Science & TechnologyS


Saturn

T Chamaeleon Gets Caught in the Act - Forming Planets, That Is

Anne Minard
Universe Today
Thu, 24 Feb 2011 08:24 UTC
Image
© ESO/L. CalçadaArtist’s impression showing the disk around the young star T Chamaeleontis. The companion object in the foreground may be either a brown dwarf or a large planet.
An international team of astronomers peering at a young star in the constellation Chamaeleon have detected a smaller companion - a dust-shrouded brown dwarf, or perhaps a planet - that appears to be carving out a large gap in the stellar disk. The discovery is a first: Although planets have been spotted before in more mature disks, this is the first detection of a planet-sized object in the disk around a young star.

Planets form from the disks of material around young stars, but the transition from dust disk to planetary system is rapid and few objects are caught during this phase. Astronomers are getting ever closer to glimpsing the births of planets, though - today's announcement comes on the heels of a discovery last week using the Subaru Telescope in Hawaii, of a stellar disk around the star LkCa 15 similar in size to our own solar system, featuring rings and gaps possibly associated with the formation of giant planets.

T Chamaeleontis (RA 1h 04m 09.131s dec -76° 27′ 19.30″), T Cha for short, is a faint, young but sun-like star in the small southern constellation of Chamaeleon, about 350 light-years from Earth. T Cha is about seven million years old.
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Telescope

Asymmetric Supernova Explosions


Calar Alto Observatory
Fri, 25 Feb 2011 00:00 UTC
Image
© Calar Alto Observatory
As one knows from the Sun, stars are nearly perfect spheres of glowing gas. One might expect that a star retained this shape, even when dramatic events happen during its lifetime. Therefore, both the slow, steady stellar winds from massive stars, as well as the cataclysmic explosions called supernovae, in which some stars end their lives, were assumed to be symmetric - quasi-spherical clouds of matter expelled into space.

However, recent developments in the observation of supernovae are providing increasing evidence that the explosion of a (nearly round) star can result in a strongly deformed fireball.
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Briefcase

Study Links Brain and White-Collar Crime

Steve Connor
The Independent
Tue, 22 Feb 2011 00:00 UTC
People who commit "white collar" crime such as credit-card fraud and computer hacking have been found to have brains that are structurally different from the brains of non-criminals with similar backgrounds, scientists have found.

Psychological tests on white-collar criminals also showed that they were better at making decisions in the kind of "higher executive" brain functions associated with being good at business, researchers said.

The study found that, in effect, white-collar criminals had more grey matter than a comparable group of non-criminals, suggesting that there may be a biological basis for this kind of criminal behaviour, according to Adrian Raine, a criminologist at the University of Pennsylvania.

"They have better executive functions. They have better executive skills, such as planning, regulation and control. So in a sense these people have all the advantages we really want in successful business people," Dr Raine said.
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Laptop

World's Smallest Computer Created


TechNewsDaily
Thu, 24 Feb 2011 19:43 UTC
Image
© Greg ChenResearchers recently unveiled the first complete millimeter-scale computing system that is about the size of the letter "N" on the back of a penny (or about the same size of the letter as it appears in this sentence).
The computing system - the tiniest fabricated to date - is a prototype of an implantable eye pressure monitor for glaucoma patients. In another important development, the unit can also link up with other computers to form wireless sensor networks. A new super-compact radio that needs no tuning to find the right communications frequency enables these computers to speak to each other.

One day, the Lilliputian devices could track pollution, monitor structural integrity, perform surveillance, or make virtually any object smart and traceable
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Bad Guys

More of the World's Crops are Genetically Engineered

Elizabeth Weise
USA Today
Wed, 23 Feb 2011 15:21 UTC
Image
© freewebs.comThe map shows the status of GM Crops in 2004
The amount of land devoted to genetically engineered crops grew 10% last year, and 7% in the year before, as farmers in major grain and soy exporting countries such as Brazil and Argentina continued to adopt the new seeds.

These so-called biotech crops, often bred with genes that allow them to tolerate weed killers or generate their own insecticides, now cover 10% of the world's farmland, up from nothing just 15 years ago.

The figures are in this year's International Service for the Acquisition of Agri-biotech Applications report, out Tuesday. Of the four most commonly planted biotech crops, a rising percentage of the total of all plantings are biotech. In 2010, 81% of all soybeans, 64% of cotton, 29% of corn and 23% of canola globally were from biotech seeds, the ISAAA says.

The most common modification is herbicide tolerance, where plants are given a gene that allows farmers to spray them with the weed killer glyphosate, known to most home gardeners as Roundup, without harming them. Sixty-one percent of biotech crops carry this gene.
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Info

Meteorites Illuminate Mystery of Chromium in Earth's Core

Anne Minard
Science
Thu, 24 Feb 2011 14:18 UTC
Earth's Interior
© Universe Today

It's generally assumed that the Earth's overall composition is similar to that of chondritic meteorites, the primitive, undifferentiated building blocks of the solar system. But a new study in Science Express led by Frederic Moynier, of the University of California at Davis, seems to suggest that Earth is a bit of an oddball.

Moynier and his colleagues analyzed the isotope signature of chromium in a variety of meteorites, and found that it differed from chromium's signature in the mantle.
Chondritic Meteorite
© NASAThin section of a chondritic meteorite.

"We show through high-precision measurements of Cr stable isotopes in a range of meteorites, which deviate by up to ~0.4‰ from the bulk silicate Earth, that Cr depletion resulted from its partitioning into Earth's core with a preferential enrichment in light isotopes," the authors write. "Ab-initio calculations suggest that the isotopic signature was established at mid-mantle magma ocean depth as Earth accreted planetary embryos and progressively became more oxidized."
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Info

Planet Formation in Action?


ESO
Thu, 24 Feb 2011 13:48 UTC
T Cha (T Chamaeleontis)
© ESO/L. CalçadaThis artist’s impression shows the disc around the young star T Cha. Using ESO’s Very Large Telescope this disc has been found to be in two parts, a narrow ring close to the star and the remainder of the disc material much further out. A companion object, seen in the foreground, has been detected in the gap in the disc that may be either a brown dwarf or a large planet. The inner dust disc is lost in the glare of the star on this picture.

Using ESO's Very Large Telescope an international team of astronomers has been able to study the short-lived disc of material around a young star that is in the early stages of making a planetary system. For the first time a smaller companion could be detected that may be the cause of the large gap found in the disc. Future observations will determine whether this companion is a planet or a brown dwarf.

Planets form from the discs of material around young stars, but the transition from dust disc to planetary system is rapid and few objects are caught during this phase.[1] One such object is T Chamaeleontis (T Cha), a faint star in the small southern constellation of Chamaeleon that is comparable to the Sun, but very near the beginning of its life.[2] T Cha lies about 350 light-years from the Earth and is only about seven million years old. Up to now no forming planets have been found in these transitional discs, although planets in more mature discs have been seen before (eso0842, heic0821).
"Earlier studies had shown that T Cha was an excellent target for studying how planetary systems form," notes Johan Olofsson (Max Planck Institute for Astronomy, Heidelberg, Germany), one of the lead authors of two papers in the journal Astronomy & Astrophysics that describe the new work. "But this star is quite distant and the full power of the Very Large Telescope Interferometer (VLTI) was needed to resolve very fine details and see what is going on in the dust disc."
The astronomers first observed T Cha using the AMBER instrument and the VLT Interferometer (VLTI).[3] They found that some of the disc material formed a narrow dusty ring only about 20 million kilometres from the star. Beyond this inner disc, they found a region devoid of dust with the outer part of the disc stretching out into regions beyond about 1.1 billion kilometres from the star.
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Info

Cassiopeia: Superfluid in Neutron Star's Core


NASA
Thu, 24 Feb 2011 13:32 UTC
Cassiopeia
© NASA/CXC/M.Weiss Supernova remnant Cassiopeia A, with inset of an illustration of a neutron star

This composite image shows a beautiful X-ray and optical view of Cassiopeia A (Cas A), a supernova remnant located in our Galaxy about 11,000 light years away. These are the remains of a massive star that exploded about 330 years ago, as measured in Earth's time frame. X-rays from Chandra are shown in red, green and blue along with optical data from Hubble in gold.

At the center of the image is a neutron star, an ultra-dense star created by the supernova. Ten years of observations with Chandra have revealed a 4% decline in the temperature of this neutron star, an unexpectedly rapid cooling. Two new papers by independent research teams show that this cooling is likely caused by a neutron superfluid forming in its central regions, the first direct evidence for this bizarre state of matter in the core of a neutron star.

The inset shows an artist's impression of the neutron star at the center of Cas A. The different colored layers in the cutout region show the crust (orange), the core (red), where densities are much higher, and the part of the core where the neutrons are thought to be in a superfluid state (inner red ball). The blue rays emanating from the center of the star represent the copious numbers of neutrinos -- nearly massless, weakly interacting particles -- that are created as the core temperature falls below a critical level and a neutron superfluid is formed, a process that began about 100 years ago as observed from Earth. These neutrinos escape from the star, taking energy with them and causing the star to cool much more rapidly.
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Info

Trembling of Volcanoes Could Predict Their Eruption

Charles Q. Choi
OurAmazingPlanet
Wed, 23 Feb 2011 13:11 UTC
Soufriere Hills volcano
© NOCThis is an aerial view of the Soufriere Hills volcano on the island of Montserrat in the Lesser Antilles. The photograph was shows one of the volcanic domes that grew and then collapsed into the sea since the volcano became active in 1995.

An earthshaking new way to warn of explosive volcanic eruptions hours or days before they happen may finally have been discovered, by analyzing the tremors around the volcano, scientists reveal.
Explosive volcanic eruptions are typically preceded by volcanic tremors, but until now scientists had not figured out a way to use these disturbances to predict whether such eruptions might actually take place.

"People would recognize that volcanoes were waking up from tremors in the seismic data - that magma inside was moving around - but there was no way to make predictions as to what would happen," said researcher Mark Jellinek, a volcanologist and geophysicist at the University of British Columbia in Vancouver.

The breakthrough that Jellinek and his colleagues made was to focus on any connections that might exist between the tremors and the structure of the magma, which appears similar in all explosive volcanic systems, as opposed to the structures of the volcanoes themselves, which vary widely.

"This is the first model to do that, and we might have an early warning system now that works on a timescale of hours to days and does a good job at predicting when volcanic behavior becomes explosive and dangerous, for every volcano in the world," Jellinek told OurAmazingPlanet. "It's awesome."
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Fish

The mathematics of fish schools and flocks of humans

Matt Ford
ArsTechnica
Wed, 23 Feb 2011 08:55 UTC
Image
© unk
What drives groups of individual animals to act in a coherent manner? Everyone has seen the oddly coordinated behavior exhibited by flocks of birds or schools of fish as they turn, sweep, and rotate seemingly as one. But how does a group of individuals make decisions about how to move and where to go at once? Do they follow some prescribed and describable mathematical behavior? A symposium at this year's AAAS conference attempted to answer this question.

Professor Ian Couzin from Princeton University opened the symposium by describing his work on modeling the underlying behavior of large groups of individuals. In his work, he describes the equation of motion for any individual entity as governed by three factors: a short-range repulsive behavior, an intermediate range desire to align with neighbors, and a long-range attraction to the group as a whole.
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