Science & TechnologyS


Meteor

Did a comet strike Earth, leaving crystalline dust in the Oklahoma Panhandle?


The Oklahoman
Mon, 02 Feb 2009 16:27 UTC
A giant comet slammed into the atmosphere and fractured. The resulting swarm of fragments also exploded, scattering tiny diamonds in widely separated locations and plunging the warming Earth into a renewed and deadly deep freeze.

When Leland Bement first heard the theory, "I was highly skeptical," he said. "You just roll your eyes."

But a discovery in the Oklahoma Panhandle changed his viewpoint. It began when Bement, research archaeologist with the Oklahoma Archaeological Survey, was contacted by a team of scientists who had read about Bement's research. For years, Bement had been studying remnants of Indian communities that existed around the end of the last Ice Age - about 13,000 years ago - in the area that is now the Panhandle.
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Meteor

Where Do Comets Come From?

Rachel Courtland
New Scientist
Mon, 02 Feb 2009 14:30 UTC
Comet Overhead
© Walter Pacholka, Astropics/SPLHale-Bopp, seen here from Joshua Tree National Park, California, was one of the brightest comets of the 20th century.
Few cosmic apparitions have inspired such awe and fear as comets. The particularly eye-catching Halley's comet, which last appeared in the inner solar system in 1986, pops up in the Talmud as "a star which appears once in seventy years that makes the captains of the ships err". In 1066, the comet's appearance was seen as a portent of doom before the Battle of Hastings; in 1456, Pope Callixtus III is said to have excommunicated it.

Modern science takes a more measured view. Comets such as Halley's are agglomerations of dust and ice that orbit the sun on highly elliptical paths, acquiring their spectacular tails in the headwind of charged particles streaming from the sun. We even know their source: they are Kuiper belt objects (KBOs) tugged from their regular orbits by Neptune and Uranus.

But there's a problem. Certain comets, such as Hale-Bopp, which flashed past Earth in 1997, appear simply too infrequently in our skies. Their orbits must be very long, far too long to have an origin in the Kuiper belt. The conclusion of many astronomers is that the known solar system is surrounded in all directions by a tenuous halo of icy outcasts, thrown from the sun's immediate vicinity billions of years ago by the gravity of the giant planets.
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Sherlock

Albania Reveals Ancient Treasures


China View
Mon, 02 Feb 2009 05:02 UTC
This sparkling stretch of the Ionian Sea is slowly giving rise to lost treasures dating back 2,500 years and shipwrecks from ancient times.

Over the past two years, a research ship carrying American and Albanian experts has combed the waters off southern Albania, using scanning equipment and submersible robots to seek out ancient wrecks. In what organizers have said is the first archaeological survey of Albania's seabed, at least five sites have been located, which could fill in blanks on ancient shipbuilding techniques.

"Albania is a tremendous untapped (archaeological) resource," U.S. archaeologist Jeffrey Royal from the Florida-based RPM Nautical Foundation, a nonprofit group leading the survey, said.
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Magnify

Turning Down Gene Expression Promotes Nerve Cell Maintenance


PhysOrg
Mon, 02 Feb 2009 10:57 UTC
Anyone with a sweet tooth knows that too much of a good thing can lead to negative consequences. The same can be said about the signals that help maintain nerve cells, as demonstrated in a new study of myelin, a protein key to efficient neuronal transmission.

Normal nerve cells have a myelin sheath, which, much like the insulation on a cable, allows for rapid and efficient signal conduction. However, in several diseases - the most well-known being multiple sclerosis - demyelination processes cause the breakdown of this "insulation", and lead to deficits in perception, movement, cognition, etc. Thus, in order to help patients of demyelinating disease, researchers are studying the pathways that control myelin formation and maintenance.
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Magnify

Single Gene Lets Bacteria Jump From Host To Host


PhysOrg
Sun, 01 Feb 2009 19:24 UTC
Gene
© William OrmerodThe diminutive bobtail squid, which feeds at night near the surface of the ocean, uses a luminescent bacterium to form a light organ that mimics moonlight and confuses predators.
All life -- plants, animals, people -- depends on peaceful coexistence with a swarm of microbial life that performs vital services from helping to convert food to energy to protection from disease.

Now, with the help of a squid that uses a luminescent bacterium to create a predator-fooling light organ and a fish that uses a different strain of the same species of bacteria like a flashlight to illuminate the dark nooks of the reefs where it lives, scientists have found that gaining a single gene is enough for the microbe to switch host animals.

The finding, reported this week (Feb. 1) in the journal Nature by a team of scientists from the University of Wisconsin-Madison, is important not only because it peels back some of the mystery of how bacteria evolved to colonize different animals, but also because it reveals a genetic pressure point that could be manipulated to thwart the germs that make us sick.
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Sherlock

How Ancient Greeks Chose Temple Locations

Graciela Flores
Natural History/LiveScience
Sat, 31 Jan 2009 18:03 UTC
To honor their gods and goddesses, ancient Greeks often poured blood or wine on the ground as offerings. Now a new study suggests that the soil itself might have had a prominent role in Greek worship, strongly influencing which deities were venerated where.

In a survey of eighty-four Greek temples of the Classical period (480 to 338 B.C.), Gregory J. Retallack of the University of Oregon in Eugene studied the local geology, topography, soil, and vegetation - as well as historical accounts by the likes of Herodotus, Homer, and Plato - in an attempt to answer a seemingly simple question: why are the temples where they are?
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Fish

Tropical Turtle Fossil Found in Arctic


LiveScience
Sun, 01 Feb 2009 14:13 UTC
The last place scientists expected to find the fossil of a freshwater, tropical turtle was in the Arctic. But they did.

The discovery, detailed today in the journal Geology, suggests animals migrated from Asia to North America not around Alaska, as once thought, but directly across a freshwater sea floating atop the warm, salty Arctic Ocean. It also provides additional evidence that a rapid influx of carbon dioxide some 90 million years ago was the likely cause of a super-greenhouse effect that created extraordinary heat in the polar region.
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Sherlock

Legendary British Warship 'Found?'


BBC News
Sun, 01 Feb 2009 15:25 UTC
Victory
© BBC NewsAn artist's impression of how HMS Victory may have looked.
A US-based salvage firm is believed to have found remains from the wreck of a legendary British warship which sank in the English Channel in 1744.

Odyssey Marine Exploration is expected to announce on Monday that it has found HMS Victory, the forerunner of Nelson's famous flagship of the same name.

The valuables from the vessel, including brass cannons, could be worth millions of pounds, some experts say.
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Rocket

Columbia Disaster Remembered; Shuttle Future Uncertain

Steve Grzanich
WBBM Newsradio 780
Sun, 01 Feb 2009 13:51 UTC
Chicago, ILL-- As the nation marks the sixth anniversary of the Space Shuttle Columbia disaster, questions remain about the future of the space program now that there's a new president. There is particular concern about the aging fleet of orbiters and proposals to extend the life of the shuttle program beyond its planned retirement next year.
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Telescope

Mystery Of Twin Quasar Brightness Revealed


Science Daily
Thu, 29 Jan 2009 02:30 UTC
Image
© Plataforma SINCThe researchers have confirmed that fluctuations in the brightness detected in image A were repeated 14 months later in Image B. If they had been caused by the gravity of planets or stars, the fluctuations in image A would not have been exactly replicated in image B.

Variations in the brightness of the Q0957+561 quasar, also known as the "twin quasar" due to its duplicated image on Earth, are intrinsic to the entity itself and not caused by the gravitational effects of possible planets or stars from a far away galaxy.

This is the conclusion of a study carried out by Spanish researchers resolving a mystery that has intrigued astronomers for the past 30 years.

The quasar Q0957+561, some 9 billion light years away in the Ursa Major constellation, was discovered in 1979 by an Anglo-American team. Since then scientists have managed to explain why two images are observed of the same object -separated by a little less than two thousandths of a degree in the sky-, but up until now had not been able to explain the origins of the "rapid" (lasting several months) variations in their brightness.
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