Science & TechnologyS


Info

A Mayan mural shows how the other half lived

Stéphan Reebs
Natural History Magazine
Mon, 08 Mar 2010 19:41 UTC
Image
© Calakmul Archaeological Project1,300-year-old mural portrays a Mayan porter carrying a large vessel.
Very old artworks provide a fascinating glimpse of ancient life, but not without limitations: they typically portray the lifestyles of the rich and famous (rulers, royals, generals, and priests), abandoning the masses to the mists of history. That's why the recent discovery of a 1,300-year-old mural at Calakmul, Mexico, is so significant. It is the only known pre-Columbian artwork depicting ordinary Maya engaged in everyday activities, rather than serving the wealthy.
Read More...
People

Vast Majority of People Feel Internet Access is a Right

Tony Bradley
PC World
Mon, 08 Mar 2010 17:49 UTC
A recent survey conducted by the BBC found that the vast majority of users around the world consider access to the Internet to be a right. The speed at which Internet access has gone from a privilege, to a luxury, and now to a right is a testament to how transformative it has been--shaping politics, news, entertainment, research, and more.

While individual users have come to view Internet and Web access as a right, it seems almost ludicrous to consider it anything other than a complete necessity for businesses today. Part of the reason that the current initiatives of the United States FCC are so important is that an open Internet is a requirement for keeping the business playing field level, and access to reasonable broadband speeds is essential for conducting business efficiently and effectively.
Read More...
Telescope

Lava Likely Made River-Like Channel on Mars


ScienceDaily
Sun, 07 Mar 2010 20:00 UTC
Image
© Jacob BleacherDetails from the Ascraeus channel (red), meandering across the surface of Mars. The insets in the black boxes show close-ups of some of the structures that lava can form: (left) branched channels, (middle) a snaking channel and (right) rootless vents; the rootless vents are also marked by yellow spots on the main image.
Flowing lava can carve or build paths very much like the riverbeds and canyons etched by water, and this probably explains at least one of the meandering channels on the surface of Mars. These results were presented on March 4, 2010 at the 41st Lunar and Planetary Science Conference by Jacob Bleacher at NASA's Goddard Space Flight Center, Greenbelt, Md. Whether channels on Mars were formed by water or by lava has been debated for years, and the outcome is thought to influence the likelihood of finding life there.

"To understand if life, as we know it, ever existed on Mars, we need to understand where water is or was," says Bleacher. Geologists think that the water currently on the surface of Mars is either held in the soil or takes the form of ice at the planet's north and south poles. But some researchers contend that water flowed or pooled on the surface sometime in the past; water in this form is thought to increase the chance of some form of past or present life.

One of the lines of support for the idea that water once flowed on Mars comes from images that reveal details resembling the erosion of soil by water: terracing of channel walls, formation of small islands in a channel, hanging channels that dead-end and braided channels that branch off and then reconnect to the main branch. "These are thought to be clear evidence of fluvial [water-based] erosion on Mars," Bleacher says.
Read More...
Sherlock

Archaeologists Amend Written History of China's First Emperor


ScienceDaily
Mon, 08 Mar 2010 00:00 UTC
Image
© Linda M. NicholasRemnants of the massive rammed-earth platform on the lower eastern slopes of Langya Mountain. This platform was built just above the sea.
The exploits of China's first emperor, Qin Shihuangdi, are richly documented in 2,000-year-old records of his conquests across eastern China. His reign was indeed noteworthy -- he is responsible for initiating construction of the Great Wall, and the discovery of life-size terracotta soldiers that guard his tomb in central China has generated worldwide attention.

But as the saying goes, history is written by the winners. Ancient texts can contain inaccuracies favorable to a strong ruler's legacy. That's why two Field Museum scientists and their Chinese collaborator have integrated textual information with archaeological research in order to further understand the impact of Shihauangdi's reign.

The scientists are Gary Feinman and Linda Nicholas -- husband and wife anthropologists who, since 1996, have spent four to six weeks each year walking across fields in rural China looking for pottery sherds and other artifacts with colleagues including Fang Hui of the School of History and Culture at Shandong University. They compared ancient written records to archaeological evidence and the result of their work is a more holistic view of China's first emperor and his influence on the eastern province of Shandong.
Read More...
Info

Fabled past awaits in Sudan desert

Guillaume Lavallee
Agence France-Presse
Sun, 07 Mar 2010 13:48 UTC
There is not a tourist in sight as the sun sets over sand-swept pyramids at Meroe, but archaeologists say the Nubian Desert of northern Sudan holds mysteries to rival Egypt.

"There is a magic beauty about these sites that is heightened by the privilege of being able to admire them alone, with the pyramids, the dunes and the sun," Guillemette Andreu, head of antiquities at the Louvre museum in Paris, says. "It really sets them apart from the Egyptian pyramids, whose beauty is slightly overshadowed by the tourist crowds."

Meroe lies about 200 kilometres northeast of Sudan's capital Khartoum and was the last capital of Kush, also called Nubia, an ancient kingdom centred on the confluence of the Blue Nile, the White Nile and the Atbara River.

Kush was one of the earliest civilisations in the Nile valley and, at first, Egypt dominated it. The Nubians gained their independence and, at the height of their power, they turned the table on Egypt and conquered it in the 8th century BC. They occupied the entire Nile valley for a century before being forced back into what is now Sudan.
Read More...
Radar

Shields down! Earth's magnetic field may drop in a flash


New Scientist
Thu, 04 Mar 2010 17:33 UTC
Image
© NASA/SPLThere'll be little warning if Earth's magnetic field flips
Even if we knew precise details of Earth's core, we would not be able to predict a catastrophic flip in the polarity of its magnetic field more than a decade or two ahead.

Our planet's magnetic field has reversed polarity from time to time throughout its history. Some models suggest that a flip would be completed in a year or two, but if, as others predict, it lasted decades or longer we would be left exposed to space radiation. This could short-circuit satellites, pose a risk to aircraft passengers and play havoc with electrical equipment on the ground.

To test whether we would see a flip coming, Gauthier Hulot of Denis Diderot University in Paris, France, and colleagues ran computer simulations of Earth's magnetic dynamo based on a range of plausible values for inputs such as the viscosity, electrical and thermal conductivity of the outer core, and the temperature difference across it. The model's predictions remained consistent over this range of values for no more than a few decades, Hulot's team will report in Geophysical Research Letters. Their result implies that we can forecast a flip only this far in advance - and then only with data that is as precise as possible. "It's like predicting the weather," says Hulot.
Read More...
Blackbox

Universe's high-energy haze gets murkier

Rachel Courtland
New Scientist
Sat, 06 Mar 2010 17:25 UTC
Image
© NASA/DOE/Fermi LAT CollaborationThe source of most of the fog of gamma-ray light beyond the Milky Way is unknown
The universe's most powerful particle accelerators are responsible for just a fraction of the fog of gamma-ray light beyond the Milky Way, a new study suggests. The source of the rest remains a mystery, but dark matter could be a contributor.

The gamma-ray sky is dominated by the glow of our Milky Way as well as other known galaxies and individual neutron stars. But the universe is also aglow with a diffuse haze of gamma-ray light, produced by sources that may be too distant, dim, or diffuse to resolve individually.

By convention, astrophysicists have long assumed that most - if not all - of this gamma-ray fog gets its start inside galaxies whose supermassive black holes are spewing jets of charged particles into space as they feed on surrounding matter.

But a new analysis of data collected by NASA's Fermi telescope suggests these so-called active galactic nuclei (AGN) account for no more than 30 per cent of the universe's gamma-ray glow.

"Most of it - 70 per cent of the background - is unexplained at the moment," says study leader Marco Ajello of the Kavli Institute for Particle Astrophysics and Cosmology in Stanford, California. Ajello spoke with reporters on Tuesday at a meeting of the High Energy Astrophysics Division of the American Astronomical Society in Waikoloa, Hawaii.
Read More...
Satellite

NASA turned on by blow-up space stations

Paul Marks
New Scientist
Wed, 03 Mar 2010 17:12 UTC
NASA is planning to investigate making inflatable space-station modules to make roomier, lighter, cheaper-to-launch spacecraft, it reveals in its budget proposal released on 22 February. We look into the technologies involved.

Read More...
Meteor

Dark, Dangerous Asteroids found Lurking near Earth

David Shiga
New Scientist
Fri, 05 Mar 2010 13:49 UTC
Asteroid
© NASA/JPL-Caltech/UCLANow you see it: a near-Earth object becomes visible in infrared.
An infrared space telescope has spotted several very dark asteroids that have been lurking unseen near Earth's orbit. Their obscurity and tilted orbits have kept them hidden from surveys designed to detect things that might hit our planet.

Called the Wide-Field Infrared Survey Explorer (WISE), the new NASA telescope launched on 14 December on a mission to map the entire sky at infrared wavelengths. It began its survey in mid-January.

In its first six weeks of observations, it has discovered 16 previously unknown asteroids with orbits close to Earth's. Of these, 55 per cent reflect less than one-tenth of the sunlight that falls on them, which makes them difficult to spot with visible-light telescopes. One of these objects is as dark as fresh asphalt, reflecting less than 5 per cent of the light it receives.

Many of these dark asteroids have orbits that are steeply tilted relative to the plane in which all the planets and most asteroids orbit. This means telescopes surveying for asteroids may be missing many other objects with tilted orbits, because they spend most of their time looking in this plane.

Fortunately, the new objects are bright in infrared radiation, because they absorb a lot of sunlight and heat up. This makes them relatively easy for WISE to spot.
Read More...
Magnify

John Hopkins Research: Over a Decade of DNA Evidence May be Faulty

Jason Mick
Daily Tech
Thu, 04 Mar 2010 15:31 UTC
Image
A close up view shows a 3D animation of a mitochondria, a tiny symbiotic helper that lives inside human cells. DNA from mitochondria has been used since the mid 1990s in certain criminal cases.
Findings could lead to appeals nationwide, if verified

"You've got the wrong man! I'm innocent!"

Many perfectly guilty criminals insist that, but what if it was true? That indeed could be true in some cases, as a new revelation casts doubt on certain verdicts in the U.S. Justice system delivered since the mid-1990s. It stems from an important finding made by a team co-led by Nickolas Papadopoulos, a Johns Hopkins University geneticist. The team discovered that DNA from tiny symbiotic bacterial-descendants called mitochondria that live in our cells and give them energy varies from tissue to tissue in the human body.

The finding is significant as mitochondrial DNA analysis was considered a proven enough technique that U.S. law enforcement has been using it as a tool to identify criminals since the mid-1990s. Mitochondrial DNA analysis was often used in the cases where the human DNA was too damaged for accurate processing (there's numerous mitochondria in a cell, so there's a better chance of accurately processing it).
Read More...