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Academia is notoriously resistant to change, which to some extent is a good thing. It was therefore no surprise that when Wikipedia became a phenomenon most academics scoffed at it as a passing fad, fatally flawed by its very core idea: anybody, and I mean anybody, can become a Wiki author and post new entries or edit existing ones. Surely, this will inevitably lead to chaos and complete unreliability, the critics said. But a few years ago a study of a sample of entries compared the accuracy of Wikipedia with that of the unquestionably prestigious Encyclopedia Britannica, and Wikipedia was at least as accurate, in some cases more.
They may look like low dunes, but the cresting ridges on Argentina's Puna Plateau are the world's largest "megaripples". Geological features of this size had been thought impossible on Earth.
Wind-formed ripples are not the same as dunes because they are shaped by the airflow less than 2 metres above the ground. The key factor for dunes is air fluctuations as high as 4 kilometres up.
Most such ripples are no bigger than those created by waves on a beach. Given high winds, light grains and geologic timescales, however, they can grow.
The mysterious stuff known as dark matter may have left a calling card at the edge of the Earth's atmosphere where a space-faring satellite named PAMELA could pick it up. Researchers are reporting that PAMELA detected a high number of the subatomic particles called positrons, the positively-charged counterpoints to electrons, which could have been created by collisions between dark matter particles. "PAMELA found a number of positrons much higher than expected," the mission's principal investigator Piergiorgio Picozza [said]. "Many think this could be a signal from dark matter" [SPACE.com]. But of course, others think there's a more mundane explanation.
© NASA/JPL/Space Science InstituteTitan may look like a sphere, but radar studies by the Cassini probe show it is slightly squashed.
Titan is 5150 kilometres across, making it larger than Mercury and only slightly smaller than the largest moon in the solar system, Jupiter's Ganymede.
By bouncing radar signals off the moon's smog-enshrouded surface, the Cassini spacecraft has now measured Titan's shape precisely for the first time.
"What we have are the first actual measurements showing that Titan's not an exact sphere - this distorted egg-shaped thing best fits the observed shape," study leader Howard Zebker of Stanford University told New Scientist.
© NASANASA's Cassini spacecraft photographed Jupiter and its Great Red Spot, seen center near the equator, in 2000.
The spot, which is actually an ancient monster storm that measures about three Earths across, lost 15 percent of its diameter between 1996 and 2006, scientists at the University of California, Berkeley, have found.
It shrank by about 1 kilometer (about 0.6 miles) a day during that time period, said Xylar Asay-Davis, a postdoctoral researcher who was part of the study.
© Rick Gomez / CorbisType A family
Many evolutionary scientists believe that those thousands of years of human behavior are no artifact: modern men still strive for status partly because it is an evolutionary advantage for improving reproductive success. But other researchers have disputed that theory by citing data showing that wealthier, higher-status men do not in fact have more children than their less moneyed, lower-status peers. (See pictures of Barack Obama's family tree.)
Now a new study in the Journal of Personality offers another theory: it is not necessarily wealth that facilitates procreation but a more basic and deeply ingrained evolutionary trait - having a Type A personality. The study finds that adolescents who say they always take charge, tell others what to do, anger quickly, get into fights easily, and walk, talk and eat fast end up having more kids than others when they grow up. That's true regardless of the kids' performance in school.
© NASA, ESA, and G. Bacon (STScI)This is an artistic illustration of the giant planet HR 8799b. The planet was first discovered in 2007 at the Gemini North observatory. The planet is young and hot, at a temperature of 1500 degrees Fahrenheit. It is slightly larger than Jupiter and may be 10 times more massive.
The method was used to find an exoplanet that went undetected in Hubble images taken in 1998 with its Near Infrared Camera and Multi-Object Spectrometer (NICMOS). Astronomers knew of the planet's existence from images taken with the Keck and Gemini North telescopes in 2007 and 2008, long after Hubble snapped its first picture of the system.
The planet is estimated to be at least seven times the mass of Jupiter. It is the outermost of three massive planets known to orbit the dusty young star HR 8799, which is 130 light-years away from Earth. NICMOS could not see the other two planets because its coronagraphic spot - a device that blots out the glare of the star - blocked its viewof the two inner planets.
© Unknown
"Completion of the National Ignition Facility is a true milestone that will make America safer and more energy independent by opening new avenues of scientific advancement and discovery," said NNSA Administrator Thomas D'Agostino. "NIF will be a cornerstone of a critical national security mission, ensuring the continuing reliability of the U.S. nuclear stockpile without underground nuclear testing, while also providing a path to explore the frontiers of basic science and potential technologies for energy independence."
© Unknown
"Space debris has recently been attracting increasing attention not only due to the growing recognition of the long-term need to protect the commercially valuable low-Earth and geosynchronous orbital zones but also due to the direct threat that existing debris poses to current and future missions," the ESA said. "While commercial and scientific uses of space have expanded across a wide range of activities, including telecommunications, weather, navigation, Earth observation and science, space debris has continued to accumulate, significantly threatening current and future missions."
Falling into a black hole might not be good for your health, but at least the view would be fine. A new simulation shows what you might see on your way towards the black hole's crushing central singularity. The research could help physicists understand the apparently paradoxical fate of matter and energy in a black hole.
Andrew Hamilton and Gavin Polhemus of the University of Colorado, Boulder, built a computer code based on the equations of Einstein's general theory of relativity, which describes gravity as a distortion of space and time.
