Science & TechnologyS


Telescope

New Eclipsing Binary: It's Spica!

Ivan Semeniuk
Sky and Telescope
Thu, 04 Jun 2009 00:51 UTC
One of the true pleasures in science comes when a new and surprising fact is uncovered about something thought to be utterly familiar. Such is the case this week with the revelation that Spica, one of the best-known stars in the night sky, is an eclipsing binary. Every 4.0145 days one of the two separate stars that makes up this system crosses in front of the other, blocking a portion of its light.

How could astronomers have missed this fact? It's no scandal. Spica's eclipses are the merest grazes. Each time it happens the total light output of the system dips by less than one hundredth of a visual magnitude. Nevertheless, these events are of interest to science because they offer a greatly improved understanding of the two star's sizes and shapes and the complex physics at work in a nearby and rather special star system. Astronomers have known since 1890 that Spica was a spectroscopic binary, but now we have a better handle on it.
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Sun

UF study finds that ancient mammals shifted diets as climate changed

Jen Laloup
Public Library of Science
Thu, 04 Jun 2009 00:35 UTC
Image
Gainesville, Fla. --- A new University of Florida study shows mammals change their dietary niches based on climate-driven environmental changes, contradicting a common assumption that species maintain their niches despite global warming.

Led by Florida Museum of Natural History vertebrate paleontologist Larisa DeSantis, researchers examined fossil teeth from mammals at two sites representing different climates in Florida: a glacial period about 1.9 million years ago and a warmer, interglacial period about 1.3 million years ago. The researchers found that interglacial warming resulted in dramatic changes to the diets of animal groups at both sites. The study appears in the June 3 issue of the open-access, peer-reviewed journal PLoS ONE.
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Sun

Cantabrian cornice has experienced seven cooling and warming phases over past 41,000 years


Spanish Foundation for Science and Technology
Thu, 04 Jun 2009 00:28 UTC
In 1996, an international team of scientists led by the University of Zaragoza (UNIZAR) started to carry out a paleontological survey in the cave of El Mirón. Since then they have focused on analysing the fossil remains of the bones and teeth of small vertebrates that lived in the Cantabrian region over the past 41,000 years, at the end of the Quaternary. The richness, great diversity and good conservation status of the fossils have enabled the researchers to carry out a paleoclimatic study, which has been published recently in the Journal of Archaeological Science.
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Info

NASA Satellite Detects Red Glow to Map Global Ocean Plant Health


Environmental News Network
Wed, 03 Jun 2009 02:43 UTC
Image
© NASA's Scientific Visualization Studio
A study published by NASA uses satellite remote sensing technology to measure the amount of fluorescent red light emitted by ocean phytoplankton and assess how efficiently the microscopic plants are turning sunlight and nutrients into food through photosynthesis. They can also study how changes in the global environment alter these processes, which are at the center of the ocean food web.

Researchers have conducted the first global analysis of the health and productivity of ocean plants, as revealed by a unique signal detected by a NASA satellite. Ocean scientists can now remotely measure the amount of fluorescent red light emitted by ocean phytoplankton and assess how efficiently the microscopic plants are turning sunlight and nutrients into food through photosynthesis. They can also study how changes in the global environment alter these processes, which are at the center of the ocean food web.
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Bizarro Earth

Earth Losing Atmosphere Faster than Venus, Mars

Irene Klotz
Discovery News
Tue, 02 Jun 2009 04:38 UTC
Researchers were stunned to discover recently that Earth is losing more of its atmosphere than Venus and Mars, which have negligible magnetic fields.

This may mean our planet's magnetic shield may not be as solid a protective screen as once believed when it comes to guarding the atmosphere from an assault from the sun.

"We often tell ourselves that we are very fortunate living on this planet because we have this strong magnetic shield that protects us from all sorts of things that the cosmos throws at us -- cosmic rays, solar flares and the pesky solar wind," said Christopher Russell, a professor of geophysics and space physics at the University of California, Los Angeles.
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Info

Robot sub reaches deepest ocean


British Broadcasting Corporation
Wed, 03 Jun 2009 02:32 UTC
Image
Nereus can switch between free-swimming and tethered configurations
A robotic sub called Nereus has reached the deepest-known part of the ocean.

The dive to 10,902m (6.8 miles) took place on 31 May, at the Challenger Deep in the Marianas Trench, located in the western Pacific Ocean.

This makes Nereus the deepest-diving vehicle currently in service and the first vehicle to explore the Marianas Trench since 1998.
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Bulb

Laser makes light bulbs super-efficient


United Press International
Wed, 03 Jun 2009 02:27 UTC
Rochester N.Y., -- U.S. scientists have used an ultra-powerful laser to turn regular incandescent light bulbs into super-efficient sources of light.

University of Rochester (N.Y.) researchers said the laser creates a unique array of nano- and micro-scale structures on the surface of a regular tungsten filament. It's those structures that make the tungsten emit light as bright as a 100-watt bulb, but consume less electricity than a 60-watt bulb.
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Info

Professor dubious about new lie detectors


United Press International
Wed, 03 Jun 2009 02:21 UTC
Champaign Ill., -- A U.S. professor says she is unconvinced new technologies such as functional magnetic resonance imaging are superior to polygraph tests for detecting lies.

University of Illinois Professor Melissa Littlefield says in today's forensically sophisticated, "CSI"-influenced world, polygraphy -- which bases its results on functions of the autonomic nervous system -- is being increasingly dismissed as dated and unreliable.
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Blackbox

Temple timbers trace collapse of Mayan culture


New Scientist
Wed, 03 Jun 2009 01:43 UTC
Temple II at Tikal, Guatemala
© Doug Traverso / Robert Harding / Rex FeaturesTemple II at Tikal, Guatemala, Central America. New evidence suggests that the Mayan civilisation collapsed because of a lack of resources rather than other factors such as disease or warfare
The builders of the ancient Mayan temples at Tikal in Guatemala switched to inferior wood a few decades before they suddenly abandoned the city in the 9th century AD. The shift is the strongest evidence yet that Mayan civilisation collapsed because they ran out of resources, rather than, say, disease or warfare.

Researchers led by David Lentz, a palaeoethnobotanist at the University of Cincinnati in Ohio, sampled wooden beams and lintels from all six major temples and two palaces within the ancient city of Tikal. The first three temples, built before AD 741, used only large, straight logs of the sapodilla tree - a particularly strong wood that is nevertheless easy to carve with ceremonial inscriptions.
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Health

Reboot Your Brain? Science Says It's Possible

Rebecca Sato
Daily Galaxy
Tue, 02 Jun 2009 17:49 UTC
Image
© UnknownHuman brain receptors
Contrary to popular belief, recent studies have found that there are probably ways to regenerate brain matter.

Animal studies conducted at the National Institute on Aging Gerontology Research Center and the Johns Hopkins University School of Medicine, for example, have shown that both calorie restriction and intermittent fasting along with vitamin and mineral intake, increase resistance to disease, extend lifespan, and stimulate production of neurons from stem cells.

In addition, fasting has been shown to enhance synaptic elasticity, possibly increasing the ability for successful re-wiring following brain injury. These benefits appear to result from a cellular stress response, similar in concept to the greater muscular regeneration that results from the stress of regular exercise.
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