Science & TechnologyS


Sun

Sunspots squeeze and stretch the day

David Shiga
New Scientist
Fri, 27 Aug 2010 14:12 UTC
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© Scharmer et al/Royal Sweedish Academy of Sciences/SPLInfluential beasts
Most of us don't notice it, but not all days are the same length. Now it seems that sunspots - dark regions that emerge on the sun's surface - may be partly responsible for the millisecond fluctuations in the time it takes Earth to rotate once on its own axis. The finding could help to steer spacecraft more accurately.

There are already explanations for why the exact length of a day varies. Changes in winds and ocean currents cause the Earth's spin to slow slightly or speed up to compensate, preserving the planet's total angular momentum. Meanwhile, shifts in how matter is distributed around the planet due to climate change may also affect the speed of Earth's spin.

The latest association, between sunspots, whose abundance rises and falls on an 11-year "solar cycle", and the Earth's spin rate, is perhaps the most bizarre yet.

Researchers have long observed that the spin rate fluctuates with the seasons, in response to shifting wind patterns. Now, a team led by Jean-Louis Le Mouël at the Paris Institute of Geophysics in France has found that this seasonal effect also grows and shrinks in an 11-year cycle, rather like sunspots. Seasons have a bigger effect on spin rate when sunspots are scarce, and a smaller effect when spots are abundant, according to an analysis of data from 1962 to 2009 (Geophysical Research Letters, vol 37, L15307).
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Info

G-Whizzes Disagree Over Gravity

Eugenie Samuel Reich
Nature
Fri, 27 Aug 2010 01:32 UTC
Interferometer
© Science Museum; H. Parks/JilaA model of Henry Cavendish’s torsion balance (left) and its latest successor, a laser interferometer.
The Newtonian constant of gravitation - known in the finely tuned business of metrology as 'big G' - has come a long way since British physicist Henry Cavendish first measured the gravitational attraction of Earth in 1798. Although G derived from Cavendish's measurements had an uncertainty of about 1%, modern measurements have tightened that to just a couple of tens of parts per million.

But the relentless honing of G may have hit a stumbling block. Two recent experiments are in striking disagreement with earlier findings, and the overall uncertainty in the value of the constant may be set to increase.

In Newton's equations of gravity, G represents the size of the gravitational force. The constant is involved in the quest to unify the theories of gravity and quantum mechanics, and efforts to determine G have contributed to progress in areas of experimental physics: elements of the apparatus first developed to measure the constant, for example, are now used in gravitational-wave detectors. But for some researchers, measuring G is an end in itself. "It's the ultimate precision experiment," says James Faller, a physicist at the University of Colorado at Boulder.
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Saturn

Stargazers Discover Seven-Planet System

Simon Bradley & Marc-André Miserez
SwissInfo
Thu, 26 Aug 2010 12:15 UTC
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© ESOThe new planetary system has as many as seven planets orbiting a sun-like star.
Astronomers have found a new planetary system with as many as seven planets orbiting a sun-like star - 127 light years from Earth.

If confirmed, the discovery by a European team, led by Christophe Lovis from Geneva University, represents "the richest" system of exo-planets - planets outside our own solar system - ever found.

This remarkable discovery highlights the fact that we are now entering a new era in exo-planet research, said Lovis.

"This shows that we are able to detect complex systems of small planets, which opens up huge perspectives, as these systems are probably very numerous," the lead researcher told swissinfo.ch.
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Sun

Kepler space telescope finds pair of distant planets, NASA says

Rich Phillips
CNN
Thu, 26 Aug 2010 11:32 UTC
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© AFP/Getty ImagesThis artist rendition obtained from NASA shows Saturn-sized planets orbiting a distant star about 2,000 light years from Earth.
Two planets slightly smaller than Saturn have been discovered orbiting a distant star, a first for NASA's Kepler space telescope, whose mission is to look for signs of planets passing in front of stars, the space agency said Thursday.

This is "the first discovery of multiple planets orbiting the same star" by looking for such transits, said William Borucki, the science principal investigator for the Kepler Mission. He spoke in a teleconference from the NASA Ames Research Center in California.

The sun-like star, designated Kepler-9, is about 2,000 light years away in the constellation Lyra, he said.

The two planets, named Kepler-9b and 9c, show a clear gravitational interaction, according to NASA. But while scientists hope Kepler will find Earth-like planets, these two do not qualify. In addition to being much larger than Earth, they are much too close to the star they are orbiting.

"The habitable zone is actually quite far out from these stars," Borucki said. These planets "are very, very hot."
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Footprints

Nike Patents Shoes That Tie Themselves

Jane McEntegart
TomsGuide
Fri, 27 Aug 2010 00:00 UTC
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© Unknown
"There's something very familiar about all this..."

The Back to the Future trilogy featured many cool things we all hoped to some day own for ourselves. Whether it was something as high-tech as hoverboards, or as simple as shoes that would lace themselves, there was plenty for us to dream about for the future.

Though hover-skateboards will probably take a bit longer, we may see those self-lacing shoes in time for 2015. Nike has filed for a patent for self-lacing shoes, complete with a charging station. Sure, not every patent filed means we can expect to see the product on the shelves, but we really hope Nike makes these shoes a reality. Who wouldn't want a pair of Marty McFlys?
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Magnify

Oetzi the Iceman May Have Been Ceremonially Buried

Nick Squires
The Telegraph, UK
Thu, 26 Aug 2010 11:25 UTC
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© Getty ImagesAfter being frozen in ice for 5,300 years, Otzi's remains were found well-preserved
The prehistoric hunter known as Oetzi the Iceman may have been ceremonially buried on a high Alpine pass rather than killed there in a deadly ambush, experts say.

Researchers believe they have found evidence which shows that Oetzi, named after the Oetz Valley in which he was found, died lower down the valley, probably violently, but was then carried up to the 10,500ft high pass for a ceremonial burial.

The new theory suggests that he may have been an important figure in his tribe or village, possibly a chieftain.

After being frozen in ice for 5,300 years, Oetzi's remains, along with a treasure trove of prehistoric artefacts, were found in a remarkable state of preservation by two German hikers in 1991, close to the modern day border between Italy and Austria.

Scientists have long believed that the Stone Age tribesman was attacked as he trekked over the mountains.
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Info

Earthquake Dating Confused by Sea Shells

Adele Rackley
Planet Earth Online
Thu, 26 Aug 2010 00:25 UTC
Coastal earthquakes that cause the earth to shift are often dated by the remains of marine creatures that are exposed and killed when the ground lifts out of the sea.

Crete Coastline
© Planet Earth OnlineCrete coastline.
But scientists have discovered that one commonly used shell can produce apparent dates thousands of years older than the event that exposed them.

In AD365 a huge earthquake tilted the whole western end of the Greek island of Crete, exposing up to 10m of previously submerged land along the south and west coasts.

The event was well documented so we can be sure of its date. And it left exposed a ring, like a tide-mark, made from algae that concreted - or set - at sea level when the quake happened. The next ring down is at current sea level, so we know that this ground was lifted up in a single event.

But when a team of scientists from the universities of Cambridge and Oxford dated the remains of two different creatures exposed by the quake they came out with widely differing results.
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Rocket

Electric Car Designed by Students Reaches Record 307 Miles Per Hour

Paul Foy
The Associated Press
Wed, 25 Aug 2010 16:00 UTC
The Buckeye Bullet, an electric car built by students
© OSUThe Buckeye Bullet, an electric car built by students, in a recent record setting speed demonstration.
A team of Ohio State University students that set out to build the fastest electric car on the planet is heading home with a broken clutch and a big grin.

The Buckeye Bullet was clocked on Utah's Bonneville Salt Flats at speeds averaging 307 mph, which could set a new record if it is verified by the governing body of motorsports. The old record for an electric car was 246 mph.

"We've been at this for 16 years now and have our newest lithium-ion powered vehicle out," team manager David Cooke said by cell phone from the salt flats, about 100 miles west of Salt Lake City. "Our vehicle was capable of going much faster."
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Pharoah

King Tut's Family Secrets

Zahi Hawass
National Geographic
Wed, 25 Aug 2010 19:50 UTC
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King Tut
© Kenneth Garrett
DNA evidence reveals the truth about the boy king's parents and new clues to his untimely death.

Mummies capture our imaginations and our hearts. Full of secrets and magic, they were once people who lived and loved, just as we do today.

I believe we should honor these ancient dead and let them rest in peace.

There are some secrets of the pharaohs, however, that can be revealed only by studying their mummies. By carrying out CT scans of King Tutankhamun's mummy, we were able in 2005 to show that he did not die from a blow to the head, as many people believed. Our analysis revealed that a hole in the back of his skull had been made during the mummification process. The study also showed that Tutankhamun died when he was only 19 - perhaps soon after he suffered a fracture to his left leg. But there are mysteries surrounding Tutankhamun that even a CT scanner cannot reveal. Now we have probed even deeper into his mummy and returned with extraordinary revelations about his life, his birth, and his death.
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Cloud Lightning

NASA/NOAA Study Finds El Niños are Growing Stronger


Jet Propulsion Laboratory
Wed, 25 Aug 2010 17:47 UTC
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Pasadena, Calif. - A relatively new type of El Niño, which has its warmest waters in the central-equatorial Pacific Ocean, rather than in the eastern-equatorial Pacific, is becoming more common and progressively stronger, according to a new study by NASA and NOAA. The research may improve our understanding of the relationship between El Niños and climate change, and has potentially significant implications for long-term weather forecasting.

Lead author Tong Lee of NASA's Jet Propulsion Laboratory, Pasadena, Calif., and Michael McPhaden of NOAA's Pacific Marine Environmental Laboratory, Seattle, measured changes in El Niño intensity since 1982. They analyzed NOAA satellite observations of sea surface temperature, checked against and blended with directly-measured ocean temperature data. The strength of each El Niño was gauged by how much its sea surface temperatures deviated from the average. They found the intensity of El Niños in the central Pacific has nearly doubled, with the most intense event occurring in 2009-10.
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