WASHINGTON - Compared to the well-studied world of Homer’s Iliad and Odyssey, the civilizations that flourished in the eastern Mediterranean just before Homer’s time are still cloaked in mystery.
Even the basic chronology of the region during this time has been heatedly debated. Now, a resolution has finally emerged -- initiated, quite literally, by an olive branch.
Scientists have discovered the remains of a single olive tree, buried alive during a massive volcanic eruption during the Late Bronze Age. A study that dates this tree, plus another study that dates a series of objects from before, during and after the eruption, now offer a new timeline for one of the earliest chapters of European civilization
Friday, May 21, 2010
Scientists get frog to shake his booty
Panamanian species gets jiggy with it to intimidate rivals.
One species of male frog shakes its booty big-time in aggressive showdowns, with the victor pulsating its rear for a longer time and with more gusto.
The shaking, which starts with the hind end and becomes a whole-body affair, sends vibrations along the red-eyed treefrog's plant perch until the shaking reaches the frog's opponent sitting on the branch — this process is called tremulation.
"In the case of red-eyed treefrogs, tremulation displays in which the frogs shake their entire bodies convey information about the status and aggressive intent of the signaler," said researcher Michael Caldwell of Boston University. "They also appear to carry information about the size of the signaler."
One species of male frog shakes its booty big-time in aggressive showdowns, with the victor pulsating its rear for a longer time and with more gusto.
The shaking, which starts with the hind end and becomes a whole-body affair, sends vibrations along the red-eyed treefrog's plant perch until the shaking reaches the frog's opponent sitting on the branch — this process is called tremulation.
"In the case of red-eyed treefrogs, tremulation displays in which the frogs shake their entire bodies convey information about the status and aggressive intent of the signaler," said researcher Michael Caldwell of Boston University. "They also appear to carry information about the size of the signaler."
Astronauts gear up for 3rd and final spacewalk
CAPE CANAVERAL, Fla. – The Atlantis astronauts have one more big job before leaving the International Space Station.
On Friday morning, two of the crew will venture out on the third and final spacewalk of their mission.
Astronauts Garrett Reisman and Michael Good will finish installing new space station batteries. They will replace two old batteries. Four new batteries went in during Wednesday's spacewalk.
Atlantis delivered the batteries along with a new Russian compartment. The chamber was opened Thursday, but had to be sealed again when metal filings were found floating inside. Flight controllers are devising a clean-up plan.
Atlantis will undock from the space station Sunday for the last time. NASA has just two shuttle missions left.
On Friday morning, two of the crew will venture out on the third and final spacewalk of their mission.
Astronauts Garrett Reisman and Michael Good will finish installing new space station batteries. They will replace two old batteries. Four new batteries went in during Wednesday's spacewalk.
Atlantis delivered the batteries along with a new Russian compartment. The chamber was opened Thursday, but had to be sealed again when metal filings were found floating inside. Flight controllers are devising a clean-up plan.
Atlantis will undock from the space station Sunday for the last time. NASA has just two shuttle missions left.
Asteroid Caught Marching Across Tadpole Nebula
new infrared image from NASA's Wide-field Infrared Survey Explorer, or WISE, showcases the Tadpole nebula, a star-forming hub in the Auriga constellation about 12,000 light-years from Earth. As WISE scanned the sky, capturing this mosaic of stitched-together frames, it happened to catch an asteroid in our solar system passing by. The asteroid, called 1719 Jens, left tracks across the image, seen as a line of yellow-green dots in the boxes near center. A second asteroid, called 1992 UZ5, was also observed cruising by, as highlighted in the boxes near the upper left (the larger boxes are blown-up versions of the smaller ones).
But that's not all that WISE caught in this busy image -- two satellites orbiting above WISE (highlighted in the ovals) streak through the image, appearing as faint green trails. The apparent motion of asteroids is slower than satellites because asteroids are much more distant, and thus appear as dots that move from one WISE frame to the next, rather than streaks in a single frame.
This Tadpole region is chock full of stars as young as only a million years old -- infants in stellar terms -- and masses over 10 times that of our sun. It is called the Tadpole nebula because the masses of hot, young stars are blasting out ultraviolet radiation that has etched the gas into two tadpole-shaped pillars, called Sim 129 and Sim 130. These "tadpoles" appear as the yellow squiggles near the center of the frame. The knotted regions at their heads are likely to contain new young stars. WISE's infrared vision is helping to ferret out hidden stars such as these.
The 1719 Jens asteroid, discovered in 1950, orbits in the main asteroid belt between Mars and Jupiter. The space rock, which has a diameter of 19 kilometers (12 miles), rotates every 5.9 hours and orbits the sun every 4.3 years.
Twenty-five frames of the region, taken at all four of the wavelengths detected by WISE, were combined into this one image. The space telescope caught 1719 Jens in 11 successive frames. Infrared light of 3.4 microns is color-coded blue: 4.6-micron light is cyan; 12-micron-light is green; and 22-micron light is red.
WISE is an all-sky survey, snapping pictures of the whole sky, including everything from asteroids to stars to powerful, distant galaxies.
JPL manages WISE for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.
This Tadpole region is chock full of stars as young as only a million years old -- infants in stellar terms -- and masses over 10 times that of our sun. It is called the Tadpole nebula because the masses of hot, young stars are blasting out ultraviolet radiation that has etched the gas into two tadpole-shaped pillars, called Sim 129 and Sim 130. These "tadpoles" appear as the yellow squiggles near the center of the frame. The knotted regions at their heads are likely to contain new young stars. WISE's infrared vision is helping to ferret out hidden stars such as these.
The 1719 Jens asteroid, discovered in 1950, orbits in the main asteroid belt between Mars and Jupiter. The space rock, which has a diameter of 19 kilometers (12 miles), rotates every 5.9 hours and orbits the sun every 4.3 years.
Twenty-five frames of the region, taken at all four of the wavelengths detected by WISE, were combined into this one image. The space telescope caught 1719 Jens in 11 successive frames. Infrared light of 3.4 microns is color-coded blue: 4.6-micron light is cyan; 12-micron-light is green; and 22-micron light is red.
WISE is an all-sky survey, snapping pictures of the whole sky, including everything from asteroids to stars to powerful, distant galaxies.
JPL manages WISE for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.
Thursday, May 20, 2010
Physicists Create Millimeter-Sized 'Bohr Atom'
Nearly a century after Danish physicist Niels Bohr offered his planet-like model of the hydrogen atom, a Rice University-led team of physicists has created giant, millimeter-sized atoms that resemble it more closely than any other experimental realization yet achieved.
Bohr offered the first successful theoretical model of the atom in 1913, suggesting that electrons traveled in orbits around the atom's nucleus like planets orbiting a star. Bohr's model led to a deeper understanding of both the chemical and optical properties of atoms and won him a Nobel Prize in 1922. But his notion of electrons traveling in discrete orbits was eventually displaced by quantum mechanics, which revealed that electrons don't have precise positions but are instead distributed in wave-like patterns.
"In a sufficiently large system, the quantum effects at the atomic scale can transition into the classical mechanics found in Bohr's model," said lead researcher Barry Dunning, Rice's Sam and Helen Worden Professor of Physics and Astronomy. "Using highly excited Rydberg atoms and a series of pulsed electric fields, we were able to manipulate the electron motion and create circular, planet-like states."
The team included members from Oak Ridge National Laboratory and Vienna University of Technology. Using lasers, the researchers excited potassium atoms to extremely high levels. Using a carefully tailored series of short electric pulses, the team was then able to coax the atoms into a precise configuration with one point-like, "localized" electron orbiting far from the nucleus. In fact, the atoms are true atomic giants, with diameters approaching one millimeter.
"Our measurements show that the electrons remain localized for several orbits and behave much as classical particles," Dunning said.
He said the work has potential applications in next-generation computers and in the study of classical and quantum chaos.
The research is available online in Physical Review Letters. Co-authors include Rice graduate students Jeffery Mestayer and Brendan Wyker, Rice postdoctoral researcher Jim Lancaster, Oak Ridge National Laboratory's Carlos Reinhold and the Vienna University of Technology's Shuhei Yoshida and Joachim Burgdörfer. The research was supported by the National Science Foundation, the Robert A. Welch Foundation, the Department of Energy and the Austrian Science Fund.
Bohr offered the first successful theoretical model of the atom in 1913, suggesting that electrons traveled in orbits around the atom's nucleus like planets orbiting a star. Bohr's model led to a deeper understanding of both the chemical and optical properties of atoms and won him a Nobel Prize in 1922. But his notion of electrons traveling in discrete orbits was eventually displaced by quantum mechanics, which revealed that electrons don't have precise positions but are instead distributed in wave-like patterns.
"In a sufficiently large system, the quantum effects at the atomic scale can transition into the classical mechanics found in Bohr's model," said lead researcher Barry Dunning, Rice's Sam and Helen Worden Professor of Physics and Astronomy. "Using highly excited Rydberg atoms and a series of pulsed electric fields, we were able to manipulate the electron motion and create circular, planet-like states."
The team included members from Oak Ridge National Laboratory and Vienna University of Technology. Using lasers, the researchers excited potassium atoms to extremely high levels. Using a carefully tailored series of short electric pulses, the team was then able to coax the atoms into a precise configuration with one point-like, "localized" electron orbiting far from the nucleus. In fact, the atoms are true atomic giants, with diameters approaching one millimeter.
"Our measurements show that the electrons remain localized for several orbits and behave much as classical particles," Dunning said.
He said the work has potential applications in next-generation computers and in the study of classical and quantum chaos.
The research is available online in Physical Review Letters. Co-authors include Rice graduate students Jeffery Mestayer and Brendan Wyker, Rice postdoctoral researcher Jim Lancaster, Oak Ridge National Laboratory's Carlos Reinhold and the Vienna University of Technology's Shuhei Yoshida and Joachim Burgdörfer. The research was supported by the National Science Foundation, the Robert A. Welch Foundation, the Department of Energy and the Austrian Science Fund.
Bees That Nest in Petals
Scientists Describe the Nest of an Uncommon Solitary Bee:
In a rare coincidence, researchers working in both Turkey and Iran discovered on the same day how a rare species of bee builds its underground nests. The females from the solitary species Osima (Ozbekosima) avoseta line the nest's brood chambers with petals of pink, yellow, blue, and purple flowers. The chambers provide nutrients for the larvae to grow and mature and protect the next generation as they wait out the winter.
In a rare coincidence, researchers working in both Turkey and Iran discovered on the same day how a rare species of bee builds its underground nests. The females from the solitary species Osima (Ozbekosima) avoseta line the nest's brood chambers with petals of pink, yellow, blue, and purple flowers. The chambers provide nutrients for the larvae to grow and mature and protect the next generation as they wait out the winter.
Scientists Listen to Faint Sounds Inside Insects Using Atomic Force Microscopy
AFM is one of major scientific tools responsible for the emergence of modern nanotechnology.
The unprecedented sensitivity of AFM allowed the Clarkson team to record sub-nano oscillations of very faint amplitude (less than the size of one atom) at high frequencies (up to 1,000 hertz or cycles per second). Previous work in the study of insects was only done at up to 5 hertz. The sounds are recorded by touching the surface of the bugs with an AFM probe.
The study of these sounds may allow researchers to discover unknown features and physiology of insects. Sokolov hopes these discoveries may help in finding solutions to the problems caused by insect pests.
"Insects are of general interest not only as the most numerous and diverse group of animals on the planet, but also as highly efficient bio-machines varying greatly in size," says Sokolov. "Some are major agricultural pests and competitors of humans for crops. Mosquitoes and other insects are important vectors of plant, animal, and human diseases. Also, vast lands of the earth are still underdeveloped because they are occupied by blood-sucking insects."
You can listen to audio files of the internal sounds of mosquitoes, flies, and ladybugs at: http://ftp.aip.org/epaps/appl_phys_lett/E-APPLAB-96-038950 .
The team consisted of Sokolov, who has appointments in Physics, and Chemistry and Biomolecular Science; Maxim Dokukin, a physics postdoctoral fellow; and Nataliia Guz, a physics graduate student; and Sergey Vasilyev, instrumental scientist. The other members of Sokolov's group, physics graduate students Dmytro Volkov, Ravi Gaikwad, and Shyuzhene Li, work on biosensors, self-assembly of particles, and the study of skin aging.
The unprecedented sensitivity of AFM allowed the Clarkson team to record sub-nano oscillations of very faint amplitude (less than the size of one atom) at high frequencies (up to 1,000 hertz or cycles per second). Previous work in the study of insects was only done at up to 5 hertz. The sounds are recorded by touching the surface of the bugs with an AFM probe.
The study of these sounds may allow researchers to discover unknown features and physiology of insects. Sokolov hopes these discoveries may help in finding solutions to the problems caused by insect pests.
"Insects are of general interest not only as the most numerous and diverse group of animals on the planet, but also as highly efficient bio-machines varying greatly in size," says Sokolov. "Some are major agricultural pests and competitors of humans for crops. Mosquitoes and other insects are important vectors of plant, animal, and human diseases. Also, vast lands of the earth are still underdeveloped because they are occupied by blood-sucking insects."
You can listen to audio files of the internal sounds of mosquitoes, flies, and ladybugs at: http://ftp.aip.org/epaps/appl_phys_lett/E-APPLAB-96-038950 .
The team consisted of Sokolov, who has appointments in Physics, and Chemistry and Biomolecular Science; Maxim Dokukin, a physics postdoctoral fellow; and Nataliia Guz, a physics graduate student; and Sergey Vasilyev, instrumental scientist. The other members of Sokolov's group, physics graduate students Dmytro Volkov, Ravi Gaikwad, and Shyuzhene Li, work on biosensors, self-assembly of particles, and the study of skin aging.
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