wrote that he immediately informed Searching for Bigfoot CEO Tom Biscardi about the discovery. Upon confrontation, Whitton and Dyer reportedly admitted to the hoax.
However, many elements of Kulls's account sharply contradict earlier statements made by Biscardi, who stood alongside Whitton and Dyer at the press conference in Palo Alto, California, last Friday.
At the conference, Biscardi said he had flown to Georgia and had actually seen, touched, and prodded the body and was satisfied it "was not a mask sewn on a bear hide." Furthermore, Biscardi said Friday that Whitton and Dyer had already given him the Bigfoot body and that it was being kept at an undisclosed location.
But according to Kulls, the body was not delivered to Searching for Bigfoot Inc. or examined in detail until after the press conference.
Biscardi did not return calls for comment.
Hoax a Crime?
"It's probably a crime, what they're doing," said Matthew Moneymaker, president of the Bigfoot Field Researchers Organization (BFRO), an international network of Bigfoot investigators.
BFRO is pushing for Biscardi, Whitton, and Dyer to be prosecuted for fraud.
"Warrants need to be issued immediately before Biscardi leaves the country," according to a statement on the BFRO Web site.
Shortly after the Bigfoot press conference last week, a message appeared on the Searching for Bigfoot Web site offering viewers a chance to see more photographs of the body for U.S. $2.
"Millions of people around the world wanted to see the photos, and Biscardi may have raked in a tidy sum," the BFRO site states.
Agent Dan Ryan of the Palo Alto police department remembers Biscardi as being part of another Bigfoot hoax a few years ago.
He told National Geographic News that the recent scam might be considered a crime—if it is discovered the group profited from it.
"If it's over the Internet, anyone could [prosecute] it, whether Georgia or here or wherever," Ryan said.
Publicado por Nathaniel en 10:22 No hay comentarios:
"Skeleton of Giant" Is Internet Photo Hoax
Blogs, emails, and even a newspaper have used this "photograph" to back up reports that the National Geographic Society had discovered an ancient race of giant humans. But the skeleton image is actually a digital collage of three different photos. A Canadian illustrator created it in 2002 for a photo-manipulation contest.
The National Geographic Society has not discovered ancient giant humans, despite rampant reports and pictures.
The hoax began with a doctored photo and later found a receptive online audience—thanks perhaps to the image's unintended religious connotations.
A digitally altered photograph created in 2002 shows a reclining giant surrounded by a wooden platform—with a shovel-wielding archaeologist thrown in for scale.
By 2004 the "discovery" was being blogged and emailed all over the world—"Giant Skeleton Unearthed!"—and it's been enjoying a revival in 2007.
The photo fakery might be obvious to most people. But the tall tale refuses to lie down even five years later, if a continuing flow of emails to National Geographic News are any indication. (The National Geographic Society owns National Geographic News.)
The messages come from around the globe—Portugal, India, El Salvador, Malaysia, Africa, the Dominican Republic, Greece, Egypt, South Africa, Kenya. But they all ask the same question: Is it true?
Perpetuating the Myth
Helping to fuel the story's recent resurgence are a smattering of media outlets that have reported the find as fact.
An often cited March 2007 article in India's Hindu Voice monthly, for example, claimed that a National Geographic Society team, in collaboration with the Indian Army, had dug up a giant human skeleton in India.
"Recent exploration activity in the northern region of India uncovered a skeletal remains of a human of phenomenal size," the report read.
The story went on to say the discovery was made by a "National Geographic Team (India Division) with support from the Indian Army since the area comes under jurisdiction of the Army."
The account added that the team also found tablets with inscriptions that suggest the giant belonged to a race of superhumans that are mentioned in the Mahabharata, a Hindu epic poem from about 200 B.C.
"They were very tall, big and very powerful, such that they could put their arms around a tree trunk and uproot it," the report said, repeating claims that initially appeared in 2004.
Voice editor P. Deivamuthu admitted to National Geographic News that his publication was taken in by the fake reports.
The monthly, which is based in Mumbai (Bombay), published a retraction after readers alerted Deivamuthu to the hoax, he said.
"We are against spreading lies and canards," Deivamuthu added. "Moreover, our readers are a highly intellectual class and will not brook any nonsense."
Other blog entries—such as a May 2007 posting on a site called Srini's Weblog—cite a report supposedly published in the Times of India on April 22, 2004. But a search of that newspaper's archive revealed no such article.
Variations of the giant photo hoax include alleged discovery of a 60- to 80-foot long (18- to 24-meter) human skeleton in Saudi Arabia. In one popular take, which likewise first surfaced in 2004, an oil-exploration team is said to have made the find.
Here the skeleton is held up as evidence of giants mentioned in Islamic, rather than Hindu, scriptures.
Web sites dedicated to debunking urban legends and "netlore" picked up on the various giant hoaxes soon after they first appeared.
California-based Snopes.com, for example, noted that the skeleton image had been lifted from Worth1000, which hosts photo-manipulation competitions.
Titled "Giants," the skeleton-and-shoveler picture had won third place in a 2002 contest called "Archaeological Anomalies 2."
The image's creator—an illustrator from Canada who goes by the screen name IronKite—told National Geographic News via email that he had had nothing to do with the subsequent hoax.
He added that he wants to remain anonymous because some forums that debated whether the giant was genuine or not "were turning their entire argument into a religious one." It was argued, for instance, that the Saudi Arabian find was entirely consistent with the teachings of the Koran.
"This was about the same time that death threats and cash bounties were being issued against cartoonists and other industry professionals for doing things like depicting the Prophet Mohammed," IronKite wrote.
How the Image Was Made
IronKite started with an aerial photo of a mastodon excavation in Hyde Park, New York, in 2000. He then digitally superimposed a human skeleton over the beast's remains.
The later addition of a digging man presented the biggest technical challenge.
"If you look, he's holding a yellow-handled shovel, but there's nothing on the end," IronKite said.
"Originally, the spade end was there. But [it] looked like it was occupying the exact same space as the skeleton's temple, making the whole thing look fake.
"Now it looks like he's just holding a stick, and people don't notice. It's funny."
IronKite also altered the color of the man's clothing to create a "uniform tie-in" with the white-shirted observer peering down from the wooden platform.
The two figures work to exaggerate the scale of the skeleton, he added.
IronKite said he's tickled that the picture—which took only about an hour and a half to create—has generated so much Internet attention.
"I laugh myself silly when some guy claims to know someone who was there, or even goes so far as to claim that he or she was there when they found the skeleton and took the picture," IronKite said.
"Sometimes people seem so desperate to believe in something that they lie to themselves, or exaggerate in order to make their own argument stronger."
Wanting to Believe
David Mikkelson of Snopes.com said such hoaxes succeed when they seem to confirm something people are already inclined to believe, such as a prejudice, political viewpoint, or religious belief.
A hoax also needs to be presented "in a framework that has the appearance of credibility," he said in an email.
The "ancient giant" has both elements, according to Mikkelson.
"It appeals to both a religious and a secular vision of the world as different and more fantastic than mere science would lead us to believe," he said.
"Proof," Mikkelson added, "comes in the form of a fairly convincing image."
For anyone who may have knowingly propagated the myth, Mikkelson added, the motivation "probably wasn't any different than the motivation for engaging in a game of ringing someone's doorbell and running away—because it's an easy way to have a laugh at someone else's expense."
Alex Boese, "curator" of the virtual Museum of Hoaxes, said fake giants have a long history going back to the at least the 1700s.
The recent hoax is reminiscent of the once famous Cardiff Giant myth, involving a ten-foot-tall (three-meter) stone figure dug up in 1869 in Cardiff, New York, Boese said.
Many people believed the figure was a petrified man and claimed he was one of the giants mentioned in the Bible's Book of Genesis: "There were giants in the Earth in those days."
Likewise, Boese said, the recent giant hoax "taps into people's desire for mystery and their desire to see concrete confirmation of religious legends."
National Geographic News photo editor Sebastian John contributed to this report.
Publicado por Nathaniel en 10:19 No hay comentarios:
Dust Older Than the Sun Found in Earth's Atmosphere
Dust grains scooped up from Earth's atmosphere contain some of the most primitive matter known, according to an April 2009 study.
The grains, carried to Earth in the tail of a comet, contain materials that date back before the sun was born.
Meteorites on the ground or icy comets millions of miles away are usually the only sources of ancient matter from the early days of the solar system.
But in a high-flying experiment, researchers have used a sort of chemical flypaper to scoop up comet dust from Earth's atmosphere—and it appears to be some of the oldest matter in our cosmic neighborhood.
The ancient specks, some of which are more than 4.5 billion years old, may support the theory that an exploding star helped trigger the birth of our sun.
The dust has survived in an unaltered state for so long because it got swept up during the formation of icy comets, researchers say.
"Comets are like refrigerators for this material," said study leader Henner Busemann, an astrophysicist at the University of Manchester in the U.K.
"They store this very pristine material, which never changes again."
Dust From the Sun's Nursery
Busemann and colleagues collected the particles in April 2003, as Earth spun through the dusty tail of comet 26P/Grigg-Skjellerup.
The team asked NASA to fly an airplane at about 12 miles (20 kilometers) up for several hours during the comet's visit, using instruments equipped with silicon oil to capture particles trapped in the upper atmosphere.
By comparing the dust to samples collected from comet-smashing probes such as Deep Impact and Stardust, the scientists were able to tell that the particles in Earth's atmosphere came from 26P/Grigg-Skjellerup.
(Related: "Stardust's Comet Clues Reveal Early Solar System.")
The team's analysis also shows that two of the grains have a unique chemical fingerprint linking them to the huge gas cloud scientists think was our sun's stellar nursery.
Also, one of the dust particles contains grains of material that match predictions for the types of matter expected to form in the cooling gas left over after a supernova explosion.
Scientists have speculated that shockwaves from a nearby supernova helped trigger the birth of our sun, and some of the comet material could have originated from that blast, Busemann said.
The astrophysicist presented his research last week at the European Week of Astronomy and Space Science conference at the University of Hertfordshire in the U.K.
Publicado por Nathaniel en 10:17 No hay comentarios:
Giant Pterosaurs Couldn't Fly, Study Suggests
Above, one of the best preserved pterosaur fossils lies embedded in a slab of limestone at a museum in Munich, Germany.
Giant pterosaurs, winged reptiles that lived alongside the dinosaurs, wouldn't have been able to flap fast enough to get off the ground or keep themselves airborne, according to an April 2009 study of how modern birds soar.
Giant pterosaurs, colossal winged reptiles that lived alongside the dinosaurs, have long been considered the heaviest animals ever to take to the skies.
But new research suggests that the notion of giant pterosaurs soaring over Earth simply doesn't fly.
Based on the weights and body sizes of modern birds, a new study finds that animals heavier than 90 pounds (41 kilograms) with wingspans greater than 16.7 feet (5.1 meters) wouldn't be able to flap fast enough to stay aloft.
The conclusion casts serious doubt on the flying ability of large pterosaurs such as Quetzalcoatlus, thought to be one of the largest airborne animals of all time.
The late-Cretaceous creature may have weighed up to 551 pounds (250 kilograms) and had up to a 34.1-foot (10.4-meter) wingspan—nearly as wide as a schoolbus is long.
"I think that the giant pterosaurs could not stay aloft in an environment similar to the present," said study leader Katsufumi Sato, an associate professor at the University of Tokyo's Ocean Research Institute.
Even if they could stay up, the bulky beasts would have had trouble getting off the ground in the first place, Sato said.
"Takeoff is the hardest task. I suppose they could not take off using only muscular efforts."
Sato, who is also a National Geographic Society emerging explorer, journeyed to the southern Indian Ocean to study the world's largest bird, the wandering albatross, and four smaller bird species. (The National Geographic Society owns National Geographic News.)
All five species are considered to be soaring birds—flyers that use a strategy of gliding punctuated by sporadic flapping, as pterosaurs are generally thought to have flown.
The researcher outfitted 26 birds with tiny accelerometers, which collected data on their flapping speeds from takeoff to landing.
Comparing the data across species, Sato found that the flapping speeds required for a bird to take off and then stay cruising are linked to its body size.
He and his team calculate that 22 pounds (10 kilograms)—the weight of a large wandering albatross—is the "pragmatic limit" for safe and sustainable flight in variable wind conditions.
Sato's findings, appearing tomorrow in the journal PLoS ONE, also suggest that, in theory, a soaring flyer can weigh no more than 90 pounds (41 kilograms) with a wingspan no wider than 16.7 feet (5.1 meters).
Other scientists are not quite convinced that Sato's research means large pterosaurs couldn't get airborne.
"One possibility is that Sato's findings don't really apply to pterosaurs or even to all birds," suggested Davin Unwin, a paleobiologist at the University of Leicester in the U.K.
For example, Argentavis, a giant bird thought to have existed six million years ago, had a wingspan of 20 feet (6 meters) and seems to have been able to fly, Unwin said.
What's more, Unwin said, giant pterosaur fossils all seem to have extraordinarily thin bone walls, which could mean the animals were lighter than their size would suggest.
Makoto Manabe, a senior scientist at the National Museum of Nature and Science in Tokyo, also thinks it's possible that pterosaurs were simply lighter than we currently think.
Or, if pterosaurs couldn't fly, Manabe wonders whether they might have been swimmers, "using their wings as fins like penguins."
"Having said that," he added, "their wings do not look very efficient at swimming."
According to study leader Sato, it's possible heavy pterosaurs overcame their difficulties during takeoff by launching themselves from high places such as trees or cliffs.
But if pterosaurs really were capable of sustained flight, "we must think about the possibility of drastic change in other environmental factors, such as much lighter gravity or much denser air over geological time," he said.
In general, Sato thinks the reactions from paleontologists have been "not so negative," despite the fact that his conclusions would bring huge pterosaurs abruptly down to Earth.
He is expecting his biggest critic to be much closer to home.
"My six-year-old son, Takuto, is a dinosaur freak," he said, "and will never agree with my findings."
Publicado por Nathaniel en 10:15 No hay comentarios:
Swine Flu Facts, Swine Flu Myths
Wearing face masks to ward off swine flu, worshipers gaze up at Our Lady of Guadalupe's in Mexico City's Basilica de Guadalupe on Sunday, April 26, 2009.
The Catholic church, Mexico's biggest, was shut down and Masses were canceled to prevent large gatherings, which encourage swine flu transmission.
The deadly, contagious new swine flu strain that sprang into being in Mexico and began setting off fears of a pandemic this past weekend has raised a lot of questions. To answer a few of the biggest, National Geographic News turned to the experts.
Q: How safe is eating pork?
A: As safe as it ever was.
Handling and consuming animal products, such as pork, can transmit some viruses. But that's not how the H1N1 swine flu virus is spreading, said Christine Layton, a public health policy analyst with the North Carolina-based nonprofit research institute RTI International.
Swine flu is a respiratory virus, spread from person to person. In other words: A sneezing chef is a threat, not the spare ribs he's basting.
In fact, if the swine flu virus were primarily being transmitted from pigs to people, public health officials probably wouldn't be so concerned. That kind of transmission tends to limit a virus's human spread to farmers and meat workers—people who are likely to come into contact with animals' bodily fluids.
(Related: swine flu pictures.)
Q. Can those face masks really protect me from swine flu?
A. Yes and no.
The blue surgical masks you've seen being passed out to Mexican pedestrians are better than nothing but probably only marginally useful, said Andrew Pekosz, associate professor of microbiology and immunology at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland.
While such masks block the relatively large, virus-carrying droplets sneezed out by infected people, the viruses themselves are much smaller and could easily pass through. Specialty masks, designated N-95 or N-99, are better filters but still not perfect.
For better protection, Pekosz recommends combining a mask with regular hand washing and keeping 3 to 4 feet (90 to 120 centimeters) away from other people.
Q. Is this just another media health scare? How worried should we be?
A. The truth lies somewhere in between panic and eye-rolling.
Making the jump from animal-to-person to person-to-person transmission is a rare skill for a flu virus to "learn." This ability makes H1N1 swine flu potentially dangerous—and makes the concern about it a bit different from the worries over bird flu, which has yet to make such a transition.
Human-to-human transmission is a big part of why public health officials are pouring resources into swine flu and why they want you to be aware that the virus is out there.
That said, experts like Johns Hopkins's Pekosz and RTI's Layton say there's currently no reason to lock yourself up in the house.
For one thing, the cases outside Mexico have been no more serious than your average flu bug. Right now, nobody is sure why that is. And while the severity of the symptoms could increase, Pekosz said there's not really an immediate, serious threat to individuals within the United States.
"However," he said, "it certainly merits the public paying attention, and it warrants the public health efforts that have been going on in terms of monitoring and research."
Q. How does a pig-bird-human mash-up swine flu virus happen, anyway?
A. Blame the pigs, and the virus.
Flu viruses are "very messy reproducers," RTI's Layton said.
All eight flu genes replicate independently. If a cell is infected with three different flu viruses, reproduction can mean a reshuffling of genetic material from multiple parents, thrown together randomly into the "baby" flu virus.
Most of the time, those cut-and-paste viruses don't work out very well, Johns Hopkins's Pekosz said. But every so often, this natural reassortment will come up with a new flu virus that has some kind of advantage over its competitors.
H1N1 swine flu is one of those, but we've certainly seen others in the past 30 years, he said. Pigs are part of the problem because they can become infected with flu viruses from birds and humans. As such, swine seem to provide a particularly good environment for this genetic square dance to take place.
Publicado por Nathaniel en 10:13 No hay comentarios:
Laser-Controlled Humans Closer to Reality
Flashes of light may one day be used to control the human brain, and that day just got a lot closer.
Using lasers, researchers at the MIT Media Lab were able to activate a specific set of neurons in a monkey’s brain. Though the technique has been used to control and explore neural circuits in fish, flies, and rodents, this is the first time the much-hyped technology has ever been used in primates.
“It paves the way for new therapies that could target a number of psychiatric disorders,” said MIT neuroscientist Ed Boyden, who led the research with post-doctoral fellow Xue Han. “This is very exciting from a translational standpoint.”
The beauty of this optogenetic technique is its specificity. By using a combination of lasers and genetic engineering, scientists can control, to the millisecond, the firing of a specific class of neurons, allowing them to pinpoint problematic cells and circuits while leaving innocent bystanders alone, thus minimizing potential side effects.
Viruses are engineered to infect neurons with a special type of channel, originally discovered in algae, which is sensitive to blue light. Once a blue laser shines on the infected neurons, the channels snap open, ions rush into the cell and the neuron fires.
Crucial to the technique is that the virus is only injected into a very small part of the brain, and only a certain class of neurons, once infected, actually turn the channel on. The sharp laser beam further zeroes in on a small portion of the brain. This precise aim is in contrast to current techniques, such as drugs and electrodes, both of which have a much broader reach.
The optogenetic method was pioneered in 2005 by Boyden and Karl Deisseroth, at Stanford University, and has since been used to understand how circuits of neurons control various behaviors, such as learning in mice and predator escape in fish. But until now, scientists had never demonstrated the technique in primates — a move essential for developing therapeutic uses for the technology in humans.
Boyden’s new research, published Wednesday in Neuron, demonstrates not only that the technology works in primates, but also that it is safe. The rhesus macaques received multiple rounds of injections and laser stimulations over the course of eight or nine months without damaging the neurons or activating the brain’s immune system, an obvious concern when viruses are involved.
“Many disorders are associated with changes in specific cell types,” said Boyden. “For therapeutic purposes, you want to affect certain cells but you want to leave normal cells intact. The ability to use light to turn specific cells on and off with very precise timing could in principle allow new therapies.”
Future applications could involve using light-emitting neural prosthetics to replace the electrodes used in deep brain stimulation, which currently activate or silence a broad range of neurons. Deep brain stimulation has shown promise in treatments of Parkinson’s disease, epilepsy and depression, but it has a number of side effects, stemming in part from its lack of specificity.
“Our ability to remedy problems in the brain may ultimately be limited by how many side effects occur,” said Boyden. “We could find ways to shut down seizures but the side effects might be intolerable. By pinpointing specific cell types, we could craft therapeutic neuromodulators and directly develop therapies, while preserving a high degree of well-being.”
Proving the method works in primate brains paves the way not only for cleaner therapies, but also for understanding the relationship between specific neural circuits and behaviors, particularly higher cognitive functions.
Genetically, mice are ideal model organisms — but their behavioral repertoire isn’t very sophisticated. If neuroscientists hope to understand and treat problems like ADHD, schizophrenia, depression and compulsive behaviors like addiction, they can run far more powerful experiments using primates.
“This is a very important and exciting step forward for all systems neuroscience,” said a neuroscientist who preferred to remain anonymous due to recent attacks against primate researchers.
“There are many limitations with the current way we try to understand neural circuits, primarily the lack of specificity. The hope is that as this sort of research continues in labs around the world, it will become possible to specifically target many different classes of neurons. We can learn how each of them contributes to specific cognitive functions.”
Publicado por Nathaniel en 10:11 No hay comentarios:
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