Science & TechnologyS


Info

Magnetic Activity in Brain 'Diagnoses Stress Disorder'

Jason Palmer
BBC News
Thu, 21 Jan 2010 15:11 UTC
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The disorder is prevalent among those exposed to life-threatening situations
A one-minute test appears to diagnose post-traumatic stress disorder with an accuracy of 90%.

The test measures the tiny magnetic fluctuations that occur as groups of neurons fire in synchrony, even when subjects are not thinking of anything.

These "synchronous neural interactions" have already been shown to distinguish signals from subjects with a range of disorders including Alzheimer's.

The latest work is reported in the Journal of Neural Engineering.

The brain's signals are effectively a symphony of electrical impulses, which in turn drive tiny magnetic fields.

Researchers have measured and mapped these fields, in a pursuit known as magnetoencephalography, since the late 1960s. It has already been used to diagnose tinnitus, and can even predict when people will make mistakes.
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Sun

Crackling Sunspot


Space Weather
Thu, 21 Jan 2010 11:01 UTC
Sunspot 1041 (a.k.a. "old sunspot 1039") is crackling with solar flares. Over the past few days, it has produced five M-class eruptions. Click here to play a movie of the latest, an M2-flare recorded by STEREO-B at 1756 GMT on Jan. 20th.

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© STEREO-B
The ongoing sequence of flares signals a sharp upturn in solar activity. Before this week, the last time the sun produced even a single M-class solar flare was in March 2008--almost two years ago. M-class solar flares have a moderate effect on Earth. Mainly, they boost the ionization of Earth's upper atmosphere and disturb the propagation of terrestrial radio signals.
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Control Panel

Acoustic Levitation: Scientists Use Sound Make Objects Levitate (Video)


The Huffington Post
Thu, 21 Jan 2010 00:51 UTC
Scientists have developed a sound generator so powerful its shock waves can stun, and even kill people.

Another group of researchers have developed another unusual application for sound: a method of "acoustic levitation" that could help maintain colonies on Mars or the moon by using high-pitched sound waves to remove alien dust.

Wired explains,
Blasting a high-pitched noise from a tweeter into a pipe that focuses the sound waves can create enough pressure to lift troublesome alien dust off surfaces, according to a study published January in the Journal of the Acoustical Society of America.
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Telescope

New Research Suggests that Near-Earth Encounters can "Shake" Asteroids

Jen Hirsch
Massachusetts Institute of Technology
Wed, 20 Jan 2010 17:00 UTC
Cambridge, Massachusetts - For decades, astronomers have analyzed the impact that asteroids could have on Earth. New research by MIT Professor of Planetary Science Richard Binzel examines the opposite scenario: that Earth has considerable influence on asteroids - and from a distance much larger than previously thought. The finding helps answer an elusive, decades-long question about where most meteorites come from before they fall to Earth and also opens the door to a new field study of asteroid seismology.

By analyzing telescopic measurements of near-Earth asteroids (NEAs), or asteroids that come within 30 million miles of Earth, Binzel has determined that if an NEA travels within a certain range of Earth, roughly one-quarter of the distance between Earth and the moon, it can experience a "seismic shake" strong enough to bring fresh material called "regolith" to its surface. These rarely seen "fresh asteroids" have long interested astronomers because their spectral fingerprints, or how they reflect different wavelengths of light, match 80 percent of all meteorites that fall to Earth, according to a paper by Binzel appearing in the Jan. 21 issue of Nature. The paper suggests that Earth's gravitational pull and tidal forces create these seismic tremors.
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Info

Cave reveals Southwest's abrupt climate swings during Ice Age

Mari N. Jensen
University of Arizona
Wed, 20 Jan 2010 20:50 UTC
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© 2010 Stella Cousins.Sarah Truebe, a geosciences doctoral student at the University of Arizona, checks on an experiment that measures how fast cave formations grow in Arizona's Cave of the Bells.
Ice Age climate records from an Arizona stalagmite link the Southwest's winter precipitation to temperatures in the North Atlantic, according to new research.

The finding is the first to document that the abrupt changes in Ice Age climate known from Greenland also occurred in the southwestern U.S., said co-author Julia E. Cole of the University of Arizona in Tucson.

"It's a new picture of the climate in the Southwest during the last Ice Age," said Cole, a UA professor of geosciences. "When it was cold in Greenland, it was wet here, and when it was warm in Greenland, it was dry here."
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Einstein

The entropy force: a new direction for gravity

Martijn van Calmthout
New Scientist
Wed, 20 Jan 2010 18:07 UTC
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© SuperStock/GettyGravity keeps us tumbling back to Earth
Although gravity has been successfully described with laws devised by Isaac Newton and later Albert Einstein, we still don't know how the fundamental properties of the universe combine to create the phenomenon.

Now one theoretical physicist is proposing a radical new way to look at gravity. Erik Verlinde of the University of Amsterdam, the Netherlands, a prominent and internationally respected string theorist, argues that gravitational attraction could be the result of the way information about material objects is organised in space. If true, it could provide the fundamental explanation we have been seeking for decades.

Verlinde posted his paper to the pre-print physics archive earlier this month, and since then many physicists have greeted the proposal as promising. Nobel laureate and theoretical physicist Gerard 't Hooft of Utrecht University in the Netherlands stresses the ideas need development, but is impressed by Verlinde's approach. "[Unlike] many string theorists Erik is stressing real physical concepts like mass and force, not just fancy abstract mathematics," he says. "That's encouraging from my perspective as a physicist."
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Stop

Car-stopping electropulse cannon to demo 'next month

Lewis Page
The Register
Wed, 20 Jan 2010 13:39 UTC
Cig-lighter EMP blaster down to suitcase size, apparently

An old friend familiar to every tech buff and sci-fi fan - namely, the circuitry-addling electropulse blaster - has moved a large step closer to reality, according to reports. A vehicle mounted pulse weapon capable of stopping a (modern) car at 200m is to be demonstrated "next month", apparently.

Flight International has the story, uncovered while following up on a recent US Air Force request for an aircraft weapon capable of "disabling moving ground vehicles while minimising harm to occupants". The USAF is more than capable of stopping such vehicles at present, but its existing methods generally reduce the car or truck and its occupants to a few mangled scraps - not to mention destroying a large section of road and quite likely anything else in the general vicinity.

Just how the Air Force will proceed remains to be seen. However the US Marines have for some years been working with California firm Eureka Aerospace to produce an electromagnetic pulse (EMP, aka High Powered Microwave or HPM) weapon for this sort of task.
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Magnify

Scientists Find a Shared Gene in Dogs With Compulsive Behavior

Mark Derr
The New York Times
Wed, 20 Jan 2010 13:23 UTC
Scientists have linked a gene to compulsive behavior - in dogs.

Researchers studied Doberman pinschers that curled up into balls, sucking their flanks for hours at a time, and found that the afflicted dogs shared a gene. They describe their findings - the first such gene identified in dogs - in a short report this month in Molecular Psychiatry.

Dr. Nicholas Dodman, director of the animal behavior clinic at the Cummings School of Veterinary Medicine at Tufts University, in North Grafton, Mass., and the lead author of the report, said the findings had broad implications for compulsive disorders in people and animals.
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Better Earth

Solar system 'on fire' burned up Earth's carbon

David Shiga
New Scientist
Tue, 19 Jan 2010 11:58 UTC
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© Christian Miller/iStockNow where did all that carbon go?
Fire sweeping through the inner solar system may have scorched away much of the carbon from Earth and the other inner planets.

Though our planet supports carbon-based life, it has a mysterious carbon deficit. The element is thousands of times more abundant in comets in the outer solar system than on Earth, relative to the amount of silicon each body contains. The sun is similarly rich in carbon. "There really wasn't that much carbon that made it onto Earth compared to what was available," says Edwin Bergin of the University of Michigan in Ann Arbor.

The conventional explanation for the deficit argues that in the inner region of the dust disc where Earth formed, temperatures soared above 1800 kelvin, enough for carbon to boil away. But observations of developing solar systems suggest that at Earth's distance from the sun the temperature would be too cool to vaporise carbon dust.

Now a team of astronomers says that fire is to blame. Hot oxygen atoms in the dusty disc would have readily combined with carbon, burning it to produce carbon dioxide and other gases, say Jeong-Eun Lee of Sejong University in Seoul, South Korea, and colleagues, including Bergin, in a paper to appear in The Astrophysical Journal Letters (arxiv.org/abs/1001.0818). Any solid carbon in the inner solar system would have been destroyed within a few years, they calculate.
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Meteor

Preparing for an asteroid strike


New Scientist
Thu, 24 Sep 2009 10:47 UTC
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© Unknown
The sight of the solar system's biggest planet being battered by the broken remains of a comet in 1994 left a vivid reminder of our own planet's vulnerability. The scars that remained after the series of giant impacts on Jupiter were more prominent even than its great red spot, and remained visible for months.

This dramatic spectacle was enough to loosen government purse strings, and the funding has supported telescope surveys to hunt down asteroids that could wallop us. A decade and a half after comet Shoemaker-Levy 9 smashed into Jupiter, those surveys have catalogued more than 80 per cent of the near-Earth asteroids larger than 1 kilometre across.

Now we have seen the results of the first exercise ever to test plans for what to do if an asteroid is on collision course with Earth (see Asteroid attack: Putting Earth's defences to the test), and they do not inspire confidence. We still have a long way to go before we can say we are prepared for this cosmic threat.
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