December 2009 Archives

Nature News: Two lines of evidence nearly brought down the last-minute climate agreement brokered last week in Copenhagen by US President Barack Obama: studies indicating that the impacts of global warming could be more severe than previously thought, and that rich countries could do more to counter the problem without breaking the bank.

Now, negotiators are seeing whether they can strengthen a deal nearly universally acknowledged as weak — or whether even the mounting scientific evidence on the most dire effects of climate change will be enough to forge a more meaningful deal.

SPACE.com: The trouble-plagued, delayed, and cost-overrun Mars Science Laboratory mission is crawling out of the technical and financial doghouse.

Still, there's one issue that could keep the roughly $2.3 billion NASA mission grounded: titanium parts that may not be strong enough for the robotic rover.

Physics Today: CLOUD (cosmics leaving outdoor droplets) is a novel experiment at CERN to investigate the possible influence of galactic cosmic rays on Earth's clouds and climate by studying the microphysical interactions.

Using the 50-year-old proton synchrotron, researchers simulate cosmic rays passing through Earth's atmosphere, in hopes of revealing the extent to which the constant background drizzle of charged particles affects cloud formation.

Earlier experiments have suggested that ionization causes clouds to "seed" and that ionization is influenced by the type and quantity of cosmic rays that reaching Earth.

CLOUD has been running since 2006 and proved that cosmic rays bombarding Earth's atmosphere may have an influence on the amount of cloud cover through the formation of new aerosols (tiny particles suspended in the air that seed cloud droplets).

This result is supported by satellite measurements, which show a possible correlation between cosmic-ray intensity and the amount of low cloud cover. Clouds exert a strong influence on Earth's energy balance; changes of only a few percent have an important effect on the climate. Understanding the microphysics in controlled laboratory conditions is a key to unravelling the connection between cosmic rays and clouds.

The experiment

The initial stage of the experiment uses a prototype detector in a particle beam. CLOUD uses CERN's Proton Synchrotron to send a beam of particles - the 'cosmic rays' - into a reaction chamber. The effect of the beam on aerosol production will be recorded and analyzed.

The roots of the experiment can be traced as far back as two centuries, to the time when the astronomer royal, William Herschel, noticed a correlation between sunspots and the price of wheat in England. Herschel's observation was the first to suggest that solar variation may affect Earth's climate. Solar-climate variability has remained a great puzzle since that time, despite an intensive scientific efforts.

During the 'Little Ice Age' around the 17th and 18th centuries, when sunspots all but disappeared for 70 years, the cosmic ray intensity increased and the climate cooled. Apparently that was merely the latest of around a dozen similar events over the past 10 000 years. At present, there is no established reason for the Sun's brightness to fluctuate on these time scales. The possibility that galactic cosmic rays, which are modulated by changes of the solar wind, may directly influence the climate is therefore attracting the interest of scientists.

The CLOUD collaboration brings together atmospheric physicists, solar physicists, and cosmic-ray and particle physicists to address a key question in the understanding of clouds and climate change. "CERN is a unique environment for this experiment," says CLOUD spokesperson Jasper Kirkby of CERN.

The first beam data from the full CLOUD experiment is expected in 2010.

Clouds are one of the primary factors in determining global surface temperature, but the United Nation's Intergovernment Panel on Climate Change admits that current level of scientific understanding of them is limited.

Wired.com: Researchers have showed the first functional transistor made from a single molecule. The transistor, which has a benzene molecule attached to gold contacts, could behave just like a silicon transistor.

The molecule’s different energy states can be manipulated by varying the voltage applied to it through the contacts. And by manipulating the energy states, researchers were able to control the current passing through it.

NPR: During the holiday season we see images of lots of geometrically incorrect snowflakes.

Chemist Thomas Koop thinks ice crystals are masterpieces of natural beauty. Unfortunately, he says, "This beauty is sometimes corrupted."

Koop, a professor at Bielefeld University in Germany, says the problem is that many of these images show ice crystals with five or eight sides. In other words, he says, they are scientific abominations.

Related news story
Christmas card snowflakes 'corrupt nature' by defying laws of physics

washingtonpost.com: Manmade climate change could bring parching droughts to the Southwest and pounding rainstorms to Washington, put Vermont maple sugar farms out of business and Key West underwater over the next century, according to a federal report released during the summer.

The report, a compilation of work by government scientific agencies, provided the most detailed picture yet of the United States in 2100, if nothing is done to cut greenhouse gas emissions. It found that a warmer world, with average US temperatures increasing four to 11 degrees, would significantly alter natural ecosystems and urban life.

Nature News: The first analysis of emissions from commercial airline flights shows that they are responsible for 4–8% of surface global warming since surface air temperature records began in 1850—equivalent to a temperature increase of 0.03–0.06 °C overall.

The analysis, by atmospheric scientists at Stanford University in Palo Alto, California, also shows that in the Arctic, aircraft vapor trails produced 15–20% of warming.

NYTimes.com: He is good-natured, funny, and thought to be among the smartest men in physics: Frank A. Wilczek, 58, a professor at the Massachusetts Institute of Technology, was one of three winners of the 2004 Nobel Prize in Physics and is a frequent columnist for Physics Today.

The award came for work Wilczek had done in his 20s, with David Gross of Princeton University, on quantum chromodynamics, a theoretical advance that is part of the foundation of modern physics.

The New York Times provides an edited version of two conversations with Wilczek, in October and this month.

guardian.co.uk: From Leonardo da Vinci to Le Corbusier, the golden ratio is believed to have guided artists and architects over the centuries.

Leonardo is thought to have used the golden ratio, a geometric proportion regarded as the key to creating aesthetically pleasing art, when painting the Mona Lisa.

Now a US academic believes he has discovered the reason why it pleases the eye.

According to Adrian Bejan, professor of mechanical engineering at Duke University in Durham, North Carolina, the human eye is capable of interpreting an image featuring the golden ratio faster than any other.

Physics Today: Our solar system is passing through a cloud of interstellar material, nicknamed the "local fluff" or the "Local Interstellar Cloud" by astronomers and now data from the decades-old Voyager spacecraft can explain why the material exists. The results are published in Nature.

An artist's concept of the Local Interstellar Cloud, also known as the "local fluff." Credit: Linda Huff (American Scientist) and Priscilla Frisch (University of Chicago)

"Using data from Voyager, we have discovered a strong magnetic field just outside the solar system," explains co-author Merav Opher, a NASA heliophysics guest investigator from George Mason University. "This magnetic field holds the interstellar cloud together and solves the long-standing puzzle of how it can exist at all."

The discovery has implications for the future when the solar system will eventually bump into other, similar clouds in our arm of the Milky Way galaxy.

The local fluff is about 30 light-years wide and contains a wispy mixture of hydrogen and helium atoms at a temperature of 6000 °C.

The existential mystery of the fluff has to do with its surroundings.

About 10 million years ago, a cluster of supernovae exploded nearby, creating a giant bubble of million-degree gas. The fluff is completely surrounded by this high-pressure supernova exhaust and should be crushed or dispersed by it.

"The observed temperature and density of the local cloud do not provide enough pressure to resist the 'crushing action' of the hot gas around it," says Opher.

So how does the Fluff survive? The Voyagers have found an answer.

"Voyager data show that the fluff is much more strongly magnetized than anyone had previously suspected--between 4 and 5 microgauss," says Opher. "This magnetic field can provide the extra pressure required to resist destruction."

NASA's two Voyager probes have been racing out of the solar system for more than 30 years. They are now beyond the orbit of Pluto and on the verge of entering interstellar space.

"The Voyagers are not actually inside the local fluff," says Opher. "But they are getting close and can sense what the cloud is like as they approach it."

The fluff is held at bay just beyond the edge of the solar system by the Sun's magnetic field, which is inflated by solar wind into a magnetic bubble more than 10 billion km wide.

Called the "heliosphere," this bubble acts as a shield that helps protect the inner solar system from galactic cosmic rays and interstellar clouds. The two Voyagers are located in the outermost layer of the heliosphere, or "heliosheath," where the solar wind is slowed by the pressure of interstellar gas.

Voyager 1 entered the heliosheath in December 2004; Voyager 2 followed almost 3 years later in August 2007. These crossings were key to Opher and her team's discovery.

The size of the heliosphere is determined by a balance of forces: Solar wind inflates the bubble from the inside while the local fluff compresses it from the outside. The spacecraft's crossings into the heliosheath revealed the approximate size of the heliosphere and, thus, how much pressure the local fluff exerts. A portion of that pressure is magnetic and corresponds to the ~5 microgauss Opher's team has reported in Nature.

The fact that the fluff is strongly magnetized means that other clouds in the galactic neighborhood could be too.

Eventually, the solar system will run into some of them, and their strong magnetic fields could compress the heliosphere even more than it is compressed now.

Additional compression could allow more cosmic rays to reach the inner solar system, possibly affecting terrestrial climate.

Related Link
A strong, highly tilted interstellar magnetic field near the solar system

1337arts: MIT students Justin Lee and Oliver Yeh have devised a low budget mechanism for space photography using off-the-shelf components: weather balloons, helium, styrofoam cooler, handwarmers, cell phone, and camera. The space photography balloon they built was launched on September 2nd, reached an altitude of 18 miles,

Space.com: Incredibly powerful waves of plasma rippling across the surface of the sun and dubbed "solar tsunamis" were first observed years ago, but were thought to be an optical illusion. Scientists have now confirmed, though, that they are really real.

latimes.com: Carbon dioxide, of course, is the poster gas for climate change.

But carbon dioxide accounts for only half the world's greenhouse gas emissions.

And a few simple strategies can be used to reduce the other pollutants that cause global warming.

Those sources include so-called black carbon, soot from incompletely burned fossil fuels and biomass, including that produced by ships and cooking stoves that collects in the atmosphere and on ice and prevents sunlight from being reflected back into space; hydrofluorocarbon chemicals, known as HFCs, used in refrigerators and air conditioners worldwide; and methane, which emanates from coal mines and landfills.

Science News: In a paper to be published in Acta Astronautica, physicist Philip Metzger of NASA's Kennedy Space Center and colleagues describe a technique to plot the paths and determine the densities of worrisome detritus kicked up during launch. This method could help flight engineers know instantly which pieces of debris threaten the spacecraft

Related Link
Photogrammetry and ballistic analysis of a high-flying projectile in the STS-124 space shuttle launch

Wired.com: As much as the 787 Dreamliner looks like the jet that carried you on that cramped, uncomfortable flight last month, almost everything about it is new.

From the extensive use of composite materials and advanced aerodynamics to its fuel-efficient Rolls Royce engines and all-electric systems, Boeing is betting the 787 will be the plane to usher in a cleaner, greener future for the airline business.

Boeing claims the 787 is 20 percent more fuel-efficient than comparably sized jets. With fuel being airlines' number one cost after payroll, Boeing's plan to build a thriftier airplane came at just the right time, said analyst Richard Aboulafia of the Teal Group.

Nature News: The conclusion that our planet is warming thanks to human activity must not be forgotten amid discussion of research ethics, say climatologists Hans von Storch and Myles Allen.

In a recent survey of US citizens conducted by electronic media company Rasmussen Reports, 49% of 1,000 respondents said that they have "very closely or somewhat closely" followed news reports about the CRU e-mail leak, and 59% find it "very likely or somewhat likely" that, in order to support their own theories and beliefs about global warming, some scientists have falsified research data. The Swedish daily newspaper Aftonbladet asked its readers—beginning on 21 November, just after the first publication of the CRU e-mails—if they considered the climate change threat to be oversold, and 51% of the almost 65,000 respondents thought so. After years of communication, researchers have to face the fact that a large body of public opinion still does not trust the evidence presented to them by the scientific community.

NYTimes.com: The ceremonial pipe organ of the 18th century was a masterpiece of human ingenuity, so elegant in its outward appearance that a casual observer could only guess at the complexity that lay within.

The builders were precision craftsmen celebrated for their skill in hand-making thousands of moving parts and in shaping and tuning metal and wooden pipes to mimic the sounds of each instrument in an orchestra.

The effect was breathtaking. "Each instrument speaks to you in a different way," said Hans Davidsson, a concert organist, sitting before the console of the organ at the cavernous Christ Church, Episcopal, in Rochester.

The organ, the Craighead-Saunders, is a unique instrument, not only because of its lovely sound, but also because it is a nearly exact copy of a late Baroque organ built by Adam Gottlob Casparini of East Prussia in 1776. The original stands in the Holy Ghost Church in Vilnius, Lithuania.

Various: Two space-based solar power projects, one that will happen in the next six years in California, and a longer term project in Japan may revive plans to beam power from space to the Earth.

California regulators proposed a plan to approve a 15-year contract with the US company Solaren Corp. to supply space-based solar power to utility giant Pacific Gas & Electric (PG&E) by 2016.

The Japan Aerospace Exploration Agency (JAXA) has also teamed up with a private Japanese coalition to design a solar space station for launch by the 2030s.

The plants collect solar power in orbit and beam the power to the Earth in the form of microwaves. The technical and economic challenges involved are immerse, says physicist Marty Hoffert, to space.com, not the least of which is that coal is cheap he adds.

Nature News: Nitrogen now stored in the planetary crust and mantle may have prevented the early Earth from freezing, scientists suggest. The study lends weight to the idea that on geological timescales atmospheric pressure helps to regulate climate and habitability of Earth-like planets.

SPACE.com: Even though NASA's Mars rover Spirit has been trapped in the sand for months, the robot has still managed to report new facts about the red planet—all by just spinning its wheels.

These findings shed light on the history of water on Mars.

The Guardian: The Copenhagen climate talks were a disaster says Mark Lynas in the Guardian.

That much is agreed. But the truth about what actually happened is in danger of being lost amid the spin and inevitable mutual recriminations. The truth is this: China wrecked the talks, intentionally humiliated Barack Obama, and insisted on an awful "deal" so western leaders would walk away carrying the blame. How do I know this? Because I was in the room and saw it happen.

China's strategy was simple: block the open negotiations for two weeks, and then ensure that the closed-door deal made it look as if the west had failed the world's poor once again. And sure enough, the aid agencies, civil society movements and environmental groups all took the bait...

...All this raises the question: what is China's game? Why did China, in the words of a UK-based analyst who also spent hours in heads of state meetings, "not only reject targets for itself, but also refuse to allow any other country to take on binding targets?" The analyst, who has attended climate conferences for more than 15 years, concludes that China wants to weaken the climate regulation regime now "in order to avoid the risk that it might be called on to be more ambitious in a few years' time".

This does not mean China is not serious about global warming... But China's growth, and growing global political and economic dominance, is based largely on cheap coal. China knows it is becoming an uncontested superpower; indeed its newfound muscular confidence was on striking display in Copenhagen. Its coal-based economy doubles every decade, and its power increases commensurately. Its leadership will not alter this magic formula unless they absolutely have to.

The BBC also lists reasons for the failure of the talks in a piece called "Why did Copenhagen fail to deliver a climate deal?"

Nature News: The US Department of Energy should build two dedicated isotope-production facilities, costing about $65 million in total, to solve worsening supply problems for researchers in medicine, physical sciences, and national security. That's the conclusion from a panel convened by the energy department's Nuclear Science Advisory Committee (NSAC).

Science: Predicting the binding rules of quantum particles is a formidable task.

Even for as few as three particles, one would need to know precisely all the details of the mutual interactions among them.

Notable exceptions have been predicted to arise if the interaction between the particles is very large, a condition where universal binding laws are expected to appear.

Because no available physical system composed of atoms, nuclei, or even elementary particles was suitable to observe the phenomenon, these ideas have been mainly confined to theory.

In Science, Scott E. Pollack and colleagues present evidence for the presence of universal scaling laws simultaneously occurring for three- and four-body bound states in an ultracold atomic system.

The observation confirms both old and new theoretical predictions, thus providing a fuller understanding of universal binding.

Related Links
Universal few-body binding
Universality in three- and four-body bound states of ultracold atoms

Physics Today: Researchers at Rice University and Baylor College of Medicine (BCM) have created a single nanoparticle that can be tracked in real time with MRI as it homes in on cancer cells, tags them with a fluorescent dye, and kills them with heat.

The all-in-one particle is one of the first examples from a growing field called "theranostics" that develops technologies physicians can use to diagnose and treat diseases in a single procedure.

The research is available online in the journal Advanced Functional Materials. Tests so far involve laboratory cell cultures, but the researchers said MRI tracking will be particularly advantageous as they move toward tests in animals and people.

"Some of the most essential questions in nanomedicine today are about biodistribution—where particles go inside the body and how they get there," said study co-author Naomi Halas. "Noninvasive tests for biodistribution will be enormously useful on the path to FDA approval, and this technique—adding MRI functionality to the particle you're testing and using for therapy—is a very promising way of doing this."

The all-in-one particles are based on nanoshells—particles Halas invented in the 1990s that are currently in human clinical trials for cancer treatment. Nanoshells harvest laser light that would normally pass harmlessly through the body and convert it into tumor-killing heat.

In designing the new particle, Halas partnered with Amit Joshi, assistant professor in BCM's Division of Molecular Imaging, to modify nanoshells by adding a fluorescent dye that glows when struck by near-infrared (NIR) light. NIR light is invisible and harmless, so NIR imaging could provide doctors with a means of diagnosing diseases without surgery.

In studying ways to attach the dye, Halas's graduate student, Rizia Bardhan, found that dye molecules emitted 40–50 times more light if a tiny gap was left between them and the surface of the nanoshell. The gap was just a few nanometers wide, but rather than waste the space, Bardhan inserted a layer of iron oxide that would be detectable with MRI. The researchers also attached an antibody that lets the particles bind to the surface of breast and ovarian cancer cells.

In the lab, the team tracked the fluorescent particles and confirmed that they targeted cancer cells and destroyed them with heat. Joshi said the next step will be to destroy whole tumors in live animals. He estimates that testing in humans is at least two years away, but the ultimate goal is a system where a patient gets a shot containing nanoparticles with antibodies that are tailored for the patient's cancer. Using NIR imaging, MRI, or a combination of the two, doctors would observe the particles' progress through the body, identify areas where tumors exist, and then kill them with heat.

"This particle provides four options—two for imaging and two for therapy," Joshi said. "We envision this as a platform technology that will present practitioners with a choice of options for directed treatment."

Eventually, Joshi said, he hopes to develop specific versions of the particles that can attack cancer at different stages, particularly early-stage cancer, which is difficult to diagnose and treat with current technology. The researchers also expect to use different antibody labels to target specific forms of the disease. Halas said the team has been careful to choose components that either are already approved for medical use or are already in clinical trials.

"What's nice is that every single component of this has been approved or is on a path toward FDA approval," Halas said. "We're putting together components that all have good, proven track records."

Science News: A cloud of ultracold atoms can store a beam of yellow light for 1.5 seconds, says a new paper by researchers led by Lene Hau of Harvard University.

The new study is "a beautiful demonstration," says Irina Novikova, a physicist at the College of William & Mary in Williamsburg, Virginia. Before this result, she says, light storage was measured in milliseconds. "Here, it's fractional seconds. It's a really dramatic time."

Related Link
Creation of long-term coherent optical memory via controlled nonlinear interactions in Bose–Einstein condensates

Bulletin of the Atomic Scientists: The belief that the US is the only declared nuclear power that isn't modernizing its nuclear arsenal is fast becoming an article of faith in nuclear weapon policy circles, says Kingston Reif in the Bulletin.

From this belief arises a dangerous argument: US allies and adversaries are adding new nuclear weapons and capabilities, while Washington is allowing its nuclear forces to atrophy. Opponents of President Barack Obama's nonproliferation and disarmament agendas are using this idea as a way of undermining his plans, alleging that by not modernizing, the US is in danger of being surpassed by Russia and China. Yet these arguments are specious and misleading.

By narrowly defining "modernization" as the production and deployment of new warheads and delivery vehicles, an inappropriate standard is set by which to judge the health of a nuclear arsenal. What matters far more than the age of warheads and other equipment is whether a country has a reliable, credible deterrent. Viewed in this light, the US cannot be said to be falling behind: Washington takes continual steps to ensure that its arsenal remains dominant, and indeed, its nuclear arsenal remains second to none.

Popular Science: Everyone knows light exposes film, but other forms of radiation do as well—a fact you can use to take pictures in some pretty unusual ways.

It's also how radioactivity was first discovered. In 1896, French physicist Henri Becquerel stored some x-ray film in a drawer along with a uranium rock which, he found after developing the film, had exposed the film.

It's not hard to repeat Becquerel's experience at home with standard film. Theodore Gray at Popular Science explains how with Fujifilm ISO 3000 instant film.

ScienceNOW: Nitrogen atoms are needed to make many important chemicals from drugs to fertilizers.

But getting those atoms into chemicals is challenging, because nitrogen molecules are tough nuts to crack.

They consist of two atoms sharing a stubborn triple bond, which chemists can break up only by scorching them with temperatures of up to 500 °C. And that results in the simple chemical ammonia, which needs further processing to produce more complicated compounds.

Now chemists have bypassed the energy-intensive reaction and devised a new one that splits molecular nitrogen at room temperature and synthesizes a common fertilizer.

The American Natural History Museum: Since 1998, the American Museum of Natural History and the Hayden Planetarium have engaged in the three-dimensional mapping of the universe.

The above movie (best seen in high definition) starts in Earth's atmosphere and pulls out further and further into the cosmos.

The Sun comes into focus, the orbits of the solar system shrink smaller and smaller, the constellations Sagittarius and Scorpio stretch and distort, and, as the Milky Way recedes, the spidery structure of millions of other galaxies comes into view. Then, you reach the limit of the observable universe, the afterglow of the Big Bang.

The movie is based on precise, scientifically accurate observations and research and is part of a new exhibit called Visions of the Cosmos: From the Milky Ocean to an Evolving Universe at the Rubin Museum of Art in New York City which opened on the 11 December.

Last year, some 30,000 people downloaded the Digital Universe—which is based on the same maps—to their personal computers. The software will soon be updated with a more accurate and user-friendly software interface and is available to the public at no cost.

BBC News: Keeping global temperature rise under 2 °C will be almost impossible unless carbon emissions begin to fall within a decade, analysis suggests.

The conclusion comes from a study by the UK Met Office (UKMO).

Even if emissions peaked in 2020, there would be a 50% chance of temperatures rising by more than 2 °C, the target adopted by the G8 at its July summit.

Meeting the lower target of 1.5 °C favored by some developing countries is virtually impossible, the UKMO says.

SPACE.com: NASA's Mars Reconnaissance Orbiter slipped into a protective "safe mode" in late August, stalling its science observations but safeguarding the $720 million probe from further damage. Instead of rousing the orbiter within a few days, as in past glitches, NASA engineers spent months trying to find the source of the probe's inexplicable computer rebooting malfunctions.

"The patient is out of danger, but more steps have to be taken to get it back on its feet," said Jim Erickson, the spacecraft's project manager at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.

JPL engineers beamed the 4-year-old orbiter a vital software upgrade last week to patch a potentially mission-killing scenario in the spacecraft's onboard computer. That scenario, the unlikely occurrence of back-to-back computer reboots, could have sent the powerful Mars orbiter offline for good, mission managers said.

The satellite's resurrection began 30 November with the software update, and new commands are being sent this week to check the spacecraft's science operations. Actual science observations may resume in earnest next week, mission managers said.

CDMS group/Physics Today: The Cryogenic Dark Matter Search (CDMS) experiment, located a half mile underground at the Soudan mine in northern Minnesota claims to have seen two events that may be dark matter. The evidence however, is not conclusive, but does limit the interaction range for seeing dark matter, and rules out some theories on how dark matter behaves.

A more detailed story will appear on the Physics Today Update section on the 28 December.

What is dark matter?

Astronomical observations from telescopes, and satellites, and measurements of the cosmic microwave background have led scientists to believe that most of the matter in the universe neither emits nor absorbs light.

This dark matter would have provided the gravitational scaffolding that caused normal matter to coalesce into the galaxies we see today. In particular, scientists think that our own galaxy is embedded within an enormous cloud of dark matter. As our solar system rotates around the galaxy, it moves through this cloud.

Particle physics theories suggest that dark matter may be composed of weakly interacting massive particles (WIMPs). Scientists expect these particles to have masses comparable to, or perhaps heavier than, atomic nuclei.

Although such WIMPs would rarely interact with normal matter, they may occasionally scatter from an atomic nucleus like billiard balls, leaving a small amount of energy that might be detectable under the right conditions.

Detecting WIMPS

The CDMS experiment uses 30 germanium and silicon detectors in an attempt to detect such WIMP scatters.

The detectors are cooled to temperatures very near absolute zero.

Particle interactions in the crystalline detectors deposit energy in the form of heat, and in the form of charges that move in an applied electric field. Special sensors detect these signals, which are then amplified and recorded in computers for later study.

A comparison of the size and relative timing of these two signals can allow the experimenters to distinguish whether the particle that interacted in the crystal was a WIMP or one of the numerous known particles that come from radioactive decays, or from space in the form of cosmic rays.

These background particles must be highly suppressed if we are to see a WIMP signal. Layers of shielding materials, as well as the half-mile of rock above the experiment, are used to limit the background "noise."

New results

The CDMS experiment has been searching for dark matter at Soudan since 2003. Previous data have not yielded evidence for WIMPs, but have provided assurance that the backgrounds have been suppressed to the level where as few as one WIMP interaction per year could have been detected.

The CDMS group is now reporting on a new data set taken in 2007-08, which approximately doubles the sum of all past data sets.

With each new data set, the CDMS group must carefully evaluate the performance of each of the detectors, excluding periods when they were not operating properly.

Detector operation is assessed by frequent exposure to sources of two types of radiation: gamma rays and neutrons.

Gamma rays are the principal source of normal matter background in the experiment.

Neutrons are the only type of normal matter particles that will interact with germanium nuclei in the billiard ball style that WIMPs would, although neutrons frequently scatter in more than one of our detectors.

Those calibration data are carefully studied to see how well a WIMP-like signal (produced by neutrons) can be seen over a background (produced by gamma rays).

The expectation is that no more than one background event would be expected to be visible in the region of the data where WIMPs should appear.

Since background and signal regions overlap somewhat, achievement of this background level required the CDMUS group to throw out roughly 2/3 of the data that might contain WIMPs, because these data would contain too many background events.

All of the data analysis is done without looking at the data region that might contain WIMP events. This standard scientific technique, sometimes referred to as "blinding," is used to avoid the unintentional bias that might lead one to keep events that have some of the characteristics of WIMP interactions but that are really from background sources.

After all of the data selection criteria have been completed, and detailed estimates of background "leakage" into the WIMP signal region are made, the CDMUS group must "open the box" and see if there are any WIMP events present.

In this new data set there are indeed two events seen with characteristics consistent with those expected from WIMPs.

However, there is also a chance that both events could be due to background particles. A strict set of criteria for determine whether a new discovery has been made, in essence that the ratio of signal to background events must be large enough that there is no reasonable doubt.

Typically there must be less than one chance in a thousand of the signal being due to background. In this case, a signal of about 5 events would have met those criteria. The CDMS group estimate that there is about a one in four chance to have seen two backgrounds events, so the CDMS group is not claiming to have discovered WIMPs.

Instead they say that the rate of WIMP interactions with nuclei must be less than a particular value that depends on the mass of the WIMP. The numerical values obtained for these interaction rates from this data set are more stringent than those obtained from previous data for most WIMP masses predicted by theories.

Such upper limits are still quite valuable in eliminating a number of theories that might explain dark matter.

What comes next?

While the same set of detectors could be operated at Soudan for many more years to see if more WIMP events appear, this would not take advantage of new detector developments and would try the patience of even the most stalwart experimenters (not to mention theorists). A better way to increase the sensitivity to WIMPs is to increase the number (or mass) of detectors that might see them, while still maintaining the CDMS group's ability to keep backgrounds under control.

This is precisely what CDMS experimenters (and many other collaborations worldwide) are now in the process of doing. By summer of 2010, the CDMS group hopes to have about three times more germanium nuclei sitting near absolute zero at Soudan, patiently waiting for WIMPs to come along and provide the perfect billiard ball shots that will offer compelling evidence for the direct detection of dark matter in the laboratory.

Vanityfair.com: Compared with the market-driven, killer-app insta-culture of the Digital Age, the new Large Hadron Collider exists in a near-magical realm, a $9 billion cathedral of science that is apparently, in any practical sense, useless.

The LHC is an almost unimaginably long-term project. It was conceived a quarter-century ago, was given the green light in 1994, and has been under construction for the last 13 years, the product of tens of millions of man-hours.

It's also gargantuan: a circular tunnel 17 miles around, fitted out with more than $9 billion worth of steel and pipe and cable more reminiscent of Jules Verne than Steve Jobs.

The believe-it-or-not superlatives are so extreme and Tom Swiftian they make you smile. The LHC is not merely the world's largest particle accelerator but the largest machine ever built.

The goal--and it's a hope, a dream, a set of strong suspicions, rather than a certainty--is to achieve a deeper, better, truer understanding of the fundamental structure and nature of existence.

In other words, it's one of the most awesome scientific enterprises of all time, even though it looks like a monumental folly. Or else, possibly, the reverse.

Physics Today: Three papers indicate new candidates for rocky Earth-type planets around other star systems.

David Charbonneau and colleagues published in Nature the clearest evidence yet for an Earth-type planet only 2.7 times larger than the Earth.

Two nearby stars, similar to the Sun, have been found to harbor "super-Earths"—rocky planets larger than Earth but smaller than ice giants such as Uranus and Neptune—of five to seven times to the size of the Earth. These results, to be published in the Astrophysical Journal and in the Monthly Notices of the Royal Astronomical Society, suggest that low-mass planets may be common around nearby Sun-like stars.

"Over the last 12 years or so nearly 400 planets have been found, and the vast majority of them have been very large―Jupiter mass or even larger," says researcher Paul Butler of the Carnegie Institution's Department of Terrestrial Magnetism. "These latest planets are part of a new trend of finding much smaller planets—planets that are more comparable to Earth."

A new technique

Charbonneau and his colleagues discovered their new low-mass planet by using eight 40-cm diameter telescopes, coupled with IR CCD light detectors. With these telescopes they looked at stars to see which ones regularly dimmed for periodic intervals, indicating the passage of a planet. The dimness is proportional to the size of the planet relative to the star. By checking small stars they were able to tease out smaller planets from the background noise.

One star, a red dwarf called GJ 1214, which is about 42 light-years from Earth, repeatedly dimmed for 52 minutes every 1.6 days, indicating a planet with an orbit of 1.6 days. The group calculated that it had a radius of 12% of that of the star, which is roughly 2.7 times the size of Earth.

The drag caused by the planet on GJ 1214 allowed the group to calculate its density, of 1.9 g cm^-3, compared with Earth's, which is 5.5 g cm^-3, which suggests that because water's density is 1 g cm^-3 , the planet is a mixture of rock and water, with other trace gases.

"Despite its hot temperature, this appears to be a waterworld," said Zachory Berta, a graduate student at the Harvard-Smithsonian Center for Astrophysics, who first spotted the hint of the planet among the data. "It is much smaller, cooler, and more Earthlike than any other known exoplanet."

Berta added that some of the planet's water should be in the form of exotic materials like Ice VII—a crystalline form of water that exists at pressures greater than 20,000 times Earth's sea-level atmosphere.

Renowned planet hunter Geoffrey Marcy from the University of California, Berkeley, writes in Nature:

"If this planet is 50% water, is it really kin of our Earth? Or did it form in a manner similar to that of Saturn or Neptune, with a rocky core that acquired large amounts of ices and gas gravitationally? By contrast, Earth has only 0.06% water, and very little H and He gas, having formed in a dry environment. This new planet is close to Earth in size, but perhaps not next of kin."

The next step for astronomers is to try to directly detect and characterize the atmosphere, which will require the Hubble Space Telescope.

"Since this planet is so close to Earth, Hubble should be able to detect the atmosphere and determine what it's made of," said Charbonneau. "That will make it the first super-Earth with a confirmed atmosphere—even though that atmosphere probably won't be hospitable to life as we know it."

Rocky planets round Sun-like stars

The international team of researchers, co-led by Butler and Steven Vogt of the University of California, Santa Cruz, was able to detect the new planetary systems by combining data from observations spanning several years at the W. M. Keck Observatory in Hawaii and the Anglo-Australian Telescope in New South Wales, Australia.

The researchers used the subtle "wobbling" of the stars caused by the planets' gravitational pull to determine the planets' size and orbits. Greg Henry at Tennessee State University independently monitored the brightness of the stars to rule out stellar "jitter"―roiling of gases on a star's surface that can be confused with a planet-induced wobble.

The bright star 61 Virginis, visible with the naked eye in the constellation Virgo, is only 28 light-years from Earth and closely resembles the Sun in size, age and other properties.

Earlier studies had eliminated the possibility of a Jupiter-sized planet orbiting 61 Virginis. In this study, the researchers found evidence of three low-mass planets, the smallest of which is five times the mass of Earth and speeds around the star once every four days.

A comparison of the orbits of the planets of 61 Virginis with the inner planets in our solar system. All three planets discovered to date in this system would lie inside the orbit of Venus.

Butler points out that the signal produced by this planet was one of the smallest ever detected. "One has to be very cautious when you claim a discovery," he says. "What gives us confidence is that we see the signal from two separate telescopes, and the two signals match up perfectly."

The other newly-discovered system orbits the star HD 1461, located 76 light-years from Earth. HD 1461 also closely resembles the Sun and is visible in the constellation Cetus. The researchers found clear evidence for one planet 7.5 times the mass of Earth and possible indications of two others. The 7.5-Earth-mass planet, designated HD 1461b, is intermediate in size between Earth and Uranus. It orbits its star once every six days.

These planets have orbits close to their stars and so they would be too hot to support life or liquid water. But Butler says that they point the way toward finding similar planets in similar orbits around nearby M-dwarfs, stars that are typically less than half the mass of the Sun and typically put out less than 2% the Sun's energy. "These sorts of planets around M dwarfs actually would be in a liquid water zone," he says. "So we are knocking on the door right now of being able to find habitable planets."

Paul Guinnessy

Related papers
A super-Earth transiting a nearby low-mass star Nature
61 Vir paper (to appear in The Astrophysical Journal)
23 Lib paper (submitted to the Monthly Notices of the Royal Astronomical Society)

Related links
Paul Butler's earthbound planet search web page

Related news stories
Extrasolar planets: Water world larger than Earth Nature
Super-earth found close by, may host water Science News
'Waterworld' planet six times the size of Earth discovered The Daily Telegraph
Nearby Super-Earth may be a waterworld Space.com
Super-Earth found close by, may host water sciencenews

Wired.com: Inspired by videos of renowned hacker Johnny Chung Lee who turned the $40 Nintendo Wiimote remote controller into a finger-tracking device and a touchscreen white board, physicist Rolf Hut of Delft University of Technology in the Netherlands has built a Wiimote wind sensor.

"It was just a bendy pole with an empty bottle on top with an LED light on the bottle," Hut said. "And it swayed in the wind."

The Wiimote can track just about anything: All that's needed is an LED light. Hydrologist Willem Luxemburg, also from Delft University of Technology demonstrated a hacked water-level sensor made from a Wiimote and a plastic boat at the meeting of the American Geophysical Union in San Francisco.

washingtonpost.com: An aquatic glider called the Scarlet Knight became the first robot to cross an ocean last week.

Scarlet Knight, also called RU-27, was at sea for 221 days. Her predecessor had disappeared on a similar trip, probably killed by a shark.

The people responsible for building, funding, and flying Scarlet hope the end of the robot's successful voyage will mark a new start in ocean and climate research.

Nature: Discussion needs to be open about how exploitation of Earth's internal heat can produce earthquakes, says Domenico Giardini, so that the alternative-energy technology can be properly utilized.

BBC News: The Moon has the coldest place in the solar system measured by a spacecraft.

Nasa's Lunar Reconnaissance Orbiter (LRO) has used its Diviner instrument since July to probe the insides of permanently shadowed craters on Earth's satellite.

Over the last few months temperatures in the lunar polar regions have changed gradually as the lunar seasons have evolved.

The tilt of the Moon's spin axis is only 1.54 degrees, and as a
consequence, lunar seasons are barely noticeable in most locations on
the Moon.

However, at the north and south poles, the height of the Sun above the horizon varies by more than 3 degrees over the course of the year. This affects the percentage of sunlit regions and surface temperatures at the poles.

During October Diviner observed the passage of summer solstice in
the southern hemisphere and winter solstice in the northern hemisphere.

The LRO launch date was chosen so that its orbital plane passed
through the noon to midnight plane in October, allowing Diviner to measure the extremes of polar temperatures.

It found mid-winter, nighttime surface temperatures inside the coldest craters—the southwestern edge of the floor of Hermite crater, the southern edges of the floors of Peary and Bosch craters in the northern polar region—can dip as low as minus 249 °C (26 Kelvin).

"One would have to travel to a distance well beyond the Kuiper belt to find objects with surfaces this cold," said the Diviner team on their website.

"The Moon has one of the most extreme thermal environments of any body in the Solar System," said David Paige.

Various: A new study from the National Cancer Institute projects 29 000 excess cancers from the 72 million CT scans that Americans got in 2007 alone. Nearly 15 000 of those cancers could be fatal.

It has been known for sometime that doctors had been overprescribing the number of CT scans for their patients, but this is one of the first comprehensive studies in the US that has quantified the risk using actual medical data.

Richard Knox at NPR reports that one of the reasons for the large number of scans is because doctors have been seduced by the high-resolution images CT scans produce, and have not considered the risk to the patient of using high-intensity x rays.

"Physicians [and their patients] cannot be complacent about the hazards of radiation or we risk creating a public health time bomb," said Rita Redberg, editor of Archives of Internal Medicine, which published the paper.

Children, younger adults and women are especially susceptible. Two-thirds of the excess cancers will occur in women, the NCI researchers say.

Projected Future Cancers Possibly Related To CT Scans In U.S.

The bars in the chart above indicate the projected average number of future cancers for each age range (95% uncertainty limits) that could be related to 2007 CT scans performed in the US, according to age at exposure. The lower and upper values represent the possible margin of error from the mean estimate.

"Although a guiding principle in medicine is to ensure that the benefit of a procedure or therapy outweighs the risk, the explosion of CT scans in the past decade has outpaced evidence of their benefit," said Redberg.

Related Links
Projected cancer risks from computed tomographic scans performed in the United States in 2007
Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer
Radiation from CT scans may raise cancer risk NPR
CT scans may pose higher risk of cancer than first thought The Daily Telegraph
Overuse of CT scans will lead to new cancer deaths, a study shows The Los Angeles Times

NYTimes.com: It is not easy to reinvent the wheel, but researchers at the Massachusetts Institute of Technology are giving it their best shot.

The Senseable City Laboratory at MIT has designed a wheel called the Copenhagen Wheel that captures the kinetic energy released when a rider brakes and saves it for when the rider needs a boost.

The Copenhagen Wheel was unveiled yesterday at the COP15 United Nations Climate Conference.

Wired.com: A team of US Geological Survey scientists have developed a web service that combines seismic data about an earthquake with tweets of surprise and angst from the popular microblogging service's users.

The goal of the project is to improve emergency response by providing a crowd-sourced window of the conditions on the ground immediately following a quake.

Physics Today: Google is working on developing a quantum computer, announced Google's Hartmut Neven at the Neural Information Processing Systems conference (NIPS 2009) in Vancouver, Canada, last week.

Neven, who is the company's technical lead manager for image recognition, gave details of the presentation on the Google research blog.

The reason for Google's interest in quantum computing is speed. As the size of the internet increases exponentially it is becoming harder and harder for Google to maintain the fast speed of the service without having to resort to building massive server farms.

A quantum-based computer could speed up searches dramatically and add a new layer of features to google's existing features, especially on images. As Neven states in the blog:

Assume I hide a ball in a cabinet with a million drawers. How many drawers do you have to open to find the ball? Sometimes you may get lucky and find the ball in the first few drawers but at other times you have to inspect almost all of them. So on average it will take you 500,000 peeks to find the ball. Now a quantum computer can perform such a search looking only into 1000 drawers. This mind boggling feat is known as Grover's algorithm.

The company has spent three years working on quantum adiabatic algorithms with the Canadian company D-Wave providing the hardware.

D-Wave's processors work by magnetically coupling superconducting loops called rf-SQUID flux qubits. "It is not easy to demonstrate that a multi-qubit system such as the D-Wave chip indeed exhibits the desired quantum behavior," says Neven.

At NIPS 2009 Neven demonstrated what google had achieved so far. The company built a detector that has learned to spot cars by looking at example pictures. "There are still many open questions," says Neven, "but in our experiments we observed that this detector performs better than those we had trained using classical solvers running on the computers we have in our data centers today."

Related Links
Primer in quantum algorithms
Training a large scale classifier with the quantum adiabatic algorithm
NIPS 2009 demonstration: Binary classification using hardware implementation of quantum annealing

ScienceNOW: In the world of nanotechnology, few things get as much billing as nanotubes. Experts say that these cylinders composed of one-molecule-thin sheets could someday be used in everything from superstrong jet engines to cancer cures. Now researchers think they've found a way to make large amounts of an elusive type of nanotube that could provide even more impressive applications.

Related Link
Very long single- and few-walled boron nitride nanotubes via the pressurized vapor/condenser method

NYTimes.com: In a speech given just a few weeks before he was lost at sea off the California coast in January 2007, Jim Gray, a database software pioneer and a Microsoft researcher, sketched out an argument that computing was fundamentally transforming the practice of science.

Gray called the shift a "fourth paradigm." The first three paradigms were experimental, theoretical, and, more recently, computational science. He explained this paradigm as an evolving era in which an "exaflood" of observational data was threatening to overwhelm scientists. The only way to cope with it, he argued, was a new generation of scientific computing tools to manage, visualize, and analyze the data flood.

Mother Jones: Attracting almost no attention, Russia may have already conducted the first-ever geoengineering field trial.

The journal Russian Meteorology and Hydrology recently published a new kind of geoengineering study whose lead author is the journal's editor, the prominent Russian scientist Yuri A. Izrael.

Izrael and his team of scientists mounted aerosol generators on a helicopter and a car chassis, and proceeded to blast out particles at ground level and at heights of up to 200 meters. Then they attempted to measure just how much sunlight reaching Earth was reduced due to the aerosol plume.

This small-scale intervention was effective, the Russian scientists say. And in an accompanying article on geoengineering alternatives, Izrael and colleagues note that "Already in the near future, the technological possibilities of a full scale use of [aerosol-based geoengineering] will be studied."

The Associated Press: E-mails stolen from climate scientists show they stonewalled skeptics and discussed hiding data—but the messages don't support claims that the science of global warming was faked, according to an exhaustive review by the Associated Press.

Physics Today: VISTA, the Visible and Infrared Survey Telescope for Astronomy, has officially gone operational.

Jim Emerson, one of the VISTA project leaders said, "history has shown us some of the most exciting results that come out of projects like VISTA are the ones you least expect—and I'm personally very excited to see what these will be."

VISTA is a survey telescope working at infrared wavelengths and is the world's largest telescope dedicated to mapping the sky. At the heart of VISTA is a 3-ton camera containing 16 detectors sensitive to infrared light, with a combined total area of 67 million pixels.

To avoid swamping the faint infrared radiation coming from space, the camera is cooled to -200 °C and is sealed with the largest infrared-transparent window ever made.

The first image to be released publicly (see right) shows a 14-minute exposure of the star-forming region known as the Flame Nebula, or NGC 2024, in the constellation of Orion. At optical wavelengths, the object is hidden by giant dust clouds. VISTA, which works at infrared wavelengths can see through the dust at the cluster of very young stars at the object's heart.

The wide-field VISTA view also includes the glow of the reflection nebula NGC 2023, just below center, and the ghostly outline of the Horsehead Nebula (Barnard 33) towards the lower right.

The bright bluish star towards the right is one of the three bright stars forming the Belt of Orion.

Its large mirror, wide field of view, and very sensitive detectors will reveal a completely new view of the southern sky.

Location, location, location

The telescope is based near the European Southern Observatory's Very Large Telescope (VLT) in Paranal, Chile, an ideal spot for carrying out infrared observations due to the low water content of the atmosphere—water absorbs most infrared light—and the high altitude of 2635 meters above sea level—which limits the amount of atmospheric turbulence that can effect the air above the telescope.

VISTA's main mirror is 4.1 meters across and is the most highly curved mirror of this size and quality ever made—its deviations from a perfect surface are less than a few thousandths of the thickness of a human hair.

Because VISTA has a large field of view it can both detect faint sources and also cover wide areas of sky quickly. Each VISTA image captures a section of sky covering about 10 times the area of the full Moon and it will be able to detect and catalog objects over the whole southern sky with a sensitivity that is 40 times greater than that achieved with earlier infrared sky surveys such as the Two Micron All-Sky Survey.

VISTA was originally conceived and developed by a consortium of 18 universities in the United Kingdom led by Queen Mary, University of London. When the UK joined ESO, VISTA was offered to the organization as an in-kind contribution as part of the UK's accession agreement.

ESO formally took over VISTA on 10 December 2009 at a ceremony at ESO's headquarters in Garching, Germany.

"VISTA is a unique addition to ESO's observatory on Cerro Paranal. It will play a pioneering role in surveying the southern sky at infrared wavelengths and will find many interesting targets for further study by the Very Large Telescope, ALMA, and the future European Extremely Large Telescope," says ESO Director General Tim de Zeeuw.

VISTA will spend almost all of its time mapping the southern sky in a systematic fashion. The telescope is embarking on six major sky surveys with different scientific goals over its first five years.

One survey will cover the entire southern sky and others will be dedicated to smaller regions to be studied in greater detail. VISTA's surveys will help our understanding of the nature, distribution, and origin of known types of stars and galaxies, map the three-dimensional structure of our galaxy and the neighboring Magellanic Clouds, and help determine the relation between the structure of the universe and dark energy and dark matter.

Paul Guinnessy

NPR: With or without a new treaty this month, the effort to curb climate change has accelerated since the 1997 Kyoto conference. Although the US never ratified the Kyoto Protocol, numerous efforts are under way in the US to limit warming by attacking the main culprit: burning fossil fuels.

NPR takes a look at some of the technologies, as well as social mechanisms, aimed at changing how we consume energy—and slow climate change.

New Scientist: Stephen Wolfram reckons he can model the entire universe using tiny computer programs. But despite being the creator of a "search engine" that provides answers, he still has to convince his peers that he's on the right track, as David Cohen discovers.

Institute Matters: With the public controversy over hacked e-mail messages from climate scientists, scientific integrity has, for some people, been put deeply in question.

Arguably the fundamental issue boils down to something described in a comment from the late Richard Feynman. He spoke of

"a kind of scientific integrity, a principle of scientific thought that corresponds to a kind of utter honesty--a kind of leaning over backwards. For example, if you're doing an experiment, you should report everything that you think might make it invalid--not only what you think is right about it: other causes that could possibly explain your results; and things you thought of that you've eliminated by some other experiment, and how they worked.... Details that could throw doubt on your interpretation must be given, if you know them.... If you make a theory, for example, and advertise it, or put it out, then you must also put down all the facts that disagree with it, as well as those that agree with it."

This quotation (from his lecture, Cargo Cult Science) appeared the other day in a Wall Street Journal letter to the editor from someone who sees it as a reminder of what climate scientists have forgotten. What I think, however—despite the lapses revealed in the hacked messages—is that it shows what climate scientists have remembered.

Science works the same in all its fields. If the integrity of science in general weren't assured to a very high degree—in the laboratory, in scientific publications, and in the practical consequences to which science leads—then neither the critics of climate scientists nor the rest of us could be using transistors, lasers, optical fibers, or pharmaceuticals. We couldn't fly with only a one-in-a-million chance of mishap, and our bridges and skyscrapers could fall down, and polio would still be feared.

Science is by its very nature an exploratory, trial-and-error venture which is also--sooner or later in every case--a self-correcting exercise. Ukrainian agronomist Trofim Lysenko's failed agricultural theories of the 1930s and 1940s and, more recently, such concepts as polywater, cold fusion, and human clones are examples of scientific pronouncements that were eventually proven wrong or fraudulent by the step-by-step process of examination, review, and repetition.

It's true that scientists are human and that the science enterprise can suffer from the frailties of any other human endeavor. I would rather think that scientists are less susceptible than are people in other professions by jealousies, excessive ego, and the desire for fame and fortune.

But these human faults do also affect scientists, which means that science sometimes suffers. Nevertheless, science recovers quickly because of its well-proven correction mechanisms that apply universally across disciplinary, political, and cultural boundaries.

The current attack on the integrity of climate science is based on the proposition that this particular field somehow operates with a special, deep disrespect for the skepticism principle that Feynman advocated in the comment quoted above.

I don't believe it.

H. Frederick Dylla

H. Frederick Dylla is the executive director of the American Institute of Physics, which publishes Physics Today. The views expressed here are the personal views of the author.

Science: Conventional solar technologies produce electricity, but most transportation fuel comes from oil. A new class of solar chemical reactors aims to make liquid fuels from air, water, and sunshine.

Physics Today: NASA's Hubble Space Telescope has made the deepest image of the universe ever taken in near-IR light.

Image credit: NASA

The faintest and reddest objects in the image are galaxies that formed 600 million years after the Big Bang. No galaxies have been seen before at such early times. The new deep view also provides insights into how galaxies grew in their formative years early in the universe's history.

The image was taken in the same region as the Hubble Ultra Deep Field (HUDF), which was taken in 2004 and is the deepest visible-light image of the universe.

Hubble's newly installed Wide Field Camera 3 (WFC3) collects light from near-IR wavelengths and therefore looks even deeper into the universe, because the light from very distant galaxies is stretched out of the ultraviolet and visible regions of the spectrum into near-infrared wavelengths by the expansion of the universe.

The photo was taken with the new WFC3/IR camera on Hubble in late August 2009 during a total of four days of pointing for 173,000 seconds of total exposure time. IR is invisible and therefore does not have colors that can be perceived by the human eye. The colors in the image are assigned comparatively short, medium, and long, near-IR wavelengths (blue, 1.05 microns; green, 1.25 microns; red, 1.6 microns). The representation is "natural" in that blue objects look blue and red objects look red. The faintest objects are about one-billionth as bright as can be seen with the naked eye.

Related News Picks

Various: A three-day conference on the relationship between science, religion, and society has been held at Pontifical Lateran University in Rome, Italy, to celebrate the 2009 International Year of Astronomy. A writeup of the conference appeared at Catholic.net.

Entitled "1609-2009: From Galilei's Telescope to Evolutionary Cosmology—Science, Philosophy and Theology in Dialogue," the conference began by clearing up the myths that still surround Galileo and his relationship with the Catholic Church.

Galileo facing the Roman Inquisition, painting by Cristiano Banti

Owen J. Gingerich, emeritus professor of astronomy and of history of science at Harvard University, swiftly ruled out the most famous and seemingly irrefutable accusation: that Galileo was tortured by the Church. The minutes of the interrogation, now preserved in the Vatican Archives, state that Galileo was to be "interrogated for vehement expression of heresy" and that included "legally being shown the instruments of torture."

In an e-mail to Physics Today, Gingerich expands on some aspects of his lecture. "In this International Year of Astronomy we read that with his telescope Galileo proved the Copernican system (that the Earth goes round the Sun)," he says. But Galileo proved no such thing, he adds.

"Galileo would dearly have loved to find an irrefutable proof of the motion of the earth, but instead all he could do was to make the motion of the earth more reasonable and to assure readers that the Copernican system was a coherent way to look at the world."

"What Galileo's Dialogo did was make the motion of the earth intellectually respectable, and not just a ridiculous idea as the vast majority of people believed at that time. When I present this interpretation, I am typically asked, "In that case, when was the aha! moment when the Copernican system was finally proved?"

"In astronomy textbooks the Foucault pendulum and the annual parallax of nearby stars are typically presented as proof for the motion of the earth. But those demonstrations came much too late, and by that time nearly everyone was already convinced by the Copernican cosmology."

"What happened was that a persuasive new theoretical structure had emerged—Newtonian physics described in Isaac Newton's Philosophiæ Naturalis Principia Mathematica—and the Principia was credentialed by a series of observations including Pierre Louis Maupertuis's demonstrations of the oblateness of the earth, the predicted return of Halley's comet, and James Bradley's discovery of the aberration of starlight. So I am not dismissing observations, which are critical in providing persuasion. But specific proofs were not what suddenly produced the acceptance of the Copernican cosmology."

Gingerich said that the Galileo controversy "essentially changed the way we do science because today science works primarily by persuasion and not by proof, and Galileo influenced how that happened."

Times Online: One of the most elaborate science experiments ever attempted—the Super-Kamiokande (Super-K) detector in Japan—got underway last month. The experiment involves a vast underground cavern, 50,000 tonnes of ultra-pure water, and thousands of light-sensitive detectors. Super-K's aim is to capture the neutrino, an elusive particle that has frustrated scientists for decades.

The machine, which successfully detected neutrinos for the first time on 22 November, should establish a more precise estimate of their mass as well determining fundamental laws governing neutrino behavior.

Physics Today: The NASA Mars rover Spirit, which got stuck in April, now has three wheels completely buried in the sand with little chance of being able to free itself.

Spirit Mars Rover (Artists impression. Credit: NASA)

On 3-4 December, a series of diagnostic tests, which were commissioned after the right-rear wheel stalled on attempts to free the rover, suggest that the wheel is close to failure, due either to the motor, the gearbox, or a rock in the wheel. Spirit already lost power to the right-front wheel in 2006.

The stalls occurred when NASA tried a two-step maneuver to extract Spirit from its location, which resulted in a 1.4-meter wheel spin and moving the rover forward by 0.5 millimeter.

Spirit's current position is a bad location for the rover to be in as the Martian winter approaches. Dust is gradually accumulating on the solar panels, limiting the charge to the battery, and the angle of the Sun in the southern hemisphere is such that the batteries could be completely exhausted by the time the Martian spring appears.

Spirit has survived a lot longer than it was originally designed for, and the mission was extended years beyond the initial proposal. However, the loss of a number of Mars probes in the last four years has helped justify keeping the rover programs operational. A tougher NASA budget next year may change that equation if the weather does not kill Spirit off.

ScienceNOW: Paper has been getting beat by electronics for years. But it may be about to stage a comeback. Researchers are reporting that they've made batteries and other energy-storage devices by printing layers of carbon nanotube–based ink atop standard photocopy paper. The result is a highly conductive sheet that can carry a charge and be easily incorporated into a flexible battery. Because of paper's low cost, that could help lower the price of batteries used in electric vehicles, wind farms, and other renewable sources.

Nature News: Rusi Taleyarkhan, of Purdue University, West Lafayette, Indiana, who claimed that he could perform "bubble fusion" in a table-top apparatus has been debarred from receiving federal funding for 28 months, according to the US Office of Naval Research.

Physics Today: The ATLAS experiment at the Large Hadron Collider has posted on its website evidence of a record-beating series of proton collisions at 2.36 TeV (1.18 TeV per beam). The previous record holder was Fermilab's Tevatron (at 1.96 TeV collisions).

The collider became the world's most powerful accelerator on 29 November. Since then CERN staff have been increasing the beam intensity, which in turn increases the number of potential collisions that can occur.

The speed at which the LHC is becoming operational has only been surpassed by the speed at which the first LHC paper using collision data was prepared and submitted by the ALICE collaboration. The paper was accepted by the European Physical Journal C on December 1.

The LHC is scheduled to shut down on 18 December for a two-week winter break. Early next year the beams will be increased in energy, first to 2 TeV and then up to 3.5 TeV, roughly half of the final operational energies the machine is expected to run at later in its lifetime.

One unknown side effect to the delays the LHC has faced this year is how expensive running the LHC during the winter will be to CERN. In past years high-energy experiments were shut down for winter, partly to conduct maintenance but also because electricity rates are 45% higher than in the summer.

Related LHC news picks

Paul Guinnessy

NPR: A NASA DC-8 plane equipped with lasers, ice-penetrating radar, and a gravity meter is revealing a dynamic and complex world beneath the massive ice sheet that covers Antarctica.

The plane is flying over Antarctica for six weeks as part of a mission to use airplanes to replace a dying NASA satellite that's been monitoring polar ice.

But the stopgap measure is providing a major scientific bonus: The DC-8 flies just 1500 feet above the ice and carries instruments that let scientists see right through the ice.

"It's going to change the way that we look at Antarctica," says Thomas Wagner, a NASA Cryosphere Program scientist.

San Francisco Chronicle: When physicist Frank Oppenheimer came back to the Bay Area from his Colorado ranch, he had a dream to create a new type of science museum.

It would be a place of wonder, he told a Chronicle reporter, "where human perception and awareness of the natural world" would awaken curious young minds to the phenomena of physics, the structure of chemical molecules, the behavior of living organisms, and the workings of the human mind."

The exhibits—"experiments," Oppenheimer called them—that he and his friends built for their museum—the Exploratorium— would so stimulate the curiosity of viewers that they would want to know more and more, asking the "whys" and "hows" and learning all the time.

Now celebrating its 40th anniversary, the Exploratorium grew to become world famous, but few visitors are aware of its singular role in changing the way teachers teach science—not just in the US, but in many other countries where reforming science education is more vital than ever.

Scientific American: Says Lawrence M. Krauss:

The rise of a ubiquitous Internet, along with 24-hour news channels has, in some sense, had the opposite effect from what many might have hoped.... It has instead provided free and open access, without the traditional media filters, to a barrage of disinformation....

.... Discerning the merits of competing claims is where the empirical basis of science should play a role. I cannot stress often enough that what science is all about is not proving things to be true but proving them to be false. What fails the test of empirical reality, as determined by observation and experiment, gets thrown out like yesterday’s newspaper. One doesn’t need to debate about whether the earth is flat or 6,000 years old. These claims can safely be discarded, and have been, by the scientific method.

What makes people so susceptible to nonsense in public discourse? Is it because we do such a miserable job in schools teaching what science is all about—that it is not a collection of facts or stories but a process for weeding out nonsense to get closer to the underlying beautiful reality of nature? Perhaps not. But I worry for the future of our democracy if a combination of a free press and democratically elected leaders cannot together somehow more effectively defend empirical reality against the onslaught of ideology and fanaticism.

NPR: Three former MIT students who formed their own company called Levant Power have developed a shock absorber for cars that takes the energy generated from bumps in the road and sends it to the drive train.

The prototype, called GenShock, along with computer simulations developed at the company, indicate that a heavy vehicle can save about 3% in fuel costs using the GenShock system.

csmonitor.com: After 12 years Mohamed ElBaradei stepped down on 27 November as head of the International Atomic Energy Agency.

He is replaced by Yukiya Amano, a quiet and experienced team player who jokingly tells colleagues he is the only Japanese they will ever meet who doesn't play golf, watch baseball, or sing karaoke.

The transition takes place amid growing international concern over Iran's nuclear program, which has increased its number of centrifuges (crucial for enriching uranium and making nuclear fuel) from zero to 8000 in recent years, with at least two violations of the IAEA rules.

Nature News: Giorgio Riccobene, a particle physicist at the Southern Laboratories of the Italian National Institute for Nuclear Physics (INFN) in Catania, was hoping to show that hydrophones could be used to detect subatomic particles called neutrinos that had come from deep space.

Giovanni Pavan, a marine biologist from the University of Pavia in Northern Italy, was there to help Riccobene deal with background noise in the recordings.

But what Riccobene and Pavan discovered as they analyzed data from a series of hydrophones placed 28 kilometers off shore was the sound clicks of sperm whales, more whales in fact than biologists believed to exist in the area (see also powerpoint presentation 7.9 Mb).

Physics Today: Los Alamos National Laboratory has conducted its first-ever double-viewpoint hydrodynamic test of a nuclear weapon component mockup at LANL's Dual Axis Radiographic Hydrodynamic Test (DARHT) facility.

DARHT has been operational for 10 years on one axis, but using a second axis simultaneously is a milestone for the facility. 

The test is part of the National Nuclear Security Administration's stockpile stewardship program to continue to maintain the viability of US nuclear weapons without having to resort to underground nuclear tests.

"This is an important development," said Brig. Gen. Garrett Harencak, NNSA principal assistant deputy administrator for military application. "The multiple X-ray images provided by [DARHT] will inform the critical work of our scientists and engineers across the nuclear security enterprise."

"Initial indications show excellent data return," said the hydrodynamic experiments division leader, David Funk.  "The baseline experiment captured five time-dependent X-ray images and a variety of data from other diagnostics of pressure, temperature, and timing.  This data provides the nation with one of the most rigorous tests of our capability to predict [nuclear] weapons performance."

Conducted inside a specially designed double-walled containment vessel, the test used high explosives to drive an implosion of a duplicate of a W78 nuclear warhead made from non-nuclear surrogate materials.  As the mockup is imploding, the DARHT facility fires two electron accelerators positioned at a 90-degree angle from one another to generate high-power x-rays that are used to create multiple images of the imploding device's inner workings, which are then compared with computer predictions.

The DARHT team solved a variety of technical challenges in the months and years leading up to this experiment.  "While the first axis of DARHT has been functioning nearly flawlessly for more than 10 years, the second axis is still an operational prototype of the world's longest pulsed electron linear accelerator, so the challenges have been monumental," said Funk.  "Just fitting the accelerator in the building had its challenges, leading to the use of a novel material with an exceptionally high magnetic field strength. Using standard materials would have required the accelerator to be five times bigger than it is, and it would not have fit in the building."

Other challenges included designing a cathode injector system that would supply enough electrical current to the accelerator and developing a target that is robust enough to survive four pulses from the extremely high-energy electron beam of the second axis.

"I couldn't be more proud of our team's accomplishments preparing and conducting this first test," said Funk.  "The test marks the beginning of what will be a very long operational lifetime for this important diagnostic tool in support of national security."

New Scientist: Solar cells have an unfortunate habit of reflecting back much of the light that hits them, rather than converting it into electricity. A technique that peppers the cells' surface with nanoscale domes could curb this tendency and improve efficiency by as much as 25% (Nano Letters, DOI: 10.1021/nl9034237).

The Economist: Airlines could take a more naturalistic approach to cutting jet-fuel use, and it would not require them to buy new aircraft.

The answer, says Ilan Kroo and colleagues at Stanford University, lies with birds. Since 1914, scientists have known that birds flying in formation—a V-shape, echelon, or otherwise—expend less energy.

Photo credit: John Avise, University of California, Irvine

The air flowing over a bird’s wings curls upwards behind the wingtips, a phenomenon known as upwash. Other birds flying in the upwash experience reduced drag, and spend less energy propelling themselves.

When applied to aircraft, the principles are not substantially different.

Kroo and his team modeled what would happen if three passenger jets departing from Los Angeles, San Francisco, and Las Vegas, and all traveling to London, were to rendezvous over Utah and assume an inverted V-formation.

They found that the aircraft consumed as much as 15% less fuel. Nitrogen-oxide emissions during the cruising portions of the flight fell by around a quarter.

Science: From early childhood we know that to interact with an object, we have either to go to it or to throw something at it. Yet, contrary to all our daily experience, there are spatially separated quantum systems that exhibit nonlocal correlations. Exploring how nature performs its trick of quantum nonlocality has led to new experiments that provide a deeper understanding of the tension between quantum physics and relativity and to proposals for disruptive technologies.

NYTimes.com: In a finding that is sure to add to one of the longest-running debates in music, a detailed analysis of the varnish on five instruments made by Antonio Stradivari reveals that he coated the wood with a rather humdrum mix of oil and resin. Those looking to the varnish as the secret to the master Italian violin maker’s renown, the study suggests, had best look elsewhere.

Physics Today: Rajendra Pachauri, the director general of the United Nations Intergovernmental Panel on Climate Change (IPCC), said in an interview with BBC Radio 4's The Report program that the IPCC will investigate allegations of data manipulation brought to light by the release of e-mails from a hacked server at the Climatic Research Unit at the University of East Anglia.

"We will certainly go into the whole lot and then we will take a position on it," he said. "We certainly don't want to brush anything under the carpet. This is a serious issue and we will look into it in detail."

Pachauri told the Guardian last week there was "virtually no possibility" of a few scientists biasing the advice given to governments by the IPCC.

"The processes in the IPCC are so robust, so inclusive, that even if an author or two has a particular bias it is completely unlikely that bias will find its way into the IPCC report," he said.

Andrew Watson, from the University of East Anglia's School of Environmental Sciences, says that "despite the best efforts of the skeptics, there is no instance in these e-mails that anyone has found so far—and there are millions of people looking—that suggests the scientists manipulated their fundamental data."

The next stage of international negotiations regarding a new greenhouse-gas emission treaty starts in Copenhagen on Monday and there is concern that the accusations by climate skeptics may derail progress in developing a new treaty.

The UK's climate change secretary Ed Miliband said: "We need maximum transparency including about all the data, but it's also very, very important to say one chain of emails, potentially misrepresented, does not undo the global science. The science is very clear about climate change and people should be in no doubt about that. There will be people that want to use this to try and undermine the science and we're not going to let them."

Paul Guinnessy

Related Links
Gordon Brown attacks 'flat-earth' climate change skeptics The Guardian
Climate science, from Bali to Copenhagen BBC

Science: Every autumn when Nobel Prize winners are announced and the world's most populous nation misses out—yet again—the mass media and blogs here blame an education system that values rote memorization over creativity. Widespread disaffection is a factor, Chinese state media observed, behind the National People's Congress's decision earlier this month to sack Education Minister Zhou Ji.

But true change may come only from the bottom up. In September, the government of Shenzhen, a city in southern China, appointed physical chemist Zhu Qingshi as president of the planned South University of Science and Technology (SUST). Zhu insisted on also being appointed the university's Communist Party secretary, making it clear he would be calling the shots.

The Daily Telegraph: The UK has lost its ability to attract the best scientists and its universities must pay academics more to reverse the "brain drain," according to research by economists.
 
Twice as many physicists from a sample of the world's elite left Britain after completing their first degree than 25 other leading scientific countries, the study found.

While Britain was second only to the US as the birthplace of the most highly-cited physicists, it fell below Germany, Switzerland, and Japan when current locations were compared.

Wired.com: Blue whales, the largest animals on Earth, are singing in ever-deeper voices every year. Among the suggested explanations are ocean noise pollution, changing population dynamics, and new mating strategies. But none of them is entirely convincing.

"We don't have the answer. We just have a lot of recordings," said Mark McDonald, president of Whale Acoustics, a company that specializes in the sonic monitoring of cetaceans.

McDonald and his collaborators first noticed the change eight years ago, when they kept needing to recalibrate the automated song detectors used to track blue whales off the California coast.

After collecting thousands of recordings taken over the last 40 years, he and his colleagues discovered that the songs' tonal frequency is falling every year by a few fractions of a hertz.

SPACE.com: All supernova explosions are violent affairs, but astronomers have spotted a new type of extremely bright cosmic explosion they think originates from an exceptionally massive star.

This breed of explosion has been long predicted, but never before seen. Like all supernovas, the blast is thought to have marked the end of a star's life. But in this case, that star may have started out with 200 times the mass of the Sun.

The supernova in question, SN2007bi, was observed in 2007 in a nearby dwarf galaxy. Scientists knew at once it was something different because it was about 50 to 100 times brighter than a typical supernova.

After analyzing its signature, astronomers published a paper in Nature confirming that it matches theoretical predictions of a so-called pair-instability supernova.

Nature News: With a US$820 million budget and about 3000 employees, the US National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, is an important supporter of basic research.

Nature discussed the future of the agency, part of the Department of Commerce, with newly confirmed NIST director Patrick Gallagher.

cleveland.com: In the labs and wind tunnels of NASA's Glenn Research Center and three other NASA facilities—Langley, Dryden, and Ames—the prospect of commercial supersonic flight is quietly coming out of mothballs. 

The back-to-basics plan lacks the hype of the government's three previous high-speed flight research efforts, which touted a future of large American-produced commercial supersonic fleets but failed to produce a viable design. 

"The programs in the past...were setting targets that were very audacious, to say the least," said Jay Dryer, director of NASA's Fundamental Aeronautics Program, of which supersonics research is a part. "I think we're going in with a more realistic expectation of what's possible, yet we're still pushing the state of the art." 

This time, NASA is taking an incremental approach. It intends to pave the way for small faster-than-sound "low-boom" business jets by 2015, 35- to 70-passenger commercial jets by 2020, and quiet airliners with the capacity and Mach 2 speed of the Concorde sometime after 2030.
 
"It's the next step in the evolution of the transportation system," said Glenn engineer Louis Povinelli, the supersonics project's senior technologist and chief scientist. "It's inevitable."

Science News: Want to make a planet that can sustain carbon-based life? Don't park it in orbit around a sunlike star.

"For the long term, the sun may not be the best star," says Edward Guinan of Villanova University in Pennsylvania, coauthor of a paper reporting a new model about the suitability of planets for life. Smaller, cooler stars called orange dwarf stars might be the most hospitable, he says.

ARN: Taiwan's Industrial Technology Research Institute (ITRI) showed off a number of flexible display screen technologies in Taipei last week as part of a show promoting e-readers and e-paper.

One of the newest technologies from ITRI was a flexible 4.1-inch color OLED (organic light-emitting diode) display.

"This is the first time we've showcased this OLED technology. It's more flexible and softer than before. It's for the next-era of portable devices," said John Chen, general director of the Display Technology Center at ITRI.

BBC News: Many recent earthquakes may have been the aftershocks of large quakes that occurred hundreds of years ago, according to scientists.

USATODAY.com: Since the 1997 international Kyoto accord to fight global warming, climate change has worsened and accelerated—beyond some of the grimmest of warnings made back then.

In Greenland and Antarctica, ice sheets have lost trillions of tons of ice. Mountain glaciers in Europe, South America, Asia, and Africa are shrinking faster than before.

And it's not just the frozen parts of the world that have felt the heat:

The world's oceans have risen by about an inch and a half.

Droughts and wildfires have turned more severe worldwide.

Temperatures over the past 12 years are 0.4 of a degree warmer than the dozen years leading up to 1997.

Even the gloomiest climate models back in the 1990s didn't forecast results quite this bad so fast.

"The latest science is telling us we are in more trouble than we thought," said Janos Pasztor, climate adviser to UN Secretary General Ban Ki-moon.

Nature: Electrical injection and detection of spin-polarized electrons in a silicon chip have now been demonstrated at room temperature, paving the way to the development of low-power semiconductor spintronics circuitry.