Here is this weeks collection of science news stories that triggered my “Hey, that’s cool” detector. As always, if I’ve missed anything that is truly cool, then drop a comment and I’ll do an update that includes a hat tip you.
The most obvious big news story this week was Stephen Hawkins declaring that we don’t need God to explain the Big Bang. I’m going to make an assumption that you got this one, and so I will skip it and move on to other stuff that you might have missed. Yes, its was big news, but I’ve already blogged about it, so here I’m now giving you other science news that falls into the “cool” category, so please tighten your seat belts … all set now? … good, then here we go ….
Did Viking Mars Landers Find Life’s Building Blocks? Missing Piece Inspires New Look at Puzzle
Experiments prompted by a 2008 surprise from NASA’s Phoenix Mars Lander suggest that soil examined by NASA’s Viking Mars landers in 1976 may have contained carbon-based chemical building blocks of life.
“This doesn’t say anything about the question of whether or not life has existed on Mars, but it could make a big difference in how we look for evidence to answer that question,” said Chris McKay of NASA’s Ames Research Center, Moffett Field, Calif. McKay coauthored a study published online by the Journal of Geophysical Research — Planets, reanalyzing results of Viking’s tests for organic chemicals in Martian soil.
The only organic chemicals identified when the Viking landers heated samples of Martian soil were chloromethane and dichloromethane — chlorine compounds interpreted at the time as likely contaminants from cleaning fluids. But those chemicals are exactly what the new study found when a little perchlorate — the surprise finding from Phoenix — was added to desert soil from Chile containing organics and analyzed in the manner of the Viking tests.
“Our results suggest that not only organics, but also perchlorate, may have been present in the soil at both Viking landing sites,” said the study’s lead author, Rafael Navarro-González of the National Autonomous University of Mexico, Mexico City.
New Mission to Skim the Sun: NASA Selects Science Investigations for Solar Probe Plus
The small car-sized spacecraft will plunge directly into the sun’s atmosphere approximately four million miles from our star’s surface. It will explore a region no other spacecraft ever has encountered. NASA has selected five science investigations that will unlock the sun’s biggest mysteries.
“The experiments selected for Solar Probe Plus are specifically designed to solve two key questions of solar physics — why is the sun’s outer atmosphere so much hotter than the sun’s visible surface and what propels the solar wind that affects Earth and our solar system? ” said Dick Fisher, director of NASA’s Heliophysics Division in Washington. “We’ve been struggling with these questions for decades and this mission should finally provide those answers.”
As the spacecraft approaches the sun, its revolutionary carbon-composite heat shield must withstand temperatures exceeding 2550 degrees Fahrenheit and blasts of intense radiation. The spacecraft will have an up close and personal view of the sun enabling scientists to better understand, characterize and forecast the radiation environment for future space explorers.
What lies beneath Antarctic ice
Persistent bubbling is stirring the water’s surface in the Erebus and Terror Gulf, a remote spot off the Antarctic Peninsula. When he saw the commotion in 2000, Argentinian geologist Rodolfo del Valle was intrigued — despite 38 years’ experience in the region. There was a chance the gas contained methane, and when del Valle’s team investigated the leak they discovered it to be 99% methane.
This is bad news. The gas is not only 25 times more powerful than carbon dioxide at heating the atmosphere; methane hydrates locked up in the Antarctic seabed and ice also contain vast amounts of carbon — overall, methane deposits contain about half of global carbon. With a recorded decline in Antarctic ice shelves, the long-term effect of deteriorating and melting ice could range from boosting global warming to helping trigger mass extinctions. Nature caught up with del Valle on the eve of his departure for the first on-the-ground study to quantify methane leakage in shallow waters and ice in the Gulf.
What’s the overall rationale for your upcoming three-year focus on methane hydrate deposits?
Statistics and figures aside, I have been participating in Antarctic expeditions for so long that I’ve seen entire ice shelves crumble into pieces small enough to prepare a Scotch on the rocks. We have had to redraw maps. Global warming is a fact, and once we quantify methane emissions we will have scientific proof that the substrate on the seabed is melting and leaking methane. If these methane deposits reach the atmosphere, they will deepen the greenhouse effect, which, in turn, will promote further methane release, thus closing the circle and ramping up warming.
Eternal black holes are the ultimate cosmic safes
If you wanted to hide something away for all eternity, where could you put it? Black holes might seem like a safe bet, but Stephen Hawking famously calculated that they leak radiation, and most physicists now think that this radiation contains information about their contents. Now, there may be a way to make an “eternal” black hole that would act as the ultimate cosmic lockbox.
The recipe for this unlikely object was discovered by looking at an even more abstruse entity, the white hole. White holes are black holes that run backwards in time, throwing out matter instead of sucking it in. Where a black hole might form from a collapsing star, a white hole would explode and leave a star in its place. White holes have never been observed, though general relativity predicts they could exist in principle.
Stephen Hsu of the University of Oregon in Eugene wanted to caculate whether a white hole would emit radiation like a black hole. He considered the special case of a white hole sitting in a perfect vacuum, and calculated that when it spits out its contents, there is a burst of radiation essentially identical to a black hole’s Hawking radiation (arxiv.org/abs/1007.2934).
Hsu realised that running the process backwards would be equivalent to a black hole forming and then existing in a perfect vacuum, with no Hawking radiation. “It becomes a black hole that’s not radiating, which is a very weird thing,” Hsu says.
Why your brain flips over visual illusions
IT’S a big skull. No, wait, it’s two people under an arch. Hold on, it’s a skull again. Two very different images can be perceived in the trick picture Blossom and Decay (see right). Now we are one step closer to working out how the brain spontaneously flips between such views, with the discovery of what may be the relevant brain region.
The precise neural mechanism that provokes the brain to switch its view of a scene is unknown, but it is thought to play a major role in perception by acting as a sort of reality check, says Ryota Kanai of University College London. “We need a trigger to prompt possible different interpretations so that we don’t get stuck with a potentially incorrect interpretation of the world.”
To find out which part of the brain might be involved, Kanai and colleagues asked 52 volunteers to watch a video of a revolving sphere and press a button when the rotation of the sphere appeared to change direction. Crucially, the sphere was not changing direction; it could simply be perceived to be rotating in either direction. How long each rotation-direction was perceived for was recorded and an average “switch rate” assigned to each of the volunteers.
Video: Brain-flip illusion
The team then used structural magnetic resonance imaging to search for active brain regions during this task. This pointed to the superior parietal lobes (SPL), two areas towards the back of the head known to control attention and process three-dimensional images. People whose cortex was thicker and better connected in this region had faster switch rates.
Why the ‘sixth extinction’ will be unpredictable
A major extinction event is under way – but predicting which species will survive could be harder than we thought. That’s the conclusion of one of the most accurate analyses ever of diversity in the marine animal fossil record.
Conventional wisdom among palaeontologists has it a group of animals that has diversified rapidly will later tend to flourish and diversify more than others after an event that causes mass extinction, such as an asteroid impact or global warming. If true, this would help us predict the outcome of the current extinction, which is often dubbed the “sixth extinction”.
Now an analysis by John Alroy of Macquarie University in Sydney, Australia, reveals that the principle does not hold. He used the Paleobiology Database of fossils, which holds data from nearly 100,000 collections, to study 20,181 genera of marine animals from 50 time periods, such as the Cambrian explosion more than 500 million years ago and the largest mass extinction event 250 million years ago.
He found that “all bets are off” for predicting what will happen to biological diversity after a major extinction event, he says.
“If you were standing around in the Cretaceous period, you would have no idea which groups would thrive and which would die out,” he says.
Large diversity within a particular group does not predict survival. For example, the worm-like Conodonta and hard-shelled Linguliformea became hugely diverse in the Cambrian period, but had died out by the end of the Ordovician 430 million years ago. “The important overall pattern is no pattern,” says Alroy.
Although the current extinction era is caused by human actions rather than natural events, the survival patterns should be similar, he adds.
Second super-fast flip of Earth’s poles found
SOME 16 million years ago, north became south in a matter of years. Such fast flips are impossible, according to models of the Earth’s core, but this is now the second time that evidence has been found.
The magnetic poles swap every 300,000 years, a process that normally takes up to 5000 years. In 1995 an ancient lava flow with an unusual magnetic pattern was discovered in Oregon. It suggested that the field at the time was moving by 6 degrees a day – at least 10,000 times faster than usual. “Not many people believed it,” says Scott Bogue of Occidental College in Los Angeles.
Now Bogue and his colleague Jonathan Glen of the United States Geological Survey in Menlo Park, California, say they have found a second example in Nevada. The lava rock suggests that in one year, Earth’s magnetic field shifted by 53 degrees (Geophysical Research Letters, DOI: 10.1029/2010GL044286). At that rate, a full flip would take less than four years, but there could be another interpretation. “It may have been a burst of rapid acceleration that punctuated the steady movement of the field,” says Bogue.
Peter Olson of Johns Hopkins University in Baltimore, Maryland, remains sceptical and points out that the effects could have been local rather than global.
Earth is overdue for a reversal, and rapid shifts would cause widespread chaos – for navigation and migratory birds for instance.
New Scientist: Click Here
Water in Earth’s Mantle Key to Survival of Oldest Continents
Earth today is one of the most active planets in the Solar System, and was probably even more so during the early stages of its life. Thanks to the plate tectonics that continue to shape our planet’s surface, remnants of crust from Earth’s formative years are rare, but not impossible to find. A paper published in Nature Sept. 2 examines how some ancient rocks have resisted being recycled into Earth’s convecting interior.
Throughout the world there exist regions of ancient crust, referred to as cratons, which have resisted being recycled into the interior of our tectonically dynamic planet. These geologic anomalies appear to have withstood major deformation thanks to the presence of mantle roots. A mantle root is a portion of Earth’s mantle that lies beneath the craton, extending like the root of a tooth into the rest of the underlying mantle.
Just like a tooth, the mantle root of a craton is compositionally different from the normal mantle into which it protrudes. It is also colder, causing it to be more rigid. These roots were formed in ancient melting events and are intrinsically more buoyant than the surrounding mantle. The melting removed much of the calcium, aluminum, and iron that would normally form dense minerals. Thus, these roots act as rafts bobbing on a vigorously convecting mantle, on which old fragments of continental crust may bask in comparative safety.
However, geophysical calculations have suggested that this buoyancy is not enough to stop destruction of the mantle roots. According to these calculations, the hotter temperatures that are widely thought to have existed in Earth’s mantle about 2.5 to 3 billion years ago should have warmed and softened up the base of these roots sufficiently to allow them to be gradually eroded from below, leading to their eventual destruction as they were entrained, piece by piece, into the convecting mantle. A stronger viscosity contrast between the root and the underlying mantle is required to ensure preservation.
In the Sept. 2 issue of Nature, Anne Peslier, an ESCG-Jacobs Technology scientist working at NASA-Johnson Space Center and her colleagues David Bell from Arizona State University and Alan Woodland and Marina Lazarov from the University of Frankfurt, published measurements of the trace water content of rocks from the deepest part of a mantle root that offer an explanation for this mystery.
“It has long been suspected, but not proven, that cratonic mantle roots are dryer than convecting upper mantle,” explains Bell, an associate research scientist in the School of Earth and Space Exploration and the department of chemistry and biochemistry in ASU’s College of Liberal Arts and Sciences. “The presence of very small quantities of water is known to weaken rocks and minerals. During partial melting, such as that experienced by the mantle roots, water — like calcium, aluminum and iron — is also removed.”
‘Lost years’ end for backyard supernova
Data from repaired Hubble telescope uncover new secrets about our nearest supernova.
As the first findings start to arrive from the Hubble Space Telescope since its repair last year, researchers are shedding new light on one of our nearest and most exciting supernova neighbours as they resume tracking its explosive history.
Supernovae form when a massive star explodes at the end of its life. Opportunities to view the event in a nearby galaxy are scarce, but in 1987 just such an explosion was observed in one of our nearest galaxies, the Large Magellanic Cloud. By a happy coincidence, Hubble was launched only 3 years later, and has been tracking the development of the remnant debris of supernova 1987A throughout its infancy (see ‘Happy Birthday, Hubble’). This is a rare and exciting opportunity, says Kevin France, an astrophysicist at the University of Colorado, Boulder, and lead author on the study.
“We’ve got this unprecedented picture. We caught it from pretty much day one and we have been watching it ever since — it’s kind of in our cosmic backyard,” he says.
But Hubble’s tracking of Supernova 1987A stopped cold in August 2004, when a power failure occurred in the Space Telescope Imaging Spectrograph. This instrument collects observations of the wavelengths of light radiated by gases, creating a ‘spectral fingerprint’ of the elements present. The problem was not fixed until May 2009.
A team of researchers led by France was among the last to observe supernova 1987A through Hubble in 2004, and has now collected some of the first data since its repair. They present their results today in Science
Insight Offered Into Superstitious Behavior
People who believe that fate and chance control their lives are more likely to be superstitious — but when faced with death they are likely to abandon superstition altogether, according to a recent Kansas State University undergraduate research project.
The project, led by Scott Fluke, a May 2010 K-State bachelor’s graduate in psychology, Olathe, focuses on personality traits that lead to superstition. Fluke received a $500 Doreen Shanteau Undergraduate Research Fellowship in 2009 to work with the team of Russell Webster, graduate student in psychology, Shorewood, Ill., and Donald Saucier, K-State associate professor of psychology.
For the project, “Re-Examining the Form and Function of Superstition,” the team defined superstition as the belief in a casual relationship between an action, object, or ritual and an unrelated outcome. Such superstitious behavior can include actions like wearing a lucky jersey or using good luck charms.
After performing two studies, the researchers developed three reasons for superstitious behavior: individuals use superstitions to gain control over uncertainty; to decrease feelings of helplessness; and because it is easier to rely on superstition instead of coping strategies.
“People sometimes fall back on their superstitions as a handicap,” Saucier said. “It’s a parachute they think will help them out.”
In the first study, the researchers conducted questionnaires with 200 undergraduates, asking about how pessimistic they were, whether they believed in chance or fate, if they liked to be in control and other questions. One of the major discoveries was that people who believe that chance and fate control their lives are more likely to be superstitious.
In the second study the researchers wanted to know how participants reacted to death, and asked them to write about how they felt about their own death. The team was surprised to find that participants’ levels of superstition went down when they thought about their own death, which the researchers attributed to death being a situation of extreme uncertainty.
“We theorized that when people thought about death, they would behave more superstitiously in an effort to gain a sense of control over it,” Fluke said. “What we didn’t expect was that thinking about death would make people feel helpless — like they cannot control it — and that this would actually reduce their superstitious belief.”
Fluke got the idea for his research in an undergraduate methods research course his first semester at K-State, when he realized there were many unanswered questions about psychology and superstition. He decided to pursue the topic further as a research project.
“I was interested in superstition because it frustrates me when people do things that don’t make sense,” Fluke said. “It boggled me that people would use a good luck charm to do well on a test rather than studying for it. We wanted to know why people would go about almost actively hurting themselves.”
The research is part of Saucier’s overall research program, and the team is now preparing results of their study for publication.
Saucier offers some tips to avoid superstitious behavior:
- Don’t believe in bad luck and take some ownership over what control you do have in situations. Sometimes we use bad luck to let ourselves off the hook, Saucier said, but we should instead focus on what we can do to avoid difficult situations in the first place.
- Be decisive and proactive.People who are less decisive believe in superstition more, Saucier said, and those who are proactive are less superstitious.
- Don’t be in a situation where you have to rely on bad luck.Bad luck would never occur if only good things happened. If something bad happens and you call it bad luck, do it as a coping mechanism after the fact rather than before the event, Saucier said.