Science & Technology
Studying simple metallic chromium, the joint UC-Argonne team has discovered a pressure-driven quantum critical regime and has achieved the first direct measurement of a "naked" quantum singularity in an elemental magnet. The team was led by University of Chicago scientist Rafael Jaramillo, working in the group of Thomas Rosenbaum, and Argonne scientist Yejun Feng of the Advanced Photon Source.

The interface between a sunspot's central and outer regions shows a complex structure.
In a breakthrough that will help scientists unlock mysteries of the sun and its impacts on Earth, scientists have created the first-ever comprehensive computer model of sunspots. The resulting visuals capture both scientific detail and remarkable beauty. The results are published this week in a paper in Science Express. The research was supported by the National Science Foundation (NSF).
The high-resolution simulations of sunspots open the way for scientists to learn more about the vast mysterious dark patches on the sun's surface, first studied by Galileo. Sunspots are associated with massive ejections of charged plasma that can cause geomagnetic storms and disrupt communications and navigational systems. They are also linked to variations in solar output that can affect weather on Earth and exert a subtle influence on climate patterns.
The US military has abruptly ended an informal arrangement that allowed scientists access to data on incoming meteors from classified surveillance satellites.
The change is a blow to the astronomers and planetary scientists who used the information to track space rocks, especially those that burn up over the oceans or in other remote locations. "These systems are extremely useful," says Peter Brown, an astronomer at the University of Western Ontario in London, Canada. "I think the scientific community benefited enormously."
When the policy changed is unclear. The website Space.com reported the end of the relationship on 10 June, but Brown says that he was told at the beginning of this year that there would be no further data releases. Mark Boslough, a physicist at Sandia National Laboratories in Albuquerque, New Mexico, says he was told this spring that he could no longer publicly discuss the classified data to which he had some access.
Neither scientist could give a reason for the end of the arrangement, and the United States Air Force, which operates the satellites, did not respond in time for Nature's deadline. The Air Force did issue a 16 March memo on the military classification of fireball data, but Nature could not confirm its contents.
The Earth eavesdropping, conducted by researchers at the Los Alamos National Laboratory in New Mexico, was intended to detect atomic weapons tests by rogue nations or organizations in remote locations.
Instead, the Los Alamos listening stations picked up the sound of two large meteors as they plunged into the atmosphere off the coast of Mexico, the Los Alamos lab said this week.
The space rocks raced across the sky in April and August. But the lab waited to announce its findings until other U.S. space scientists last week confirmed the two objects.
The meteors were unusually big, between 6 and 10 feet in diameter. The first one created an explosive pressure wave with as much energy as 2,000 to 3,000 tons of TNT, according to Los Alamos researchers. The second, larger one could have produced a shock wave equivalent to 8,000 tons of TNT.
"Had anyone seen the April 23 event, they would have seen quite a show. That meteor was one of the five brightest ever recorded," Los Alamos scientist Doug ReVelle said.
Avalanches rumbling down mountainsides, the seething magma inside volcanoes as eruptions near, the violent twisting air of tornadoes and even the crash of ocean waves -- all send out ultra-long-wave, low-frequency vibrations known as infrasound.
Using sensitive instruments, scientists are studying whether detection of infrasound can provide advance warning of these natural disasters. They also are using infrasound to detect the nuclear weapon tests of enemy nations.
Infrasound is the opposite of the extreme high-frequency whistles that dogs can hear but humans can't, or the high-pitched ultrasound echolocation that bats use home in on their prey or that modern physicians use to create images of a fetus in the womb.
All sound waves are actually pulses of air pressure -- rapid pulses in the case of high-frequency sounds, and very slow-moving pressure waves with extremely long wavelengths in the infrasound ranges.
Asteroids routinely hit the Earth's atmosphere but the impact by one over northern Africa Monday was the first time astronomers saw one coming and accurately predicted the time and place it would hit, a University of Hawaii astronomer said yesterday.
That successful prediction bodes well for a Maui-based system in development to warn against potentially hazardous space rocks, David Tholen said.
The impact occurred at 4:46 p.m. Hawaii time Monday over northern Sudan. A colleague compared the asteroid, called 2008 TC3, with the size of a Volkswagen, he said.
NASA's Jet Propulsion Laboratory in Pasadena, Calif., sent an e-mail saying the impact occurred yesterday at 2:46 a.m. universal time but provided no details, said Tholen, who hunts for hazardous near-Earth asteroids.
Tholen said more than 500 observations were made of the asteroid approaching Earth by astronomers all over the world, primarily in Europe and western Asia.
"It was the first opportunity to really test the whole impact-prediction software system on a real object," he said, adding that it was 100 percent accurate.
There was one report of a visual sighting by a KLM Airlines pilot, but it was far from the impact location and merely saw "a streak of light," he said.
The only other solid piece of data came from an infrasound station in Kenya that listens for very low-frequency sound waves and can detect the entry of fireballs, he said.

Space-based instruments can image minute Earth movements to within a few centimeters (fractions of an inch), measuring the slow buildup of deformation along faults and mapping ground deformation after earthquakes occur. Among these tools are the Global Positioning System and interferometric synthetic aperture radar, or InSAR.
The reason: lurking underground, just a few kilometers to the northeast, lays a sleeping giant: the 160-kilometer-(100-mile) long southern segment of the notorious 1,300-kilometer- (800-mile) long San Andreas fault.
Scientists were concerned that the recent earthquake swarm at the Salton Sea's Bombay Beach could perhaps be the straw that broke the camel's back, triggering "the big one," a huge earthquake that could devastate Southern California.
The southern end of the San Andreas has remained silent, at least for now. But the earthquake swarm and more recent, widely felt earthquakes in the Los Angeles area have stirred renewed interest in earthquake research.
From listening in on volcanoes to detecting nuclear explosions, a global network of infrasound detectors is allowing researchers to tune in to our atmosphere, explain Michael Hedlin and Barbara Romanowicz
Our atmosphere is filled with sounds that we cannot hear. The Earth hums; volcanoes howl, pop and whistle; storms roar menacingly; and meteors scream before exploding high above the ground. We are oblivious to this perpetual symphony because it takes place at frequencies below the lower limit of human hearing, otherwise known as infrasound.
The human ear is sensitive to sounds with frequencies between about 20 and 20,000 Hz. These mid-range waves lose energy rapidly, which means we can only hear sounds coming from our immediate surroundings. But sounds exist both above and below the audible range - ultrasound, for example, can have frequencies of several megahertz. Ultrasound decays very quickly and cannot be detected very far from its source, which makes it useful for biological imaging. But with frequencies as low as a few millihertz, infrasound can travel distances of several thousand kilometres.
It was the eruption of the Indonesian volcano Krakatoa in 1883 that showed scientists that what we can hear is just a narrow slice of the full acoustic spectrum. This eruption generated the loudest recorded sound in history, and was distinctly heard some 4800 km away on the island of Mauritius. However, had barometers - which are sensitive to very gradual changes in air pressure - not recorded the cataclysmic event, most of the rest of the world would only have found out about it by word of mouth.
"We are trying to get a better estimate of how dangerous a particular event will be," says Brian Thomas of Washburn University in Topeka, Kansas.
Thomas and his colleagues will be studying the wide-range of astrophysical phenomena that could fling high energy radiation across interstellar space to Earth's doorstep [as occured in a colossal blast detected in 2004]. The team also will radiate different types of phytoplankton to understand how life would be affected by a stellar blast, since life around the globe is highly dependent on these microscopic plants.
Comment: Star explosions are certainly not one of our grave concerns at the moment, as the coming ice age along with a space debris rain and psychopathy are humanity's real threads. For starters read:
Tunguska, Psychopathy and the Sixth Extinction
Fire and Ice: The Day After Tomorrow







Comment: See Space.com's report: Best of the Web: Military Hush-Up: Incoming Space Rocks Now Classified
We propose that the witholding of information is because key authorities know that the risk of catastrophic impact from comet debris recently took at sharp upturn from possible to probable:
What are they hiding? Flight 447 and Tunguska Type Events