Nasa's Gravity Twins Now Circling Moon
|9:51:47 PM, Monday, January 02, 2012|
“The US space agency (Nasa) has succeeded in placing two new satellites in orbit around the Moon.
Both spacecraft were put in elliptical paths around the lunar body over the weekend after performing braking manoeuvres following their more than 100-day journey from Earth.
The identical Grail twins are to map gravity variations across the lunar body in unprecedented detail.
This will help scientists refine our theories for how the Moon formed.
It will also enable them to test new ideas, such as the provocative suggestion made earlier this year that there were probably two moons in the sky above Earth billions of years ago.
Lead scientist Dr Maria Zuber is certainly hoping for some dramatic discoveries.
"Grail is a journey to the centre of the Moon and it will use exceedingly precise measurements of gravity to reveal what the inside of the Moon is like," the Massachusetts Institute of Technology (MIT) researcher said.
"This information will be combined with the plethora of remarkable observations of the Moon that have been taken by other satellites before, and together they will enable us to reconstruct the Moon's early evolution."
The 300kg Grail spacecraft were launched from Cape Canaveral, Florida, last September, and took a long spiral out to their destination.
This weekend, they approached the Moon over the south pole, 25 hours apart. Each satellite in turn fired its main engine to slow it and put it in an elliptical orbit around the lunar sphere.
This orbit has a period of 11.5 hours and must now gradually be reduced in size and circularised before any science can begin.
A series of further burns on each spacecraft should achieve this goal by March.
The twins will then map the small variations in gravity across the lunar surface from an altitude of 55km.
These gravity differences are the result of an uneven distribution of mass. Obvious examples at the Moon's surface include big mountain ranges or deep impact basins, but even inside the lunar body the rock will be arranged in an irregular fashion, with some regions being denser than others.
All this will have a subtle influence on the pull of gravity sensed by the over-flying spacecraft.
The Grail twins will make their measurements by carrying out a carefully calibrated pursuit of each other.
As the lead spacecraft flies through the uneven gravity field, it will experience small accelerations or decelerations. The second spacecraft, following some 100-200km behind, will detect these disturbances as very slight changes in the separation between the pair - deviations that are not much more than the width of a human red blood cell.
When the gravity map is combined with comparable-resolution topographical information showing the surface highs and lows, scientists should be able to deduce the Moon's probable internal structure and composition. This is fundamental knowledge that will play into theories of how the lunar body formed and how it has changed through time…”
LHC Reports Discovery of its First New Particle
|12:03:27 AM, Friday, December 23, 2011|
“(BBC) The Large Hadron Collider (LHC) on the Franco-Swiss border has made its first clear observation of a new particle since opening in 2009.
It is called Chi_b (3P) and will help scientists understand better the forces that hold matter together.
The as-yet unpublished discovery is reported on the Arxiv pre-print server.
The LHC is exploring some of the fundamental questions in "big physics" by colliding proton particles together in a huge underground facility.
Detail in the sub-atomic wreckage from these impacts is expected to yield new information about the way the Universe is constructed.
The Chi_b (3P) is a more excited state of Chi particles already seen in previous collision experiments, explained Prof Roger Jones, who works on the Atlas detector at the LHC.
"The new particle is made up of a 'beauty quark' and a 'beauty anti-quark', which are then bound together," he told BBC News.
"People have thought this more excited state should exist for years but nobody has managed to see it until now.
"It's also interesting for what it tells us about the forces that hold the quark and the anti-quark together - the strong nuclear force. And that's the same force that holds, for instance, the atomic nucleus together with its protons and the neutrons."
The LHC is designed to fill in gaps in the Standard Model - the current framework devised to explain the interactions of sub-atomic particles - and also to look for any new physics beyond it.
In particular, it is using the collisions to try to pin down the famous Higgs particle, which physicists hypothesize can explain why matter has mass.
Discoveries such as Chi_b (3P) are an important part of this quest because they add to the wider background knowledge, says Prof Jones, from Lancaster University, UK.
"The better we understand the strong force, the more we understand a large part of the data that we see, which is quite often the background to the more exciting things we are looking for, like the Higgs.
"So, it's helping put together that basic understanding that we have and need to do the new physics."
Prof Paul Newman, from the University of Birmingham, added: "This is the first time such a new particle has been found at the LHC. Its discovery is a testament to the very successful running of the collider in 2011 and to the superb understanding of our detector which has been achieved by the Atlas collaboration already."
And Andy Chisholm, a PhD student from Birmingham who worked on the analysis, said: "Analysing the billions of particle collisions at the LHC is fascinating. There are potentially all kinds of interesting things buried in the data, and we were lucky to look in the right place at the right time."”
NASA's Kepler Finds Two Earth-Size Planets Around Sunlike Star
|4:36:03 AM, Wednesday, December 21, 2011|
“Two new planets found orbiting a sunlike star are the first truly Earth-size worlds discovered by NASA's Kepler mission, scientists announced today.
The find comes on the heels of Kepler's first potentially Earthlike planet orbiting squarely within its star's water-friendly "Goldilocks zone"—the region that's not too hot and not too cold for liquid water to exist on a planet's surface.
Designated Kepler-20e and Kepler-20f, the two new planets are comparable in size to Earth and Venus: At 0.87 times the size of Earth, Kepler-20e is slightly smaller than Venus, while Kepler-20f is 1.03 times Earth's radius.
But both new extrasolar planets—or exoplanets—orbit their star much too closely to be within the habitable zone.
In fact, the entire Kepler-20 system is believed to contain at least five planets all orbiting their star within a distance smaller than that between Mercury and the sun.
This orbital distance makes the planets very hot. For instance, Kepler-20e is estimated to have an average surface temperature of 1,400ºF (760ºC), while Kepler-20f is a "cooler" 800ºF (427ºC).
By contrast, Earth's average surface temperature is 57.2ºF (14°C).
Still, this is the first confirmation of truly Earth-size planets by the Kepler team—a key goal of the overall mission.
"December 2011 may be remembered as the first time humanity was able to discover an Earth-size planet in orbit around another star," lead author Francois Fressin, of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts, said today during a NASA teleconference.
The discovery "demonstrates for the first time that Earth-size planets exist around other stars, and that we are able to detect them."
New Planets a Tight-Knit Group
Previously discovered exoplanets have all been considerably larger than Earth.
Even the just announced Goldilocks world, Kepler-22b, was estimated to be 2.4 times Earth's radius and is thought to have a fairly low density, meaning it could have a thick atmosphere and a surface quite unlike Earth's.
With the new Kepler discovery, we now have confirmation of planets that "are exactly the right size [to be Earthlike] ... but are too hot" for life as we know it, team member David Charbonneau, also with the CfA, told National Geographic News…”
In Memoriam: Writer Christopher Hitchens Dies, 1949-2011
|1:03:49 AM, Friday, December 16, 2011|
-- An intellectual champion among us lowly primates. Below is a very recent video that sums it all up really well. I raise my glass to you, Hitch! Thank you.
Baby Seal Breaks Into House and Curls Up on Sofa
|9:04:44 PM, Thursday, December 15, 2011|
"New Zealander Annette Swoffer got the surprise of her life when she found a baby seal in her kitchen, who later began to snooze on her couch, the New Zealand Herald reports.
According to the report, the seal wandered from the bay waterfront, through a residential area, across busy roads, under a gate, through a cat door, and up some stairs before he was found at around 9:30 p.m.
"I thought 'I'm hallucinating, this is just wrong,'" Swoffer told the paper. "Then it looks at me with those huge brown eyes. It was so cute..."
Swoffer then called the Society for the Prevention of Cruelty to Animals (SPCA), who called the Department of Conservation. According to a report by Stuff.co.nz, the department was already looking for the pup.
When biodiversity program manager Chris Clark came to pick up the animal, he told Swoffer he'd been looking for the seal all afternoon and that it had likely just been weaned from its mother.
Department of Conservation's Katrina Knill elaborated on the state of the New Zealand fur seal population in an email to The Huffington Post:
"NZ fur seal populations are starting to recover in the western Bay of Plenty, and are believed to be breeding on Motuanau (Plate) Island, which is approximately 12km offshore.
At this time of year, young seals are dispersing from the rookeries. Seal pups may often spend days at a time alone, whilst the mother is away foraging for food.
Seals usually occupy rocky shores in places that have some protection from heavy seas and are often found resting on Bay of Plenty beaches.
Occasionally they travel inland (usually via estuaries and waterways). When on land they can become disoriented and have been found on previous occasions in unexpected places such as backyards, drains and streets.
Seals are wild animals and the Department's policy is to return them to the care of their natural habitat."
Knill went on to write that seals can carry infectious diseases and injure humans, so members of the public should contact authorities (0800DOCHOT in NZ) if they see a seal in trouble or in an odd location. Click here to learn more about New Zealand's fur seals."
Supermassive black hole will 'eat' gas cloud
|4:06:08 AM, Thursday, December 15, 2011|
"Researchers have spotted a giant gas cloud spiralling into the supermassive black hole at our galaxy's centre.
Though it is known that black holes draw in everything nearby, it will be the first chance to see one consume such a cloud.
As it is torn apart, the turbulent area around the black hole will become unusually bright, giving astronomers a chance to learn more about it.
The cloud, which is described in Nature, should meet its end in 2013.
Researchers using the European Southern Observatory's Very Large Telescope estimate that despite its size, the cloud has a total mass of only about three times that of Earth.
They have plotted the cloud's squashed, oval-shaped path and estimate it has doubled its speed in the last seven years - to 2,350km per second.
It should spiral in to within about 40 billion kilometres of the black hole in the middle of 2013.
Our local supermassive black hole, dubbed Sagittarius A*, lies about 27,000 light-years away, and has a mass about four million times that of our Sun.
As the name implies, beyond a certain threshold point - the event horizon - nothing can escape its pull, not even light itself.
But outside that regime is a swirling mass of material, not unlike water circling a drain. In astronomical terms, is a relatively quiet zone about which little is known.
That looks set to change, though, as the gas cloud approaches.
It does not comprise enough matter to hold itself together under its own gravity, as a star might, so the cloud will begin to elongate as it meets its doom.
"The idea of an astronaut close to a black hole being stretched out to resemble spaghetti is familiar from science fiction," said lead author of the study Stefan Gillessen, from Max Planck Institute for Extraterrestrial Physics in Germany.
"But we can now see this happening for real to the newly discovered cloud. It is not going to survive the experience."
It is likely that about half of the cloud will be swallowed up, with the remainder flung back out into space.
But this violent process will literally shed light on the closest example we have of an enigmatic celestial object.
The acceleration of the cloud's constituent material will create a shower of X-rays that will help astronomers learn more about our local black hole.
As astronomer Mark Morris of the University of California Los Angeles put it in an accompanying article in Nature, "many telescopes are likely to be watching"."
Atom Smasher's Higgs Particle Findings: Physicists React
|12:35:32 AM, Wednesday, December 14, 2011|
"Scientists at the world's largest particle accelerator announced today (Dec. 13) that they'd narrowed down the possibilities for the existence of the elusive Higgs boson particle. This particle, long theorized but not yet detected, is thought to explain why particles have mass.
The data so far from the Large Hadron Collider (LHC) indicate that if it exists at all, the Higgs must weigh between 115 and 130 times the mass of a proton (a unit denoted by gigaelectronvolts, or GeV). Two experiments at LHC, called ATLAS and CMS, also show hints that they've seen a particle weighing about 124 or 125 GeV that could be the Higgs boson.
Though it's too soon for physicists to declare a definite discovery of the Higgs, experts said the findings so far represent an important step forward. Here's what some leading physicists have to say about today's announcement:
"This is not the end, but the beginning. The Higgs was just the last missing piece of the Standard Model of particles. But that theory is ugly; it is a theory only a mother can love. The real breakthrough is when the LHC discovers dark matter or strings. That would be spectacular. So there is a whole new universe beyond the Higgs."
—Michio Kaku, City College of New York theoretical physicist, told LiveScience
"Both experiments showed a very impressive turnaround in processing the data and very good understanding of their detectors. It is unprecedented to have full data samples from such complex experiments to be analyzed in a fairly sophisticated way in just one month since the end of the proton-proton run.
—Greg Landsberg, Brown University physicist, CMS physics coordinator at the LHC, told LiveScience
"ATLAS data, just like CMS ones contain interesting excesses. Whether what we both see is a real signal or just a funny game [that] statistics often play with us, remains to be seen.
"This looks to me like a lot more than 'intriguing hints': it's about what you would expect if a Higgs was there at 125 GeV, highly unlikely to see if there is no Higgs there."
— Peter Woit, Columbia University mathematician, from his blog "Not Even Wrong"
"Essentials: what we're seeing is pretty consistent with the existence of a Higgs boson around 123-126 GeV. The data aren't nearly conclusive enough to say that it's definitely there. But the LHC is purring along, and a year from now we'll know a lot more.
"It's like rushing to the tree on Christmas morning, ripping open a giant box, and finding a small note that says 'Santa is on his way! Hang in there!' The LHC is real and Santa is not, but you know what I mean."
—Sean Carroll, California Institute of Technology physicist, from his blog "Cosmic Variance," hosted by Discover Magazine
"All in all, it's a definite maybe. Putting the results together in the way only a frequentist can the result is a 2.4 sigma detection. In other words, nothing any serious scientist would call convincing."
—Pete Coles, Cardiff University theoretical astrophysicist, from his blog "In The Dark"
"Two independent (and highly competitive) research teams, involving thousands of scientists, using each of these detectors have seen moderately convincing evidence that the elusive Higgs particle has been created in some of the proton–proton collisions.
"This is a challenging experiment as the detectors can't see the Higgs particle directly — it is a short-lived particle that quickly falls apart (decays) — but, rather, they infer its presence by seeing its decay products."
—Brian Greene, Columbia University physicist, on the "World Science Festival" blog
"The proof will come in the next year. The spectacularly successful LHC accelerator (which the Europeans built when the U.S. killed the superconducting super collider in Texas) will produce 4 times more Higgs particles in the next year. The significance of the hints reported today could turn into proof beyond a doubt come next October..."
Meteor Crater Helps Unlock Planetary History
|11:20:50 PM, Thursday, December 08, 2011|
"The Barringer meteorite crater — known popularly as "Meteor Crater" — near Winslow, Ariz., was formed some 50,000 years ago in the flat-lying sedimentary rocks of the Southern Colorado Plateau in Arizona. Now, scientists are using the crater to study mysteries near and far.
This out-of-the-blue geological feature is considered a prime example of a young, well-preserved and well-documented simple impact crater.
That means it represents one of the most common morphological features on planetary surfaces, both on Earth, and elsewhere in our solar system. Scientists are using this crater to probe not just our own planetary history, but the mechanics of space rock impacts throughout the universe.
Meteor Crater is one of very few impact sites on our planet where the geologic details of crater excavation and ejecta emplacement are preserved. While the outline of most simple craters is circular, the shape of Arizona's Meteor Crater strongly deviates from a circle and resembles a quadrangle.
"Hole Earth" catalog
The bowl-shape crater is surprisingly well preserved by terrestrial standards. That makes it a "kiss and tell" terrestrial feature that is being plumbed by researchers far and wide.
The crater is roughly 0.75 miles (1.2 kilometers) in diameter. That giant hole in the ground sports a rim that rises up to 196 feet (60 meters) above the surrounding landscape. The crater floor falls to a depth of 590 feet (180 meters).
The upper crater walls have average slopes of 40 to 50 degrees, although they also include vertical to near-vertical cliffs. The rock ejected from the crater forms a debris blanket that slopes away from the crater rim out to a distance of 0.6 miles (1 km).
This impact crater is viewed as a treasured scientific site, not only here on Earth but in shaping future moon and Mars exploration plans. It has become a training ground for astronauts and robot hardware as well as a learning lab for planetary geologists who are investigating impact cratered terrains on other planets.
Indeed, it's a "hole Earth catalog" of processes that keeps on giving.
Honing exploration skills
When a cosmic interloper slammed into Earth tens of thousands of years ago, more than 175 million metric tons of rock were excavated and deposited on the crater rim and the surrounding terrain in a matter of a few seconds, said David Kring, a senior staff scientist and geologist at the Lunar and Planetary Institute in Houston.
Kring has been engaged in studies of the crater for decades. He uses the site as a teaching tool for students, as well as a locale for honing the exploration skills to lunge beyond Earth.
"Those rocks and the processes they record remain the focus of our studies next year," Kring told SPACE.com. "At the same time, we will conduct training activities that are designed to enhance the success of exploration of the moon and planetary surfaces throughout the solar system."
There are a lot of activities at the crater, Kring said. He made two trips there in October alone, he added..."
Halliburton 'Destroyed' Gulf of Mexico Spill Evidence
|2:05:22 AM, Thursday, December 08, 2011|
"(BBC) Oil giant BP has accused oilfields services firm Halliburton of destroying damaging evidence relating to last year's oil well blast in the Gulf of Mexico in which 11 people were killed.
At a hearing in a New Orleans' court, BP said Halliburton had "intentionally" destroyed test results on its cement product used at the Macondo well.
Halliburton denied this, saying the claims were "without merit".
Cement was a key factor in causing America's worst offshore oil spill.
The blast that followed at the Deepwater Horizon oil rig in April led to the release of 780m litres (206m gallons) of crude oil in the Gulf of Mexico.
BP and Halliburton are locked in a legal battle ahead of a trial on damages early next year.
Through their lawyers, the former partners in the venture are seeking maximum pre-trial advantage, the BBC's Steve Kingstone in Washington reports.
BP made its accusations in a court filing on Monday.
It said that after reviewing the test results, Halliburton "destroyed records of the testing as well as the physical cement samples used in the testing".
The company also said that Halliburton had failed to produce computer modelling evidence, which showed how the cement performed.
In its motion, BP asked for sanctions against Halliburton, claiming that the company's cement slurry was "unstable".
In its turn, Halliburton rejected the claim, saying it would contest it in court.
The world's second-largest oilfields services provider also accused BP of fraud and defamation in the investigation.
The contractor alleged that BP had ordered last-minute changes to the cement.
The two companies traded allegations ahead of the trial over the spill disaster in February.
The trial is expected to apportion blame and quantify damages arising from the spill.
There will also be other phases of the case over clean-up costs and other claims."
500 Million-Year-Old Super Predator Had Remarkable Vision
|1:20:00 AM, Thursday, December 08, 2011|
"South Australian Museum and University of Adelaide scientists working on fossils from Kangaroo Island, South Australia, have found eyes belonging to a giant 500 million-year-old marine predator that sat at the top of the earth's first food chain.
This important discovery will be accompanied by an artist's impression of the super predator on the front cover of the 8 December 2011 issue of Nature.
Palaeontologists have discovered exceptionally preserved fossil eyes of the top predator in the Cambrian ocean from over 500 million years ago: the fearsome metre-long Anomalocaris.
The scientists show that the world's first apex predator had highly acute vision, rivalling or exceeding that of most living insects and crustaceans.
The international team behind this discovery includes two Adelaide researchers, Dr Michael Lee (SA Museum and University of Adelaide) and Dr Jim Jago (SA Museum and UniSA), and was led by Dr John Paterson (University of New England).
The World's Oldest Apex Predator
Anomalocaris is the stuff of nightmares and sci-fi movies. It is considered to be at the top of the earliest food chains because of its large body size, formidable grasping claws at the front of its head and a circular mouth with razor-sharp serrations.
Supporting evidence of this predator's dominance includes damage to contemporaneous trilobites, and even its fossilised poo (or coprolites) containing the remains of its prey.
The discovery of its stalked eyes - showing astonishing details of its optical design - from a 515 million-year-old deposit on Kangaroo Island in South Australia now confirms it had superb vision to support its predatory lifestyle.
All The Better To See You With…
The fossils represent compound eyes - the multi-faceted variety seen in arthropods such as flies, crabs and kin - and are amongst the largest to have ever existed, with each eye up to 3 cm in length and containing over 16,000 lenses.
The number of lenses and other aspects of their optical design suggest that Anomalocaris would have seen its world with exceptional clarity whilst hunting in well-lit waters. Only a few arthropods, such as modern predatory dragonflies, have similar resolution.
The existence of highly sophisticated, visual hunters within Cambrian communities would have accelerated the predator-prey 'arms race' that began during this important phase in early animal evolution over half a billion years ago.
The discovery of powerful compound eyes in Anomalocaris confirms it is a close relative of arthropods, and has other far-reaching evolutionary implications. It demonstrates that this particular type of visual organ appeared and was elaborated upon very early during arthropod evolution, originating before other characteristic anatomical structures of this group, such as a hardened exoskeleton and walking legs."
NASA Vows $8.8 bn Space Telescope on Track for 2018
|12:43:04 AM, Thursday, December 08, 2011|
"After a series of delays and billions spent over budget, the potent James Webb Space Telescope is on track to launch in 2018 at a total project cost of $8.8 billion, NASA vowed on Tuesday.
The project, which aims to build the world's most powerful telescope, 100 times more sensitive than the Hubble space telescope, has been riddled by poor management and cost overruns.
Though a Congressional subcommittee threatened to ax the project altogether earlier this year as lawmakers grappled with how to reduce a more than $15 trillion national deficit, Congress has since agreed to fully fund it at the level NASA requested.
But NASA's new JWST program manager Rick Howard who came on board last year, still faced an acrimonious grilling on Tuesday from lawmakers in the House Committee on Science, Space and Technology.
Committee chair Ralph Hall described the project as "another case study of NASA mismanagement" and said the NASA reshuffle was "the agency's last opportunity to hold this program together."
"We have changed the management, the priority and the approach," Howard told the committee hearing. "We can deliver JWST within costs."
In February, NASA inspector general Paul Martin told lawmakers that the telescope had gone way over its initial budget of $3.5 billion and was likely to come in at around $6.5 billion.
NASA has also pushed back its scheduled launch -- initially set for 2013 -- numerous times. It is now set for October 2018.
Garth Illingworth, an astronomer and professor at University of California, Santa Cruz, was part of an independent comprehensive review panel (ICRP) that reviewed NASA's work on the JWST and issued a report last year.
"I feel that NASA has actually done a very good job on this replan. They have developed a plan that is I would say uniquely conservative for NASA in the level of reserves and the approach that they are taking," Illingworth told lawmakers.
"They realized that they had seriously flawed management before the time of the ICRP and are trying to rectify it, as Rick said," he added.
"I am highly encouraged by what I have seen over the last six to nine months on this program."
Republican lawmaker James Sensenbrenner asked how the US space agency would carry out any repairs on the telescope, recalling how the orbiting Hubble needed numerous service missions by the space shuttle program, which retired this year.
"We don't have the shuttle anymore. What is going to happen if we need to repair the James Webb Space Telescope or if we find out some the parts were not properly done?" he asked.
Howard responded that NASA was already in the process of testing and checking the mirrors at operating temperature, and noted that the telescope's path would take it beyond where the world's spacecraft have the capacity to carry humans, anyway.
"We know that we only have one chance to get this right," Howard said.
"It is not going to be in orbit around the Earth, it is going to a distance four times further away than the moon. So we are taking every step we can to mitigate the risks to make sure that we do have a system that can work."
"You've just increased my skepticism given the history, and I have been on this committee longer than anybody else," Sensenbrenner answered.
"I can see another money pit coming up.""
Silicon Rival MoS2 Promises Small, Low-Energy Chips
|7:43:25 PM, Monday, December 05, 2011|
"The first computer chip made out of a substance described as a "promising" alternative to silicon has been tested by researchers.
The Switzerland-based team used molybdenite disulfide (MoS2) - a dark-coloured, naturally occurring mineral.
The group said the substance could be used in thinner layers than silicon, which is currently the most commonly used component in electronics.
It said MoS2 could make smaller, more flexible chips that used less energy.
The substance is currently used as an ingredient in engine lubricants, ski waxes and as a strengthening agent for plastics.
Prof Andras Kis, the director of the Laboratory of Nanoscale Electronics and Structures (LANES) in Lausanne, published details of the research in the latest edition of the ACS Nano journal.
He said the team chose to experiment with this semiconductor, rather than another material, in part because it was easily available.
"There is something like 19 million metric tonnes around," Prof Kis told the BBC.
"You can just go on some websites on the internet and buy a 1cm by 1cm crystal for around $100 [£64]."
To obtain a thin layer of the material to work with, Prof Kis's team put a strip of sticky plastic over the crystal, peeled it off and then attached the sliver to a support. The plastic was then peeled off to leave the very thin layer of MoS2 exposed.
Using this, the team built a prototype microchip circuit to which they attached up to six serial transistors allowing them to carry out simple logic operations.
Although the integrated circuit was basic, Prof Kis said it proved that more complex designs would be possible on thinner chips than could be produced with silicon.
"The problem with silicon is that you cannot make very thin things from it because it is very reactive," he said.
"The surface likes to oxidise - to bind with oxygen and hydrogen - and that makes its electrical properties degrade when you want to make a very thin film."
As a result the thinnest usable layers of silicon used in computer chips have been around two nanometres thick. MoS2, by contrast, can be used in layers just three atoms thick, allowing chips to be made at least three times smaller.
Stiff as steel
A key advantage of having a thinner material is that the transistors can also be shrunk in size.
"If you have a transistor that is very thin it will also automatically dissipate less power - so it spends less power. So in a nutshell it allows you to make electronics that spend less electrical energy," Prof Kis said.
MoS2 also has the advantage that it is as stiff as stainless steel, but is also capable of being flexible.
"It can be bent to large angles and can be stretched a lot," said Prof Kis.
"If you take a sheet of molybdenite you can stretch it so that it increases its length by 10% - that is a lot in this context.
"If you did the same with silicon it would break like glass."
Astronomers Discover Biggest Black Holes Ever
|5:40:59 PM, Monday, December 05, 2011|
"University of California, Berkeley, astronomers have discovered the largest black holes to date two monsters with masses equivalent to 10 billion suns that are threatening to consume anything, even light, within a region five times the size of our solar system.
These black holes are at the centers of two galaxies more than 300 million light years from Earth, and may be the dark remnants of some of the very bright galaxies, called quasars, that populated the early universe.
"In the early universe, there were lots of quasars or active galactic nuclei, and some were expected to be powered by black holes as big as 10 billion solar masses or more," said Chung-Pei Ma, UC Berkeley professor of astronomy. "These two new supermassive black holes are similar in mass to young quasars, and may be the missing link between quasars and the supermassive black holes we see today."
Black holes are dense concentrations of matter that produce such strong gravitational fields that even light cannot escape. While exploding stars, called supernovas, can leave behind black holes the mass of a single star like the sun, supermassive black holes have presumably grown from the merger of other black holes or by capturing huge numbers of stars and massive amounts of gas.
"These black holes may shed light on how black holes and their surrounding galaxies have nurtured each other since the early universe," said UC Berkeley graduate student Nicholas McConnell, first author of a paper on the discovery being published in the Dec. 8 issue of the British journal Nature by McConnell, Ma and their colleagues at the university of Toronto, Texas and Michigan, as well as by the National Optical Astronomy Observatory in Arizona.
To date, approximately 63 supermassive black holes have been found sitting in the cores of nearby galaxies. The largest for more than three decades was a 6.3 billion solar mass black hole in the center of the nearby galaxy M87.
One of the newly discovered black holes is 9.7 billion solar masses and located in the elliptical galaxy NGC 3842, the brightest galaxy in the Leo cluster of galaxies, 320 million light years away in the direction of the constellation Leo. The second is as large or larger and sits in the elliptical galaxy NGC 4889, the brightest galaxy in the Coma cluster about 336 million light years from Earth in the direction of the constellation Coma Berenices.
According to McConnell, these black holes have an event horizon – the "abandon all hope" edge from which not even light can escape – that is 200 times the orbit of Earth, or five times the orbit of Pluto. Beyond the event horizon, each black hole has a gravitational influence that would extend over a sphere 4,000 light years across.
"For comparison, these black holes are 2,500 times as massive as the black hole at the center of the Milky Way Galaxy, whose event horizon is one fifth the orbit of Mercury," McConnell said..."
Kepler 22-b: Earth-Like Planet Confirmed
|5:32:30 PM, Monday, December 05, 2011|
"Astronomers have confirmed the existence of an Earth-like planet in the "habitable zone" around a star not unlike our own.
The planet, Kepler 22-b, lies about 600 light-years away and is about 2.4 times the size of Earth, and has a temperature of about 22C.
It is the closest confirmed planet yet to one like ours - an "Earth 2.0".
However, the team does not yet know if Kepler 22-b is made mostly of rock, gas or liquid.
During the conference at which the result was announced, the Kepler team said that it had spotted some 1,094 new candidate planets.
The Kepler space telescope was designed to look at a fixed swathe of the night sky, staring intently at about 150,000 stars. The telescope is sensitive enough to see when a planet passes in front of its host star, dimming the star's light by a minuscule amount.
Kepler identifies these slight changes in starlight as candidate planets, which are then confirmed by further observations by Kepler and other telescopes in orbit and on Earth.
Kepler 22-b was one of 54 candidates reported by the Kepler team in February, and is just the first to be formally confirmed using other telescopes.
More of these "Earth 2.0" candidates are likely to be confirmed in the near future, though a redefinition of the habitable zone's boundaries has brought that number down to 48.
Kepler 22-b lies at a distance from its sun about 15% less than the distance from the Earth to the Sun, and its year takes about 290 days. However, its sun puts out about 25% less light, keeping the planet at its balmy temperature that would support the existence of liquid water.
The Kepler team had to wait for three passes of the planet before upping its status from "candidate" to "confirmed".
"Fortune smiled upon us with the detection of this planet," said William Borucki, Kepler principal investigator at Nasa's Ames Research Center.
"The first transit was captured just three days after we declared the spacecraft operationally ready. We witnessed the defining third transit over the 2010 holiday season."
The results were announced at the Kepler telescope's first science conference, alongside the staggering number of new candidate planets. The total number of candidates spotted by the telescope is now 2,326 - of which 207 are approximately Earth-sized.
In total, the results suggest that planets ranging from Earth-sized to about four times Earth's size - so-called "super-Earths" - may be more common than previously thought."
Your Brain Knows a Lot More Than You Realize
|1:12:18 AM, Wednesday, November 30, 2011|
"Only a tiny fraction of the brain is dedicated to conscious behavior. The rest works feverishly behind the scenes regulating everything from breathing to mate selection. In fact, neuroscientist David Eagleman of Baylor College of Medicine argues that the unconscious workings of the brain are so crucial to everyday functioning that their influence often trumps conscious thought. To prove it, he explores little-known historical episodes, the latest psychological research, and enduring medical mysteries, revealing the bizarre and often inexplicable mechanisms underlying daily life.
Eagleman’s theory is epitomized by the deathbed confession of the 19th-century mathematician James Clerk Maxwell, who developed fundamental equations unifying electricity and magnetism. Maxwell declared that “something within him” had made the discoveries; he actually had no idea how he’d achieved his great insights. It is easy to take credit after an idea strikes you, but in fact, neurons in your brain secretly perform an enormous amount of work before inspiration hits. The brain, Eagleman argues, runs its show incognito. Or, as Pink Floyd put it, “There’s someone in my head, but it’s not me.”
There is a looming chasm between what your brain knows and what your mind is capable of accessing. Consider the simple act of changing lanes while driving a car. Try this: Close your eyes, grip an imaginary steering wheel, and go through the motions of a lane change. Imagine that you are driving in the left lane and you would like to move over to the right lane. Before reading on, actually try it. I’ll give you 100 points if you can do it correctly.
It’s a fairly easy task, right? I’m guessing that you held the steering wheel straight, then banked it over to the right for a moment, and then straightened it out again. No problem.
Like almost everyone else, you got it completely wrong. The motion of turning the wheel rightward for a bit, then straightening it out again would steer you off the road: you just piloted a course from the left lane onto the sidewalk. The correct motion for changing lanes is banking the wheel to the right, then back through the center, and continuing to turn the wheel just as far to the left side, and only then straightening out. Don’t believe it? Verify it for yourself when you’re next in the car. It’s such a simple motor task that you have no problem accomplishing it in your daily driving. But when forced to access it consciously, you’re flummoxed.
The lane-changing example is one of a thousand. You are not consciously aware of the vast majority of your brain’s ongoing activities, nor would you want to be—it would interfere with the brain’s well-oiled processes. The best way to mess up your piano piece is to concentrate on your fingers; the best way to get out of breath is to think about your breathing; the best way to miss the golf ball is to analyze your swing. This wisdom is apparent even to children, and we find it immortalized in poems such as “The Puzzled Centipede”:
A centipede was happy quite,
Until a frog in fun
Said, “Pray tell which leg comes after which?”
This raised her mind to such a pitch,
She lay distracted in the ditch
Not knowing how to run.
The ability to remember motor acts like changing lanes is called procedural memory, and it is a type of implicit memory—meaning that your brain holds knowledge of something that your mind cannot explicitly access. Riding a bike, tying your shoes, typing on a keyboard, and steering your car into a parking space while speaking on your cell phone are examples of this. You execute these actions easily but without knowing the details of how you do it. You would be totally unable to describe the perfectly timed choreography with which your muscles contract and relax as you navigate around other people in a cafeteria while holding a tray, yet you have no trouble doing it. This is the gap between what your brain can do and what you can tap into consciously.
The concept of implicit memory has a rich, if little-known, tradition. By the early 1600s, René Descartes had already begun to suspect that although experience with the world is stored in memory, not all memory is accessible. The concept was rekindled in the late 1800s by the psychologist Hermann Ebbinghaus, who wrote that “most of these experiences remain concealed from consciousness and yet produce an effect which is significant and which authenticates their previous existence.”
To the extent that consciousness is useful, it is useful in small quantities, and for very particular kinds of tasks. It’s easy to understand why you would not want to be consciously aware of the intricacies of your muscle movement, but this can be less intuitive when applied to your perceptions, thoughts, and beliefs, which are also final products of the activity of billions of nerve cells. We turn to these now.
Chicken Sexers and Plane Spotters
When chicken hatchlings are born, large commercial hatcheries usually set about dividing them into males and females, and the practice of distinguishing gender is known as chick sexing. Sexing is necessary because the two genders receive different feeding programs: one for the females, which will eventually produce eggs, and another for the males, which are typically destined to be disposed of because of their uselessness in the commerce of producing eggs; only a few males are kept and fattened for meat. So the job of the chick sexer is to pick up each hatchling and quickly determine its sex in order to choose the correct bin to put it in. The problem is that the task is famously difficult: male and female chicks look exactly alike.
Well, almost exactly. The Japanese invented a method of sexing chicks known as vent sexing, by which experts could rapidly ascertain the sex of one-day-old hatchlings. Beginning in the 1930s, poultry breeders from around the world traveled to the Zen-Nippon Chick Sexing School in Japan to learn the technique.
The mystery was that no one could explain exactly how it was done. It was somehow based on very subtle visual cues, but the professional sexers could not say what those cues were. They would look at the chick’s rear (where the vent is) and simply seem to know the correct bin to throw it in.
And this is how the professionals taught the student sexers. The master would stand over the apprentice and watch. The student would pick up a chick, examine its rear, and toss it into one bin or the other. The master would give feedback: yes or no. After weeks on end of this activity, the student’s brain was trained to a masterful—albeit unconscious—level..."
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