November 2009 Archives

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.

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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.

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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.

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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.

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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.

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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.

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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

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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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Water found in moon crater USA Today
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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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Fire news from Mt. Wilson Observatory

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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Soft colloids make strong glasses

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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Biomechanics of running indicates endothermy in bipedal dinosaurs

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 Guardian's science correspondent Ian Sample talks to Lynn Evans, project manager of Cern's Large Hadron Collider, who relives the moment he found out something had gone horribly wrong

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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Big dreams come true
Aufbau Ost: Max Planck's East German experiment

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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Running-specific prostheses limit ground-force during sprinting Biology Letters

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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Options given for the future of US particle astrophysics

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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Preserving electron spin coherence in solids by optimal dynamical decoupling

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.

Related Links
Clean the air, heat the planet?
Improved attribution of climate forcing to emissions

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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Related Politics
Congress expresses concern over LHC failures
UK prepares for tough science funding environment

Related Physics Today articles
Mostly recovered, the LHC readies for restart October 2009
Mishap shuts down LHC until April November 2008
Multiple problems push LHC start to next spring September 2007

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.

Related Link
Multiferroic behavior associated with an order−disorder hydrogen bonding transition in metal−organic frameworks (MOFs) with the perovskite ABX₃ architecture

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.