Physicists Create a Working Transistor From a Single Atom
|7:29:42 PM, Tuesday, February 21, 2012|
“(NYT) Australian and American physicists have built a working transistor from a single phosphorus atom embedded in a silicon crystal.
The group of physicists, based at theUniversity of New South Wales andPurdue University, said they had laid the groundwork for a futuristic quantum computer that might one day function in a nanoscale world and would be orders of magnitude smaller and quicker than today’s silicon-based machines.
In contrast to conventional computers that are based on transistors with distinct “on” and “off” or “1” and “0” states, quantum computers are built from devices called qubits that exploit the quirky properties of quantum mechanics. Unlike a transistor, a qubit can represent a multiplicity of values simultaneously.
That might make it possible to factor large numbers more quickly than with conventional machines, thereby undermining modern data-scrambling systems that are the basis of electronic commerce and data privacy. Quantum computers might also make it possible to simulate molecular structures with great speed, an advance that holds promise for designing new drugs and other materials.
“Their approach is extremely powerful,” said Andreas Heinrich, a physicist at I.B.M. “This is at least a 10-year effort to make very tiny electrical wires and combine them with the placement of a phosphorus atom exactly where they want them.”
Dr. Heinrich said the research was a significant step toward making a functioning quantum computing system. However, whether quantum computing will ever be harnessed for useful tasks remains uncertain, and the researchers noted that their work demonstrated the fundamental limits that today’s computers would be able to shrink to.
“It shows that Moore’s Law can be scaled toward atomic scales in silicon,” said Gerhard Klimeck, a professor of electrical and computer engineering at Purdue and leader of the project there. Moore’s Law refers to technology improvements by the semiconductor industry that have doubled the number of transistors on a silicon chip roughly every 18 months for the past half-century. That has led to accelerating increases in performance and declining prices. “The technologies for classical computing can survive to the atomic scale,” Dr. Klimeck said.
Demonstrations of single-atom transistors date from 2002, but the researchers from Purdue and New South Wales said they had made advances on two fronts: in the precision with which they placed the Lilliputian switch; and in the use of industry-standard techniques to build the circuitry, making it possible to read and write information from the tiniest conceivable switch.
The results were reported on Sunday in the journal Nature Nanotechnology.
Until now, single-atom transistors have been created on a hit-or-miss basis, the scientists said.“But this device is perfect,” Michelle Simmons, a group leader and director of the ARC Centre for Quantum Computation and Communication at the University of New South Wales, said in a statement. “This is the first time anyone has shown control of a single atom in a substrate with this level of precise accuracy.”In the 1950s, the physicist Richard P. Feynman predicted a world where there would be “plenty of room at the bottom,” opening new vistas into engineering disciplines that would use individual atoms as bricks and mortar in fields as diverse as computing and biology.
Since then, computer designers have moved ever closer to the smallest components that are possible to fabricate. Now, with the publication of the New South Wales and Purdue research, the scientists said they had shown the fundamental limits to which the components of silicon-based computers would be able to shrink in the future. Currently, the smallest dimension in state-of-the-art computers made by Intel is 22 nanometers — less than 100 atoms in diameter.
If the semiconductor industry remains on its current pace, it might be possible to reach that limit within two decades, Dr. Klimeck noted.
The scientists placed the single phosphorus atom using a device known as a scanning tunneling microscope. They used it to essentially scrape trenches and a small cavity on a surface of silicon covered with a layer of hydrogen atoms. Phosphine gas was then used to deposit a phosphorus atom at a precise location, which was then encased in further layers of silicon atoms.
While offering astounding precision for research, these microscopes are not currently applicable as manufacturing tools to make chips that contain billions or even trillions of transistors. Moreover, the devices now operate at very low temperatures…”
Russians Revive Ice Age Flower from Frozen Siberian Burrow
|2:52:29 PM, Tuesday, February 21, 2012|
“It was an Ice Age squirrel's treasure chamber, a burrow containing fruit and seeds that had been stuck in the Siberian permafrost for over 30,000 years. From the fruit tissues, a team of Russian scientists managed to resurrect an entire plant in a pioneering experiment that paves the way for the revival of other species.
The Silene stenophylla is the oldest plant ever to be regenerated, the researchers said, and it is fertile, producing white flowers and viable seeds.
The experiment proves that permafrost serves as a natural depository for ancient life forms, said the Russian researchers, who published their findings in Tuesday's issue of Proceedings of the National Academy of Sciences of the United States.
"We consider it essential to continue permafrost studies in search of an ancient genetic pool, that of pre-existing life, which hypothetically has long since vanished from the earth's surface," the scientists said in the article.
Canadian researchers had earlier regenerated some significantly younger plants from seeds found in burrows.
Svetlana Yashina of the Institute of Cell Biophysics of the Russian Academy Of Sciences, who led the regeneration effort, said the revived plant looked very similar to its modern version, which still grows in the same area in northeastern Siberia.
"It's a very viable plant, and it adapts really well," she told The Associated Press in a telephone interview from the Russian town of Pushchino where her lab is located.
She voiced hope the team could continue its work and regenerate more plant species.The Russian research team recovered the fruit after investigating dozens of fossil burrows hidden in ice deposits on the right bank of the lower Kolyma River in northeastern Siberia, the sediments dating back 30,000-32,000 years.
The sediments were firmly cemented together and often totally filled with ice, making any water infiltration impossible - creating a natural freezing chamber fully isolated from the surface.
"The squirrels dug the frozen ground to build their burrows, which are about the size of a soccer ball, putting in hay first and then animal fur for a perfect storage chamber," said Stanislav Gubin, one of the authors of the study, who spent years rummaging through the area for squirrel burrows. "It's a natural cryobank."
The burrows were located 125 feet (38 meters) below the present surface in layers containing bones of large mammals, such as mammoth, wooly rhinoceros, bison, horse and deer.
Gubin said the study has demonstrated that tissue can survive ice conservation for tens of thousands of years, opening the way to the possible resurrection of Ice Age mammals."If we are lucky, we can find some frozen squirrel tissue," Gubin told the AP. "And this path could lead us all the way to mammoth."
Japanese scientists are already searching in the same area for mammoth remains, but Gubin voiced hope that the Russians will be the first to find some frozen animal tissue that could be used for regeneration.
"It's our land, we will try to get them first," he said.”
Vega Rocket Set for Maiden Voyage
|12:57:35 AM, Friday, February 17, 2012|
“(BBC UK) Europe's Vega rocket is finally set to make its maiden flight on Monday.
The 30m-tall vehicle, first conceived in the 1990s, will launch on what is termed a qualification flight from the Kourou spaceport in French Guiana.
It will carry nine satellites into orbit but the object of the mission is really to prove the rocket's systems all work as designed.
Vega has been developed to assure European access to space for payload classes weighing less than 2.5 tonnes.
At the moment, these smaller satellites tend to ride converted Russian ICBMs to get into orbit and they can sometimes wait many months to get a launch slot.
Vega should allow European operators to have more control over the schedules of their space projects. It also means that the value of what it is an immensely high-tech enterprise will return to the European economy, not to foreign industry.
"Vega gives Europe the ability to launch small satellites," said Jean-Jacques Dordain, director general of the European Space Agency (Esa).
"New technologies - and in particular the miniaturisation of technologies - are making for more and more small satellites. This is particularly true of scientific satellites such as Earth observation spacecraft. So, Vega has a fantastic perspective in front of it provided we succeed," he told me.
The launch in French Guiana is scheduled to take place between 10:00 and 12:00 GMT.
There will inevitably be a degree of nervousness in launch control at Kourou come lift-off time. According to statistics compiled by the Ascend aerospace consultancy, 58% (11 out of 19) of new rockets since 1990 have experienced a major anomaly on their first flight.
It is for this reason that the satellites carried on Vega's maiden voyage have all been given a "free ride...""
Athens Protest Photos
|12:53:04 AM, Friday, February 17, 2012|
-- 12 February 2012
Inspired by Gecko Feet, Scientists Invent Super-Adhesive Material
|12:44:33 AM, Friday, February 17, 2012|
“For years, biologists have been amazed by the power of gecko feet, which let these 5-ounce lizards produce an adhesive force roughly equivalent to carrying nine pounds up a wall without slipping. Now, a team of polymer scientists and a biologist at the University of Massachusetts Amherst have discovered exactly how the gecko does it, leading them to invent "Geckskin," a device that can hold 700 pounds on a smooth wall.
Doctoral candidate Michael Bartlett in Alfred Crosby's polymer science and engineering lab at UMass Amherst is the lead author of their article describing the discovery in the current online issue of Advanced Materials. The group includes biologist Duncan Irschick, a functional morphologist who has studied the gecko's climbing and clinging abilities for over 20 years. Geckos are equally at home on vertical, slanted, even backward-tilting surfaces.
"Amazingly, gecko feet can be applied and disengaged with ease, and with no sticky residue remaining on the surface," Irschick says. These properties, high-capacity, reversibility and dry adhesion offer a tantalizing possibility for synthetic materials that can easily attach and detach heavy everyday objects such as televisions or computers to walls, as well as medical and industrial applications, among others, he and Crosby say.
This combination of properties at these scales has never been achieved before, the authors point out. Crosby says, "Our Geckskin device is about 16 inches square, about the size of an index card, and can hold a maximum force of about 700 pounds while adhering to a smooth surface such as glass."
Beyond its impressive sticking ability, the device can be released with negligible effort and reused many times with no loss of effectiveness. For example, it can be used to stick a 42-inch television to a wall, released with a gentle tug and restuck to another surface as many times as needed, leaving no residue.
Previous efforts to synthesize the tremendous adhesive power of gecko feet and pads were based on the qualities of microscopic hairs on their toes called setae, but efforts to translate them to larger scales were unsuccessful, in part because the complexity of the entire gecko foot was not taken into account. As Irschick explains, a gecko's foot has several interacting elements, including tendons, bones and skin, that work together to produce easily reversible adhesion.
Now he, Bartlett, Crosby and the rest of the UMass Amherst team have unlocked the simple yet elegant secret of how it's done, to create a device that can handle excessively large weights. Geckskin and its supporting theory demonstrate that setae are not required for gecko-like performance, Crosby points out. "It's a concept that has not been considered in other design strategies and one that may open up new research avenues in gecko-like adhesion in the future."
The key innovation by Bartlett and colleagues was to create an integrated adhesive with a soft pad woven into a stiff fabric, which allows the pad to "drape" over a surface to maximize contact. Further, as in natural gecko feet, the skin is woven into a synthetic "tendon," yielding a design that plays a key role in maintaining stiffness and rotational freedom, the researchers explain.
Importantly, the Geckskin's adhesive pad uses simple everyday materials such as polydimethylsiloxane (PDMS), which holds promise for developing an inexpensive, strong and durable dry adhesive.
The UMass Amherst researchers are continuing to improve their Geckskin design by drawing on lessons from the evolution of gecko feet, which show remarkable variation in anatomy. "Our design for Geckskin shows the true integrative power of evolution for inspiring synthetic design that can ultimately aid humans in many ways," says Irschick.”
Restoring Vintage Vehicles with New Modern Drivetrain and Mechanics
|4:08:54 AM, Thursday, February 16, 2012|
Two Earth-Size Planets Born of Battered 'Jupiter'?
|9:05:43 PM, Sunday, February 12, 2012|
“Two Earth-size worlds orbiting perilously close to their dying star may be the fractured remnants of a Jupiter-like gas giant, a new study suggests.
The planetary pair—discovered using NASA's Kepler space telescope andannounced in the journal Nature last December—are just under Earth's radius. Both orbit a so-called subdwarf B star dubbed KIC 05807616, which sits about 4,000 light-years away.
When sunlike stars run out of hydrogen fuel, they enter a red giant phase, in which their gas envelopes can swell to several hundred times their original size.
Eventually a red giant's gas envelope will slough off entirely, leaving behind a dense stellar corpse known as a white dwarf. Sometimes, however, a red giant will lose its gas envelope prematurely to form a subdwarf B star, like KIC 05807616.
The scientists who discovered the roughly Earth-size planets in Kepler's data had proposed that both worlds were once gas giants, like Jupiter or Saturn, that had been pulled nearer to their star when it ballooned during the red giant phase.
Plowing through the dying star's swollen atmosphere burned away the planets' liquids and gases, that team suggested, leaving behind the two rocky pits that Kepler sees as Earth-size worlds.
But a new study, by astrophysicists Ealeal Bear and Noam Soker of the Israel Institute of Technology, offers an alternate explanation.
It's possible that both worlds actually come from a single gas giant planet at least five times more massive than Jupiter that was stripped naked by the dying star, the researchers say.
The lone planet's rocky core was then ripped apart by the star's gravity into several Earth-size chunks.
Planets' Resonance a Problem?
Bear and Soker developed the new theory because of their concerns over the Earth-size planets' orbital resonance, a gravitational interaction that involves two objects orbiting a third body in a predictable pattern.
The Kepler planets have an orbital resonance that's almost exactly 3:2—that is, one of the planets completes three orbits around the star in the time it takes the other planet to complete two orbits.
The planets' discoverers had suggested at the time that the worlds had already been in a 3:2 resonance before they were engulfed by their star's envelope of hot gas.
But Bear and Soker argue that such a scenario is improbable, because the act of being swallowed by the bloated star would likely have destroyed any existing resonance between the planets.
The engulfment process "is a violent one that proceeds rapidly," Soker said.
According to the new study, the lone giant planet would have also played a major role in the evolution of its parent star.
As it was consumed, the planet deposited energy into the stellar envelope, which helped strip away the star's gas layers, leaving behind a naked stellar core.
In this scenario, at least two of the pieces of the gas giant's core survived and continued to orbit the star, while the others may have fallen into the star or been ejected out of the system altogether…”
'Vampire' Parasite Found Entombed in Amber
|8:54:37 PM, Sunday, February 12, 2012|
“The first known fossil of a rare bloodsucker called the bat fly has been found in 20-million-year-old amber. What's more, the ancient bug was host to batmalaria, an even rarer find, according to a new study.
George Poinar, Jr., an expert on insects preserved in amber at Oregon State University, discovered the bat fly in a mine in the Dominican Republic.
Although the newfound genus is extinct, bat flies still exist today, feeding exclusively on bats' blood. Some of the insects have even become specialized to live on specific bat species.
While there are hundreds of known bat fly species, most are poorly understood.
"First of all, it's hard to catch bats," Poinar said, "and [combing the bats for parasites is] like looking for fleas on mice. You don't see them."
Before Poinar discovered the amber containing the fossilized fly, nobody knew how recently the bugs had evolved to prey on bats alone. But even the 20-million-year-old fossil shows interesting bat-specific modifications, he said.
"The front legs are flattened, and they're held up between the head. These flattened legs kind of act as a plowshare, so as they are plowing along, they kind of part the hair of the bats so the [fly's] body can move all over the bat."
When Poinar examined the ancient fly under a microscope, he also found a new species of bat malaria, a parasitic disease so rare that perhaps five or six scientific papers have discussed it to date, he said.
The fossilized fly shows that bat malaria existed and was carried by bat flies as far back as 20 million years ago.
No Ancient Bats to Be Resurrected
Bat flies rarely leave their hosts, but they do roam in order to mate. This specimen was likely on the hunt for a partner when it got trapped in tree resin, which then fossilized to become amber.
Before he became a specialist in ancient diseases inside equally ancient bugs, Poinar had worked on attempting to extract DNA from insects trapped in amber—work which author Michael Crichton has acknowledged as part of his inspiration for Jurassic Park.
But no ancient bats will be reconstructed from this specimen, even if it were possible.
"As far as I'm concerned," Poinar said, "this specimen is so rare that we wouldn't want to attempt to try it."”
Higgs Signal Gains Strength
|3:39:37 PM, Tuesday, February 07, 2012|
"Today the two main experiments at the Large Hadron Collider (LHC), the world’s most powerful particle accelerator, submitted the results of their latest analyses. The new papers boost the case for December’s announcement of a possible Higgs signal, but let’s not get too excited.
First, there are no new data in there — the LHC stopped colliding protons back in November, and these latest results just rehash that earlier run. In the case of the Compact Muon Solenoid (CMS), physicists have been able to look at another possible kind of Higgs decay, and that allows them to boost their Higgs signal from 2.5 sigma to 3.1 sigma. Taken together with data from the other detector, ATLAS, the overall Higgs signal now unofficially stands at about 4.3 sigma. In other words, if statistics are to be believed, then this signal has about a 99.996% chance of being correct.
It all sounds very convincing, but keep your hat on, because the fact is that statistical coincidences happen every day. Over at Cosmic Variance, Sean Carroll points out that there is a 3.8-sigma signal in the Super Bowl coin toss. Does that mean that they’ve discovered a super-partner to the bowl? No. (If you don’t get that joke, don’t worry, it was written only as punishment for those who would).
After the LHC starts this spring, we’ll be much closer to knowing what’s actually going on. Right now, scientists are meeting in Chamonix, France to decide at what power to run the collider this coming year. The latest rumours are that the machine will push from 7 to 8 tetraelectronvolts, and it will also increase its luminosity (the number of collisions per pass).
For a little context more about what’s going on, check out this video of my trip back in November:"
'Lost World' reached: 20 million yr old Antarctic lake 'drilled'
|10:28:36 PM, Monday, February 06, 2012|
“After 30 years spent drilling through a four-kilometer-thick ice crust, researchers have finally broken through to a unique subglacial lake. Scientists are set to reveal its 20-million-year-old secrets, and imitate a quest to discover ET life.
The Vostok project breathes an air of mystery and operates at the frontiers of human knowledge. The lake is one of the major discoveries in modern geography; drilling operations at such depths are unprecedented; never before has a geological project required such subtle technologies.
The main inspiration for the project – the Russian scientist who posited the lake’s existence – died just six months before the moment of contact with the lake’s surface. Now, the whole world is looking to Lake Vostok for crucial data which might help to predict climate change.
“Yesterday [on Sunday] our scientists at the Vostok polar station in the Antarctic completed drilling at depths of 3,768 meters and reached the surface of the subglacial lake,” RIA Novosti reported, quoting an unnamed Russian scientist.
Meanwhile, Itar-Tass news agency says the scientists still have a few meters to go.
Lake Vostok is a unique closed ecosystem hidden under some four kilometers of ice. Its water has been isolated from the atmosphere – and therefore from any contact with the outside world – since before man existed. The key question for scientists is, could the lake harbour life?
If some primitive bacteria or even more complex life-forms are found to have survived the isolation, it could offer an earth-shattering insight into our planet’s past.
But if the lake proves to be a closed system devoid of any life, it would offer scientists the chance to test their theories on how to search for extra-terrestrial life on future space trips. Conditions in the lake are often described as “alien," as they resemble lakes on Jupiter's moon Europa.
When drilling work began around Vostok Station in the Antarctic in the 1970s, scientists had no idea a mysterious lake lay under the massive ice sheet. It was only in 1996 that Russian specialists, supported by their British counterparts, discovered with sonar and satellite imaging what later proved to be one of the world’s largest freshwater reservoirs. In size, Lake Vostok matches Lake Ontario…”
-- Oops! Apparently they did reach it this last Sunday; that article is a few days old.
Russians 'Close' to Drilling Into Antarctica's Lake Vostok
|10:17:26 PM, Monday, February 06, 2012|
“(National Geographic News) Russian scientists are "very, very close" to reaching the surface of afreshwater lake 2.3 miles (3,768) meters under the Antarctic ice, news reports say. It would be the first time anyone has penetrated a subglacial lake on the frozen continent.
The Russian news agency RIA Novosti reported today that the team has in fact breached the Lake Vostok.
However Mahlon C. Kennicutt II, a professor of oceanography at Texas A&M University who leads several Antarctic research groups, said the report should be viewed with skepticism until an official announcement is made.
"I would be surprised if it was announced officially this quiet. Also, the one source [in the article] is unnamed, so it is hard to tell," he said.
Montana State ecologist John Priscu echoed Kennicutt's caution. "There are a lot of rumors going around about penetrating the lake, and we need the Russian program to make the official announcement," Priscu told National Geographic News via email.
Scientists have been drilling this shaft toward Lake Vostok—one of the world's largest freshwater lakes—since the lake was discovered in 1996. This field season, the Russian team has been drilling since the beginning of January.
As of February 6, the team was within 16 to 32 feet (5 to 10 meters) of reaching the under-ice lake, Priscu told BBC News.
With the Antarctic summer rapidly coming to a close, it's now or next year for the scientists, who are hoping to probe the Great Lake-size water body for the first time in 25 million years.
Once it happens, "it'll be a big splash, and I mean that metaphorically," Texas A&M's Kennicutt said.
Race to the Lake
Lake Vostok is the largest of more than 145 subglacial lakes—most of them several kilometers long—that have been discovered under the Antarctic ice in past decades.
These subglacial lakes may open a new window onto our planet, for example by offering new insights into climate history or revealing unknown life-forms.
Montana State's Priscu, for instance, has found evidence that microbes could live in the subglacial lake, deriving energy from minerals—"eating rocks," as he told National Geographic News in 2007.
Regardless of what they find, if the Russian team succeeds, "their efforts will transform the way we do science in Antarctica and provide us with an entirely new view of what exists under the vast Antarctic ice sheet," Priscu said Monday…”
The Naked and Famous – Punching In A Dream
|4:18:51 PM, Saturday, February 04, 2012|
Two New Moons Found Orbiting Jupiter
|1:17:38 PM, Saturday, February 04, 2012|
“(National Geographic News) Two new moons have been found orbiting Jupiter, bringing the Jovian family count up to 66 natural satellites, astronomers revealed this week.
Currently known as S/2011 J1 and S/2011 J2, the new moons were first identified in images acquired with the Magellan-Baade Telescope at the Las Campanas Observatory in Chile on September 27, 2011.
The objects are among the smallest moons yet discovered in the solar system, each measuring only about a kilometer (0.62 mile) wide.
Unlike Jupiter's four large Galilean moons, which are visible from Earth with even small backyard telescopes, both new moons are dim and very distant from the planet, taking about 580 and 726 days to complete their orbits.
Scientists had previously discovered new Jovian satellites in 2010, and astronomers think there may be more—lots more.
"The satellites are part of the outer retrograde swarm of objects around Jupiter," said Scott Sheppard, of the Department of Terrestrial Magnetism at the Carnegie Institute for Science in Washington, D.C., who reported the discovery.
Retrograde satellites are moons that orbit "backward"—in the opposite direction of a planet's axial rotation. Including the two new moons, the Jupiter swarm features 52 known retrograde satellites, which are all relatively tiny.
"It is likely there are about a hundred satellites of this size" in the swarm, Sheppard said.
New Moons Are Likely Captured Bodies
Like most of Jupiter's other retrograde satellites, S/2011 J1 and J2 are also classified as irregular moons, because they orbit far from the planet and have highly eccentric and inclined orbits.
Due to their odd orbits, the moons are likely asteroid or comet pieces that were long ago captured by Jupiter's gravity rather than developing in place during the formation of the planet itself.
"Because these outer irregular satellites were captured during the solar system's early years, they can give us insight into the planet's formation and evolution process," Sheppard added.
As far as more imaginative names are concerned, that will require more time and more data.
By established convention, satellites in the Jovian system are named for lovers and descendants of the Roman god Jupiter or his Greek counterpart, Zeus.
But "satellites in general are not given Roman or Greek mythological names until they have at least one year of observations," Sheppard said.
The new Jupiter moons were announced this week in the International Astronomical Union's Central Bureau for Astronomical Telegrams.”
Space Pictures This Week: Sun Loops, Blue Marble, More
|5:02:26 PM, Saturday, January 28, 2012|
"Huge loops of plasma?superheated, charged gas?rise from an active region on the sun in a newly released picture from NASA's Solar Dynamics Observatory. Each loop is as tall as several Earths stacked on top of each other.
The plasma loops trace the sun's otherwise invisible magnetic field lines, which rise from the star's magnetically active regions?the starting points for huge eruptions of radiation known as solar flares..."
-- Been neglecting the page a bit, but I'm trying to get back into at least making somewhat regular updates.
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