07.11.2010

New Zealand leave India tottering in Test match

AHMEDABAD, India (AFP) – Fast bowler Chris Martin snared two quick wickets to rock India's second innings on the fourth day of the first Test against New Zealand on Sunday.

Martin (2-0) removed struggling opener Gautam Gambhir for a duck off the third ball of the innings before Virender Sehwag was run out in the next over at the Sardar Patel Stadium in Ahmedabad.

The paceman returned to dismiss India's first-innings centurion Rahul Dravid for just one in his third over, leaving the hosts tottering at 2-3 at tea.

The Indians currently lead by 30 runs.

New Zealand were earlier boosted by the efforts of 20-year-old Kane Williamson, who scored a resilient 131 to steer the team to 459 in their first innings, just 28 short of India's first-innings 487.

Williamson hit 10 fours in his patient 299-ball knock and shared a stand of 86 for the sixth wicket with captain Daniel Vettori (41).

After Williamson's dismissal on the stroke of lunch, India removed Vettori, Gareth Hopkins, Jeetan Patel and Hamish Bennett in quick succession.

Part-time bowler Suresh Raina had Vettori caught behind before left-arm spinner Pragyan Ojha trapped Hopkins (14) plumb in front to finish with career-best figures of 4-107.

Patel and Bennett were cleaned up by fast bowlers Shanthakumaran Sreesanth and Zaheer Khan, who tasted his first success in two days.

Resuming on his overnight 87, Williamson struck Zaheer for two fours to race to the 100-run mark, becoming the eighth -- and youngest -- New Zealand batsman to score a century on debut.

The baby-faced batsman celebrated the moment by raising his bat and helmet towards the dressing room, where his teammates gave him a standing ovation.

Vettori achieved a personal milestone on 38, as he became the third all-rounder after Ian Botham of England and India's Kapil Dev to complete the Test double of 4,000 runs and 300 wickets.

Williamson's marathon knock came to an end when he edged to Venkatsai Laxman at first slip in the last over before lunch, bowled by Ojha.

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Saturn's Shimmying Rings May Be Imitating Galaxy

The dazzling rings ofSaturn spontaneously shake and shimmy, and a new study suggests that theprinciple behind the movement is also at work in the spiral arms of the wholegalaxy.

Researchers analyzingimages from NASA's Cassinispacecraft in orbit around Saturn have found that the oddoscillations in the planet's massive B ring aren't caused by moons or any otherbodies.

Instead, the ring isdense enough, and its edges are sharp enough, for unforced "free"waves to grow on their own and then reflect back again at the edge, scientistssay. [Newphoto of Saturn's B ring.]

Researchers thinkthis behavior is common in other disk systems, such as spiral galaxiesincluding our own Milky Way, and in protoplanetary disks found around nearbystars.

While the phenomenonhas been modeled in computer simulations, it had never been observed in nature— until now.

"We have foundwhat we hoped we'd find when we set out on this journey with Cassini nearly 13years ago: visibility into the mechanisms that have sculpted not only Saturn'srings, but celestial disks of a far grander scale, from solar systems, like ourown, all the way to the giant spiral galaxies," said Carolyn Porco of theSpace Science Institute in Boulder, Colo., a study co-author and leader of theCassini imaging team.

The new observationscould help explain the bewildering variety of structures seen throughout thedensest regions of Saturn's rings, according to the study appearing today (Nov.1) in the online version of Astrophysical Journal.

Saturn's mysteryoscillations

Scientists have knownsince the early 1980s, when NASA's Voyager spacecraft flew by Saturn, that theouter edge of the planet's B ring was sculpted into a rotating,flattened-football shape. The strongest gravitational resonance in Saturn'srings is caused by the planet's moonMimas.

Resonances inSaturn's rings occur where the relative orbital positions between ringparticles and a moon continually repeat, altering the particles' orbits. In thecase of the Mimas resonance, the particle orbits are changed from circles toellipses that form a two-lobed pattern rotating with Mimas.

But it was clear,even in Voyager's findings, that the outer B ring's behavior was far morecomplex than anything Mimas alone could cause, researchers said.

Now, analysis ofthousands of Cassiniimages of the B ring edge, taken over the course of four years,has revealed the source of most of the complexity: the presence of at leastthree additional, independently rotating wave patterns, or oscillations.

These oscillationshave spontaneously arisen as a result of the B ring's density and its crispedges, which allow wave patterns to form and bounce around, researchers said.

"Theseoscillations exist for the same reason that guitar strings have natural modesof oscillation, which can be excited when plucked or otherwise disturbed,"said Joseph Spitale of the Space Science Institute, the study's lead author anda member of the Cassini imaging team. "The ring, too, has its own naturaloscillation frequencies, and that's what we're observing."

Just like a spiralgalaxy

Astronomers believethat such self-excited oscillations exist in other, distant disk systems.However, motions within these remote systems cannot be directly observed, andresearchers have instead resorted to computer simulations to study them.

Now that has changed.

The new observationsconfirm the first large-scale wave oscillations of this type in a broad disk ofmaterial anywhere in nature, researchers said.

This same processmight explain all the puzzling chaotic waveforms found in Saturn's densestrings, from tens of meters up to hundreds of kilometers wide.

"Normallyviscosity, oresistance to flow, damps waves, the way sound waves travelingthrough the air would die out," said Peter Goldreich, a planetary ringtheorist at the California Institute of Technology in Pasadena, who was notinvolved in the study.

"But the newfindings show that, in the densest parts of Saturn'srings, viscosity actually amplifies waves, explaining mysteriousgrooves first seen in images taken by the Voyager spacecraft," he added.

More Saturn moons?

Images of the Bring's outer edge also have revealed at least two perturbed regions, one ofthem a long arc of narrow shadow-casting peaks extending as high as 2.2 miles(3.5 km) above the ring plane.

The study suggeststhat these regions are likely populated by small moons that may have migratedacross the outer part of the B ring sometime in the past, eventually becomingtrapped near the edge in a zone affected by the gravity of Mimas. Such aprocess is commonly thought to have helped configure the present-day solarsystem, researchers said.

Spitale and Porcopropose that these regions very likely contain small moons, hundreds of metersto possibly a kilometer or more across, that dramatically compress and forceupward the ring material passing around them in this agitated environment atthe B ring's edge.

The authors alsotheorize that the outer part of the B ring may, at one time, have beenpopulated by a collection of small bodies, in the same way Saturn's outer Aring today is home to dozens of moonlets that create the "propeller"features recently discovered by Cassini.

Gallery: The Rings and Moons of Saturn Cassini's Greatest Hits: Photos of Saturn Video: The Source of Saturn's G Ring

 

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Bernanke defends new Fed plan to boost economy

JEKYLL ISLAND, Ga. – Federal Reserve Chairman Ben Bernanke defended the Fed's new $600 billion program to aid the economy on Saturday, rejecting concerns that it will spur runaway inflation.

Critics, including some Fed officials, fear that all the money being injected into the economy could ignite inflation or speculative bubbles in the prices of bonds or commodities.

Speaking to a conference on the Georgia coast, Bernanke said the new program, announced Wednesday, won't push inflation to "super ordinary" levels.

The Fed will buy $600 billion worth of government bonds in a bid to make loans cheaper and get Americans to spend more. Doing so would help the economy and prompt companies to boost hiring.

The economy hasn't been growing fast enough to reduce unemployment, which has been stuck at a high of 9.6 percent for three straight months. The Fed worries that high unemployment, lackluster wage gains and still-weak home values will weigh on consumer spending, a major drive of overall economic activity.

Because companies are loath to raise retail prices in this climate, inflation has been running at very low levels. That gives the Fed leeway to launch the new aid program.

Earlier in the week, Bernanke expressed confidence that once the economy is on firm footing, the Fed will be able to smoothly soak up all that money without harming the economy and unleashing inflation.

___

AP Economics Writer Jeannine Aversa in Washington contributed to this report.

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