Science & Technology
There has been debate over the issue because with some researchers believing water likely formed many features of the planet's landscape and others pointing to evidence indicating that early Mars was cold with temperatures well below the freezing point of water.
Fri, 22 May 2009 00:45 UTC
Many scientists had thought the violent pelting by massive asteroids during the period known as the Late Heavy Bombardment would have melted the Earth's crust and vaporized any life on the planet.
But new three-dimensional computer models developed by a team at the University of Colorado at Boulder shows much of Earth's crust, and the microbes living on it, could have survived and may even have thrived.
Thu, 21 May 2009 23:20 UTC
The Hollywood blockbuster, The Golden Compass, adapted from the first volume of Pullman's classic sci-fi trilogy, "His Dark Materials" portrays various universes as only one reality among many, but how realistic is this kind of classic sci-fi plot? While it hasn't been proven yet, many highly respected and credible scientists are now saying there's reason to believe that parallel dimensions could very well be more than figments of our imaginations.
"The idea of multiple universes is more than a fantastic invention - it appears naturally within several scientific theories, and deserves to be taken seriously," stated Aurelien Barrau, a French particle physicist at the European Organization for Nuclear Research (CERN).
Wed, 20 May 2009 04:32 UTC
In a recent study, researchers have experimentally demonstrated for the first time a celebrated model of "phyllotaxis," the study of mathematical regularities in plants. In 1991, S.L. Levitov proposed a model of phyllotaxis suggesting that the appearance of the Fibonacci sequence and golden mean in the pattern of spines on a cactus can be replicated for cylindrically constrained, repulsive objects. Now, researchers have constructed a "magnetic cactus" with 50 outward-pointing magnets acting as spines, which are mounted on bearings and free to rotate on a vertical axis acting as the plant stem. With this setup, the researchers, from Los Alamos National Laboratory in New Mexico; Cornell University in Ithaca, New York; and The Pennsylvania State University (PSU), have verified Levitov's model, and their study has been published in a recent issue of Physical Review Letters.
In their experiment, the researchers put the system in a low-energy state by mechanical agitation. Then the scientists observed as the magnets (spines) arranged to form phyllotactic spirals, generating a so-called Farey tree of unfavorable angles. The unfavorable angles are fractional multiples of 2π (i.e. 2πi/j, such as 2π/3, 4π/3, etc.). The spines on the magnetic cactus, like those on a plant, form a helix around the cylindrical stem by growing around these particular angles.
A new study finds some people can remember faces of people they met years ago and only in passing. Others of us, of course, aren't blessed with that ability. In fact about 2 percent of the population have prosopagnosia, a condition characterized by great difficulty in recognizing faces.
The "super-recognizers," as they're being called, excel at recalling faces and suggest that there is - as with many things - a broad spectrum of ability in this realm. The research involved administering standardized face recognition tests. The super-recognizers scored far above average on these tests - higher than any of the normal control subjects.
"There has been a default assumption that there is either normal face recognition, or there is disordered face recognition," said Richard Russell, a postdoctoral researcher in the Department of Psychology at Harvard. "This suggests that's not the case, that there is actually a very wide range of ability."
Super-recognizers recognize other people far more often than they are recognized. So they often compensate by pretending not to recognize someone they met in passing, so as to avoid appearing to attribute undue importance to a fleeting encounter, Russell said.
Many depend on the satellite navigation network to beam precise directions from A to B into users' cars or on their mobile phones.
But mismanagement and a lack of investment means the 20-year-old system could lead consumers into nothing but trouble.
The first replacement satellite was supposed to be launched into space in 2007, but won't be ready until November - nearly three years too late.
The find confirms suspicions that some solar ejections can occur even though the surface of the sun looks tranquil.
The eruption was a coronal mass ejection (CME) - a bubble of plasma that, if energetic enough and pointed at Earth, could zap satellites, endanger astronauts, and knock out power grids (see Space story alert: 90 seconds from catastrophe).
When it comes to the universe, "flatness" refers to the fate of light beams travelling large distances parallel to each other. If the universe is "flat", the beams will always remain parallel. Matter, energy and dark energy all produce curvature in space-time, however. If the universe's space-time is positively curved, like the surface of a sphere, parallel beams would come together. In a negatively curved, saddle-shaped universe, parallel beams would diverge.
Thanks in part to the Wilkinson Microwave Anisotropy Probe (WMAP) satellite, which revealed the density of matter and dark energy in the early universe, most astronomers are confident that the universe is flat. But that view is now being questioned by Joseph Silk at the University of Oxford and colleagues, who say it's possible that the WMAP observations have been misinterpreted.
National Geographic News
Wed, 20 May 2009 01:21 UTC
Ancient peoples of southern North America went to "dentists" - among the earliest known - to beautify their chompers with notches, grooves, and semiprecious gems, according to a recent analysis of thousands of teeth examined from collections in Mexico's National Institute of Anthropology and History (such as the skull above, found in Chiapas, Mexico).
University of Alberta
Wed, 20 May 2009 01:17 UTC
University of Alberta Earth and Atmospheric Sciences PhD student Colin Cooke's results from two seasons of field work in Peru have now provided the first unambiguous records of pre-industrial mercury pollution from anywhere in the world and will be published in the May 18th Early Edition of the Proceedings of the National Academy of Sciences (PNAS).