Science & TechnologyS


Info

'Evil water' linked to mysterious drownings

It may sound like a superstitious excuse for a poor day's swimming, but it is not uncommon for triathletes to complain that the water is behaving badly - even that it is "evil". Now a study suggests what they are feeling is real.

Leo Maas, a fluid dynamicist at the Royal Netherlands Institute for Sea Research, and colleagues found that "dead water" - an obstructive effect encountered by ships at sea - can strike swimmers too.

As ships sail over a layer of warm water sitting over saltier, or colder, layers, waves form in the boundary between the two layers. As these waves grow, they form a gulf beneath the ship, sucking away its speed. This effect can stall boats at sea, reducing their speed by up to 80%.

Maas and his colleagues ran two experiments see if dead water could strike swimmers too.

Target

Scientists seek ways to ward off killer asteroids

A blue-ribbon panel of scientists is trying to determine the best way to detect and ward off any wandering space rocks that might be on a collision course with Earth.

Clock

Calls to scrap the 'leap second' grow

clock
© Joe Cornish/GETTY10, 9, 8, 7, 6, 5, 4, 3, 2, 1, and 1 again, happy new year!
At midnight on New Year's Eve, time will stop momentarily. Guardians of atomic clocks around the world will add an extra "leap second" to 2008 to keep time synched with the Earth's rotation. Arguably, the rise of GPS makes this tweak unnecessary.

In 1972, global commerce began to set its clocks by Coordinated Universal Time (UTC), based on the oscillations of the caesium atom. The snag was that other things, such as shipping and aircraft navigation, still relied on UT1 time, which divides one rotation of the Earth into 86,400 seconds. But the Earth's spin is slowing, so the two systems gradually go out of synch. "Over the course of a millennium, the differences would accumulate to about an hour," says Robert Nelson of the Satellite Engineering Research Corporation in Bethesda, Maryland.

To compensate, the ITU, or International Telecommunications Union, adds a leap second to atomic time every few years. However, many argue that we should stop tinkering with time, not least because of the glitches it causes (see "Add second...").

Now a group within the ITU, called Working Party 7A - after deliberating over the leap second for years - has told New Scientist that it recommends abolishing the leap second. Group member Elisa Felicitas Arias, of the International Bureau of Weights and Measures in Paris, France, argues that a timescale that doesn't need regular tweaking is essential in an increasingly interconnected world. What's more, she says, ships and aircraft now navigate via GPS rather than the old time system. GPS runs on a version of atomic time.

Info

First cases of touch-emotion synaesthesia discovered

For a 22-year-old woman known as AW, denim evokes feelings of depression, disgust and worthlessness. Corduroy causes confusion, and silk provides utter contentment. She is one of two people known to experience a newly discovered form of synaesthesia, where textures give rise to strong emotions.

HS, another young woman who experiences tactile-emotion synaesthesia, gets no kick out of denim. Fleece and dry leaves disgust her, while the touch of tennis balls, fresh leaves and sand are heaven.

Other forms of synaesthesia include numbers and letters that evoke colours, shapes that evoke tastes shapes and colours with their very own fragrances.

AW and HS's sensations, unusual though they may seem, are an extreme form of the positive feelings most people associate with a soft blanket or the aversion to sharp knives and jagged rocks, says V. S. Ramachandran, a neuroscientist at the University of California, San Diego.

"We have an affinity for fur because when were evolving in the ice age, we needed coats," he says. "This is the architecture on which [tactile-emotion synaesthesia] is built."

Powertool

Ancient Roman oil lamp "factory town" found in Italy

Image
© Soprintendenza per i Beni Archeologici dell'Emilia-RomagnaDecorator styles
Italian researchers have discovered the pottery center where the oil lamps that lighted the ancient Roman empire were made.

Evidence of the pottery workshops emerged in Modena, in central-northern Italy, during construction work to build a residential complex near the ancient walls of the city.

"We found a large ancient Roman dumping filled with pottery scraps. There were vases, bottles, bricks, but most of all, hundreds of oil lamps, each bearing their maker's name," Donato Labate, the archaeologist in charge of the dig, told Discovery News.

Sun

Sun Induces Strange 'Breathing' of Earth's Atmosphere

San Francisco, California - New satellite observations have revealed a previously unknown rhythmic expansion and contraction of Earth's atmosphere on a nine-day cycle.

This "breathing" corresponds to changes in the sun's magnetic fields as it completes rotations once every 27 days, NASA and University of Colorado, Boulder, scientists said Monday at the American Geophysical Union annual meeting.
Image
The dark regions of the image indicate coronal holes.

The sun's coronal holes, seen as dark regions in the image above, direct plasma away from the sun and out into the solar system. When these particles get to the Earth, they heat the upper atmosphere, causing the outer atmosphere to expand and contract.

Saturn

Tiny Saturn Moon ID'd As Good Candidate For Alien Life

saturn moon
© nasa
San Francisco, California - Saturn's tiny moon Enceladus may be one of the best candidates for extraterrestrial life in our solar system.

Scientists for the first time have gathered comprehensive evidence suggesting Enceladus may have all the necessary ingredients to harbor life in the ocean beneath its icy crust.

Particles in a large plume of water vapor emanating from the surface suggest the moon has an active ocean that circulates life-sustaining nutrients picked up from the rocky interior below.

Magnify

Asteroid may have caused New York tsunami 2,300 years ago

Scientists have found new evidence suggesting a giant tsunami that crashed in New York City 2,300 years ago, was caused by an asteroid 330 feet in diameter, which slammed into the Atlantic Ocean nearby.

According to a report in Discovery News, Katherine Cagen of Harvard University and a team of researchers found clues in the form of slit in the Hudson River, which indicates an asteroid impact in the past.

While sifting through samples, the researchers found carbon spherules, which are perfectly round particles that form in the extreme pressures of an impact.

"But the main thing that closes the deal is that we looked in the spherules and found nano-diamonds," said Dallas Abbott of Columbia University, a co-author on the work. "These have only been found in impact ejecta or in meteorites," he added.

Sherlock

Giant Dinosaur Fossil Found in Sahara Desert

Paleontologists claim they have unearthed a new type of pterosaur and a previously
dino fossil
© n/aA probable sauropod bone unearthed by researchers in the Sahara in Morocco. Shown are University College Dublin graduate student Nizar Ibrahim and David Martill of the University of Portsmouth, in England. Credit: Bob Loveridge, University of Portsmouth
unknown sauropod dinosaur in the Sahara Desert.

The probable pterosaur was identified by a large fragment of beak from the giant flying reptile, and the probable sauropod, an herbivore, was represented by a long bone measuring more than a yard long, indicating an animal nearly 65 feet (20 meters) in length. Now extinct, both would have lived almost 100 million years ago.

The fossils were found in southeast Morocco, near the Algerian border, during a month-long expedition.

Better Earth

'Dark energy' expands, contracts universe: researchers

dark energy
© AFPThis August 2008 image taken by the Hubble Space Telescope and Chandra X-ray Observatory show a clear separation between dark and ordinary matter during a clash 5.7 billion light years from Earth.
Mysterious "dark energy" works simultaneously to expand the universe and shrink objects inside it, astronomers in the United States said Tuesday.

By studying how gravity competes with the expansion of galaxy clusters, scientists have found "a crucial independent test of dark energy," said the research compiled by scientists using NASA's Chandra X-ray Observatory.

"This result could be described as 'arrested development of the universe,'" said lead researcher Alexey Vikhlinin of the Smithsonian Astrophysical Observatory in the northeastern state of Massachusetts.

"Whatever is forcing the expansion of the universe to speed up is also forcing its development to slow down."

Dark energy makes up about 70 percent of the universe, said the research to be published in the February 10 issue of Astrophysical Journal.