Science & Technology
A controversial new idea suggests that a large space rock exploded over North America 13,000 years ago.
The blast may have wiped out one of America's first Stone Age cultures as well as the continent's big mammals such as the mammoth and the mastodon.
The blast, from a comet or asteroid, caused a major bout of climatic cooling which may also have affected human cultures emerging in Europe and Asia.
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| A space rock may have exploded in the air over North America
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Two University of Oregon researchers are on a multi-institutional 26-member team proposing a startling new theory: that an extraterrestrial impact, possibly a comet, set off a 1,000-year-long cold spell and wiped out or fragmented the prehistoric Clovis culture and a variety of animal genera across North America almost 13,000 years ago.
Astronomers now have a new "eye" for determining the distance to certain mysterious bodies in and around our Milky Way galaxy. By taking advantage of the unique position of NASA's Spitzer's Space Telescope millions of miles from Earth, and a depth-perceiving trick called parallax, they were able to pin down the most probable location of one such object. The findings will ultimately help astronomers better understand the different components of our galaxy.
A robotic vehicle designed for underwater exploration plunged repeatedly into the depths of Mexico's mysterious El Zacatón sinkhole in late May, finding its previously undiscovered bottom 318 meters below the surface and generating a sonar map of its inner dimensions. The vehicle employed autonomous navigation and mapping systems developed by Carnegie Mellon University's Robotics Institute.
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| ©Deep Phreatic Thermal Explorer (DEPTHX) Project
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| The DEPTHX vehicle, 2.5 meters in diameter, included 56 sonars.
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"There is also an undoubted tendency of physicists (read "scientists") to work within a so-called paradigm (the American Philosopher of science Thomas Kuhn's famous expression) and pay at best fleeting attention to ideas that do not fit within the established patterns of thought"
- quoted from Julian Barbour's book "The End of Time - The Next Revolution in Physics"
"All is geometry"
- Albert Einstein
"...we have learned that the eye must have a fantastic mechanism for finding a balance point within a band of wave-lengths"
- Edwin Land
A Belgian mathematician hopes to use the science of chaos, the butterfly effect and strange attractors to help build a complete model of climate and resources that will lead to a new approach to sustainable development.
Jacques Nihoul of the department of Model Environment at the University of Liège, in Belgium, writing in the inaugural issue of the International Journal of Computing Science and Mathematics published by Inderscience, explains how a new approach to sustainable development and climate change could emerge from his research.
Sustainable development is high on the socio-political and scientific agenda. However, while it has become the focus of major attention in international from national and international organisations across the globe there is currently no all-encompassing approach to understanding what is needed to achieve it in developed and developing countries.
Xerox said on Wednesday that its scientists have perfected a new method for printing hidden fluorescent wording using standard digital printing equipment.
According to the company, the discovery paves the way for customers and businesses alike to add an additional layer of security to commonly printed materials such as checks, tickets, coupons, and other high-value documents.
The hidden fluorescent words and letters show up only under ultraviolet light, said Reiner Eschbach, a research fellow in the Xerox Innovation Group, and the co-inventor of the patented process. What's more, the method for printing them doesn't require the use of special fluorescent inks.
"What's amazes people about the new technology is that we can create fluorescent writing on a digital printer without using fluorescent ink," said Eschbach in a statement on Wednesday.
New charcoal and plant microfossil evidence from Mexico's Central Balsas valley links a pivotal cultural shift, crop domestication in the New World, to local and regional environmental history. Agriculture in the Balsas valley originated and diversified during the warm, wet, postglacial period following the much cooler and drier climate in the final phases of the last ice age. A significant dry period appears to have occurred at the same time as the major dry episode associated with the collapse of Mayan civilization, Smithsonian researchers and colleagues report in the Proceedings of the National Academy of Sciences online.
"Our climate and vegetation studies reveal the ecological settings in which people domesticated plants in southwestern Mexico. They also emphasize the long-term effects of agriculture on the environment," said Dolores Piperno, curator of archaeobotany and South American archaeology at the Smithsonian's National Museum of Natural History and the Smithsonian Tropical Research Institute in Panama.
PSUSat, 02 Jun 2007 06:54 UTC
In a simple experiment on a mixture of water, surfactant (soap), and an organic salt, two researchers working in the Pritchard Fluid Mechanics Laboratory at Penn State have shown that a rigid object like a knife passes through the mixture at slow speeds as if it were a liquid, but rips it up as if it were a rubbery solid when the knife moves rapidly.
The mixture they study shares properties of many everyday materials -- like toothpaste, saliva, blood, and cell cytoplasm -- which do not fall into the standard textbook cases of solid, liquid, or gas. Instead, these "viscoelastic" materials can have the viscous behavior of a fluid or the elastic behavior of a solid, depending on the situation. The results of these experiments, which are published in the current issue of the journal Physical Review Letters and are featured on its cover, provide new insights into how such materials switch over from being solid-like to being liquid-like.
A man has made a potentially exciting archaeological discovery while diving with seals off the north Northumberland coast.
Dr Ben Burville, 38, has been diving for more than 22 years and for the last seven has specialised in swimming with seals and other marine mammals.
Comment: And if it happened once, there's no reason why it couldn't happen again. Particularly if these type of events turn out to be cyclic, as the evidence suggests.