Rabu, 29 September 2010

Could 'Goldilocks' planet be just right for life?

Could 'Goldilocks' planet be just right for life?

AP Photo/Zina Deretsky, National Science Foundation

WASHINGTON – Astronomers say they have for the first time spotted a planet beyond our own in what is sometimes called the Goldilockszone for life: Not too hot, not too cold. Juuuust right.

Not too far from its star, not too close. So it could contain liquid water. The planet itself is neither too big nor too small for the proper surface, gravity and atmosphere.

It's just right. Just like Earth.

"This really is the first Goldilocks planet," said co-discoverer R. Paul Butler of the Carnegie Institution of Washington.

The new planet sits smack in the middle of what astronomers refer to as the habitable zone, unlike any of the nearly 500 other planets astronomers have found outside our solar system. And it is in our galactic neighborhood, suggesting that plenty of Earth-like planets circle other stars.

Finding a planet that could potentially support life is a major step toward answering the timeless question: Are we alone?

Scientists have jumped the gun before on proclaiming that planets outside our solar system were habitable only to have them turn out to be not quite so conducive to life. But this one is so clearly in the right zone that five outside astronomers told The Associated Press it seems to be the real thing.

"This is the first one I'm truly excited about," said Penn State University's Jim Kasting. He said this planet is a "pretty prime candidate" for harboring life.

Life on other planets doesn't mean E.T. Even a simple single-cell bacteria or the equivalent of shower mold would shake perceptions about the uniqueness of life on Earth.

But there are still many unanswered questions about this strange planet. It is about three times the mass of Earth, slightly larger in width and much closer to its star — 14 million miles away versus 93 million. It's so close to its version of the sun that it orbits every 37 days. And it doesn't rotate much, so one side is almost always bright, the other dark.

Temperatures can be as hot as 160 degrees or as frigid as 25 degrees below zero, but in between — in the land of constant sunrise — it would be "shirt-sleeve weather," said co-discoverer Steven Vogt of the University of California at Santa Cruz.

It's unknown whether water actually exists on the planet, and what kind of atmosphere it has. But because conditions are ideal for liquid water, and because there always seems to be life on Earth where there is water, Vogt believes "that chances for life on this planet are 100 percent."

The astronomers' findings are being published in Astrophysical Journal and were announced by the National Science Foundation on Wednesday.

The planet circles a star called Gliese 581. It's about 120 trillion miles away, so it would take several generations for a spaceship to get there. It may seem like a long distance, but in the scheme of the vast universe, this planet is "like right in our face, right next door to us," Vogt said in an interview.

That close proximity and the way it was found so early in astronomers' search for habitable planets hints to scientists that planets like Earth are probably not that rare.

Vogt and Butler ran some calculations, with giant fudge factors built in, and figured that as much as one out of five to 10 stars in the universe have planets that are Earth-sized and in the habitable zone.

With an estimated 200 billion stars in the universe, that means maybe 40 billion planets that have the potential for life, Vogt said. However, Ohio State University's Scott Gaudi cautioned that is too speculative about how common these planets are.

Vogt and Butler used ground-based telescopes to track the star's precise movements over 11 years and watch for wobbles that indicate planets are circling it. The newly discovered planet is actually the sixth found circling Gliese 581. Two looked promising for habitability for a while, another turned out to be too hot and the fifth is likely too cold. This sixth one bracketed right in the sweet spot in between, Vogt said.

With the star designated "a," its sixth planet is called Gliese 581g.

"It's not a very interesting name and it's a beautiful planet," Vogt said. Unofficially, he's named it after his wife: "I call it Zarmina's World."

The star Gliese 581 is a dwarf, about one-third the strength of our sun. Because of that, it can't be seen without a telescope from Earth, although it is in the Libra constellation, Vogt said.

But if you were standing on this new planet, you could easily see our sun, Butler said.

The low-energy dwarf star will live on for billions of years, much longer than our sun, he said. And that just increases the likelihood of life developing on the planet, the discoverers said.

"It's pretty hard to stop life once you give it the right conditions," Vogt said.



The National Science Foundation: http://www.nsf.gov

NASA: http://www.nasa.gov/topics/universe/features/gliese_581_feature.html


A Different Kind of Eyeglasses

A Different Kind of Eyeglasses

by Michael Totty
Tuesday, September 28, 2010

provided by

TruFocal eyeglasses from Zoom Focus Eyewear. (Zoom Focus Eyewear)

For many people past the age of 40, focusing on close objects restaurant menus, — for instance — just gets harder and harder.

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Most people with this condition, called presbyopia, eventually give in and get reading glasses, bifocals or glasses with progressive lenses.

But what if there were another alternative that didn't require people to carry an extra set of glasses or have only part of their field of vision in focus at any one time?

Zoom Focus Eyewear LLC, of Van Nuys, Calif., has just such an option, and with it won this year's Silver Innovation Award. The solution: eyeglasses, called TruFocals, that the wearer can manually adjust to give clear, undistorted vision whether reading a book, working on a computer or looking into the distance.

The judges praised the potential large-scale benefit of TruFocals. Richard S. Lang, one of the judges and a physician at the Cleveland Clinic, called the technology a paradigm shift in the way it addresses a problem "that has been handled the same way for many years."

Mimicking the Eye

For more than 100 years, researchers have tried to come up with adjustable eyeglasses; a Baltimore inventor filed a patent on the idea in 1866. But a workable product that's easy to adjust, thin, lightweight and accurate proved elusive.

Stephen Kurtin, a California inventor who previously devised one of the first word-processing programs, turned to the problem in the early 1990s. His solution, TruFocal eyeglasses, mimic the way that the lens of the human eye stretches and contracts to adjust focus.

Each TruFocal lens is actually a set of two lenses: an outer lens, and an inner lens made of a flat glass plate attached to a flexible membrane that contains a clear, silicone-based liquid. A manual slider on the bridge of the eyeglasses adjusts the focus by changing the shape of the membrane. The outer lens can be custom made to correct other vision problems besides presbyopia, including nearsightedness and astigmatism.

Once the TruFocal lenses are adjusted, the entire field of vision is in focus, unlike bifocals and progressive lenses, which keep only a limited area in sharp focus. So a user can adjust the glasses to focus only on the book he's reading, then look up and readjust them to focus solely on the TV across the room.

One Shape, Several Colors

There were some false starts along the way. Mr. Kurtin considered using liquid-crystal electronics to adjust the focus, but the batteries proved problematic. The first model weighed seven pounds. But after nearly 20 years of refinements, the first TruFocal glasses were introduced in 2009.

There's a downside for the fashion conscious: The glasses come in one shape — round — and have been compared to the spectacles worn by Harry Potter. (They are sold in several colors, though.) The circular lenses are necessary to the workings of the technology; with any other shape, the flexible membrane couldn't keep a spherical shape when compressed.

TruFocals aren't the only glasses with adjustable lenses. But other products are mainly designed for users in the developing world, where optometrists aren't widely available; they are meant to be adjusted once by the user to correct the focus at a given distance and then set that way. The Zoom Focus product is aimed at wearers who want to make constant adjustments in their vision.

Next month, TruFocals will be rebranded as Superfocus glasses. The company will also change its name, to Superfocus LLC.


Northern Lights hit 100-year low point

Northern Lights hit 100-year low point

Northern Lights hit 100-year low pointAFP/File – Swedes watch a display of Aurora Borealis in Ostby in 2006. The Northern Lights have petered out during …

HELSINKI (AFP) – The Northern Lights have petered out during the second half of this decade, becoming rarer than at any other time in more than a century, the Finnish Meteorological Institute said Tuesday.

The Northern Lights, or aurora borealis, generally follow an 11-year "solar cycle", in which the frequency of the phenomena rises to a maximum and then tapers off into a minimum and then repeats the cycle.

"The solar minimum was officially in 2008, but this minimum has been going on and on and on," researcher Noora Partamies told AFP.

"Only in the past half a year have we seen more activity, but we don't really know whether we're coming out of this minimum," she added.

[Oceans of fire? A 'dance' of dead spirits? Myths and facts about the polar auroras' curtains of light]

The Northern Lights, a blaze of coloured patterns in the northern skies, are triggered by solar winds crashing into the earth and being drawn to the magnetic poles, wreaking havoc on electrons in the parts of the atmosphere known as the ionosphere and magnetosphere.

So a dimming of the Northern Lights is a signal that activity on the sun which causes solar winds, such as solar flares and sun sports, is also quieting down.

For researchers like Partamies, it is the first time they can observe through a network of modern observation stations what happens to this solar cycle when it becomes as badly disrupted as it is now.

"We're waiting to see what happens, is the next maximum going to be on time, is it going to be late, is it going to be huge?" Partamies said.

During the cycle's peak in 2003, the station on Norway's Svalbard island near the North Pole, showed that the Northern Lights were visible almost every single night of the auroral season, which excludes the nightless summer months.

That figure has fallen to less than 50y percent, while the southernmost station, situated in southern Finland, has been registering only two to five instances annually for the past few years.

Selasa, 28 September 2010

Eurocopter unveils new-look helicopter

Eurocopter unveils new-look helicopter

The Eurocopter's X3 high-speed hybrid helicopter demonstrator is seen at the Istres flight testing centerReuters – The Eurocopter's X3 high-speed hybrid helicopter demonstrator is seen at the Istres flight testing …

MARSEILLE, France (Reuters) – European group Eurocopter showed off a revolutionary winged helicopter on Monday, in a bid to counter U.S. rival Sikorsky's efforts to break the speed barrier by rewriting rotorcraft design rules.

The X3 hybrid helicraft -- which combines forward-facing propellers astride two short aircraft wings with the familiar overhead rotor blades seen on any normal helicopter -- was unveiled following months of secrecy.

The half-plane, half-helicopter design aims to overcome chronic obstacles to high-speed helicopter flight by combining the advantages of fixed-wing aircraft with those of a standard helicopter -- allowing it to fly at 220 knots or 400 km/hour.

The move by the world's largest civil helicopter maker came less than two weeks after United Technologies unit Sikorsky claimed an unofficial speed record of 250 knots (460 km/hour) with its own avant-garde prototype called X2.

Today's helicopters typically cruise around 130-40 knots.

Eurocopter, part of European aerospace group EADS, said its X3 hoverplane, sporting black-and-white striped propellers, had first flown on September 6 at a closely guarded military test base.

"We just wanted a place where we knew we were alone, no plane spotters," Eurocopter chief executive Lutz Bertling told Reuters, adding Eurocopter had paid the French defense ministry for the right to use army facilities even though the project was so far funded entirely out of the company's research budget.

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Sikorsky's X2 made its maiden flight in 2008.

In an operation echoing the secrecy of the project itself, reporters were briefed at Eurocopter headquarters, transported to one base by helicopter and bussed to another where no-one except test crew had seen the new hoverplane, sitting in an isolated hangar after its first flight three weeks ago.

The announcement confirmed the existence of the X3 for the first time after Reuters reported Eurocopter's plans to unveil it on Friday, ending months of speculation.


The extraordinary secrecy reflected fierce competition between helicopter makers to deliver more speed without losing efficiency, a potential source of future profit.

Under current helicopter designs, rotor tips approach supersonic speeds when pushed to fly too fast and this can threaten the stability of the base of the rotor, executives said.

Helicopter makers have devoted years of research to solving the problem, but typically the faster a helicopter flies, the less efficient it is when hovering and vice-versa.

The Sikorsky solution features two main rotors atop the cabin, which spin in opposite directions. That both neutralizes the spinning force applied to a traditional single-main-rotor helicopter and provides a speed boost.

One thing the European and U.S. machines have in common is their new design eliminates the need for the sideways tail rotor used to stabilize traditional helicopters.

Bertling said the X3 concept would be more cost-efficient for heavy helicopters than competitors, which also include the existing Bell Boeing V22 tilt-rotor aircraft.

"All big helicopter manufacturers are looking for more distance and more speed," Bertling told reporters. "It only makes sense to increase speed if in the end what you gain is not over-compensated by increased cost."

The X3 is, for now, simply a technology demonstrator meaning that, if successful, the concept can be applied to helicopters which could be sold in their usual form or with X3-type wings.

Eurocopter refused to give figures on development costs or market potential but said such a helicopter might typically cost 20-25 percent more and go 50 percent faster than a normal type.

Target markets include long-distance search and rescue, inter-city shuttle services or military uses includingspecial forces operations. The wing-mounted propellers would be disengaged when the helicopter lands to avoid injury.

(Editing by Michael Shields and Dan Lalor)