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October 12, 2006, 8:10 PM CT

Headcount Of Local Black Holes

Headcount Of Local Black Holes
NASA researchers using the Swift satellite have conducted the first complete census of galaxies with active, central black holes, a project that scanned the entire sky several times over a nine-month period.

The all-sky survey contains more than 200 supermassive black holes called Active Galactic Nuclei, or AGN, and provides a definitive census of black hole activity in the local universe. The team uncovered a number of new black holes that were previously missed, even in well-studied galaxies, and other surprises as well.

"We are confident that we are seeing every active, supermassive black hole within 400 million light years of Earth," said Jack Tueller of NASA's Goddard Space Flight Center, Greenbelt, Md., who led the effort. "With each passing month, we are able to probe deeper into the universe, and the census becomes richer."

AGN have a mass of millions to billions of suns, which are confined within a region about the size of our solar system. The term "active" refers to the process of actively pulling in gas and whole stars and generating copious amounts of energy from a tiny galactic core in the process. Examples include quasars and Seyfert galaxies.

Swift was built primarily to study gamma-ray bursts. During waiting times between bursts, Swift's Burst Alert Telescope, which is sensitive to the highest-energy X-rays, scans the sky. AGN generate X-rays as well as a number of other forms of light. A number of AGN, however, are hidden behind dust and gas, which block lower-energy light, such as visible light. Because higher-energy X-rays are so penetrating, Swift can detect AGN missed by other surveys, allowing for an unbiased count.........

Posted by: Edwin      Permalink         Source


October 12, 2006, 8:00 PM CT

Secrets Of Black Hole Jets

Secrets Of Black Hole Jets

NASA and Italian scientists using Swift have for the first time determined what the particle jets streaming from black holes are made of.

Black hole particle jets are commonly seen in quasars and other celestial objects, shooting off at nearly light speed. According to the Swift team, these jets appear to be made of protons and electrons, solving a mystery as old as the discovery of jets themselves in the 1970s. The jets observed by Swift contain about the mass of Jupiter if it were pulverized and blasted out into intergalactic space.

Black hole particle jets typically escape the confines of their host galaxies and flow for hundreds of thousands of light years. They are a primary means of redistributing matter and energy in the universe. They are a key to understanding galaxy formation and are tied to numerous cosmic mysteries, such as the origin of ultrahigh-energy cosmic rays.

"Black hole jets are one of the great paradoxes in astronomy," said Rita Sambruna of NASA's Goddard Space Flight Center, Greenbelt, Md. "How is it that black holes, so efficient at pulling matter in, can also accelerate matter away at near light speed? We still don't know how these jets form, but at least we now have a solid idea about what they're made of".

The composition of black hole jets has been the topic of heated debate for several decades. Scientists generally agree that the jets must be made either of electrons and their antimatter partners, called positrons, or an even mix of electrons and protons. Recent theoretical and observational advances have pointed in the direction of the latter. The Swift data provides the most compelling evidence to date that the jets must have protons.........

Posted by: Edwin      Permalink         Source


October 12, 2006, 4:59 AM CT

Cassini Finds More Rings

Cassini Finds More Rings
Images taken by NASA's Cassini spacecraft, looking in the direction of the Sun, have provided researchers fresh insights into the dynamic nature of the rings and, in particular, the creation of new rings made from tiny particles released from larger bodies.

Cassini findings being presented this week at the Division for Planetary Sciences Meeting of the American Astronomical Society held in Pasadena, Calif. include several new faint ring structures formed by processes acting on and within Saturn's moons and main rings.

A series of unique observations gathered in mid-September by NASA's Saturn-orbiting Cassini spacecraft as it drifted slowly through Saturn's shadow, allowed the entire ring system to be seen from a perspective that highlights microscopic ring particles: in a number of cases, particles only recently released into Saturn orbit. While observing from this locale, Cassini spotted, a single faint new ring, announced previously, in the shared orbit of the moons Janus and Epimetheus.

Researchers are now ecstatic to find even more rings. A second new diffuse but narrow ring is coincident with the orbit of the tiny moon Pallene, also discovered by Cassini's imaging cameras and only 4 kilometers (2.5 miles) across. Curiously, another similar-sized moon called Methone, discovered earlier in the mission in roughly the same region, does not seem to sport a ring.........

Posted by: Edwin      Permalink         Source


October 11, 2006, 8:25 PM CT

More Powerful Computer Chips

More Powerful Computer Chips
A University of Central Florida research team has made a substantial inroad toward establishing extreme ultraviolet light (EUV) as a primary power source for manufacturing the next generation of computer chips.

The team, led by Martin Richardson, university trustee chair and UCF's Northrop Grumman professor of X-Ray optics, successfully demonstrated for the first time an EUV light source with 30 times the power of previous recorded attempts enough to power the stepper machines used to reproduce detailed circuitry images onto computer chips.

The successful use of EUV light for this purpose marks a milestone in an industry-wide effort to create the most efficient and cost-effective power source for the next generation of chip production. Chips are now manufactured using longer-wavelength ultraviolet light sources.

The UCF breakthrough came as a result of a collaboration between Richardson and Powerlase Ltd., a company based in England. The company provided UCF with a powerful Starlase laser to combine with the specialized laser plasma source technology that the UCF team has developed. The unique technology combines the high conversion of laser light to EUV and effectively eliminates the neutral and charged particles that are associated with existing EUV plasma sources. If allowed to stream freely away from the source, those particles can harm the expensive optics used in EUV steppers.........

Posted by: John      Permalink         Source


October 11, 2006, 5:02 AM CT

Water Temperatures, Pollution Have Oysters In Hot Water

Water Temperatures, Pollution Have Oysters In Hot Water
Oysters exposed to high water temperatures and a common heavy metal are unable to obtain sufficient oxygen and convert it to cellular energy, according to a new study presented at The American Physiological Society conference, Comparative Physiology 2006.

The study showed how cadmium, a heavy metal, reduces the oyster's tolerance of warmer water temperatures and makes it more vulnerable during the summer when water temperatures rise. Half of the oysters exposed to the pollutant in 28 C (82 F) water died within 20 days, said lead researcher Gisela Lannig. Oysters exposed to cadmium at lower temperatures showed much lower mortality rate, suggesting that the combination of high temperature and cadmium is more stressful than each of these conditions alone, she said.

The study "Temperature tolerance in the oyster, Crassostrea virginica, is affected by cadmium," was carried out by Lannig, of the Alfred Wegener Institute for Polar & Marine Research, Bremerhaven, Germany, and Jason Flores and Inna Sokolova, of the University of North Carolina at Charlotte. The work was done in North Carolina. The researchers presented the study October 10 during a poster session at Comparative Biology 2006: Integrating Diversity in Virginia Beach.

Oyster population decimated........

Posted by: Nora      Permalink         Source


October 11, 2006, 4:51 AM CT

Giant Insects Might Reign

Giant Insects Might Reign Image courtesy of rusinsects.com
The delicate lady bug in your garden could be frighteningly large if only there was a greater concentration of oxygen in the air, a new study concludes. The study adds support to the theory that some insects were much larger during the late Paleozoic period because they had a much richer oxygen supply, said the study's lead author Alexander Kaiser.

The study, "No giants today: tracheal oxygen supply to the legs limits beetle size,'' will be presented Oct. 10 and 11 at Comparative Physiology 2006: Integrating Diversity. The conference will be held Oct. 8-11 in Virginia Beach. The research was carried out by Alexander Kaiser and Michael C. Quinlan of Midwestern University, Glendale, Arizona; J. Jake Socha and Wah-Keat Lee, Argonne National Laboratory, Argonne, IL; and Jaco Klok and Jon F. Harrison, Arizona State University, Tempe, AZ. Harrison is the principal investigator.

The Paleozoic period, about 300 million years ago, was a time of huge and abundant plant life and rather large insects -- dragonflies had two-and-a-half-foot wing spans, for example. The air's oxygen content was 35% during this period, compared to the 21% we breathe now, Kaiser said. Researchers have speculated that the higher oxygen concentration allowed insects to grow much bigger.

Tubes carry oxygen........

Posted by: Nora      Permalink         Source


October 10, 2006, 10:31 PM CT

EPA to monitor water systems

EPA to monitor water systems
Sandia National Laboratories scientists are working with the U.S. Environmental Protection Agency (EPA), University of Cincinnati and Argonne National Laboratory to develop contaminant warning systems that can monitor municipal water systems to determine quickly when and where a contamination occurs.

It's all part of the EPA's Threat Ensemble Vulnerability Assessment (TEVA) program to counter threats against water systems. The program uses a computational framework containing a suite of software tools that can simulate threats and identify vulnerabilities in drinking water systems, measure potential public health impacts, and evaluate mitigation and response strategies.

The EPA became especially concerned about potential water system contamination after the Sept. 11, 2001 attacks on Washington, D.C. and New York.

U.S. water systems consist of large networks of storage tanks, valves, and pipes that transport clean water to customers over vast areas. By the very nature of their design, they provide multiple points for potential contamination -- either accidental or intentional.

Sandia is a National Nuclear Security Administration laboratory.

"Our involvement dates back about three years ago when the EPA became aware of some LDRD [internally-funded Laboratory Directed Research and Development program] research we were doing to model threat assessments to water systems," says Sean McKenna, Sandia project researcher. "We started working with the EPA in March 2003".........

Posted by: John      Permalink         Source


October 10, 2006, 10:04 PM CT

Gems Of Knowledge

Gems Of Knowledge
By processing vast amounts of data, computers helped astronomers make new discoveries about the universe. Now they're helping banks and other companies learn more about their customers.

As telescopes scan the heavens they generate huge amounts of data. Take the Hubble Space Telescope, for example. It produces about 1,000 gigabytes of data each year - enough to fill more than 200 million pages. Newer telescopes generate even more.

So what does all this data tell us? That's the question PPARC asked scientists at the University of Edinburgh more than 10 years ago.

All and nothing.

The answer is both all and nothing.

Like other scientific instruments, telescopes only give us the basic facts. They report everything they find - the positions of the objects in space, their brightness and more. And they report it all as accurately as they are able.

Unfortunately telescopes don't explain anything. Why are the stars where they are? What makes them move? Which stars are in which galaxy? And why does their brightness change? Telescopes haven't a clue.

To answer questions like these, astronomers have to put the facts together. Patterns in the data give them vital clues about how the universe works. The problem is that there is so much data to look through.........

Posted by: Edwin      Permalink         Source


October 10, 2006, 9:25 PM CT

Nobelists' Work Supports Big-bang Theory

Nobelists' Work Supports Big-bang Theory
MIT alumnus George F. Smoot has been awarded the 2006 Nobel Prize in physics, together with John C. Mather, for work that looks back into the infancy of the universe and attempts to gain some understanding of the origin of galaxies and stars.

The work, based on measurements of the cosmic microwave background radiation made with NASA's COBE satellite, provides increased support for the big-bang theory of the origin of the universe. The COBE (Cosmic Background Explorer) measurements also mark the inception of cosmology as a precise science. For the first time, cosmological calculations could be compared with data from real measurements.

As per the big bang scenario, the cosmic microwave background radiation is a relic of the earliest phase of the universe. Immediately after the big bang itself, the universe can be in comparison to a glowing body emitting radiation at a temperature of almost 3,000 degrees Celsius.

Since then, the radiation has cooled as the universe has expanded. The background radiation we can measure today corresponds to a temperature that is barely 2.7 degrees above absolute zero. The new Nobel laureates were able to calculate this temperature thanks to the COBE measurements.

COBE also had the task of seeking small variations of temperature in the cosmic background radiation in different directions. Extremely small differences of this kind--in the range of a hundred-thousandth of a degree--offer an important clue to how the galaxies came into being. The variations in temperature measured by COBE show us how the matter in the universe began to "aggregate." This was necessary if the galaxies, stars and ultimately life forms like us were to be able to develop.........

Posted by: Edwin      Permalink         Source


October 10, 2006, 9:21 PM CT

No Hands Video

No Hands Video
Now, a St. Louis-area teenage boy and a computer game have gone hands-off, thanks to a unique experiment conducted by a team of neurosurgeons, neurologists, and engineers at Washington University in St. Louis.

The boy, a 14-year-old who suffers from epilepsy, is the first teenager to play a two-dimensional video game, Space Invaders, using only the signals from his brain to make movements.

Getting subjects to move objects using only their brains has implications toward someday building biomedical devices that can control artificial limbs, for instance, enabling the disabled to move a prosthetic arm or leg by thinking about it.

A number of gamers think fondly of Atari's Space Invaders, one of the most popular breakthrough video games of the late '70s. The player controls the motions of a movable laser cannon that moves back and forth across the bottom of the video screen. Row upon row of video aliens march back and forth across the screen, slowly coming down from the top to the bottom of the screen. The objective is to prevent any one of the aliens from landing on the bottom of the screen, which ends the game. The player has an unlimited ammunition supply.

The aliens can shoot back at the player, who has to evade, moving left and right. There are lots of levels of play, reflecting the speed at which the aliens descend. The Washington University subject mastered the first two levels of play, using just his imagination.........

Posted by: John      Permalink         Source


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