Science & TechnologyS


Magnet

Let There Be Light: Teaching Magnets To Do More Than Just Stick Around


ScienceDaily
Mon, 24 Aug 2009 10:00 UTC
Megnets
© Daniel Gamelin/University of WashingtonStrong dopant-exciton magnetic exchange coupling in doped QDs can allow formation of magnetic polarons, where the spins of the dopants spontaneously align with the exciton spin.
That palm tree magnet commemorating your last vacation is programmed for a simple function - to stick to your refrigerator. Similarly, semiconductors are programmed to convey bits of information small and large, processing information on your computer or cell phone.

Scientists are working to coax those semiconductors to be more than conveyers, to actually perform some functions like magnets, such as data recording and electronic control. So far most of those effects could only be achieved at very cold temperatures: minus 260 degrees Celsius or more than 400 below zero Fahrenheit, likely too cold for most computer users.

However, researchers led by a University of Washington chemist report on Aug. 21 in Science that they have been able to train tiny semiconductor crystals, called nanocrystals or quantum dots, to display new magnetic functions at room temperature using light as a trigger.

Silicon-based semiconductor chips incorporate tiny transistors that manipulate electrons based on their charges. Scientists also are working on ways to use electricity to manipulate the electrons' magnetism, referred to as "spin," but are still searching for the breakthrough that will allow "spintronics" to function at room temperature without losing large amounts of the capability they have at frigid temperatures.
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Sherlock

Relics Uncovered at University of Georgia's Building


Action News/The Associated Press
Sat, 22 Aug 2009 12:09 UTC
A renovation project on one of the University of Georgia's oldest buildings has turned into an archaeological treasure hunt, and after weeks of digging, the treasure pile just keeps growing.

Another relic from UGA's past turned up in New College's historic North Campus building days ago: a ticket to a long-ago UGA baseball game, buried in the dirt.

Though some of the letters are missing from the faded piece of paper, enough remained to see clearly the 50-cent ticket was issued by the UGA Athletic Association's Baseball Department.

Campus Architect Danny Sniff hopes retired UGA tennis coach and media relations director Dan Magill or someone else familiar with Bulldog athletic history will be able to help date the ticket.
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Telescope

Scientists Spy New Type of Death Star

Irene Klotz
Discovery News
Mon, 24 Aug 2009 15:22 UTC
Nebulae
© Royal Astronomical SocietyAn optical image of the brightest Radio Planetary Nebula, also known as super planetary nebulae, in the Small Magellanic Cloud, JD 04.
Astronomers have long wondered what happens to the dying bodies of stars somewhat bigger than the sun.

Objects roughly one-third to two-thirds the size of the sun blow out their mass into beautifully glowing shells of gas and dust called planetary nebulae.

But no similar structures have been found for stars about one to eight times the size of the sun.

Now a team of Australian and U.S. scientists think they have an answer: The bigger stars create planetary nebulae that radiate strongly in radio waves, as opposed to visible light. They call these new objects "super planetary nebulae."

"There's been a difference between what (these stars) should have shed and what has been assessed," astronomer Martin Cohen, with the University of California at Berkeley, told Discovery News.
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Sherlock

Archaeologists Unearth Home of Lord of Man

Adrian Darbyshire
IOM Today
Mon, 24 Aug 2009 12:00 UTC
Archaeologists have unearthed the ruins of the former home of Lord of Man, the Seventh Earl of Derby.

Lathom House, near Ormskirk, West Lancashire, was the setting of an infamous Civil War siege.

Ordered by the King to fortify the Isle of Man against a possible Scottish invasion, Lord Derby left his wife Charlotte de La Tremouille in charge to defend the house, the last remaining Royalist stronghold in Lancashire, against the Parliamentarian forces.

In his absence, the Roundheads urged the Countess to surrender but she refused, insisting that to do so would dishonour her husband.

The ensuing siege, which pitted 2,000 Parliamentarian soldiers against a garrison of 300, lasted from late February to late May 1644.
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Telephone

Maya Altar Found In Highway Work Zone


Art Daily
Mon, 24 Aug 2009 11:22 UTC
Mayan Altar
Each stone has been registered, ready until it is decided to rebuild the altar
Maya ceremonial altar recently found at the highway that communicates Merida, Yucatan with Campeche is in custody of Uman municipal authorities, waiting to be relocated where it can be appreciated by the public.

Archaeologist Eunice Uc Gonzalez, researcher at Yucatan INAH Center, commented that the National Institute of Anthropology and History (INAH) and the Ministry of Communications and Transportation are structuring agreements to determine the place that guarantees its best conservation state.
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Blackbox

Ice Ages Linked To Slight Shifts In Solar Radiation


Space Daily / SPX
Mon, 24 Aug 2009 03:59 UTC
Image
© UnknownSometime around now, scientists say, the Earth should be changing from a long interglacial period that has lasted the past 10,000 years and shifting back towards conditions that will ultimately lead to another ice age unless some other forces stop or slow it. But these are processes that literally move with glacial slowness, and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.
A team of researchers says it has largely put to rest a long debate on the underlying mechanism that has caused periodic ice ages on Earth for the past 2.5 million years - they are ultimately linked to slight shifts in solar radiation caused by predictable changes in Earth's rotation and axis.

In a publication to be released Friday in the journal Science, researchers from Oregon State University and other institutions conclude that the known wobbles in Earth's rotation caused global ice levels to reach their peak about 26,000 years ago, stabilize for 7,000 years and then begin melting 19,000 years ago, eventually bringing to an end the last ice age.

The melting was first caused by more solar radiation, not changes in carbon dioxide levels or ocean temperatures, as some scientists have suggested in recent years.

"Solar radiation was the trigger that started the ice melting, that's now pretty certain," said Peter Clark, a professor of geosciences at OSU. "There were also changes in atmospheric carbon dioxide levels and ocean circulation, but those happened later and amplified a process that had already begun."
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Telescope

A 9th-Magnitude Messenger From The Early Universe


Space Daily / SPX
Mon, 24 Aug 2009 03:54 UTC
Image
© DSS images from STScI and AAO/ROEThe ninth-magnitude star BD+44 493 (center) is by far brightest among the stars in this area.
Old stars are keys to understanding the nature of the first stars and the earliest stages of the formation of the universe. Observations with the Subaru Telescope, fitted with its High Dispersion Spectrograph (HDS), have yielded data about the chemical composition of an old, bright star - BD+44 493 - that shed light on how the early stars may have developed during the infancy of the universe.

According to the Big Bang theory, the early universe was composed almost entirely of hydrogen and helium. The creation of elements other than hydrogen and helium (heavy elements technically referred to as "metals" in astrophysics) occurred later, through a process of nucleosynthesis, when new atomic nuclei are developed inside the stars.

Therefore, the proportion of metals in an astronomical object (its "metallicity") may provide an indication of its age. Older stars have lower metallicities than younger stars such as our Sun. Because their atmospheres usually preserve the chemical composition of the gas from which they formed, old, low-metallicity stars hold evidence of their own creation - information that provides clues to processes occurring in the early universe.
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Sherlock

UK: Boy Finds Meteorite When Egg Collecting

Matt O'Leary
Sideways News
Sun, 23 Aug 2009 10:00 UTC
Rock
© SidewaysJosh Chapple found a 6cm meteorite in the back garden.
It's been quite a summer for things dropping out of the sky. In June, German teenager Gerrit Blank was struck by a pea-sized meteorite on his way to school in Essen: the projectile glanced off his hand and then left a foot-wide crater in the road next to him.

In the same month, reports reached us of a woman in Loughborough left amazed by a football-sized chunk of ice dropping from the heavens and slamming into her Renault. In July, David Gammon was enjoying lunch in his garden in Bristol when a 2kg block of ice fell into his lap, presumably from an aeroplane.

However, this week six-year-old Josh Chapple went one better by finding a 6cm meteorite in the back garden of his family home in Bratton Fleming, near Barnstaple, Devon.
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Cow

MSU robot dairy lets cows decide when to be milked


Chicago Tribune
Sun, 23 Aug 2009 05:53 UTC
Michigan State University is inviting the public to take a look at its new robotic cow milking operation, which the school says makes life easier for farmers as well as cows.

The milking machines let cows come in to be milked when they need or want to. Robots also collect health and other data on the cows.
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Robot

Robot's Gentle Touch Aids Delicate Cancer Surgery


ScienceDaily
Sun, 23 Aug 2009 05:49 UTC
New, delicate surgery techniques to hunt for tumours could benefit from a lighter touch - but from a robot, rather than from a human hand. Canadian researchers have created a touchy-feely robot that detects tougher tumour tissue in half the time, and with 40% more accuracy than a human. The technique also minimises tissue damage.

Surgeons have developed new minimally invasive surgery (MIS) techniques and instruments so that procedures that would previously have required a large incision can now be performed through a tiny 10mm cut. These new methods reduce tissue damage and infection compared with more traditional surgery, and can reduce recovery times and costs.
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