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Tuesday, February 24, 2009

Dark Energy to Erase Big Bang's Fading Signal

Big Bang's Traces to Be Erased
Big Bang's Traces to Be Erased | Discovery News Video

Irene Klotz, Discovery News

When astronomers in the distant future cast their eyes around the cosmos, they will come to the conclusion that our galaxy is alone in the universe.

Even with the most sensitive detectors, future scientists will not be able to observe the leftover radiation from the Big Bang explosion, study the motion of distant galaxies to conclude that space is expanding or even see distant objects.

In the future, the force astronomers now known as dark energy, will stretch the universe beyond detection, with objects receding faster than the speed of light.

"Nothing can move through space faster than the speed of light, but space can do whatever the hell it wants as far as we know," Arizona State University cosmologist Lawrence Krauss said last week at the American Association for the Advancement of Science meeting in Chicago.

Even without dark energy, there are regions of space moving away from us faster than the speed of light, Krauss added.

"When that happens, they carry objects with them, like a surfer on a wave. The light from those objects cannot reach us. So, eventually the universe will disappear before our eyes," Krauss said.

Scientists have some time to figure it out. Based on the currently understood estimates of inflation, the new dark ages won't occur for another 50 billion years or so. The sun would have long since died, likely taking Earth along with it, but civilizations could be living elsewhere in the galaxy.

"It's perfectly reasonable to expect that there will be civilizations not that different than our own that could arise, but they will live in an empty, dark universe," Krauss said.

Scientists are on a quest for what may be the smoking gun for this inflationary view of the universe -- gravitational waves, which might have been imprinted as polarity in the background radiation left over by the Big Bang explosion.

"I think we'll know in 10 years time whether we can detect gravitational waves," said Massachusetts Institute of Technology's Alan Guth.

In April, the European Space Agency plans to launch its Planck telescope which will study cosmic background radiation. Physicists also may get some clues from experiments conducted in the world's biggest and most powerful particle accelerator, the Large Hadron Collider, which will be used to produce subatomic particles that may represent conditions in the extreme, high-energy environment of space.

"We live at a very interesting time, namely the only time in which we can empirically verify that we live in a very interesting time," Krauss said.

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NASA and ESA to send next big mission to moons of Jupiter

By Kunio M. Sayanagi

NASA and ESA to send next big mission to moons of Jupiter

NASA and ESA have jointly announced their plan to send the next big joint planetary exploration mission to Europa and Ganymede, two of the four planet-sized moons of Jupiter. The decision follows years of anticipation in the planetary science community, where the last such big decision was made back in 1988 when NASA and ESA agreed to work together on the Cassini-Huygens mission to Saturn and Titan. That completed its primary mission phase in 2008 and is now in the extended mission, still in orbit around Saturn.

The decision this time came down to a choice between two mission concepts. The plan that was not picked was another mission to the Saturn-Titan system, which capitalized on the momentum gained through the huge and continuing success achieved by Cassini-Huygens. The anticipation among planetary scientists was evident at formal meetings and in coffee rooms, where it has been a major topic of conversation for months. Even Nature weighed in last month and ran a two-page special report and an editorial on the subject, giving their push to the Saturn-Titan mission, arguing that the technological breakthroughs planned for the mission, including a hot-air balloon to float in the sky of Titan, will further open up frontiers of space exploration.

The final pick by NASA and ESA, called the Europa Jupiter System Mission (EJSM), involves two spacecrafts launched separately by NASA and ESA. The plan calls for sending NASA’s orbiter to Europa, and ESA’s to Ganymede. The probes are, for now, called Jupiter Europa Orbiter (JEO) and Jupiter Ganymede Orbiter (JGO). The decision was based on, among many factors, the maturity of the mission idea. NASA has been studying mission concepts for Europa since the late 1990s, the first of which was the Europa Orbiter, developed under the Faster, Better, Cheaper strategy but subsequently canceled after a series of FBC-mission failures.

Visiting the moons

Next came the Jupiter Icy Moons Orbiter. JIMO was part of Project Prometheus, which aimed to launch a series of probes powered by nuclear reactors; however, in 2005, the plan was deemed too ambitious and the entire project was frozen indefinitely. Up to now, all missions to the outer planets have employed thermocouples driven by the heat generated by blocks of radioactive isotopes, as the dim sun makes solar panels an ineffective source of power in the outer solar system, but we've never sent a full-blown reactor.

The mission plan started converging toward the current EJSM design through the Europa Geophysical Explorer (EGE) plan in 2005 and the Europa Explorer (EE) in 2006. Both EGE and EE design concepts included an optional plan to land on the surface of Europa. Although the current design for NASA’s JEO seems to be directly based on the EE concept, JEO does not include any lander.

Europa makes an exciting scientific target because it is believed to harbor a deep ocean underneath a relatively thin (i.e., tens of kilometers thick) shell of ice at the surface. Its craterless surface suggests that it is refreshed by geological processes, most likely through convection in the ice shell, and scientists are seriously studying the potential for life in the vast salty ocean under the shell. The potential for life was recognized soon after the Voyager flybys of the Jovian system in 1979 returned close-up pictures of Europa, which generated a huge amount of excitement in the field and inspired science fiction works such as 2010: Odyssey Two, which featured alien organisms crawling out of icy crevasses on the moon’s surface.

Ganymede, the target of ESA’s JGO, is the largest satellite in our solar system, with a radius that is bigger than that of the planet Mercury. Like Europa, it is also believed to harbor a deep ocean underneath its icy crust, except that its ice shell is estimated to be much thicker than that of Europa. The surface exhibits a mixture of old, highly cratered terrain and relatively younger surfaces, suggesting that geological activities at least partially renewed its surface in its past.

The moon also has characteristic grooved terrains, which is believed to be “wrinkles” formed when the size of the moon changed as the inner ocean partially froze and thawed in the past—when the liquid water ocean freezes, its volume expands, and the radius of the moon increases; the radius shrinks when the ice thaws. Thus, the surface geological features carry important hints to the thermal history of the moon.

What to watch for

Both JEO and JGO will carry ice-penetrating radars to peer through the surface. The radar on JEO is designed to be sensitive to ice layers at 3-30km depth, thus enabling it to detect the boundary between the ice shell and the underlying ocean, at least where the ice shell is at its thinnest. As Ganymede’s ice shell is much thicker than that of Europa, the radar onboard JGO is not designed to sense the solid-liquid boundary but instead it will search for warm chunks of ice underneath the surface, which would provide hints of geologically actively spots.

Both spacecraft will also carry laser altimeters to observe how the shape of the satellites deform as they orbit in the strong gravitational field of Jupiter. And of course, they will carry a suite of imaging instruments that will take photographs at many different wavelengths of light. These cameras will survey not only the moons the probes orbit around but the entire Jovian system. In addition to JEO and JGO, the Japanese space agency JAXA is considering pitching in by launching its own orbiter, to be called Jupiter Magnetospheric Orbiter, which will take three-dimensional measurements of Jupiter’s extensive magnetosphere.

The new mission to the Jupiter system will be the latest addition to the short list of "flagship" missions NASA has launched to the outer planets. The flagship-class missions are quite ambitious, typically costing several billion dollars (JEO is currently projected to cost NASA about $3.8 billion, while JGO will cost ESA 650 million). Since the 1970s, there has been about one flagship mission to the outer planets every decade: Pioneer 10 and 11 visited Jupiter and Saturn in mid-1970s; Voyager 1 and 2 toured the outer solar system in the 1980s and continue to explore the outer fringe of the solar system today; Galileo was in orbit around Jupiter from 1994-2003; and Cassini has been in Saturnian orbit since 2004. The launches of the EJSM spacecrafts are currently planned for 2020 and should arrive at the Jupiter system in 2026.

As for the Saturn-Titan mission concept that was not picked this time, none of the efforts that went into forming the mission will be wasted. NASA is forwarding the results of the mission-design studies to the National Research Council, which is conducting the Planetary Science Decadal Survey that will recommend a broad plan of solar system exploration for the next decade, 2013-2022—the report is due in March 2011. The exploration of Europa was the single top flagship priority listed by the previous decadal survey released in 2002. The well-defined Saturn-Titan mission concept is sure to get the attention of the new survey, and hopefully the mission will get a green light in the next round, probably in 10 years or so.

These large flagship missions have the potential to define the careers of many planetary scientists. For example, I am a recent PhD specializing in the atmospheres of Jupiter and Saturn, and I will be in my late 40s if JEO and JGO arrive at their destinations as planned in 2026. If I am privileged to stay in the field until then, the data they return will surely keep me busy for the rest of my scientific career, and I am hopeful that the Saturn-Titan mission will also materialize before i retire.

In the meantime, the development and construction of the spacecraft hardware will soon begin, and scientists will continue to study the Jupiter systems using existing data to predict what the mission will discover, and to better refine the requirements for the instruments that will be onboard JEO and JGO in order to ensure that their capabilities are optimally tuned for what they will observe. There’s tons of work to be done ahead of us, and many exciting discoveries to look forward to!

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Does a "Great Filter" Exist? (Or, Why We've Never Discovered Signs of Alien Life)

2001_8_3








The Great Filter is the idea that there is some single, almost insurmountably improbable barrier on the path to the stars that explains why we've never seen any sign of alien life. It combines aspects of astronomy, biology and history to arrive at one inescapable conclusion: university professors dream of book deals.

Robin Hanson of George Mason University posits a "Great Filter" that prevents the rise of intelligent, self-aware, technologically advanced, space-colonizing civilizations. The "filter" would be one or more improbable steps along the path that starts with the creation of a planet and ends with a race capable of colonizing the galaxy.

Somewhere between those two points, philosopher Nick Bostrom points out, "the Great Filter operates, and it must be powerful enough that even with all the billions of possible starting worlds on which life might evolve - all those rolls of the cosmic dice - one ends up with nothing: no aliens, no spacecraft, no signals, at least not in our neck of the woods."

The very existence of life makes finding a four-leafed clover with winning lottery tickets for leaves look like a sure thing. Add the staggering improbability of our evolution from single cells and you end up with odds so vast they've driven the invention of everything from the Drake equation to an invisible sky-beard who seems unnecessarily preoccupied with what we do one day out of every seven. People who study this subject file all that under "Shit we already knew", and were too busy actually working on the science to come up with a garbage buzzword phrase that would look really awesome in bold type on the cover of a hardback book (available now for $29.99!) Luckily Robin Hanson was ready to do that for them.

There isn't actually a book yet, but the Great Filter "theory" is so clearly designed to be publisher-ready you can almost see the page numbering. It talks in grand terms about a vast threat facing humanity, and if it never seems to have any idea what that threat actually is, was or will be then who cares? Most of the 'evidence' is based on the scarcity of life in the cosmos in general and how that describes threats to Earth specifically, otherwise known as "Fundamental misunderstanding of statistics #1". He goes on to talk around this ethereal menace and all the effects it could have on THE SURVIVAL OF EARTH, combining lots of different fields in compelling pop-science friendly chapters without ever coming up with an actual result.

Not that we're claiming that Professor Hanson doesn't understand all this; just that he's made a tactical decision not to care. His real intentions are further revealed by the way he throws around "possibility of world-destroying physics experiments" (we're assuming he'll scribble "I'M TALKING ABOUT THE LARGE HADRON COLLIDER" on autographed copies). This is a great buzzword for catching media attention and popular sales, at the tiny price of sacrificing even the pretense of scientific validity. Everyone who's even heard of the basic physics of the LHC knows these cataclysm quotes are garbage.

Bostrom, director of the awesomely titled Future of Humanity Institute at Oxford University, claims that the Great Filter poses an "Existential Risk". That's a perfect choice of words because he thinks it means a threat to our very existence, when it's really a made-up Nietzschean problem for people who should be delighted but are determined to be miserable anyway. He confirms this assessment by telling us we should take any discovery of alien life as terrible news, as that would put this mysteriously unspecified Filtering Boogeyman in our future instead of the past.

Listen: if we discover life on Mars and you can honestly call that a bad thing, then it's not just that you aren't a scientist. We're not even sure you could be described as human.

Posted by Luke McKinney.

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Quark star may hold secret to early universe

by Paul Parsons

(Image: P Challis and R Kirshner (Harvard-Smithsonian Center For Astrophysics)/NASA/ESA/STScI/SPL)

(Image: P Challis and R Kirshner (Harvard-Smithsonian Center For Astrophysics)/NASA/ESA/STScI/SPL)


A NEW kind of star may be lurking in the debris from a nearby supernova explosion. If confirmed, the "quark star" could offer fresh insights into the earliest moments of the universe.

When supernovae explode, they leave behind either a black hole or a dense remnant called a neutron star. However, recent calculations suggest a third possibility: a quark star, which forms when the pressure falls just short of creating a black hole.

Astronomers believe these form after the neutron star stage, when the pressure inside a supernova rises so high the neutrons disintegrate into their constituents - quarks. These form an even denser star than neutrons.

Observing a quark star could shed light on what happened just after the big bang, because at this time, the universe was filled with a dense sea of quark matter superheated to a trillion °C. While some groups have claimed to have found candidate quark stars, no discovery has yet been confirmed.

Now Kwong-Sang Cheng of the University of Hong Kong, China, and colleagues have presented evidence that a quark star formed in a bright supernova called SN 1987AMovie Camera (pictured), which is among the nearest supernovae to have been observed.

The birth of a neutron star is known to be accompanied by a single burst of neutrinos. But when the team examined data from two neutrino detectors - Kamiokande II in Japan and Irvine-Michigan-Brookhaven in the US - they found that SN 1987A gave off two separate bursts. "There is a significant time delay between [the bursts recorded by] these two detectors," says Cheng. They believe the first burst was released when a neutron star formed, while the second was triggered seconds later by its collapse into a quark star. The results will appear in The Astrophysical Journal (www.arxiv.org/abs/0902.0653v1).

"This model is intriguing and reasonable," says Yong-Feng Huang of Nanjing University, China. "It can explain many key features of SN 1987A." However, Edward Witten of the Institute for Advanced Study in Princeton, New Jersey, is not convinced. "I hope they're right," he says. "My first reaction, though, is that this is a bit of a long shot."

High-resolution X-ray observatories, due to fly in space in the next decade, may have the final say. Neutron stars and quark stars should look very different at X-ray wavelengths, says Cheng.

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Do gravity holes harbour planetary assassins?

by Stuart Clark

NASA's STEREO spacecraft will search for objects trapped at the Lagrangian points (Image: Johns Hopkins University Applied Physics Laboratory / NASA)

NASA's STEREO spacecraft will search for objects trapped at the Lagrangian points (Image: Johns Hopkins University Applied Physics Laboratory / NASA)

THEY are the places gravity forgot. Vast regions of space, millions of kilometres across, in which celestial forces conspire to cancel out gravity and so trap anything that falls into them. They sit in the Earth's orbit, one marching ahead of our planet, the other trailing along behind. Astronomers call them Lagrangian points, or L4 and L5 for short. The best way to think of them, though, is as celestial flypaper.

In the 4.5 billion years since the formation of the solar system, everything from dust clouds to asteroids and hidden planets may have accumulated there. Some have even speculated that alien spacecraft are watching us from the Lagrangian points, looking for signs of intelligence.

Putting little green men to one side for the moment, even the presence of plain old space rocks would be enough to keep most people happy. "I think you certainly might find a whole population of objects at L4 and L5," says astrophysicist Richard Gott of Princeton University.

After nearly a century of speculation, we are on the verge of finding out what they are hiding once and for all. Later this year, two spacecraft that spend their lives studying the sun will begin their slow journeys through L4 and L5.

Space scientists plan to use instruments on board NASA's STEREO probes A and B to search for celestial objects becalmed at the Lagrangian points. What they find could hugely enhance our view of how the solar system formed, tell us more about the colossal impact that formed the moon, and warn us if another major collision is on the cards.

The Lagrangian points were first discovered in 1772 by the mathematician Joseph-Louis Lagrange. He calculated that the Earth's gravitational field neutralises the gravitational pull of the sun at five regions in space, making them the only places near our planet where an object is truly weightless.

Of the five Lagrangian points, L4 and L5 are the most intriguing. They are the only ones that are stable: while a satellite parked at L1 or L2 will wander off after a few months unless it is nudged back into place, any object at L4 or L5 will stay put due to a complex web of forces. Lying 150 million kilometres away, along the line of Earth's orbit, L4 circles the sun 60 degrees in front of our planet while L5 lies at the same angle behind (see diagram).

Evidence for such gravitational potholes appears around other planets too. In 1906, Max Wolf discovered an asteroid outside of the main belt between Mars and Jupiter, and recognised that it was sitting at Jupiter's L4 point. Wolf named it Achilles, and so began the tradition of naming these asteroids after characters from the Trojan wars.

The realisation that Achilles would be trapped in its place and forced to orbit with Jupiter, never getting much closer or further away, started a flurry of telescopic searches for more examples. There are now more than 1000 asteroids known to reside at each of Jupiter's L4 and L5 points.

Searches for "Trojan" asteroids around other planets have met with mixed results. Saturn seemingly has none, and only in the last decade have Trojans been found at Neptune. Naturally, astronomers have often wondered about asteroids at Earth's L4 and L5 points.

Fly-through zones

The trouble is that our L4 and L5 points are not easy to see from the ground. They appear to lie close to the sun, so by the time night falls, the trailing L5 region is low in the sky and setting fast. On the other side of the sky, the preceding L4 point rises in darkness but the dawn is hot on its heels.

That didn't prevent Paul Weigert at the University of Western Ontario in Canada and his colleagues from conducting a number of searches in the 1990s with the Canada-France-Hawaii telescope on Mauna Kea, Hawaii. It was a tough job because L4 and L5 appear wider in the sky than the full moon so a large number of observations would be needed to search them thoroughly. Alas, Weigert and colleagues came up empty-handed as their search wasn't detailed enough.

More recently, automated asteroid searches, such as the Lincoln Near Earth Asteroid Research project, have begun to creep closer to the Lagrangian points in their nightly robotic scans of the sky, but at this stage no Lagrangian asteroids have been identified. "The field has languished because we are all waiting for somebody to see something," says Weigert.

NASA's STEREO spacecraft could change everything - even though they were never designed to look for asteroids. Launched in 2006, one of the twin STEREO probes was placed ahead of Earth, the other behind. Tracing Earth's orbit, STEREO A gradually outpaces the Earth while its sister ship, STEREO B, trails ever further behind. From these two vantage points, the spacecraft monitor the region of space directly between the Earth and the sun, looking for solar storms that can wreak havoc with electrical equipment on satellites and on Earth.

L4 and L5 are particularly good vantage points from which to warn the Earth of incoming solar storms. "We talked at one stage about actually stopping the STEREO spacecraft when they got there, because you get about two or three days warning of a coming storm," says Michael Kaiser of the Goddard Space Flight Center in Greenbelt, Maryland, and STEREO's project scientist.

Ultimately the STEREO team discovered that it would take too much fuel to stop their spacecraft at L4 and L5. So they settled for a leisurely fly through instead, though they are still travelling too fast to get stuck. "These are big regions of space," says Kaiser, "It's going to take STEREO months to travel through them."

That's when it struck Richard Harrison of the Rutherford Appleton Laboratory in Oxfordshire, UK, and a member of the STEREO team, that the probes' cameras might be put to another use. He began to investigate the possibilities and realised that a pair of instruments known as heliospheric imagers could be used to search for asteroids. "They were not designed to do this work," says Harrison, who is the imagers' principal investigator. "It's an added bonus."

Even so, asteroid hunters face a painstaking task because a Lagrangian asteroid will appear as little more than a dot moving against a background of thousands of stars. Thankfully there is already a force of volunteers who scan the STEREO images via the internet for signs of near-Earth asteroids.

In addition to these efforts, Harrison is hoping to find some professional manpower for the L4 and L5 crossings. "The close-up investigation of L4 and L5 is completely new. That makes it something we should be driving," he says. In these cash-strapped times, however, that might be more easily said than done.

If investigators do find an asteroid in their sights, it will be worth their effort. "Wouldn't it be spectacular if we actually backed past an asteroid? Saw it come creeping into view around the camera," says Harrison.

They will be able to watch it and tell how it rotates from the variation in light it reflects from the sun. "We will be able to measure the distribution of any asteroids and dust in the Lagrangian points," says Harrison.

Armed with that information, we may be able to answer one of the most perplexing mysteries of the solar system: why Earth has such a large moon.

Most astronomers believe that the moon formed from the debris generated when a Mars-sized object struck the Earth a glancing blow about 4 billion years ago. Their problem is in understanding where the object came from.

Computer models show that incoming objects from elsewhere in the solar system would tend to strike the Earth with too much energy. Instead of creating the moon, they obliterate the Earth. So the impactor must have originated close by, the theory goes, where it could not accelerate too much before hitting.

Planetary leftovers

Another clue is that the moon contains the same abundance of oxygen isotopes as the Earth, hinting that whatever hit us must also have had the same isotope abundance. When astronomers look out into the solar system, to Mars for example, the isotope abundances are different. So this, too, hints that the impactor formed close by. But where?

What is puzzling is how an object could grow so close to the Earth and reach the size of Mars before a collision took place. Their mutual gravity should have pulled them together long before. Unless, says Gott, it formed at a Lagrangian point. "An object could sit at one of these stable points and just grow," he says.

Once it grew sufficiently large, gravitational interactions with other objects, such as Venus, could nudge it out of the Lagrangian point and onto a collision course with Earth.

"It would have the same oxygen isotopes as Earth, because it formed in the same region of the solar system," says Gott. Also, being in essentially the same orbit as Earth, the two planets would not be travelling at vastly different velocities when they collided (New Scientist, 14 August 2004, p 26).

Gott thinks that any objects still in L4 and L5 may be leftovers from the formation of that impacting body. "Let's say that you find a number of objects there. In that case, they would be great targets for a sample-return mission to see if they had the same oxygen isotope abundances as Earth," says Gott. If they do, Gott believes this strengthens the case for the Earth-impactor to have formed there.

In preparation for the crafts' arrivals at L4 and L5, Harrison is discussing with colleagues how best to manoeuvre the two probes for the optimal views. Strange as it sounds, the twin spacecraft do not look where they are going. Instead they fly facing backwards, with several of their electronic eyes pointed close to our planet, on the lookout for incoming solar storms. For the best views of the Lagrangian points, the spacecraft would have to be flipped over, so the heliospherical imagers point forwards while the other instruments remain trained on the sun.

The journey through L4 and L5 is potentially fraught with danger. Clouds of dust are thought to be trapped at these Lagrangian points and if the STEREO team is unlucky, a collision with a badly placed dust particle could be devastating. "If one hits us inside the camera, we are no more," says Chris Davis, part of the heliospheric imager team from Rutherford Appleton Laboratory.

The risk may be reduced by flipping the cameras back towards Earth as the spacecraft pass through the most dangerous spots. The rest of the STEREO team is confident that they will survive: ever since launch, the craft have been taking hits from dust that happens to lie along Earth's orbit. "It varies a lot, from a few, to a few thousand per day," says Chris St Cyr of the Goddard Space Flight Center, who heads the investigation to understand these dust events.

No one knows how many asteroids the STEREO probes will see. Weigert and colleagues have performed a number of computer simulations that showed how asteroids can be nudged from a Lagrangian point due to Venus's gravity; it can happen on a timescale of a million years or so. However, the same simulations showed that this works both ways, with asteroids being nudged into the Lagrangian points by Venus as well. These results, and the failure of telescopes to find a Lagrangian asteroid to date, have made Weigert cautious about the number and size of the asteroids he expects STEREO to find. "I think there may be a few asteroids, but not hundreds, and I'm thinking that they are less than a kilometre across. In the main asteroid belt, a typical asteroid is 100 kilometres across."

Such doubts do not concern Harrison. "Some think we will see something, others think we won't," he says. "But if we let this opportunity pass us by without even looking, we will regret it."

If we see a big asteroid there, it might be worth taking it out pre-emptively. And by that, I mean blowing it to pieces

Could another planet be stalking the Earth?

Most astronomers accept that the moon was formed when a Mars-sized planet crashed into Earth during its infancy. Some research suggests that this kamikaze planet formed at either the L4 or L5 Lagrangian point where gravity from the Earth and sun cancel each other out. So could some other threat be lurking there today?

"Absolutely not," says Paul Weigert at the University of Western Ontario, Canada. There are not enough dust particles or pebbles in the solar system.

It was a different story 4.5 billion years ago when the solar system was swathed in its birth clouds. The planets were forming from this mix of dust and gas, and L4 and L5 would have been prime places for matter to accumulate into larger bodies. "These days, there simply isn't enough material around to build anything that large," says Weigert.

OK, so nothing planet-sized. But Richard Gott of Princeton University reckons there may still be threatening asteroids. "If we see something big in there, it would be like a ticking time bomb," says Gott. That is because gravitational nudges from the other planets, particularly Venus, could pull the asteroid just far enough so that it escapes the Lagrangian point. Once outside this trap, it could easily fall into a collision course with Earth.

"If we see a big asteroid there, it might be worth taking it out pre-emptively," says Gott, "and by that I mean blowing it to pieces."

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High-energy portrait of approaching comet released

by Maggie McKee

This image of Comet Lulin, taken on 28 January, merges data from Swift's Ultraviolet/Optical Telescope (blue and green) and X-Ray Telescope (red). The comet's tail extends off to the right, while a cloud of oxygen and hydrogen atoms extends far Sun-ward of the comet. At the time of the observation, the comet was 160 million km from Earth and 185 million km from the Sun (Image: NASA/Swift/U of Leicester/DSS/STScI/ AURUA/Bodewits et al.)

This image of Comet Lulin, taken on 28 January, merges data from Swift's Ultraviolet/Optical Telescope (blue and green) and X-Ray Telescope (red). The comet's tail extends off to the right, while a cloud of oxygen and hydrogen atoms extends far Sun-ward of the comet. At the time of the observation, the comet was 160 million km from Earth and 185 million km from the Sun (Image: NASA/Swift/U of Leicester/DSS/STScI/ AURUA/Bodewits et al.)


A space telescope that usually studies the most powerful explosions in the universe has set its sights on an approaching comet. Its observations at ultraviolet and X-ray wavelengths should help reveal the comet's composition, structure and its interaction with the solar wind.

Comet Lulin, which was discovered in 2008 by astronomers at the Lulin Observatory in Taiwan, will make its closest pass near Earth on 24 February. At that time, it will come within 61 million kilometres, or 40% the Sun-Earth distance, from our planet.

Amateur astronomers have been watching the approaching comet, which is bright enough to be visible with the naked eye from dark sites (see this image taken by Jack Newton).

Now, NASA's Swift space telescope, designed to study cosmic explosions called gamma-ray bursts, has released an image of the comet.

'Quite active'

The icy body is shedding gas and dust as it nears the Sun, whose ultraviolet light breaks apart the comet's water molecules into hydrogen atoms and hydroxyl (OH) molecules. Swift's Ultraviolet/Optical Telescope (UVOT), which can detect the hydroxyl molecules, found that they fill a cloud more than 400,000 km across.

"The comet is quite active," team member Dennis Bodewits of NASA's Goddard Space Flight Center in Maryland said in a statement. "The UVOT data show that Lulin was shedding nearly 800 gallons of water each second" - enough to fill an Olympic-size swimming pool in less than 15 minutes.

Farther from the comet, solar ultraviolet radiation also breaks up hydroxyl molecules - into oxygen and hydrogen atoms.

"The UV will [teach] us about the composition of the comet," Bodewits told New Scientist, adding that such studies are interesting because comets might have brought water to Earth several billion years ago.

Glowing wind

Studying the comet in X-rays reveals how it interacts with the solar wind, a stream of charged particles from the Sun. That's because positive ions in the solar wind steal electrons from neutral gases, such as hydroxyl, that they hit.

Since the stolen electrons are in an excited state, "this makes the solar wind glow when it interacts with a comet", says Bodewits.

The observations could lend insight into why Mars has such a thin atmosphere. "The Earth is lucky because we have a magnetic field that protects us from most of the solar wind," he continues. "But Mars, lacking such a shield, might have lost its atmosphere because of the interaction with the solar wind."

Jenny Carter of the University of Leicester in the UK, who is leading Swift's studies of the comet, says the team plans to continue its observations. "We are looking forward to future observations of Comet Lulin, when we hope to get better X-ray data to help us determine its makeup," she said. "They will allow us to build up a more complete 3D picture of the comet during its flight through the solar system."

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Social websites harm children's brains: Chilling warning to parents from top neuroscientist

By David Derbyshire

Social networking websites are causing alarming changes in the brains of young users, an eminent scientist has warned.

Sites such as Facebook, Twitter and Bebo are said to shorten attention spans, encourage instant gratification and make young people more self-centred.

The claims from neuroscientist Susan Greenfield will make disturbing reading for the millions whose social lives depend on logging on to their favourite websites each day.

Facebook founder and CEO Mark Zuckerberg

Facebook founder and CEO Mark Zuckerberg. The popular website has made him a very rich man, but at what cost to human relationships?

But they will strike a chord with parents and teachers who complain that many youngsters lack the ability to communicate or concentrate away from their screens.

More than 150million use Facebook to keep in touch with friends, share photographs and videos and post regular updates of their movements and thoughts.

A further six million have signed up to Twitter, the 'micro-blogging' service that lets users circulate text messages about themselves.

But while the sites are popular - and extremely profitable - a growing number of psychologists and neuroscientists believe they may be doing more harm than good.

Baroness Greenfield, an Oxford University neuroscientist and director of the Royal Institution, believes repeated exposure could effectively 'rewire' the brain.

Girl Using Computer

Experts are concerned children's online social interactions can 'rewire' the brain

Computer games and fast-paced TV shows were also a factor, she said.

'We know how small babies need constant reassurance that they exist,' she told the Mail yesterday.

'My fear is that these technologies are infantilising the brain into the state of small children who are attracted by buzzing noises and bright lights, who have a small attention span and who live for the moment.'

Professor Susan Greenfield

Professor Susan Greenfield: Concerned

Her comments echoed those she made during a House of Lords debate earlier this month. Then she argued that exposure to computer games, instant messaging, chat rooms and social networking sites could leave a generation with poor attention spans.

'I often wonder whether real conversation in real time may eventually give way to these sanitised and easier screen dialogues, in much the same way as killing, skinning and butchering an animal to eat has been replaced by the convenience of packages of meat on the supermarket shelf,' she said.

Lady Greenfield told the Lords a teacher of 30 years had told her she had noticed a sharp decline in the ability of her pupils to understand others.

'It is hard to see how living this way on a daily basis will not result in brains, or rather minds, different from those of previous generations,' she said.

She pointed out that autistic people, who usually find it hard to communicate, were particularly comfortable using computers.

'Of course, we do not know whether the current increase in autism is due more to increased awareness and diagnosis of autism, or whether it can - if there is a true increase - be in any way linked to an increased prevalence among people of spending time in screen relationships. Surely it is a point worth considering,' she added.

Psychologists have also argued that digital technology is changing the way we think. They point out that students no longer need to plan essays before starting to write - thanks to word processors they can edit as they go along. Satellite navigation systems have negated the need to decipher maps.

A study by the Broadcaster Audience Research Board found teenagers now spend seven-and-a-half hours a day in front of a screen.

Educational psychologist Jane Healy believes children should be kept away from computer games until they are seven. Most games only trigger the 'flight or fight' region of the brain, rather than the vital areas responsible for reasoning.

Sue Palmer, author of Toxic Childhood, said: 'We are seeing children's brain development damaged because they don't engage in the activity they have engaged in for millennia.

'I'm not against technology and computers. But before they start social networking, they need to learn to make real relationships with people.'

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How We Think Before We Speak: Making Sense Of Sentences

We engage in numerous discussions throughout the day, about a variety of topics, from work assignments to the Super Bowl to what we are having for dinner that evening. We effortlessly move from conversation to conversation, probably not thinking twice about our brain's ability to understand everything that is being said to us. How does the brain turn seemingly random sounds and letters into sentences with clear meaning?
n a new report in Current Directions in Psychological Science, a journal of the Association for Psychological Science, psychologist Jos J.A. Van Berkum from the Max Planck Institute in The Netherlands describes recent experiments using brain waves to understand how we are able to make sense of sentences.

In these experiments, Van Berkum and his colleagues examined Event Related Potentials (or ERPs) as people read or heard critical sentences as part of a longer text, or placed in some other type of context. ERPs are changes in brain activity that occur when we hear a certain stimulus, such as a tone or a word. Due to their speed, ERPs are useful for detecting the incredibly fast processes involved in understanding language.

Analysis of the ERPs has consistently indicated just how quickly the brain is able to relate unfolding sentences to earlier ones. For example, Van Berkum and colleagues have shown that listeners only need a fraction of a second to determine that a word is out of place, given what the wider story is about. As soon as listeners hear an unexpected word, their brain generates a specific ERP, the N400 effect (so named because it is a negative deflection peaking around 400 milliseconds). And even more interesting, this ERP will usually occur before the word is even finished being spoken.

In addition to the words themselves, the person speaking them is a crucial component in understanding what is being said. Van Berkum also saw an N400 effect occurring very rapidly when the content of a statement being spoken did not match with the voice of the speaker (e.g. "I have a large tattoo on my back" in an upper-class accent or "I like olives" in a young child's voice). These findings suggest that the brain very quickly classifies someone based on what their voice sounds like and also makes use of social stereotypes to interpret the meaning of what is being said. Van Berkum speculates that "the linguistic brain seems much more 'messy' and opportunistic than originally believed, taking any partial cue that seems to bear on interpretation into account as soon as it can."

But how does the language brain act so fast? Recent findings suggest that, as we read or have a conversation, our brains are continuously trying to predict upcoming information. Van Berkum suggests that this anticipation is a combination of a detailed analysis about what has been said before with taking 'quick-and-dirty' shortcuts to figure out what, most likely, the next bit of information will be.

One important element in keeping up with a conversation is knowing what or whom speakers are actually referring to. For example, when we hear the statement, "David praised Linda because. . .," we expect to find out more about Linda, not David. Van Berkum and colleagues showed that when listeners heard "David praised Linda because he. . .," there was a very strong ERP effect occurring with the word "he," of the type that is also elicited by grammatical errors. Although the pronoun is grammatically correct in this statement, the ERP occurred because the brain was just not expecting it. This suggests that the brain will sometimes ignore the rules of grammar when trying to comprehend sentences.

These findings reveal that, as we make sense of an unfolding sentence, our brains very rapidly draw upon a wide range of information, including what was stated previously and who the speaker is, in helping us understand what is being said to us. Sentence understanding is not just about diligently combining stored word meanings. The brain rapidly throws in everything it knows, and it is always looking ahead.

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9 Life-Changing Inventions the Experts Said Would Never Work

by Mike Sowden

The lightbulb. The telephone. Email. If you’re a specialist in your field, there are two ways to become a household name: create something new…or claim it can never be done. If you want to be remembered on the Internet, choose the second one. Here are 9 examples of breakthroughs, inventions and innovations the experts were completely wrong about.

1. The Electric Lightbulb

"… good enough for our transatlantic friends … but unworthy of the attention of practical or scientific men." British Parliamentary Committee, referring to Edison’s light bulb, 1878.

"Everyone acquainted with the subject will recognize it as a conspicuous failure." Henry Morton, president of the Stevens Institute of Technology, on Edison’s light bulb, 1880.

The Brits get sniffy about American innovation (not for the first time) - and miss the invention of the century. Now our light bulbs comes in all shapes and sizes, and we’re eco-innovating faster than ever. Not too shabby for a conspicuous failure.

2. The A/C

"Fooling around with alternating current is just a waste of time. Nobody will use it, ever." Thomas Edison, 1889.

Oh Tom, you were doing so well. Edison enjoyed sniping at the efforts of his rival George Westinghouse (who bought the patent for a/c transmission from Nikola Tesla), and look where it got him. Fact is, it’s easier and far more efficient to distribute power with a/c than with Edison’s darling direct current. Oops.

3. The Personal Computer

We have reached the limits of what is possible with computers. John Von Neumann, 1949

Somewhat wide of the mark. Along came the integrated circuit (better known as the microchip), and things went crazy. Computers have allowed our species to really connect. We can even study and regulate our own planet - and there’s still no computing limits in sight.

4. The Microchip

"But what… is it good for?" An engineer at the Advanced Computing Systems Division of IBM, commenting on the microchip in 1968.

Hardly anything - well, apart from virtually every piece of electronic equipment in gadgets, vehicles, computer networks, power stations, homes, offices and every other conceivable part of everyday life for this century and probably the next. But otherwise, yes - useless.

5. Data Transmission

Image: anomalous4

"Before man reaches the moon, your mail will be delivered within hours from New York to Australia by guided missiles. We stand on the threshold of rocket mail." Arthur Summerfield, U.S. Postmaster General under Eisenhower, 1959.

"Transmission of documents via telephone wires is possible in principle, but the apparatus required is so expensive that it will never become a practical proposition."
Dennis Gabor, British physicist, 1962.

A brilliant scientist, Gabor received the Nobel Prize for inventing holography - but entirely failed to anticipate e-mail and the modem. (To be fair, so did everyone else). Nowadays, entire bookshelves can be transmitted for a few cents in the blink of an eye, making scientific collaboration a truly global enterprise. And all without rockets.

6. Online Shopping

Image: i’m george

"Remote shopping, while entirely feasible, will flop - because women like to get out of the house, like to handle merchandise, like to be able to change their minds." TIME, 1966.

It’s true that both sexes like the tactile experience of shopping in person. But e-commerce? As PayPal’s proft margins will attest, remote shopping is here to stay - and helps get money to where it’s most needed.

7. The Automobile


Image: Cyberesque
"The ordinary "horseless carriage" is at present a luxury for the wealthy; and although its price will probably fall in the future, it will never, of course, come into as common use as the bicycle." Literary Digest, 1899.
If only that were true. But the infernal combustion engine shows no signs of slowing - in 2005, an estimated 53 million new cars hit the world’s streets, fuelling all sorts of problems. Happily, we’re fast rediscovering the bicycle and rethinking the automobile.
8. The Television

Image: Narisa

"While theoretically and technically television may be feasible, commercially and financially it is an impossibility, a development of which we need waste little time dreaming."
Lee DeForest, American radio pioneer and inventor of the vacuum tube, 1926.

Dream on. There are currently around 220 million "impossibilities" in the United States alone. TV is everywhere. It’s just a shame the old types are full of lead - but every year sees a cleaner version, like the new Philips Eco FlatTV here.

9. Possibility

Image: Jake Shears

"Everything that can be invented has been invented."

Supposedly said by Charles H. Duell, Commissioner, U.S. Office of Patents, 1899 - except he probably didn’t. So the last word goes to actor and humorist Peter Ustinov:

"If the world should blow itself up, the last audible voice would be that of an expert saying it can’t be done."

In green tech, there are some truly audacious ideas that plenty of "experts" have been quick to write off. As they relate to every day living and things you can do to help the environment, we’ll be covering them here, so be sure to bookmark us. ;) If the history of technology offers any lesson, it’s that today’s most cynical eco experts could very well end up with egg on their faces. Naturally we’ll be diligently reporting on it all.

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Hamsters in jackets harnessed for energy

By Matthew Moore

BBC reports theft of hamster five days earlier as breaking news
It would take 1,000 hamsters to generate enough energy to power a mobile phone Photo: GETTY

The devices are strapped to the animals as they run on their cage wheels, capturing the biomechanical energy they release as they exercise.

Experts believe the technique could one day be used to capture power produced by humans.

Dr Zhong Lin Wang of Georgia University's Nano Research Group developed the flexible jackets, which are fitted with wires plugged into a nanogenerator that produces energy when they are bent and stretched.

In tests one hamster named Campbell's Dwarf produced small amounts of AC power – around one twentieth of the output of an AA battery.

Although it would take 1,000 hamsters to generate enough energy to power a mobile phone, Dr Wang said the technology could have practical applications when applied to larger animals and humans.

"We believe that this is the first demonstration of a live animal producing current with nano-generators," she told The Sun.

Dr Wang added that the technology could be ready to be fitted into clothes within five years. It would capture energy produced not only when humans are active, but also from smaller movements such as when people are sat at computers.

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Scientist Looks to Weaponize Ball Lightning

By David Hambling

Two hundred years ago this week, the warship HMS Warren Hastings was struck by a weird phenomenon: "Three distinct balls of fire" fell from the heavens, striking the ship and killing two crewmen, leaving behind "a nauseous, sulfurous smell," according to the Times of London.

Ball lightning has been the subject of much scientific scrutiny over the years. And, as with many powerful natural phenomena, the question arises: "Can we turn it into a weapon?" Peculiar as it may seem, that's exactly what some researchers are working on -- even though it hasn't even been properly replicated in the laboratory yet.

The exact cause and nature of ball lighting has yet to be determined; there may be several different types, confusing matters further. But generally it manifests as a grapefruit-sized sphere of light moving slowly through the air which may end by fizzling out or exploding.

In the mid-'60s, the U.S. military started exploring ways that the phenomenon might be weaponized. Take this 1965 Defense Technical Information Center report on Survey of Kugelblitz Theories For Electromagnetic Incendiaries, (Kugelblitz is German for ball lighting). The document summarizes and evaluates the ball lightning theories then prevalent, and recommends "a theoretical and experimental Kugelblitz program... as a means of developing the theory into a weapons application." This led to an Air Force program called Harness Cavalier, which seems to have ended without producing anything conclusive.

However, some years later scientist Dr. Paul Koloc was looking at methods of containing high-temperature plasma during nuclear fusion. There are many schemes for containing plasma in donut-shaped magnetic fields using a device called a Tokomak. Koloc's insight was that, under the right conditions, a donut-shaped mass of moving plasma would generate the required fields for containment itself. No Tokomak would be required for this "plasmoid," which would be completely stable and self-sustaining. It is a very close equivalent of the smoke ring -- another type of dynamic "vortex ring," which remains stable over a period of time, unlike an unstructured cloud of smoke.

Koloc also theorized that if a donut-shaped plasmoid was created accidentally -- say, during a lightning strike -- it would remain stable for a period of seconds of minutes. This he believes is the explanation for ball lightning. He has a lot of competition from other, wildly different theories of ball lightning, though, from nanobatteries to vaporized silicon to black holes. There is no scientific consensus.

In the '80s, Koloc's team succeeded in creating small, short-lived plasmoids from "chicken egg to softball" size in the laboratory. It was a good start, but not enough to convince the world that he's right about ball lightning. Ultimately the work might lead to a means of containing nuclear fusion... but there were some engineering challenges to tackle. Moreover, the scientific mainstream has not bought into the concept. While giant programs to achieve controlled fusion like ITER are sucking up billions, Koloc has found it much harder to attract funding. This is not like cold fusion or bubble fusion which has been challenged on scientific grounds, but it's been very much sidelined in favor of other "confinement concepts" for fusion power.

However, in 2002, Koloc's company, Prometheus II, briefly obtained funding from the Missile Defence Agency. The aim was to create stable 'magnetoplasmoids' a foot in diameter which would last between one and five seconds. In the subsequent phase, the magnetoplasmoid would be compressed and accelerate to two hundred kilometers a second. This "encapsulated EMP bullet" would make an idea anti-missile weapon, generating an intense electromagnetic pulse on impact which would scramble the guidance system and any electronics, as well as causing thermal damage.

Koloc called the weapon "Phased Hyper-Acceleration for Shock, EMP, and Radiation" -- PHASER.

"It can be used for a range of purposes from stunning personnel to destroying the functionality of electronically operated devices, smaller rockets, vehicles and packages that represent an immediate threat to the United States," he wrote. "This dial-able PHASER weapon can be set on 'Stun' or dialed down, selecting a non-lethal level for persons needed for later interrogation... One mundane application for law enforcement would be the disruption of the engine electronics to stop vehicles that would otherwise be the target of a high-speed chase. Dialable versions of the PHASER will be available for use in civilian encounters."

Nothing seems to have resulted after the Phase I contract, so I contacted Koloc to see how his research had progressed. He confirmed that they had successfully formed plasmoids a foot in diameter, but that these could not be made sufficiently stable.

To make it work and overcome the stability problem, they need a device known as a "fast rising parallel plate transmission line." There was not enough funding for this and the company is still trying to raise funds.

"Once the re-engineered formation system becomes operational, we will proceed to form plasmoids of approximately 35 to 45 centimeters in diameter with a stable lifetime of from one to thirty seconds," says Prometheus II Vice President D. M. Cooper. "The plasmoids should be rugged and energetic, and should attain quiescence (thus becoming very stable) within two or three milliseconds of the formation pulse. The plasmoids will be useful for energy applications even if the military applications are not pursued."

So a ball lightning weapon remains tantalizingly out of reach –- or does it? As I noted in a previous article on military ball lightning, the USAF’s Phillips Laboratory examined a very similar concept in 1993. Again, this involved accelerating a donut-shaped mass of plasma to high speed as an anti-missile weapon in a project called Magnetically Accelerated Ring to Achieve Ultra-high Directed Energy and Radiation, or MARAUDER. Based on the Air Force's awesome Shiva Star power system, experiments spat out plasmoids at ultra-high speed that were expected to reach 3,000 kilometers a second by 1995. But nothing was published after 1993, and MARAUDER was classified, disappearing into the black world of secret programs.

Ball lighting is still mysterious 200 years later… and the next time a warship gets struck by weird fireballs they will probably be as baffled as were the sailors aboard the HMS Warren Hastings.

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Does Religion Make People Happier? Scientists Search to Explain Why People Believe in a God

Shutterstock_3010157_2Researchers accidentally discovered that people with religious beliefs tend to be more content in life while studying an unrelated topic. While not the original objective, the recent European study found that religious people are better able to cope with shocks such as losing a loved one or getting laid off of a job.

Professor Andrew Clark, from the Paris School of Economics, and co-author Dr Orsolya Lelkes, from the European Centre for Social Welfare Policy and Research, analyzed the a variety of factors among Catholic and Protestant Christians and found that life satisfaction seems to be higher among the religious population. The authors concluded that religion in general, might act as a "buffer" that protects people from life's disappointments.

"We originally started the research to work out why some European countries had more generous unemployment benefits than others, but our analysis suggested that religious people suffered less psychological harm from unemployment than the non-religious,” noted Professor Clark. "They had higher levels of life satisfaction".

Data from thousands of European households revealed higher levels of "life satisfaction" in believers. Professor Clark suspects that a variety of aspects are at play, and that perhaps a “religious upbringing” could be responsible for the effect, rather than any particular religious beliefs.

The researchers say they found that the religious crowd tended to experience more “current day rewards”, rather than storing them up for the future. Previous studies have also found strong correlations between religion and happiness. The idea that religion may offer substantial psychological benefits in life, is in sharp contrast with another common viewpoint that religion is repressive and has a negative influence on human development.

Professor Leslie Francis, from the University of Warwick believes that the benefit might involve the increased "purpose of life" experienced by many believers that may not be as strongly felt among nonbelievers.

"These findings are consistent with other studies which suggest that religion does have a positive effect, although there are other views which say that religion can lead to self-doubt, and failure, and thereby have a negative effect,” said Francis. "The belief that religion damages people is still in the minds of many."

Terry Sanderson, a leading UK secularist, gay rights activist and president of the National Secular Society, said that any study describing a link between happiness and religion is "meaningless".

"Non-believers can't just turn on a faith in order to be happy. If you find religious claims incredible, then you won't believe them, whatever the supposed rewards in terms of personal fulfillment,” he said. "Happiness is an elusive concept, anyway - I find listening to classical music blissful and watching football repulsive. Other people feel exactly the opposite. In the end, it comes down to the individual and, to an extent, their genetic predispositions."

While no one would argue that genetics don’t influence one’s disposition, Justin Thacker, head of Theology for the Evangelical Alliance, says that there are definitely other factors worth considering. He says a belief in God increases one’s feeling that life is meaningful.

"There is more than one reason for this - part of it will be the sense of community and the relationships fostered, but that doesn't account for all of it. A large part of it is due to the meaning, purpose and value which believing in God gives you, whereas not believing in God can leave you without those things."

Previous studies have concluded that humans are biologically predisposed to believe in God. Historically, most cultures have developed some sort of religious belief that included at least some form of a “higher power”. From an evolutionary and psychological perspective, these questions have intrigued scientists for decades, but the physiological and cognitive study of religion is still relatively young.

Both believers and non-believers can agree on the scientific findings, and still interpret it quite differently notes Ian Ramsey Centre for science and religion in the University of Oxford researchers who are currently working on a project to better understand the cognitive science of religion.

“One element of the current project is to develop philosophical and theological treatments of what the findings from cognitive science of religion means for various theological positions,” states the Cognition, Religion and Theology Project outline. “

“One element of the project is scientifically explaining not just belief in gods but why some people become atheists. If scientists can explain why people tend to believe in gods and also why other people tend to believe there are no gods, then surely the presence of a scientific explanation cannot mean that you should not believe one way or the other just on the presence or possibility of such an explanation.

Non-believers might find satisfaction in a sound scientific explanation of why people tend to believe in God because they can now account for why people persist in believing in a fictitious being. The believer might find satisfaction in the scientific documentation of how human nature predisposes people to believe in God because it could reinforce the idea that people were divinely designed to know and believe in God. Both believers and non-believers can agree on the scientific findings.”

Posted by Rebecca Sato.

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NASA Study Predicted Outbreak Of Deadly Virus


A risk-assessment map shows the areas of increased risk of Rift Valley Fever (RVF) in eastern Africa from fall 2006 to spring 2007. Pink areas depict increased risk of disease, while pale green areas reflect normal risk. Yellow dots represent reported RVF cases in high-risk areas, while blue dots represent occurrences in non-risk areas. (Credit: Assaf Anyamba and the NASA Earth Observatory)

An early warning system, more than a decade in development, successfully predicted the 2006-2007 outbreak of the deadly Rift Valley fever in northeast Africa, according to a new study led by NASA scientists.

Rift Valley fever is unique in that its emergence is closely linked to interannual climate variability. Utilizing that link, researchers including Assaf Anyamba, a geographer and remote sensing scientist with the University of Maryland Baltimore County and NASA's Goddard Space Flight Center in Greenbelt, Md., used a blend of NASA and National Oceanic and Atmospheric Administration measurements of sea surface temperatures, precipitation, and vegetation cover to predict when and where an outbreak would occur.

The final product, a Rift Valley fever "risk map," gave public health officials in East Africa up to six weeks of warning for the 2006-2007 outbreak, enough time to lessen human impact. The researchers described their findings in the Proceedings of the National Academy of Sciences.

The first-of-its-kind prediction is the culmination of decades of research. During an intense El Niño event in 1997, the largest known outbreak of Rift Valley fever spread across the Horn of Africa. About 90,000 people were infected with the virus, which is carried by mosquitoes and transmitted to humans by mosquito bites or through contact with infected livestock.

The 1997 outbreak provoked the formation of a working group--funded by the U.S. Department of Defense Global Emerging Infections Surveillance and Response System--to see if predictions of an outbreak could be made operational. Such predictions would not only aid mitigation efforts in the endemic countries and protect the global public, but would help protect American civilian and military personnel located and traveling overseas, ensure the safety of imported goods and animals, and prevent infected humans or mosquitoes from entering the United States.

"To do all that, we need to understand a disease in the endemic region," Anyamba said.

The link between the mosquito life cycle and vegetation growth was first described in a 1987 Science paper by co-authors Kenneth Linthicum of the U.S. Department of Agriculture and Compton Tucker of NASA Goddard. Then, a subsequent 1999 Science paper described link between the disease and the El Niño-Southern Oscillation (ENSO). ENSO is a cyclical, global phenomenon of sea surface temperature changes that can contribute to extreme climate events around the world.

For some areas, the warm phase of ENSO brings drought, while in some areas like the Horn of Africa, ENSO leads to above-normal rainfall. Excessive, sustained rainfall awakens the eggs of mosquitoes infected with Rift Valley fever that can remain dormant for up to 15 years in dried-out dambos—shallow wetlands common in the region.

Building on that research, Anyamba and colleagues set out to predict when conditions were ripe for excessive rainfall, and thus an outbreak. They started by examining satellite measurements of sea surface temperatures. One of the first indicators that ENSO will bring an abundance of rainfall is a rise in the surface temperature of the eastern equatorial Pacific Ocean and the western equatorial Indian Ocean.

But perhaps the most telling indicator of a potential outbreak is a measure of the mosquito habitat itself. The researchers used a satellite-derived vegetation data set--processed at NASA Goddard and called the Normalized Difference Vegetation Index—that measures the landscape's "greenness." Greener regions have more than the average amount of vegetation, which means more water and more potential habitat for infected mosquitoes.

"Greenness describes habitat and represents life," Anyamba said. "Without such systematic, continuous Earth system measurements from satellites, we would not be able to translate the information into outbreak predictions."

The final product is a risk map for Rift Valley fever, showing areas of anomalous rainfall and vegetation growth over a three-month period. The forecast is updated and issued monthly as a means to guide ground-based mosquito and virus surveillance.

As early as September 2006, the monthly advisory from Anyamba and colleagues indicated an elevated risk of Rift Valley fever activity in East Africa. By November, Kenya's government had begun collaborating with non-governmental organizations to implement disease mitigation measures—restricting animal movement, distributing mosquito bed nets, informing the public, and enacting programs to control mosquitoes and vaccinate animals.

"There is no human vaccine," Anyamba said, "so prevention is critical."

Between two and six weeks later—depending on the location—the disease was detected in humans.

"Satellite data is a valuable tool that allowed us to look remotely at large sections of land in Africa and understand what was happening on the ground," Linthicum said.

After the 2006-2007 outbreak, Anyamba and colleagues assessed the effectiveness of the warning maps. They compared locations that had been identified as "at risk" with the locations where Rift Valley fever was reported.

Of the 1,088 cases reported in Kenya, Somalia, and Tanzania, 64 percent fell within areas delineated on the risk map. The other 36 percent of cases did not occur within "at risk" areas, but none were more than 30 miles away, leading the researchers believe that they had identified most of the initial infection sites.

The potential for mapping the risk of disease outbreaks is not limited to Africa. Previous research has shown that risk maps are possible whenever the abundance of a virus can be linked to extremes in climate conditions. Chikungunya in east Africa and Hantavirus and West Nile virus in the United States, for example, have been linked to conditions of rainfall extremes.

"We are coming up on almost 30 years of vegetation data from satellites, which provides us with a good basis for predicting," Linthicum said upon returning from a Rift Valley fever workshop in Cairo, Egypt in January. "At this meeting, it was clear that using this tool as a basis for predictions has become accepted as the norm."

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A collapsing carbon market makes mega-pollution cheap

Julian Glover

'Roll up for the great pollution fire sale, the ultimate chance to wreck the climate on the cheap. You sir, over there, from the power company - look at this lovely tonne of freshly made, sulphur-rich carbon dioxide. Last summer it cost an eyewatering €31 to throw up your smokestack, but in our give-away global recession sale, that's been slashed to a crazy €8.20. Dump plans for the wind turbine! Compare our offer with costly solar energy! At this low, low price you can't afford not to burn coal!"

Set up to price pollution out of existence, carbon trading is pricing it back in. Europe's carbon markets are in collapse.

Yet the hiss of escaping gas is almost inaudible. There's no big news headline, nothing sensational for TV viewers to watch; no queues outside banks or missing Texan showmen. You can't see or hear a market for a pollutant tumble. But at stake is what was supposed to be a central lever in the world's effort to turn back climate change. Intended to price fossil fuels out of the market, the system is instead turning them into the rational economic choice.

That there exists something called carbon trading is about all that most people know. A few know, too, that Europe has created carbon exchanges, and traders who buy and sell. Few but the professionals, however, know that this market is now failing in its purpose: to edge up the cost of emitting CO2.

The theory sounded fine in the boom years, back when Nicholas Stern described climate change as "the biggest market failure in history" - a market failure to which carbon trading was meant to be a market solution. Instead, it's bolstering the business case for fossil fuels.

Understanding why is easy. A year ago European governments allocated a limited number of carbon emission permits to their big polluters. Businesses that reduce pollution are allowed to sell spare permits to ones that need more. As demand outstrips this capped supply, and the price of permits rises, an incentive grows to invest in green energy. Why buy costly permits to keep a coal plant running when you can put the cash into clean power instead?

All this only works as the carbon price lifts. As with 1924 Château Lafite or Damian Hirst's diamond skulls, scarcity and speculation create the value. If permits are cheap, and everyone has lots, the green incentive crashes into reverse. As recession slashes output, companies pile up permits they don't need and sell them on. The price falls, and anyone who wants to pollute can afford to do so. The result is a system that does nothing at all for climate change but a lot for the bottom lines of mega-polluters such as the steelmaker Corus: industrial assistance in camouflage.

"I don't know why industrials would miss this opportunity," said one trader last week. "They are using it to compensate for the tightening of credit and the slowdown, to pay for redundancies."

A lot of the blame lies with governments that signed up to carbon trading as a neat idea, but then indulged polluters with luxurious quantities of permits. The excuse was that growth would soon see them bumping against the ceiling.

Instead, exchanges are in meltdown: a tonne of carbon has dropped to about €8, down from last year's summer peak of €31 and far below the €30-€45 range at which renewables can compete with fossil fuels.

The lesson of the carbon slump, like the credit crunch, is that markets can be a conduit, but not a substitute, for political will. They only work when properly primed and regulated. Europe hoped that the mere creation of a carbon market would drive everyone away from fossil fuels. It forgot that demand had to outstrip supply, and that if growth stops, demand drops too.

There is not much time to rescue the system. Carbon trading remains at the heart of the international response to climate change. Obama backs what Americans call cap and trade. Australia wants to try the same thing. It should be at the heart of a deal at the Copenhagen summit this winter. But both are hesitating, given Europe's mess.

The market must be unashamedly rigged to force supply below demand. The obvious way would be to cut the number of permits in circulation, but in a recession no government will be brave enough to do that. And private initiatives such as Sandbag, which encourages individuals to buy and lock away permits, can exert little pressure on price in a market awash with them.

Europe can choke off tomorrow's supply, however, without hitting business today. First the EU must stop importing permits from countries such as Russia - a bonus for a paper transaction. No one really believes that 15m tonnes of imported permits will not still be emitted by a steelworks somewhere east of Novosibirsk.

Second, it must publish plans to crack down on the surplus of permits when the recession is over. Warnings of famine ahead, when the scheme enters its third stage in 2012, would raise prices now, if believed.

Like medieval pardoners handing out unlimited indulgences, governments have created a glut. Reformation must follow. Wanted - a modern Martin Luther to nail a shaming truth to industry's door: Europe's whizz-bang carbon market is turning sub-prime.

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