November 2009 Archives

Science News: Some 30,000 light-years from Earth, a tiny gravitational monster is tearing material from a companion star, blasting x-rays into space, and sporadically hurling out jets of radio-wave-emitting blobs at close to the speed of light.

Known as Cygnus X-3, this mercurial star system—thought to be either a small black hole or a neutron star orbiting an ordinary partner—has fascinated astronomers for more than four decades with its surprisingly bright x-ray emissions.

Now, two teams of researchers have made the first definitive detection of high-energy gamma rays, the most powerful type of electromagnetic radiation, from this small but nearby stellar system.

Related Link
Discovery of extreme particle acceleration in the microquasar Cygnus X-3

Wall Street Journal: A recent study by consultancy Booz & Co of 1000 of the world's biggest research-and-development spenders found they are focusing on products with quick revenue opportunities, and killing less-promising projects. Nearly half of the respondents said they have tightened criteria for approving new projects.

The survey found a shift away from basic research and toward applying existing technology to new products. That is a longstanding trend in corporate labs and has accelerated during the recession, says Booz partner Barry Jaruzelski.

The Guardian: Iran has sent a defiant signal to the international community by announcing plans to build 10 uranium enrichment plants days after it was condemned by the United Nations for concealing activities that are feared may be designed to produce an atomic bomb.

Mahmoud Ahmadinejad's government said the plants would be the same size as the main enrichment complex at Natanz, central Iran, and work would begin within two months.

BBC News: One of the world's oldest scientific institutions is marking the start of its 350th year by putting 60 of its most memorable research papers online.

The Royal Society, founded in London in 1660, is making public manuscripts by figures like Isaac Newton.

Benjamin Franklin's account of his infamous kite-flying experiment is also available on the Trailblazing website.

Society president Martin Rees said the papers documented some of the most "thrilling moments" in science history.

The site will remain free to the public until the end of February 2010.

Physics Today: Updated 9:44 EST: The CERN twitter feed reports that both beams at the Large Hadron Collider have passed 1.18 TeV at 00:42 Central European Time on Monday.

The LHC is now the highest-energy accelerator in the world, beating Fermilab's Tevatron collider, which has energies of 0.98 TeV.

"We are still coming to terms with just how smoothly the LHC commissioning is going," said CERN Director General Rolf Heuer. "It is fantastic. However, we are continuing to take it step by step, and there is still a lot to do before we start physics in 2010. I'm keeping my champagne on ice until then."

"I was here 20 years ago when we switched on CERN's last major particle accelerator, LEP," said Research and Technology Director Steve Myers. "What took us days or weeks with LEP, we're doing in hours with the LHC. So far, it all augurs well for a great research program."

Next on the LHC's schedule is increasing the beam intensity and delivering large quantities of proton collision rates to the experiments before Christmas.

The current commissioning phase aims to make sure that these higher intensities can be safely handled and that stable conditions can be guaranteed for the experiments during collisions.

This phase is estimated to take around a week, after which the LHC will be colliding beams for calibration purposes until the end of the year.

Related coverage of the LHC

Wired.com: BMW has revealed the early results of field tests of its electric Mini which it leases to 450 people for nearly $900 per month.

Displaying considerable candor, BMW North America manager of electric vehicle operations and strategy Rich Steinberg said the small-scale rollout was more difficult than expected.

The biggest problem, he said at the company's headquarters here, is infrastructure.

Installing the chargers in homes and buildings was more difficult and took longer than the company expected, he said. And even though the car, which BMW is leasing to customers in what is a big R&D project, offers 100 miles on a charge, people still worry about the battery dying.

Eight key factors would ease the acceptance of electric cars, according to Steinberg's interpretation of the Mini E field test data:

In terms of the environmental impact the electric version generated only 45 percent as much CO₂ per mile as the gas version, even though the battery ads 573 pounds to the Mini's overall weight (and loses the back seat).

Electric cars generate 1.7 times more CO₂ per unit of energy than gasoline, but use that same unit of energy 3.1 times more efficiently than gas cars, according to John DiCiccio of the University of Michigan.

Times Online: Last year John Gurney was told he had prostate cancer.

His specialist suggested a wait-and-watch approach. But at the age of 67, and with the prospect of having to live with the disease for years, Gurney decided that the uncertainty was going to be less bearable than surgery. "Everyone I had met said it wasn't going to kill me till I was 80, but if you are waiting around like that you want to do something. I had to get on the robot."

The robot in question is the $2 million da Vinci Surgical System, and one Monday a few weeks back, John Gurney got on it—or more precisely was maneuvered under it.

Urologist surgeon's who use robots are finding that up to 50% of their surgeries are now with the device, and 40% of the remaining are laparoscopic operations using small incisions, cameras and probes. The robots limit back pain, a common complaint among surgeon's who carry out prostate surgery.

The da Vinci is a spider-like unit the size of a double fridge, with overhanging mechanical joints wrapped in transparent sheeting.

The surgeon marked out four small incisions on Gurney's stomach and after using his scalpel "for the first and only time", started screwing a camera port into place.

Justin Vale, consultant urologist and pre-eminent robotic surgeon, said that the advantage is that you can pull things in and out easily.

Within a few minutes, two robotic arms were busying away removing John Gurney's prostate.

NPR: Researchers are hoping to improve solar energy installations by coupling a solar panel to an efficient hydrolysis unit that splits water into oxygen and hydrogen. Daniel Nocera of MIT says the approach could lead to personal solar power units that could get many houses off the grid.

Science: After several decades of controversy, scientists now know that over billions of years, water can collect as ice in some of the coldest places in the solar system. Whether there's enough lunar water ice for future astronauts to drink or turn into rocket fuel, however, remains to be seen, says Richard Kerr in Science.

guardian.co.uk: IPCC chairman Rajendra Pachauri accuses the Indian environment ministry of "arrogance" for its report claiming there is no evidence that climate change has shrunk Himalayan glaciers.

Nature: Exoplanets are distant worlds that orbit stars other than our Sun. More than 370 such planets are known, and a growing fraction of them are discovered because they transit their star as seen from Earth. The special transit geometry enables us to measure masses and radii for dozens of planets, and we have identified gases in the atmospheres of several giant ones.

Within the next decade, we expect to find and study a "habitable" rocky planet transiting a cool red dwarf star close to our Sun, says Drake Deming and Sara Seager. "Eventually, we will be able to image the light from an Earth-like world orbiting a nearby solar-type star," they say.

washingtonpost.com: A growing storm of debris flying around in space is dramatically increasing the risk of orbital crashes, and steps to avoid them will add greatly to the costs of future spaceflight, UK space experts say.

Their study predicts that near misses between debris and spacecraft in orbit will rise by 50% in the next 10 years and by 250% by 2059, to more than 50,000 a week.

"The time to act is now, before the situation gets too difficult to control," said Hugh Lewis of the University of Southampton's school of engineering science, who led the study. "The number of objects in orbit is going to go up, and there will be impacts from that."

Macworld: If you are in need of finding out if there is ammonia, chlorine gas or methane in the air around you, there's an iPhone app for that.

A researcher at NASA's Ames Research Center has developed what NASA calls a proof of concept of new technology that would bring compact, low-cost, low-power, high-speed nanosensor-based chemical sensing capabilities to cell phones.

Nature: Light from a distant γ-ray burst backs up a key prediction of Albert Einstein's theory of relativity—that photon speed is the same regardless of energy. But it might set the stage for evolution of the theory.

The Guardian: Walk round the National Museum of Computing at Bletchley Park and sooner or later you'll hear a cry of recognition and someone will say: "I remember using one of those."

It probably doesn't happen often to The Millionaire, a mechanical calculator that went into production in 1893, but Sir Maurice Wilkes spotted it, adding: "We used to have one in the lab. I hope it's still there."

In this case, "the lab" was what became the Cambridge University Computer Lab, which Wilkes headed from 1945 until 1980.

It was where he built Electronic Delay Storage Automatic Calculator (Edsac), one of the world's first electronic computers, using sound beams traversing baths of mercury for the memory units.

NYTimes.com: The Department of Homeland Security has spent $230 million to develop better technology for detecting smuggled nuclear bombs but has had to stop deploying the new machines because the United States has run out of helium-3.

“I have not heard any explanation of why this was not entirely foreseeable,” said Representative Brad Miller, Democrat of North Carolina, who is the chairman of a House subcommittee that is investigating the problem.

The demand for helium 3 appeared to be 10 times the supply.

Related Physics Today article
US government agencies work to minimize damage due to helium-3 shortfall October 2009
Helium shortage hampers research and industry June 2007

NASA: One of three teams in a NASA competition to demonstrate power beaming technology won $900,000 in prize money last week.

Seattle-based LaserMotive won the prize by using laser power to move a climber robot up a one-kilometer ribbon at a speed of about four meters a second, twice the speed needed to qualify for the prize.

Two other teams also participated in the competition but fell short of the minimum speed needed to qualify for a share of the prize purse.

The prize is meant to demonstrate wireless power transmission, a key technology needed for space elevators as well as other transportation applications. The competition is one of several that is part of NASA's Centennial Challenges prize program.

Nature News: Scientific advice is frequently sought in the UK, but on security-related issues the advice usually comes from inside the government.

Now, the UK government has recruited a group of 11 academics to tackle tricky scientific problems related to defense, similar to the JASON group in the US.

The UK group was assembled by Mark Welland, the UK Ministry of Defence's chief scientific adviser, and John Beddington, the UK government's chief scientific adviser.

The group was tasked with looking at ways to improve radiation detection at the nation's ports to prevent terrorism and smuggling of nuclear material.

Science: Jet turbine engines have benefited from decades of development of nickel-based superalloys, which have allowed a steady increase in engine operating temperatures and led to improved performance and efficiency.

However, operating temperatures are now reaching limits posed by the melting temperatures of these materials.

New materials, including alloys based on metals with higher melting points, such as molybdenum (Mo) and niobium (Nb) alloyed with silicon (Si), are now being seriously examined as alternatives by academic and industrial groups.

NPR: The stars of the Big Bang Theory are two fictional Caltech physicists, but the physics problems they study are real. Bill Prady, the program's co-creator and executive producer, talks about including real-world science in the script, from dark matter to magnetic monopoles

Physics Today: The Large Hadron Collider (LHC) has circulated two beams (at 450 GeV) simultaneously for the first time, allowing the operators to test the synchronization of the beams and giving the experiments their first chance to look for proton–proton collisions.

Early in the afternoon, the beams were made to cross at points 1 and 5, home to the ATLAS and CMS detectors; later, beams crossed at points 2 and 8, home to the ALICE and LHCb experiments.

“It was standing room only in the ALICE control room and cheers erupted with the first collisions,” said ALICE spokesperson Jurgen Schukraft. “This is simply tremendous.”

“The tracks we’re seeing are beautiful,” said LHCb spokesperson Andrei Golutvin, “we’re all ready for serious data taking in a few days time.”

Collisions at CMS

“It’s a great achievement to have come this far in so short a time,” said CERN Director General Rolf Heuer. “But we need to keep a sense of perspective—there’s still much to do before we can start the LHC physics program.”

Next on the schedule is an intense commissioning phase aimed at increasing the beam intensity and accelerating the beams. All being well, by Christmas, the LHC should reach 1.2 TeV per beam, and have provided good quantities of collision data for the experiments’ calibrations.

Science: In 2006, when North Korea carried out its first nuclear test, a US plane detected radionuclides—faint wind-borne traces of radioactive elements such as xenon from nuclear explosions—within days, and a Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) monitoring station as far away as Yellowknife in Canada picked them up 12 days after the test.

North Korea declared on 25 May that it had carried out a second underground nuclear test—a blast that clearly showed up on seismometers across the globe.

But at a scientific conference during the summer, the CTBTO revealed that its global network of radionuclide detectors had not picked up anything it could pin on the Korean test, nor had the South Koreans or another US Air Force plane.

Researchers are speculating that the test occurred deep underground and in rock that melts easily, forming a seal around the explosion chamber and limiting the release of radionuclides.

Mother Jones: Democrat Jim Webb of Virginia threw another wrench in the Senate climate debate last week, announcing that he is cosponsoring an alternative bill with Republican Senator Lamar Alexander of Tennessee. Their solution to the climate problem? A $100 billion subsidy to the nuclear industry instead of a cap and trade scheme.

NPR: John Dabiri, bioengineer at Caltech, has developed new techniques for studying the motion of aquatic animals. In a recent study in the journal Nature, Dabiri and Kakani Katija explain how swimming animals contribute to ocean mixing—the process that distributes heat, nutrients and gasses throughout the sea.

Related Link
A viscosity-enhanced mechanism for biogenic ocean mixing

Cambridge News: Michael Green speaks to Stephen Exley about life as Cambridge University's new Lucasian Professor of Mathematics

Physics Today: Updated: 2:38PM EST and 4:40PM EST: Scientists at the Large Hadron Collider (LHC), announced that they have sent a particle beam around the 27-kilometer collider.

"It’s great to see beam circulating in the LHC again," said CERN director general Rolf Heuer. "We’ve still got some way to go before physics can begin, but with this milestone we’re well on the way."

The LHC circulated its first beams on 10 September 2008, but suffered a serious malfunction nine days later. It has taken over a year repairing and consolidating the machine to ensure that such an incident cannot happen again.

"The LHC is a far better understood machine than it was a year ago," said CERN’s Director for Accelerators, Steve Myers. "We’ve learned from our experience, and engineered the technology that allows us to move on. That’s how progress is made."

The next important milestone will be low-energy collisions at 450 GeV, expected in about a week from now. Ramping the beams to high energy will follow in preparation for collisions at 7 TeV (3.5 TeV per beam) next year.

Recent coverage of the LHC by Physics Today can be found here.

Related news stories
Scientists at Cern hold their breath as they prepare to fire up the LHC The Guardian

Nature: With microfluidic devices gaining prominence for many applications in chemistry and biology, the hunt is on to find ways of accurately controlling the motion of liquid droplets. In Angewandte Chemie, Antoine Diguet et al. describe a method for using light to trap and move oil droplets floating on an aqueous solution.

Related Link
Photomanipulation of a droplet by the chromocapillary effect

Science: Four of Russia's most prominent physics labs are to be merged into a new national research center. The institutes, which have languished in the post-Soviet era, have cautiously welcomed the raised profile the merger will bring.

But a different reform aimed at separating basic and applied research at one of the institutes—the Kurchatov Institute in Moscow, Russia's premier lab for nuclear energy research--has researchers up in arms.

The merger, announced in a presidential decree last month, will combine the Institute for High Energy Physics (IHEP) in Protvino, 100 kilometers south of Moscow; the B. P. Konstantinov Petersburg Nuclear Physics Institute (PNPI) in St. Petersburg; and two Moscow labs--the Institute for Theoretical and Experimental Physics (ITEP) and the Kurchatov. The reorganization is aimed at smoothing the path of innovations into industry, says Sergei Kiriyenko, chief of the nuclear energy agency Rosatom and one of the key officials behind the decree.

washingtonpost.com: In 1982, a Pakistani military C-130 left the western Chinese city of Ürümqi with a highly unusual cargo: enough weapons-grade uranium for two atomic bombs, and a blueprint of how to build one say accounts written by the father of Pakistan's nuclear weapons program, Abdul Qadeer Khan.

Khan is currently under house arrest.

The uranium transfer was part of a broad-ranging, secret nuclear deal approved years earlier by Chinese premier Mao Zedong and Prime Minister Zulfikar Ali Bhutto.

US officials say they have known about the transfer for decades and once privately confronted the Chinese—who denied it—but have never raised the issue in public or sought to impose direct sanctions on China for it.

The transfer also started a chain of proliferation in which Khan's nuclear smuggling network shared related Chinese design information with Libya and possibly Iran.

China's refusal to acknowledge the transfer and the unwillingness of the United States to confront the Chinese publicly demonstrate how difficult it is to counter nuclear proliferation writes the Washington Post's R. Jeffrey Smith and Joby Warrick.

Related Link
Pakistani nuclear scientist said to affirm Post article's accuracy

APS Physics: Most metrics of a scientist’s impact in a field, like the h-index, rely primarily on the number of times his or her papers have been cited, and can miss the more subtle ways that knowledge and credit for this research spread among scientists.

Filippo Radicchi, Santo Fortunato, Benjamin Markines, and Alessandro Vespignani are instead proposing a way to rank scientists that reflects the diffusion of scientific credit in time.

Their method, based on an algorithm similar to Google’s PageRank, takes into account several nontrivial effects such as the fact that being cited by an important author has more influence than being cited by one who is less well known.

Related Link
Diffusion of scientific credits and the ranking of scientists

Nature News: Last week, US particle physicists staked their claim in a daring new venture to develop the next generation of accelerators by proposing the world's first muon collider.

The collider could overtake two more-mature concepts, each of which plan to smash together electrons and positrons that have been accelerated through long, straight tunnels.

But some physicists at the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, are concerned about the expense and feasibility of the linear colliders, and question whether they would push the boundaries of physics beyond what the Large Hadron Collider is expected to achieve.

They are now trying to rally enthusiasm for a collider that smashes muons, a particle that is about 200 times more massive than the electron.

Related Link
Next-generation atom smashers: Smaller, cheaper and super powerful Wired.com

Physics Today: A new study of Antarctica's past climate reveals that temperatures during the warm periods between ice ages (interglacials) may have been higher than previously thought.

The findings, reported in Nature by scientists from the British Antarctic Survey (BAS), the Open University and University of Bristol could help us understand more about rapid Antarctic climate changes.

The conclusions come the latest analysis of ice core records that suggests that Antarctic temperatures may have been up to 6°C warmer than the present day. (see image left. This Slice of ice core from Berkner Island, was dug up from a depth 120 meters below the surface. Trapped air bubbles (an archive of the past atmosphere) are visible in the ice. Photo credit: BAS)

Previous analysis of ice cores has shown that the climate consists of ice ages and warmer interglacial periods roughly every 100,000 years.

This new investigation shows temperature 'spikes' within some of the interglacial periods over the last 340,000 years. This suggests Antarctic temperature shows a high level of sensitivity to greenhouse gases at levels similar to those found today.

"We didn't expect to see such warm temperatures, and we don't yet know in detail what caused them," says Louise Sime of the British Antarctic Survey and the lead author of the author. "But they indicate that Antarctica's climate may have undergone rapid shifts during past periods of high CO2."

During the last warm period, about 125,000 years ago, sea level was around 5 meters higher than today.

"If we can pin down how much warmer temperatures were in Antarctica and Greenland at this time, then we can test predictions of how melting of the large ice sheets may contribute to sea level rise," says BAS's Eric Wolff.

Related Links
Antarctic temperature spike surprises climate researchers
Evidence for warmer interglacials in East Antarctic ice cores

Space.com: The world's largest collection of radio telescopes is being tied together for 24 hours starting today to observe more than two hundred energetic galaxies known as quasars.

During those 24 hours, 35 telescopes on all seven continents will observe 243 distant quasars in an effort to improve the precision of the reference frame scientists use to measure positions in the sky.

NYTimes.com: The controversy over the direction and temperature of the US climate has existed for hundred of years.

Benjamin Franklin understood climatic forcing factors better than anyone, surmising in a 1763 letter to Ezra Stiles that "cleared land absorbs more heat and melts snow quicker."

Franklin, later surmised (correctly) that a prevailing haze over parts of North America and northern Europe was associated with the eruption of the Laki volcano in Iceland in June 1783, and was possibly the source for the exceptional chill experienced in the winter of 1783-84 in the colonies.

In the 1780s, Thomas Jefferson opined in his "Notes on Virginia" that "both heats and colds are become much more moderate within the memory even of the middle-aged."

Noah Webster quarreled with Jefferson, insisting that he relied too heavily on the memories of "elderly and middle-aged people" for his observation that the climate had moderated, a debate that was not resolved in Jefferson's favor for years until more meticulous climate observations had been made.

Says meteorologist Ben Gelber:

Now we have satellites monitoring high-latitude snow cover, thinning sea ice and deep-layered atmospheric temperature increases, coupled with ground observations revealing the disappearing snows of Kilimanjaro (85 percent ice loss since 1912) and many other glaciers.

The wealth of data now at our disposal, enhanced by high-resolution computer models that pioneer climatologists would have craved, has, curiously, not turned down the thermostat on the centuries-old global climate change debate, quite likely because the stakes are so much higher.

CNET News: SolarReserve and Preneal have garnered the necessary permit to build a 50-megawatt thermal-solar plant in Spain that will use molten salt to store and release solar energy.

The project will be built in Alcazar de San Juan, a town about 110 miles south of Madrid.

The Register: Ericsson is pulling out of its R&D facility at Ansty Park, in the UK, jeopardizing 700 jobs in the process despite only moving in six months ago.

BBC News: Average temperatures across the world are on course to rise by up to 6°C without urgent action to curb CO₂ emissions, according a new analysis.

Related news story
Global temperatures will rise 6C by end of century, say scientists The Guardian

Science News: Studying with the radio on may not be the best way to remember what you've read. But scientists have now built a data storage device whose memory gets a boost from noise.

The device can store one bit of information, such as a 0 or a 1, only when surrounded by electronic noise, which is normally a problem in computer circuits.

"If you remove the noise, it doesn't store the bit at all," says Diego Grosz of the Instituto Tecnológico de Buenos Aires, a coauthor of the study.

Related Link
One-bit stochastic resonance storage device

ScienceNOW: The way light moves, with its fixed speed and its ability to act like either a wave or a particle, often leads to some of the most curious paradoxes of physics. A new one has just been found: Make holes in a film of gold so thin that it's already semitransparent, and less light gets through.

Physics Today: A white dwarf star called V445 in the constellation of Puppis, that is digesting its closest neighbor, is a prime candidate to explode as a Type Ia Supernova, ejecting a large quantity of matter into space.

V445 Puppis has been under a two-year observation by the European Southern Observatory's Very Large Telescope. The star was discovered by a amateur Japanese astronomer when it became visible as a nova in November 2000. It is the only nova appearing that has no hydrogen and provides the first evidence for an outburst on the surface of a white dwarf dominated by helium.

"This is critical, as we know that Type Ia supernovae lack hydrogen and the companion star in V445 Pup fits this nicely by also lacking hydrogen," says Danny Steeghs, from the University of Warwick, and one of the key team members observing the star. A earlier paper by astronomers Mariko Kato and Izumi Hachisu that modeled the star's behavior suggested as much.

The shell—unlike any previously observed for a nova—is itself moving at about 24 million kilometers per hour. A thick disc of dust, which must have been produced during the last outburst, obscures the two central stars.

"As the white dwarf feeds on its companion, the captured gas accumulates on its surface until thermonuclear reactions begin, causing a massive explosion which ejects matter out into space at phenomenal speeds," says co-researcher Tim O'Brien, of the Jodrell Bank Centre for Astrophysics in the UK.

If the white dwarf continues to gain mass, "it will eventually reach a point where it will be ripped apart in a titanic supernova explosion and its cycle of outbursts will come to an end," adds O'Brien.

Type Ia supernovae are critical for studies of dark energy and for measuring distances in the universe.

V445 Puppis is over 10,000 times brighter than the Sun, implying that it is near its fatal limit to turn into a supernova.

Patrick Woudt, from the University of Cape Town, and the lead author of an Astrophysical Journal paper describing V445 Puppis says that "one of the major problems in modern astrophysics is the fact that we still do not know exactly what kinds of stellar system explode as a Type Ia supernova" which is "rather embarrassing."

"Whether V445 Puppis will eventually explode as a supernova, or if the current nova outburst has pre-empted that pathway by ejecting too much matter back into space is still unclear," Woudt adds. "But we have here a pretty good suspect for a future Type Ia supernova."

Related Link
The expanding bipolar shell of the helium nova V445 Puppis

Slate Magazine: Communicating the dangers of nuclear waste to unfathomably remote descendants may seem like a topic best left to third-drink philosophers in dorm rooms.

It's actually been left to the US Department of Energy.

According to government guidelines, DoE must plan for the continuing safety of nuclear waste sites over the next 10 millenniums.

So in 1991, the department (through Sandia National Laboratories) hired 13 linguists, scientists, and anthropologists at a cost of about $1 million to devise a conceptual plan for a 10,000-year marker system.

The summary report, dryly titled "Expert Judgment on Markers To Deter Inadvertent Human Intrusion Into the Waste Isolation Pilot Plant," was published in 1993.

The report takes seriously the quixotic goal of warning far-off civilizations and ultimately proposes a system as elaborate as it is futile says Slate's Juliet Lapidos.

Times Online: Greenland’s ice sheet is melting at an accelerating pace, according to the most detailed observations to date.

Until now scientists had been unable to establish whether the loss of the ice sheet had speeded up significantly since the 1990s.

Using two independent measurement techniques, the latest study reveals that the melting accelerated rapidly over the period 2000-2008.

If the acceleration of melting continues at the same rate, the sea level from Greeland’s ice alone would rise by 40cm by the end of the century.

If the melting continues at a steady pace—the best-case scenario according to Met Office predictions—Greenland ice will contribute an 18cm rise in sea level.

Related News Story
Greenland ice loss 'accelerating' BBC News

Nature: The fractional quantum Hall effect (FQHE) is a fascinating form of collective electronic behavior.

It arises when electrons in a strong magnetic field—applied at a right angle to the plane in which the electrons flow—act together to behave like particles with a charge that is a fraction of an electron's charge.

Its observation requires the use of two-dimensional systems virtually free of disorder. This is why, since its discovery by Daniel Tsui and Horst Störmer in 1982—for which they won the 1998 Nobel Physics prize—the effect has been studied in ultrapure semiconductor heterostructures (devices that contain thin layers of one or more semiconductors) grown in an ultrahigh vacuum.

Two papers, one by Xu Du and colleagues and Kirill I. Bolotin and colleagues, show that the FQHE can also be observed in graphene—a one-atom-thick sheet of graphitic carbon, the production of which requires no more sophistication than a common adhesive tape to manually exfoliate graphite in ambient conditions

Related Links
Fractional quantum Hall effect and insulating phase of Dirac electrons in graphene
Observation of the fractional quantum Hall effect in graphene

Wired.com: The US military spent tens of millions of dollars and years of work developing a microwave “pain beam,” but a combination of technical difficulties and political concerns kept the Pentagon from fielding the thing.

Now, an Israeli team says they’re working on their own portable version. And it’ll cost just $250,000.

NPR: NASA has announced a plan to extricate its rover Spirit, which has been stuck in a Martian sand trap since April.

The space agency will begin transmitting commands to the exploration robot today. Based on tests conducted on Earth this spring that simulated conditions at the Martian site, researchers do not expect the effort to be quick or easy.

BBC News: Astronomers may have found a way to identify those Sun-like stars most likely to harbour orbiting planets.

A survey of stars known to possess planets shows the vast majority to be severely depleted in lithium.

To date, scientists have detected just over 420 worlds circling other stars using a range of techniques.

Garik Israelian and colleagues tell the journal Nature that future planet hunts could be narrowed by going after stars with particular compositions.

Physics Today: The Moon is wetter than previously believed, say NASA scientists Friday, reporting the results of the Lunar CRater Observation and Sensing Satellite (LCROSS) impact probe, that slammed into lunar polar craters a month ago.

"There's water, and it is not just a little water, but significant amounts," says NASA's Anthony Colaprete, chief science investigator for the LCROSS in a press conference earlier today.

The LCROSS Centaur upper stage rocket was used to create a plume on the 9 October by smashing into the permanently shadowed region of Cabeus crater near the moon's south pole.

The resulting impact created a two-part plume of material from the bottom of the crater. The first part was a high angle plume of vapor and fine dust and the second a lower angle ejecta curtain of heavier material. This material has not seen sunlight in billions of years.

Since the impacts, the LCROSS science team has been working almost nonstop analyzing the huge amount of data the spacecraft collected. The team concentrated on data from the satellite's spectrometers, which provide the most definitive information about the presence of about 26 gallons of water.

"We are ecstatic," said Colaprete, "multiple lines of evidence show water was present in both the high angle vapor plume and the ejecta curtain created by the impact. The concentration and distribution of water and other substances requires further analysis, but it is safe to say Cabeus holds water."

The team took the known near infrared spectral signatures of water and other materials and compared them to the spectra collected by the LCROSS near infrared spectrometer of the impact.

"We were only able to match the spectra from LCROSS data when we inserted the spectra for water," said Colaprete. "No other reasonable combination of other compounds that we tried matched the observations. The possibility of contamination from the Centaur also was ruled out."

Additional confirmation came from an emission in the ultraviolet spectrum that was attributed to hydroxyl, one product from the break-up of water by sunlight. When atoms and molecules are excited, they release energy at specific wavelengths that are detected by the spectrometers. A similar process is used in neon signs. When electrified, a specific gas will produce a distinct color. The ultraviolet visible spectrometer detected hydroxyl signatures just after impact that are consistent with a water vapor cloud in sunlight.

Data from the other LCROSS instruments are being analyzed for additional clues about the state and distribution of the material at the impact site. The LCROSS science team along with colleagues are poring over the data to understand the entire impact event, from flash to crater, with the final goal being the understanding of the distribution of materials, and in particular volatiles, within the soil at the impact site.

"The full understanding of the LCROSS data may take some time. The data is that rich," said Colaprete. "Along with the water in Cabeus, there are hints of other intriguing substances. The permanently shadowed regions of the moon are truly cold traps, collecting and preserving material over billions of years."

A short trip

LCROSS was launched on the 18 June as a companion mission to the Lunar Reconnaissance Orbiter. After separating from LRO, the LCROSS spacecraft held onto the spent Centaur upper stage rocket of the launch vehicle, executed a lunar swingby and entered into a series of long looping orbits around the Earth.

After traveling approximately 113 days and nearly 9 million kilometers, the Centaur and LCROSS separated on final approach to the moon.

Traveling as fast as a speeding bullet, the Centaur impacted the lunar surface shortly after 4:31 am PDT Oct. 9 with LCROSS watching with its onboard instruments. Approximately four minutes of data was collected before the LCROSS itself impacted the lunar surface.

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latimes.com: The soil around Mount Wilson Observatory still smolders, burning what root systems remain after the devastating wildfire was declared contained weeks ago. Fire crews are monitoring the area.

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Backreaction: The Heidelberg Ion-Beam Therapy Center (HIT)—the first medical heavy-ion machine in Europe—has opened.

Close to the GSI facility near Darmstadt, the Heidelberg Ion-Beam Therapy Center is a dedicated heavy-ion accelerator for deployment in radiotherapy to treat tumors.

Treatment center at the focus of the HIT Gantry. Credit: HIT

Physicist Stefan Scherer briefly takes a look at this new facility and the physics behind it.

Nature: The mechanisms that govern the rate at which glasses soften on heating have long been a mystery. The finding that colloids can mimic the full range of glass-softening behaviors offers a fresh take on the problem.

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NYTimes.com: About a year from now, if all goes well, a box called LightSail-1, about the size of a loaf of bread, will pop out of a rocket some 500 miles above the Earth.

There in the vacuum it will unfurl four triangular sails (see left image for an artist's rendition of LightSail-1 by Rick Sternbach. Credit: Planetary Society) as shiny as moonlight and only barely more substantial. Then it will slowly rise on a sunbeam and move across the stars.

LightSail-1 will sail only a few hours and gain a few miles in altitude.

But those hours will mark a milestone in the quest to navigate the cosmos on winds of starlight the way sailors for thousands of years have navigated the ocean on the winds of the Earth.

guardian.co.uk: Tyrannosaurus rex was an athletic, warm-blooded animal that jogged rather than lumbered around its territory, according to a new study.

Researchers led by Herman Pontzer at Washington University in St Louis examined the anatomical details of 14 dinosaurs of different sizes to work out how much energy the animals might have needed to move around.

He found that, for dinosaurs weighing from a few kilograms to tons, the power their muscles needed was far too high for the animals to have been cold-blooded.

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Science Progress: When Mary Ann Mason was graduate dean at the University of California, Berkeley, a frequent question she heard from women graduate students was "when is a good time to have a baby?"

For women in academic science careers, the conventional wisdom was that waiting until she had achieved tenure was the best approach.

In 1985, the national average age of scientists winning tenure was 36. But by 2003, it was over 39.

"So it's increasingly poor advice to wait until you get to tenure," she says.

Her belief is that women researchers should be able to have children whenever they want, and her new report, co-authored with colleagues Marc Goulden and Karie Frasch, explains the work-family policies that are driving women out of the academic pipeline.

Their data, taken from extensive surveys of graduate students and postdoctoral researchers within the University of California system, shows that work-life issues, and particularly decisions about when to get married and when to have children, account for the most significant loss of academic scientists in the pipeline between PhD and tenured positions.

"The leak is almost entirely, or least due primarily to family formation," said Mason, who is currently a professor and co-faculty director of the Berkeley Law Center on Health, Economic, and Family Security at the UC Berkeley.

Science Progress has a podcast discussing these issues with the authors of the study.

NPR: As the world prepares for crucial climate-change talks in Copenhagen next month, there is a growing rift between the US and some of the world's poorest nations. The gap grew wider this past week, at the final official pre-Copenhagen talks in Barcelona.

Space.com: The amount of junk floating in space is getting out of hand and the US must step up its effort to control orbital trash, say experts.

The chief of US Strategic Command said Wednesday that America needs better tools to monitor the orbital debris that's up there and plan to avoid collisions with valuable satellites.

"We are decades behind where we should be, in my view," said Air Force General Kevin P. Chilton in a speech at Offutt Air Force Base, Nebraska.

Chilton called for more personnel and more sensors and equipment to study and combat the threat.

NPR: The US Department of Energy is offering $10 million to the first individual or company to develop an energy-efficient LED replacement for the standard 60-watt incandescent bulb.

DOE lighting program manager James Brodrick discusses the L Prize with NPR, and what makes a better bulb.

The New Yorker: Pakistan has been a nuclear power for two decades, and has an estimated 80 to 100 warheads, scattered in facilities around the country.

Last month 10 gunmen penetrated the Pakistan army’s main headquarters, in Rawalpindi, instigating a 22-hour standoff that left 23 dead and the military thoroughly embarrassed.

The success of the latest attacks raises an obvious question, says the New Yorker's Seymour M. Hersh: Are the bombs safe?

The Economist: There is a lot of water on Earth, but more than 97% of it is salty and over half of the remainder is frozen at the poles or in glaciers.

Meanwhile, around a fifth of the world’s population suffers from a shortage of drinking water and that fraction is expected to grow.

One answer is desalination—but it is an expensive answer because it requires a lot of energy.

Now, though, a pair of Canadian engineers, through a company called Saltworks Technologies, have come up with an ingenious way of using the heat of the Sun to drive the process. Such heat, in many places that have a shortage of fresh water, is one thing that is in abundant supply.

A test plant in Vancouver, Canada, will open this month.

ScienceNOW: A new study has found that nanoscale materials, used in everything from medical imaging to cancer treatment, can damage genetic material in our bodies, feeding public fears.

But this particular study has little relevance to human exposure risks, experts say, and it is deeply flawed in other ways.

NYTimes.com: Microscopes are invaluable tools to identify blood and other cells when screening for diseases like anemia, tuberculosis, and malaria. But they are also bulky and expensive.

Now an engineer, using software that he developed and about $10 worth of off-the-shelf hardware, has adapted cell phones to substitute for microscopes.

USA Today: Saturn's geyser-spewing moon, Enceladus—visited by the international Cassini spacecraft on its closest flyby this week—presents planetary scientists with a geophysical locked-room mystery.

How does something buried inside an ice ball only 500 kilometers wide provide the pop to propel a plume 965 kilometers out of the moon's south pole?

"The biggest puzzle with Enceladus is where is the heat source," says Cassini scientist Linda Spilker of NASA's Jet Propulsion Laboratory, which manages the mission. "This tiny moon 'should' be frozen over like the others orbiting Saturn."

Physics Today: Tests on parts of the Large Hadron Collider over the weekend were fairly successful, suggest CERN documents.

Particles up to 450 GeV were injected into four sectors of the storage ring (sector 23, 78, 67, and 56).

For the first time—at 8:00pm local time on Saturday—the Compact Muon Solenoid (CMS) detector observed beam "splash" in the LHC, a major milestone for the experiment (see yellow indicators in image below).

Image credit: CERN

These injection tests are the final phase before the main test on 20 November in which particles will traverse across the entire ring. Actual collisions between two opposing beams should occur at roughly the same date.

Over a 24-hour period on Monday, the sectors will be checked for radiation. Once the risk has been minimized, researchers and technicians will inspect the billion-dollar collider for any damage.

The LHC will run at reduced power for the next two years, in an attempt to minimize risk to the magnets.

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The Register: A bird dropping a piece of bread onto outdoor machinery has been blamed for a technical fault at the Large Hadron Collider (LHC) this week which saw significant overheating in sections of the mighty particle-punisher's subterranean 27-km supercooled magnetic doughnut.

According to scientists at the project, had the LHC been operational—it is scheduled to recommence beaming later this month—the snag would have caused it to fail-safe and shut down automatically.

This would put the mighty machine out of action for a few days while it was restarted, but there would be no repeat of the catastrophic damage suffered last September.

Science: When the Max Planck Society planted institutes across the former East Germany, it recruited scientists from around the world for its ambitious project.

But only two out of more than 60 directors in the newly founded institutes were recruited from the East itself. Today, the society has 267 active directors; only five grew up on the eastern side of the divided Germany. And only one started a career before 1989.

Those statistics are a sign of the mixed blessings that reunification brought for East German scientists.

For many, especially the younger ones, it was a great opportunity. But others were set adrift when entire preexisting eastern institutes were closed or cut to a fraction of their original size.

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The Guardian: The International Atomic Energy Agency has asked Iran to explain evidence suggesting that Iranian scientists have experimented with an advanced nuclear warhead design, says the Guardian.

The very existence of the technology, known as a "two-point implosion" device, is officially secret in both the US and the UK, but according to previously unpublished documentation in a dossier compiled by the IAEA, Iranian scientists may have tested high-explosive components of the design.

A two-point implosion device, once mastered, allows for the production of smaller and simpler warheads than first-generation warheads. It makes it easier to put a nuclear warhead on a missile.

guardian.co.uk: Prosthetics worn by disabled sprinters confer no speed advantage, scientists have found. If anything, they may reduce the top speed a runner can achieve.

The research supports the case made by the South African Paralympic runner Oscar Pistorius, who uses flexible carbon-fiber blades in races.

Pistorius has long argued that he should be allowed to compete alongside able-bodied athletes in races, but athletics authorities banned him from doing so in last year's Olympic games, claiming that his blades gave him an unfair advantage over able-bodied athletes.

But the new study by Alena Grabowski at the Massachusetts Institute of Technology suggests the authorities may have come to the wrong conclusion.

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Nature News: The rise and fall this year of the Joint Dark Energy Mission (JDEM)—a satellite meant to pin down the repulsive force that is accelerating the universe's expansion—is partly due to strife between two US agencies, NASA and the Department of Energy, and a third potential partner, the European Space Agency.

In addition, scientists working on the JDEM designs have not presented a unified front, owing to disagreements over the best observational method to use at a time when an influential astrophysics panel is about to prioritize the next decade's best and most organized missions.

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ScienceNOW: When Spanish conquistadors seized the Inca emperor Atawalpa in 1532, they demanded an enormous ransom of silver and gold that took weeks to collect.

Such an enormous stash suggests that the Andean people knew sophisticated metallurgy, but there has been little evidence to support this.

Now a team of geologists and archaeologists have found clues that may indicate that these indigenous people refined gold with mercury amalgamation, an important metallurgical technique that is still in use today.

Wired.com: Beaming high-powered lasers into the sky allows scientists to study changing weather patterns, pollution in Earth’s atmosphere, and even gravity on the Moon. But if one of those helpful lasers happens to cross paths with an airplane, it can temporarily blind or distract the pilot and potentially cause a crash.

The current method to avoid plane–laser collisions is decidedly low-tech: Federal Aviation Administration regulations require anyone who’s sending a laser up into the atmosphere to employ multiple human observers, called “spotters,” to watch for planes flying within 25 degrees of the laser beam. Now, researchers have created a radio-tracking device that can perform the same task as a pair of eyes, without the potential for human error.

NYTimes.com: Despite a six-year effort to build trusted computer chips for military systems, the Pentagon now manufactures in secure facilities run by American companies only about 2 % of the more than $3.5 billion of integrated circuits bought annually for use in military gear.

That shortfall is viewed with concern by current and former US military and intelligence agency executives who argue that the menace of so-called Trojan horses hidden in equipment circuitry is among the most severe threats the nation faces in the event of a war in which communications and weaponry rely on computer technology.

Nature: Quantum systems habitually leak information, limiting their usefulness for practical applications. By optimally reversing the leak, this information loss has been reduced to a trickle in the solid state.

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guardian.co.uk: It can see to the edge of the observable universe. It can peer back in time to the aftermath of the Big Bang. Just don't ask it to send the secret of creation by e-mail.

The R332 million ($40 million) Southern African Large Telescope (SALT) is an internationally renowned science facility with everything but fast broadband. Its astronomers have found download speeds so slow that they are forced to send their cosmic findings by road.

The problem is all too familiar to South African residents: painfully slow service delivery. Politicians have called on a telephone company to resolve the matter "before the country's standing as a credible international scientific partner is irreparably damaged."

The Daily Telegraph: Growers are using powerful cameras on board a satellite 500 miles above Earth's surface to take images of their vineyards, showing them where to plant vines and when to harvest the grapes.

The high-resolution pictures are so accurate they can calculate the number of leaves per square meter which is directly proportional to the quality and yield of grapes.

Farmers will also be able to scan surrounding areas to see what land may be good for cultivation and so help the industry expand.

The technology known as Oenoview is developed by Infoterra, a division of the European Aeronautic Defence and Space Company, and has already been used in various wine-growing areas of France.

It works by calculating the density of foliage on vines by analyzing the light that reflects off them.

Usatoday.com: The most likely explanation for what force could have permanently bent a ring in our Milky Way Galaxy within the last 60 million years appears to be a giant clump of dark matter.

The dark matter is suspected to consist of enigmatic physics particles born in the fiery aftermath of the Big Bang and weighing as much as 10 million suns.

Left behind by this cataclysm was a tilted swirl of newborn stars circling within the galaxy called the "Gould Belt," which incidentally may have sent comets hurtling towards Earth, suggests astrophysicist Kenji Bekki of Australia's University of New South Wales in a recent Monthly Notices of the Royal Astronomical Society journal.

Science: Many aerosols cool the atmosphere (a negative forcing), whereas ozone and black carbon aerosol have a warming effect (a positive forcing).

There is thus a strong motivation for treating air pollution control and climate change in common policy frameworks, argue Almut Arneth and colleagues in Science.

However, changes in pollutant and precursor emissions, atmospheric burden, and radiative forcing are not necessarily proportional.

Drew T. Shindell and colleagues at NASA Goddard Institute for Space Studies in New York, report that current models do not capture many of the complex atmospheric processes involving aerosols and reactive trace gases.

As Arneth and colleagues state:

Changing aerosol burdens may alter local and regional cloud cover and precipitation, change the intensity or timing of the monsoon circulation, and even shift precipitation across national borders. Changes in cloud cover and precipitation will also feed back on the photochemistry and rainout of short-lived species. These issues must be considered if aerosol emissions are to become part of climate policy.

Given the toxicity of pollutants, the question is not whether ever stricter air pollution controls will be implemented, but when and where. The jury is out on whether air pollution control will accelerate or mitigate climate change. Still, the studies available to date mostly suggest that air pollution control will accelerate warming in the coming decades.

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The Observer: At first glance, the piece of metal in Steve Myers's hands could be taken for a harmonica or a pen. Only on closer inspection can you make out its true nature.

Myers, director of accelerators at the CERN particle physics laboratory outside Geneva, is clutching a section of copper piping from which a flat electrical cable is protruding.

It looks unremarkable. Yet a piece of cable like this one was responsible last year for the world's most expensive short circuit.

More than $50 million-worth of damage was done to the Large Hadron Collider (LHC), the most advanced particle accelerator ever built, a few days after its ceremonial opening.

It has taken Myers—and hundreds of other CERN scientists—more than a year to pinpoint the guilty piece of cable and repair the wreckage.

"It was a very small piece, but it did immense damage," he said. It remains to be seen whether Myers can fix CERN's tattered technological reputation in the process—when his team restart their great machine in a few weeks. "I am not a nervous person," said the 63-year-old Belfast-born engineer. "And that is probably just as well."

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Physics Today: A Russian Rokot launcher has successfully taken off from the Plesetsk Cosmodrome with Europe's Soil Moisture and Ocean Salinity satellite on board.

SMOS, a small 658-kg satellite, will provide the first global maps of the amount of moisture held in soils and of the quantity of salts dissolved in the oceans.

"Salinity is one of the drivers for the Thermohaline Circulation, the large network of currents that steers heat exchanges within the oceans on a global scale," says Volker Liebig, ESA's director of Earth observation programs. "Its survey has long been awaited by climatologists who try to predict the long-term effects of today's climate change."

The satellite was developed by ESA in cooperation with France's CNES and Spain's Centro para el Desarrollo Tecnológico Industrial (CDTI).

Its only instrument is called the Microwave Imaging Radiometer using Aperture Synthesis (MIRAS). The device works by connecting together 69 receivers mounted on three deployable arms to measure the temperature of the reflection of Earth's surface in the microwave frequency range. This temperature is linked to both the actual temperature of the surface and its conductive characteristics, which are in turn linked to soil moisture for land surface and to water salinity for sea surface.

"The data collected by SMOS will complement measurements already performed on the ground and at sea to monitor water exchanges on a global scale," says Liebig. "Since these exchanges—most of which occur in remote areas—directly affect the weather, they are of paramount importance to meteorologists."

SMOS is the second satellite launched under ESA's Earth Explorer program to gather new environmental data. It follows the Gravity and steady-state Ocean Circulation Explorer (GOCE), which was launched in March.

Next February, Cryosat-2 will be launched to measure the thickness of the ice sheets. This will be followed in 2011 by ADM-Aeolus—designed to study atmospheric dynamics—and the Swarm mission to monitor the weakening of Earth's magnetic field. Finally in 2013 the EarthCARE mission will study clouds and aerosols.

Nature: Materials that combine ferroic properties—such as ferromagnetism and ferroelectricity—are highly desirable, but rare. A new class of multiferroic solids heralds a fresh approach for making such materials.

Multiferroics are attractive candidates for use in electrically controllable microwave elements, magnetic-field sensors and possibly even in spintronics.

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After the slow-burning evolution of hominins in Africa, our ancestral populations erupted out into Eurasia in a geological eye-blink, spread into the Americas by way of the Bering land bridge (sea levels being somewhat lower during the ice ages) and finally reaching even the remotest islands of oceania around twelve thousand years ago.

Today we're ubiquitous. Even our pre-industrial ancestral cultures...occupied a slew of geographical environments that put cockroaches to shame.

So you'd think that, to a first approximation, the Earth is inhabitable by human beings. And this tends to colour our approach the prospects of finding extrasolar planets that might be hospitable to human life.

"Actually," says Charles Stross, "I think this is not quite the case. In fact, to a first approximation, from the perspective of prospective interstellar colonists, the Earth is uninhabitable."

That we could imagine otherwise bespeaks a profound cognitive bias on our part (and a degree of relativism: because when all's said and done, the Earth is a lot less hostile than, say, the surface of Venus or the cloud base of Jupiter).

Why is the Earth uninhabitable? To find out, read the entire column.