Science & TechnologyS


Info

Archaeologists Trace Early Irrigation Farming In Ancient Yemen


Terra Daily
Mon, 21 Jul 2008 01:19 UTC
In the remote desert highlands of southern Yemen, a team of archaeologists have discovered new evidence of ancient transitions from hunting and herding to irrigation agriculture 5,200 years ago.

Image
©SPX File Photo
Southern Yemen.

As part of a larger program of archaeological research, Michael Harrower from the University of Toronto and The Roots of Agriculture in Southern Arabia (RASA) team explored the Wadi Sana watershed documenting 174 ancient irrigation structures, modeled topography and hydrology, and interviewed contemporary camel and goat herders and irrigation farmers.

"Agriculture in Yemen appeared relatively late in comparison with other areas of the Middle East, where farming first developed near the end of the last ice age about 12,000 years ago," says author Michael Harrower, Department of Anthropology, University of Toronto.

"It's clear early farmers in Yemen faced unique environmental and social opportunities and challenges. Our findings show farming in southern Yemen required runoff diversion technologies that were adapted to harness monsoon (summer) runoff from the rugged terrain along with new understandings of social landscapes and rights to scarce water resources."
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Telescope

NASA Spacecraft Shows Diverse, Wet Environments On Ancient Mars


Mars Daily
Sun, 20 Jul 2008 22:07 UTC
Two studies based on data from NASA's Mars Reconnaissance Orbiter have revealed that the Red Planet once hosted vast lakes, flowing rivers and a variety of other wet environments that had the potential to support life.

One study, published in the July 17 issue of Nature, shows that vast regions of the ancient highlands of Mars, which cover about half the planet, contain clay minerals, which can form only in the presence of water.

Image
©NASA/JPL/JHUAPL/MSSS/Brown University
A color-enhanced image of the delta in Jezero Crater, which once held a lake. Researchers led by CRISM team member and Brown graduate student Bethany Ehlmann report that ancient rivers ferried clay-like minerals (shown in green) into the lake, forming the delta. Clays tend to trap and preserve organic matter, making the delta a good place to look for signs of ancient life.

Volcanic lavas buried the clay-rich regions during subsequent, drier periods of the planet's history, but impact craters later exposed them at thousands of locations across Mars. The data for the study derives from images taken by the Compact Reconnaissance Imaging Spectrometer for Mars, or CRISM, and other instruments on the orbiter.

"The big surprise from these new results is how pervasive and long-lasting Mars' water was, and how diverse the wet environments were," said Scott Murchie, CRISM principal investigator at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.
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Telescope

Dwarf planet near Pluto named for Polynesian god

Maggie Fox
Reuters
Sat, 19 Jul 2008 19:50 UTC
A dwarf planet orbiting beyond Neptune has been designated the third plutoid in the solar system and given the name Makemake, the International Astronomical Union said on Saturday.

The red methane-covered dwarf planet formerly known as 2005 FY9 or "Easterbunny" is named after a Polynesian creator of humanity and god of fertility.

Just last month the IAU, which names planets and other heavenly bodies, decided to create a new class of sub-planets called plutoids.

Pluto, demoted from planet status, and Eris are the other two plutoids. A fourth dwarf planet named Ceres has been excluded from the plutoid club because it orbits in the asteroid belt between Mars and Jupiter.
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Rocket

NASA used cadavers in Orion landing tests

Mark Carreau
Houston Chronicle
Fri, 18 Jul 2008 18:59 UTC
Personnel working under contract for NASA used cadavers in tests to develop landing systems, spacesuits and seats in the new Orion moonship, space agency officials said Friday. Three human bodies were used in the tests at Ohio State University Medical Center last summer and fall.
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People

Understanding the false consensus effect

Praveen Aggarwal & Rajiv Vaidyanathan
livemint.com
Sun, 20 Jul 2008 16:31 UTC
Research has shown that people tend to believe that most others are similar to them in their beliefs, attitudes, and behaviour.

Comment: It's unfortunate that the authors didn't think to include - maybe because of the very effect under discussion - a far more crucial example: the destructive effect of pathological deviants in our society.

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Info

New Photonic Integrated Circuit sends Internet speeds through the roof

Stevie Smith
The Tech Herald
Thu, 10 Jul 2008 13:12 UTC


University of Sydney
©SeaBob/Flickr
Scientists at the University of Sydney claim increased Internet speeds 100 times greater than current networks.

Bemoaning the poor load speed of Web pages or the crawl of media downloads could soon become a thing of the past following news that a team of Australian scientists have developed a technology capable of making the Internet up to 100 times faster than the current top-end performance offered by leading network providers.
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Cloud Lightning

Researchers question lightning's link to X-rays


Xinhuanet
Fri, 18 Jul 2008 02:20 UTC
Beijing -- Many of the basics of lightning have been revealed, but scientists admit they don't really understand how lighting gets from one place to another and lightning link to X-rays is still a mystery.

"Nobody understands how lightning makes X-rays," says Martin Uman, a professor of electrical and computer engineering at the University of Florida. "Despite reaching temperatures five times hotter than the surface of the sun, the temperature of lightning is still thousands of times too cold to account for the X-rays observed.

"It's obviously happening. And we have put limits on how it's happening and where it's happening."

As lightning comes down from a cloud, it moves in steps, each 30 to 160 feet long. In this "step leader" process, X-rays shoot out just below each step millionths of a second after the step completes, the researchers learned.
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Meteor

Tunguska catastrophe: Evidence of acid rain supports meteorite theory


Science Centric
Sat, 19 Jul 2008 18:17 UTC
The Tunguska catastrophe in 1908 evidently led to high levels of acid rain. This is the conclusion reached by Russian, Italian and German researchers based on the results of analyses of peat profiles taken from the disaster region.
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Fish

Human Speech Traced to Talking Fish


Live Science
Sat, 19 Jul 2008 16:47 UTC
From Don Knotts' portrayle of "Mr. Limpet" to the children's favorite "Nemo" and the tuna-pitching character in the "Sorry, Charlie" commercials, we all have seen fish that can talk. But that's just fiction, right? Well ...

Researchers say real fish can communicate with sound, too. And they say (the researchers, that is) that your speech skills and, in fact, all sound production in vertebrates can be traced back to this ability in fish. (You got your ears from fish, too.)

The new study was led by Andrew Bass (we did not make this up) of Cornell University.

The scientists mapped developing brain cells in newly hatched midshipman fish larvae and compared them to those of other species. They found that the chirp of a bird, the bark of a dog and all the other sounds that come out of animals' mouths are the products of the neural circuitry likely laid down hundreds of millions of years ago with the hums and grunts of fish.

"Fish have all the same parts of the brain that you do," Bass explained.
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Einstein

Distribution Of Creatures Great And Small Can Be Predicted Mathematically


Science Daily
Sat, 19 Jul 2008 16:17 UTC
In studying how animals change size as they evolve, biologists have unearthed several interesting patterns. For instance, most species are small, but the largest members of a taxonomic group -- such as the great white shark, the Komodo dragon, or the African elephant -- are often thousands or millions of times bigger than the typical species.

Elephant matriarch cow
©iStockphoto/Jonathan Heger
Elephant matriarch cow leading a herd. Most species are small, but the largest members of a taxonomic group -- such as the great white shark, the Komodo dragon, or the African elephant -- are often thousands or millions of times bigger than the typical species.

Now for the first time two SFI researchers explain these patterns within an elegant statistical framework.

"The agreement between our model and real-world data is surprisingly close," says SFI Postdoctoral Fellow Aaron Clauset, who, along with SFI Professor Douglas Erwin, presented the findings in a July 18 Science paper.
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