New Scientist: Using crime data from southern California, Jeffrey Brantingham of the University of California, Los Angeles, and his colleagues set out to calculate how the movements of criminals and victims create opportunities for crime, and how police can reduce it. They came up with a pair of equations that could explain how local crime hotspots form—which turned out to be similar to those that describe molecular reactions and diffusion.
February 2010 Archives
Science: What is the formula for the momentum of light zipping through a transparent material? That may sound like a question on a high-school physics quiz, but physicists have been debating the matter ever since two different formulas were proposed more than 100 years ago. Now Stephen Barnett, a theorist at the University of Strathclyde in Glasgow, U.K., says he has resolved the famed "Abraham-Minkowski dilemma." Both formulas are correct, he says, but they denote different things and apply in different contexts.
BBC News: It weighs almost a ton, has cost more than $2 billon and, in 2013, it will be lowered on to the surface of Mars with a landing system that has never been tried before.
The Mars Science Laboratory will "revolutionize investigations in science on other planets," says Doug McCuistion, director of Nasa's Mars exploration program.
It will, he says, lay the foundations for future missions that will eventually bring Martian rocks to Earth.
"The ability to put a metric ton on the surface... gives us the capability to undertake sample collection," says McCuistion. "To collect and launch samples back into orbit will require that size of a vehicle."
But it has been a rather bumpy road to revolution, including 1000 parts made from a "bad batch" of titanium
The project has been struggling with technical challenges for several years, but Jim Green, the director of Nasa's planetary science division, recently announced to the planetary science subcommittee that the project had finally turned the corner.
Nature News: Running more than a year behind schedule and at half its intended energy, the world's most powerful particle accelerator is slated to begin its first full scientific run this week. Along with relief, the occasion is bringing some soul-searching. One senior scientist who helped to build the Large Hadron Collider (LHC) at CERN, Europe's particle-physics laboratory near Geneva, Switzerland, is claiming that the cause of the delay—a major accident in 2008—could have been avoided.
"Any technical fault is a human fault," says Lucio Rossi, a physicist who oversaw the production of the accelerator's superconducting magnets. In a paper published this week, he concludes that the catastrophic failure of a splice between two magnets was not a freak accident but the result of poor design and lack of quality assurance and diagnostics. The project, he says, will be coping with the consequences for many months to come.
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LHC repair plan points to weaknesses in original design
Late start for Large Hadron Collider
KEK: The Japanese-led multinational T2K collaboration announced today that they had made the first detection of a neutrino which had travelled 295 km from their neutrino beamline at the Japanese Proton Accelerator Research Complex (J-PARC) facility in Tokai village to the Super- Kamiokande underground neutrino detector near the west coast of Japan.
"Switching on one of the world's first neutrino superbeams is a great achievement," said CERN Director General Rolf Heuer. "Even in a time of financial difficulty around the globe, it's important not to lose sight of the fact that basic science is and always will be a crucial element of progress. It is therefore heartening to see such an important new basic science initiative getting underway now."
"It is a big step forward," said T2K spokesperson Takashi Kobayashi. "We've been working hard for more than 10 years to make this happen."
J-PARC now produces the world's most powerful neutrino beams to study neutrino oscillations.
"Neutrinos are the elusive ghosts of particle physics," Kobayashi explains. "They come in three types, called electron neutrinos, muon neutrinos, and tau neutrinos, which used to be thought to be immutable."
Interacting only weakly with matter, neutrinos can traverse the entire earth with vastly less attenuation than light passing through a window. The very weakness of their interactions allows physicists to make what should be very accurate predictions of their behavior, and thus it came as a shock when measurements of the flux of neutrinos coming from the thermonuclear reactions which power our sun were far lower than predicted.
A second anomaly was then clearly demonstrated in 1998 by Super-Kamiokande, when it showed that the flux of different types of neutrino generated within our atmosphere by cosmic ray interactions was different depending on whether the neutrinos were coming from above or below (which should not have been possible given our understanding of particle physics). Other experiments, such as Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND), have conclusively demonstrated that these anomalies are caused by neutrino oscillations, whereby one type of neutrino turns into another.
The first T2K event seen in Super-Kamiokande is seen in the image above. Each dot is a photomulipler tube which has detected photons. The two circles of hits indicate that a neutrino has probably produced a particle called a π 0, perfectly in time with the arrival of a pulse of neutrinos from J-PARC. Another faint circle surrounds the viewpoint of this image, showing a third particle was created by the neutrino.
The T2K experiment has been built to make measurements of unprecedented precision of known neutrino oscillations, and to look for a so-far unobserved type of oscillation which would cause a small fraction of the muon neutrinos produced at J-PARC to become electron neutrinos by the time they reach Super-Kamiokande.
Observing the new type of oscillation would open the prospect of comparing the oscillations of neutrinos and anti-neutrinos, which many theorists believe may be related to one of the great mysteries in fundamental physics—why is there more matter than anti-matter in the universe? "The observation of this first neutrino means that the hunt has just begun," said Koichiro Nishikawa, director of the Institute for Particle and Nuclear Studies at KEK and founder of T2K. "The first physics results are expected later this year." Today's news he says, "is the beginning."
AAAS Meeting: Margaret Murnane and Henry Kapteyn group at JILA, a joint institute of the University of Colorado at Boulder and NIST, has made some breakthroughs on how to build a tabletop x-ray laser. The laser could be used for super high-resolution imaging, while also giving scientists a new way to at the nanoscale at objects such as a single cell.
Murnane and Kapteyn presented highlights of their research at the American Association for the Advancement of Science annual meeting in San Diego.
"Our goal is to create a laser beam that contains a broad range of x-ray wavelengths all at once that can be focused both in time and space," Murnane said. "If we have this source of coherent light that spans a huge region of the electromagnetic spectrum, we would be able to make the highest resolution light-based tabletop microscope in existence that could capture images in 3-D and tell us exactly what we are looking at. We're very close."
Most of today's x-ray lasers require so much power that they rely on fusion laser facilities the size of football stadiums or larger, making their use impractical. Murnane and Kapteyn generate coherent laser-like x-ray beams by using an intense femtosecond laser and combining hundreds or thousands of visible photons together with a desktop-size system.
They can already generate laser-like x-ray beams in the soft x-ray region and believe they have discovered how to extend the process all the way into the hard x-ray region of the electromagnetic spectrum.
"If we can do this, it could lead to all kinds of possibilities," Kapteyn said. "It might make it possible to improve x-ray imaging resolution at your doctor's office by a thousand times. The x-rays we get in the hospital now are limited. For example, they can't detect really small cancers because the x-ray source in your doctor's office is more like a light bulb, not a laser. If you had a bright, focused laser-like x-ray beam, you could image with far higher resolution."
Their method can be thought of as a coherent version of the x-ray tube, according to Murnane. In an x-ray tube, an electron is boiled off a filament, then it is accelerated in an electric field before hitting a solid target, where the kinetic energy of the electron is converted into incoherent x-rays. These incoherent x-rays are like the incoherent light from a light bulb or flashlight—they aren't very focused.
In the tabletop setup, instead of boiling an electron from a filament, they pluck part of the quantum wave function of an electron from an atom using a very intense laser pulse. The electron is then accelerated and slammed back into the ion, releasing its energy as an x-ray photon. Since the laser field controls the motion of the electron, the x-rays emitted can retain the coherence properties of a laser, Murnane said.
Being able to build a tabletop x-ray laser is just the beginning, said Kapteyn.
"An analogy that is pretty close to what is going on in this field is the MRI, which started as just a fundamental investigation," said Kapteyn. "People then started using it for microscopy, and then it progressed into a medical diagnostic technique."
The Economist: In 2008 part of the Wilkins ice shelf on the edge of the Antarctic peninsula suddenly disintegrated.
The Wilkins shelf may or may not have been the victim, ultimately, of climate change. Regardless of what weakened it, though, it was not rising temperatures that caused the sudden breakup. Peter Bromirski of the Scripps Institution of Oceanography in San Diego thinks he knows what did: a little-studied phenomenon called infragravity waves.
NPR: Doctors use expensive CT scanners and MRI machines thousands of times every day to look for brain damage. But sometimes cheap and simple is definitely better.
washingtonpost.com: Megacities are something new on the planet. Earthquakes are something very old. The two are a lethal combination, as seen in the recent tragedy in Port-au-Prince, where more than 200 000 people perished—a catastrophe that scientists say is certain to be repeated somewhere, and probably soon, with death tolls that once again stagger the mind.
Related news story
Disaster awaits cities in earthquake zones New York Times
Yahoo! News: The world weather agencies have agreed to collect more precise temperature data under a proposal from the UK's Met Office.
The proposal asks climate scientists around the world to measure land surface temperatures as often as several times a day, and allow independent scrutiny of the data—a move that would go some way toward answering demands by skeptics for access to the raw figures used to predict climate change.
"This effort will ensure that the datasets are completely robust and that all methods are transparent," said the Met Office. The agency added that "any such analysis does not undermine the existing independent datasets that all reflect a warming trend."
The proposal was approved in principle by some 150 delegates meeting under the auspices of the World Meteorological Organization this week in Antalya, Turkey.
Nature: The finding that the normal phase of an ultracold gas of fermionic atoms in the strongly interacting regime is close to a Fermi liquid isn't quite what theorists expected for these systems.
The Atlantic: In an age when scientists slice, dice, and replicate the human genome for research purposes, is our DNA private property? As ever more countries—and even private companies—launch spacecraft into the universe, shouldn’t we have clear rules in place about appropriate space etiquette? And with more kids than ever mastering Guitar Hero instead of hitting the books, isn’t there something different we can try to get them excited about math and science?
At the annual meeting of the American Association for the Advancement of Science this week, these were just a few of the topics explored by the scientists, engineers, educators, and policymakers in attendance. The Atlantic takes a look at some of the conversations.
guardian.co.uk: Ex-weatherman Anthony Watts says many US weather stations produce unreliable data because they are located next to artificial heat—but a scientific analysis suggests that, if anything, such stations underestimate warming.
Nature News: Roll out the micro-carpet—a new solar-cell design based on a blanket of silicon rods could produce electricity at a fraction of the cost of conventional solar devices.
SPACE.com: The stellar birth rate of the young universe has long been known to be much higher than it is today, but scientists weren't sure why the early universe was so fertile.
A new study finds that this could be because early galaxies had more cold gas to "feed" to forming baby stars.
Science: A view of a coastline appears as a fractal—an object that appears the same at all length scales (perhaps only statistically).
Fractals actually abound in nature, but fractals can occur in the quantum realm as well, even though they have never been observed there, until, perhaps, now.
In Science, Anthony Richardella and associates report direct measurements of quantum mechanical electron waves that indicate that they may also possess a fractal nature.
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Visualizing critical correlations near the metal-insulator transition in Ga1-xMnxAs
Times Online: The UK research councils (RCUK), which oversees the UK government’s spending on science and technology, has said it believes that many of the obstacles associated with producing fusion power are close to being overcome.
The RCUK wants to commit Britain to a 20-year research and construction plan that would see a fusion power station in operation around 2030. Didcot in Oxfordshire is among the sites under consideration for the European High Power laser Energy Research (HiPER) project: a facility dedicated to demonstrating the feasibility of laser driven fusion as a future energy source.
Nature News: International patent applications in 2009 dropped for the first time on the back of a double-digit fall in US applications—but China, with a 30% surge, claimed a bigger piece of the shrunken pie. Yet observers say the quality of Chinese applications has not kept pace with their volume, and the country still has far to go before it can establish itself as a dominant player in intellectual property.
The Economist: The great hope of transplant surgeons is that they will, one day, be able to order replacement body parts on demand. That possibility may be closer with the arrival of the first commercial 3D bio-printer for manufacturing human tissue and organs.
The new machine, which costs around $200,000, has been developed by San Diego–based Organovo, a company that specializes in regenerative medicine, and an Australian engineering and automation firm called Invetech.
To start with, only simple tissues, such as skin, muscle, and short stretches of blood vessels, will be made for research purposes.
Organovo expects that within five years, once clinical trials are complete, the printers will produce blood vessels for use as grafts in bypass surgery.
WSJ.com: Scientific revolutions are often led by the youngest scientists, and yet such innovation in the US could be at risk, says Jonah Lehrer in the Wall Street Journal, as the number of successful young scientists is dramatically shrinking.
In 1980, the largest share of grants from the National Institutes of Health went to scientists in their late 30s. By 2006 the curve had been shifted sharply to the right, with the highest proportion of grants going to scientists in their late 40s. This shift came largely at the expense of young scientists.
In 1980, researchers between the ages of 31 and 33 received nearly 10% of all grants; by 2006 they accounted for approximately 1%. And the trend shows no signs of abating: In 2007, the most recent year available, there were more grants to 70-year-old researchers than there were to researchers under the age of 30.
Science: Last fall, Iranian physicist Farhad Ardalan was named a fellow of the American Physical Society, in part because of his efforts to connect Iran to the global scientific community and strengthen bonds between Iran and the US.
The new class of fellows will be honored at the society's meeting next month in Portland, Oregon. But US consular officials have derailed Ardalan's application for a visa after telling him that US government records show he was arrested in the US in 1983 for an unspecified offense. They also say that he may have been involved in deportation proceedings 20 years earlier.
Ardalan denies both charges, and his US colleagues say that the State Department is making a big mistake. "He is precisely the kind of person who should be welcomed to the US," says Stanford University physicist Herman Winick.
Nature: A technique used primarily to study fundamental issues in quantum mechanics has now been shown to have promise as a powerful practical tool for making ultra-precise measurements.
NPR: A new study used cell phone billing data for 50,00 people in a European country to show that people's travel patterns are extremely predictable. That's true for both homebodies and jet setters. Regardless of age, language group, and so forth, people's movements were predictable 93% of the time. The study shows the emerging power of using cell phone data for social science research.
Science: One of the quests of condensed-matter physics is to discover materials with new types of collective electronic properties, such as the giant magnetoresistance materials now used for memory storage or high-temperature superconductors.
Such "strongly correlated electron" materials challenge our understanding and provide the grist for future technologies.
However, identifying new kinds of electronic behavior is still serendipitous, largely because the materials structures of greatest interest do not crystallize to order.
In Science H. Shishido and associates introduce a systematic approach based on molecular beam epitaxy for the preparation of complex interacting electron materials, thus opening up the possibility of making available many new structures not currently accessible to direct chemical synthesis.
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Tuning the dimensionality of the heavy fermion compound CeIn3
The Guardian: Philip Campbell, editor-in-chief of Nature, was forced to resign from an independent panel to investigate claims that climate scientists covered up flawed data on global warming, after skeptics questioned his impartiality.
The news came just hours after the panel's official launch, and after an interview emerged in which he said there was nothing to suggest a cover-up by climate scientists at the University of East Anglia.
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Climate data allegations to be investigated
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Tallahassee Democrat: Florida State University lured Mike Wetz away from the University of North Carolina with the offer of an assistant professor position in FSU’s highly regarded Department of Oceanography.
Wetz’s first day at FSU was 23 December 2008. Less than six months later, in June 2009, Wetz received a layoff notice.
Wetz had done nothing wrong, by all accounts. He was one of five faculty members in his 15-person department whose positions were being eliminated as FSU decided to merge oceanography, geological sciences, and meteorology in the wake of massive reductions in state revenue.
Two of his colleagues being terminated are tenured, which traditionally means their positions are secure.
Geological sciences fared even worse, losing 6 of 13 positions including four tenured faculty. No positions were eliminated in meteorology.
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APS Meeting - ISNS: A new gamma ray map of the universe produced by the Fermi Gamma-Ray Space Telescope shows that some cosmic rays are coming from exploding stars known as supernovas. The map was made public in Washington DC at the April meeting of the American Physical Society.
Credit: NASA|DOE|Fermi LAT Collaboration
Cosmic rays are energetic particles that stream through the universe. Some slam into Earth's atmosphere, triggering a cascade of other particles detectable on the ground. A popular theory in astrophysics holds that cosmic rays are created in supernovas.
Until now this has been difficult to prove due to the considerable distance cosmic rays must travel before they reach Earth. In addition magnetic forces can deflect cosmic rays during their trip through space, confusing our sense of their origin.
Some theories predict that some of the supernovae cosmic rays crash into nearby gas clouds in space, where they convert into gamma light. Unaffected by magnetism in space, it is this light that continues on toward Earth, eventually striking the Fermi telescope.
The telescope acts like a huge digital camera taking pictures of the supernova debris. Because it can take hundreds or thousands of years for the light to complete the trip to our planet, the light that we can currently see shows the supernova as it was centuries or millennia ago.
Stanford physicist Stefan Funk said that the gamma pictures, combined with observations made with other telescopes sensitive to other kinds of light, allowed astronomers to confirm that many high-energy cosmic rays come from supernovas.
Phillip F. Schewe
Inside Science News Service
Edited by Paul Guinnessy
NYTimes.com: Just as the worldwide shortage of technetium 99—radioactive isotope used in millions of medical procedures—is about to get worse, officials say a new source for the substance has emerged: a nuclear reactor in Poland.
The Daily Telegraph: The Sun follows an 11-year cycle in which its radiation output and sunspot activity waxes and wanes. Currently the Sun is at its minimum radiation output.
A new report in the UK suggests that as the Sun's output rises to a new maximum, satellite navigation devices will be susceptible from the expected increase in solar flares.
The bursts of radiation caused by the flares interfere with signals from satellites orbiting Earth, causing receivers to fail and lose track of their position.
Nature News: The burning of fossil fuels such as coal and oil releases carbon dioxide that alters the balance of carbon isotopes naturally found in the environment—an effect that is now being found in food, reveals a US study.
Science News: Once Martian sand grains hop, they don’t stop.
That’s the conclusion of a new aeolian study that finds sand can move on Mars without much windy encouragement.
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Dunes on Mars: How sand shifts without wind NPR
APS Meeting - New Scientist: Several times a month, teams of astronomers from three observatories blast the Moon with pulses of light from a powerful laser and wait for the reflections from a network of mirrors placed on the lunar surface by the Apollo missions, as well as two Soviet Lunokhod landers.
By timing the light's round trip, they can pinpoint the distance to the Moon with an accuracy of around a millimeter—a measurement so precise that it has the potential to reveal problems with general relativity.
But now Tom Murphy from the University of California, San Diego, thinks the mirrors have become coated in Moon dust. "The lunar reflectors are not as good as they used to be by a factor of 10," he says.
APS Meeting: Physics Today: Physicists at Brookhaven National Laboratory's Relativistic Heavy Ion Collider (RHIC) have discovered some additional experimental hints of why there is matter in the universe by replicating the conditions of the first microseconds after the Big Bang.
The results from RHIC's Pioneering High Energy Nuclear Interaction eXperiment (PHENIX) and STAR detector were discussed at the April meeting of the American Physical Society yesterday and published in Physical Review Letters.
When the Big Bang occurred, according to the symmetry rules that govern the universe, equal parts of matter and antimatter should have been created leading to all matter being annihilated. But this was not the case: Why?
A hot start
To find out, you have to replicate conditions of the early universe. RHIC can duplicate the conditions of the first microseconds by colliding gold atoms together near the speed of light. The resulting collision is hot enough to melt protons and neutrons into a quark gluon plasma, according to the PHENIX's researchers.
Predictions made prior to RHIC's initial operations in 2000 expected that the quark-gluon plasma would exist as a gas. But RHIC's first three years of operation showed that the matter produced at RHIC behaves as a liquid, whose constituent particles interact very strongly among themselves. This liquid matter has been described as nearly "perfect" in the sense that it flows with almost no frictional resistance, or viscosity. Such a "perfect" liquid doesn't fit with the picture of "free" quarks and gluons physicists had previously used to describe the quark-gluon plasma.
In papers published in 2005, RHIC physicists laid out a plan of crucial measurements to clarify the nature and constituents of this "perfect" liquid. Measuring the temperature early in the collisions was one of those goals. Models of the evolution of the matter produced in RHIC collisions had suggested that the initial temperature might be high enough to melt protons, but a more direct measurement of the temperature required detecting photons—particles of light—emitted near the beginning of the collision, which travel outward undisturbed by their surroundings.
"This was an extraordinarily challenging measurement," explained PHENIX spokesperson Barbara Jacak. "There are many ways that photons can be produced in these violent collisions. We were able to 'eliminate' the contribution from these other sources by exploiting RHIC's flexibility to measure them directly and to make the same measurement in collisions of protons, rather than of gold nuclei. Thus we could pin down excess production in the gold-gold collisions, and determine the temperature of the matter that radiated the excess photons. By matching theoretical models of the expanding plasma to the data, we can determine that the initial temperature of the 'perfect' liquid has reached about four trillion degrees Celsius." At its hottest stage, the infusion may reach 7 trillion °C.
"This is the hottest matter ever created in the laboratory" and qualifies as the "highest temperature known in our present universe," said Steven Vigdor, Brookhaven's associate laboratory director for nuclear and particle physics, who oversees research at RHIC.
Breaking the universe's rules
Cosmologists have predicted that the solution to this dichotomy of why equal amounts of matter and antimatter were not created would be bubbles or local regions in which there would be a breakdown in the existing rules governing the behavior of particles in the universe.
The symmetry "rule" suggests that events should occur in exactly the same way whether seen directly or in a mirror, with no directional dependence. But STAR has observed regions in the quark-gluon plasma at the heart of the RHIC collisions in which asymmetric charge separations occurs.
STAR observed that positively charged quarks may prefer to emerge parallel to the magnetic field in a given collision event, while negatively charged quarks prefer to emerge in the opposite direction. Because this preference would appear reversed if the situation were reflected through a mirror, it appears to violate mirror symmetry.
"In all previous studies of systems governed by the strong force among quarks and gluons, it has been found to very high precision that events and their mirror reflections occur at exactly the same rate, with no directional dependence," said Vigdor. "So this observation at STAR is truly intriguing."
STAR data also suggest the local breaking of another form of symmetry, known as charge conjugation–parity or CP invariance. According to this fundamental physics principle, when energy is converted to mass or vice versa according to Einstein's famous E=mc2 equation, equal numbers of particles and oppositely charged antiparticles must be created or annihilated. If CP symmetry had not been broken at some very early time in the evolution of our universe, the particles and antiparticles created in equal numbers in the Big Bang would subsequently have annihilated one another in pairs, leaving no matter to form the galaxies, stars, planets.
While some small violations of CP symmetry have been found in previous laboratory experiments, those violations are far too weak to account for the amount of matter remaining in the universe today.
"These new results thus suggest that RHIC may have a unique opportunity to test in the laboratory some crucial features of symmetry-altering bubbles," said Vigdor.
The signs of possible local CP violation at STAR cannot completely explain the global predominance of matter in today's universe, but they may offer some insight into how such symmetry violations occur. CERN's Large Hadron Collider, which restarts this week, will eventually produce collisions 3 times more powerful than those at RHIC to see if this quark-gluon plasma actually does transition into a gas.
RHIC will be upgraded over the next few years to investigate these broken symmetry effects more closely but there could also be less sexy explanations for the observed charge separation, said Berndt Mueller, a theorist at Duke University in Durham, North Carolina, to ScienceNOW's Lauren Schenkman. If more refined analyses do turn up conclusive evidence of parity violation, it would be like mining for silver and finding gold, said Mueller.
Paul Guinnessy
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Scientists re-create high temperatures from Big Bang USA Today
Hottest temperature ever heads science to Big Bang Reuters
In Brookhaven collider, scientists briefly break a law of nature New York Times
Particle collision puts twist in early universe ScienceNOW
New Scientist: Gil Bub and Peter Kohl's team at the University of Oxford wanted to record rat heart cells in action, so they trained two cameras on tissue samples in their lab. A high-speed movie camera filmed the cell's pulsing activity, while a normal stills camera captured detailed images. But aligning the two sets of images proved fiddly and frustrating.
So the team took an off-the-shelf video camera to pieces and rebuilt it to perform both roles, simultaneously recording high-speed video and high-resolution stills.
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The Economist: Thanks to advances in manufacturing techniques, which allow miniature mechanical components to be built into electronic chips, it is now possible to add better noise-canceling features to phones, and also to other products, such as the small “earbuds” used to listen to music players.
Arizona Daily Star: These are heady times for solar astronomers, with the Solar Dynamics Observatory launched and accelerated funding found for the Advanced Technology Solar Telescope situated on Haleakala Peak, on Hawaii's Maui Island.
But the new facilities come at a cost. The McMath-Pierce Solar Telescope which has been based on Kitt Peak since 1962, could close as funding for other areas of solar astronomy face a tight squeeze.
NPR: Although climate-change skeptics have been arguing that the recent snow storms blanketing the East Coast show that climate change isn't happening, climate scientists express a different view.
"The fact that the oceans are warmer now than they were, say, 30 years ago means there's about on average 4 percent more water vapor lurking around over the oceans than there was, say, in the 1970s," says Kevin Trenberth, a climate scientist at the National Center for Atmospheric Research in Colorado.
Warmer water means more water vapor rises up into the air, and what goes up must come down.
"So one of the consequences of a warming ocean near a coastline like the East Coast and Washington, DC, for instance, is that you can get dumped on with more snow partly as a consequence of global warming," he says.
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Climate-change debate is heating up in deep freeze New York Times
Wired.com: In 2006, Oleg Khinsagov was caught trying to smuggle 100 grams of refined uranium into Georgia with the aim of selling it to a Muslim man he believed was connected to “a serious organization.”
The amount was small, but enriched enough to make a bomb, and Khinsagov said he had another 2 to 3 kilograms stored in his apartment that he was willing to sell.
That should be the opening scene of a new documentary on nuclear proliferation, but instead it’s tucked into the middle of Countdown to Zero, which aims to do for antinuclear proliferation what An Inconvenient Truth did for the environmental movement.
The film takes a while to work up to its most important point—that anyone with a relatively small amount of money has the ability to obtain enough nuclear weapons material to incinerate everything in a five-mile radius of a large city. And he or she wouldn’t have to missile it into the US, they could simply detonate it in a container ship at a port.
Science Friday: For the past week, the Hayden Planetarium at the American Museum of Natural History in New York has been home to an unusual sight—performances of Il Mondo Della Luna, a comic opera about the Moon written by Joseph Haydn in 1777.
The performance blends traditional opera with laser and light technology provided by the planetarium. NPR's Science Friday's Ira Flatow talks with the director of the performance.
Nature News: Scientists are foreseeing unprecedented opportunities to send up research payloads on anything from a suborbital trip of a few minutes to a sojourn lasting several weeks on a commercial space station by using a new generation of commercial space launchers such as the Falcon 9.
"We have never had a capability like this in 50 years of human space exploration," says planetary scientist Alan Stern of the Southwest Research Institute in Boulder, Colorado.
Stern is a former science chief for NASA and is helping to organize the first meeting dedicated to research opportunities in suborbital space, to be held on 18–20 February in Boulder.
Science: New techniques are now making it possible to produce molecules and trap them at temperatures within one-millionth of a degree of absolute zero.
Here, all the thermal averaging is removed; the molecules occupy the lowest possible quantum translational states, and all their motions are completely controllable.
S. Ospelkaus and colleagues describe chemical reactions between molecules in this new regime and find that tiny changes, such as flipping the orientation of a single nuclear spin, can have profound consequences for how (and whether) chemical reactions occur.
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Quantum-state controlled chemical reactions of ultracold potassium-rubidium molecules
optics.org: The first IR-emitting germanium laser has been created by researchers in the US. The development could be an important step towards creating optical components such as lasers from silicon—which like germanium is an indirect-gap semiconductor—rather than direct-gap materials such as indium phosphide.
NPR: Determining what is real and what is fake has long been a problem for art curators. It is estimated that 20% of the worldwide art market is made up of forgeries. But art lover and Dartmouth College mathematics department chairman Daniel Rockmore has developed a technique that is helping to determine the difference between excellent copy and the real McCoy.
Science: The different colors on the surface of a soap bubble arise from the interference of light waves reflecting from the outer and inner surface of the liquid film. As the thickness of the film varies, so will the wavelength of light that undergoes constructive interference and remains visible.
According to quantum mechanics, even material particles such as electrons behave like waves. In addition to their charge, electrons also have two distinguishable spin states, spin-up and spin-down.
In Science, Petta and associates demonstrate beam splitting and interferometry for the spin degrees of freedom of two electrons on a semiconductor chip.
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A coherent beam splitter for electronic spin states
Various: Iran has begun enrichment of higher grade uranium, reports the Guardian.
The news has caused the Obama administration to increase work with its allies on a series of sanctions that would take aim at the Islamic Revolutionary Guards Corps of Iran, says the New York Times, publicly singling out the organization’s vast array of companies, banks, and other entities in an effort to curb Tehran’s nuclear ambitions.
The Daily Telegraph: Royal Society president Martin Rees celebrates 350 years of one of the UK's greatest institutions and looks towards the changing nature of scientific publishing.
Nature News: In an effort to put the world's largest scientific experiment back on track after delays and cost overruns, Europe is shaking up the agency overseeing its portion of the multinational ITER reactor.
On 16 February, Frank Briscoe, a UK fusion scientist, will take the reins as interim director of Fusion for Energy (F4E), the agency in Barcelona, Spain, that manages Europe's ITER contribution—the largest of any partner's. Briscoe replaces Didier Gambier, a French physicist who joined the F4E as director when it formed in 2007. Gambier was originally appointed for a five-year term.
NYTimes.com: The America’s Cup has always been a showcase for innovation: The 1895 victor, Defender, for example, used aluminum, steel, and bronze in the hull, an unheard–of combination at the time. And sailing in general, and high-level racing in particular, are no strangers to technology. But it has not been used at such an extreme scale before.
The most obvious advance can be seen rising above USA-17, which is owned by Lawrence J. Ellison, president of the software company Oracle. It looks as if someone wrenched a wing off a large jetliner and perched it, tip up, atop a trailer hitch on the boat’s middle hull.
Related Physics Today articles
The physics of sailing February 2008
Sailing and the physics of lift (letters about the previous article) September 2008
Ship hydrodynamics June 1978
BusinessWeek: Mitsubishi Heavy Industries Ltd. of Japan has agreed to work with South Africa’s Pebble Bed Modular Reactor Ltd. to “explore cooperation” and the possible construction of a mini nuclear reactor.
The troubled PBMR prototype is behind schedule and over budget.
Science: The two women tapped to head the European Union's efforts on science and climate over the next 5 years have a lot in common.
Both were elected to parliament in their mid-20s—one in Denmark and the other in Ireland—but left politics later on. Both wrote for national newspapers and had stints in television broadcasting. Both are described as strong-willed and smart.
The difference is that one is virtually unknown to scientists and science policymakers, and the other is almost an international celebrity.
Danish energy and climate minister Connie Hedegaard was nominated to become the first European commissioner for climate action.
Máire Geoghegan-Quinn, the proposed new commissioner for research and innovation, has spent the past 9 years examining the EU's finances as the Irish representative of the less-than-glamorous Court of Auditors in Luxembourg.
Slate: What will NASA do with all the technology that it has already developed but can no longer continue financing?
Give it away, sell it, or toss it. When NASA cancels a program or no longer needs certain pieces of equipment, it hands the material over to a property disposal officer who then finds the best way to get rid of it.
Related Physics Today article
NASA sells technology rights to highest bidder January 2009
NPR: In northeastern Indiana, environmentalists are closely watching a project on a scale that hasn't been attempted before in the US.
Ball State University is constructing the largest geothermal heating and cooling system of its kind—and promises to cut its carbon emissions in half.
It works because a few dozen meters below Earth's surface, the temperature is between 11 and 13 °C. Depending on the time of year, geothermal systems use Earth's temperature as a heat source—or sink—by sending water through miles of pipes and concentrating it to meet the temperature the thermostat calls for.
Ball State is attempting to use more than 660 acres to heat and cool nearly 50 buildings as part of its project.
CSMonitor.com: For the first time, astronomers have detected methane gas glowing like a fluorescent bulb in the atmosphere of a planet orbiting a distant star.
Researchers have had glimpses of the atmospheres of so-called exoplanets before, but never in this way. The fluorescent signature of HD 189733b, a Jupiter-size planet in the faint constellation of Vulpecula, could help astronomers explore exoplanets in more detail—including ways that help them in the search for life elsewhere in the galaxy.
WSJ.com: Steven Weinberg has declared that the Obama administration's new approach to NASA's future is a positive development because the "manned space flight program frequently masquerades as science, but actually crowds out real science at NASA, which is all done on unmanned missions."
Weinberg writes:
Soon after Mr. Bush's [2004] announcement [of the "Vision for Space Exploration"] I predicted that sending astronauts to the moon and Mars would be so expensive that future administrations would abandon the plan. This prediction seems to have come true. All of the brilliant past discoveries in astronomy for which NASA can take credit have been made by unmanned satellite-borne observatories, and there is much more to be done.
By studying the polarization of cosmic microwave radiation, we may find evidence of gravitational waves emitted in the first fraction of a second of the big bang. By sending laser beams between teams of satellites, we should be able to detect gravitational waves directly from collisions between neutron stars and black holes. By correlating the distances and velocities of many galaxies, we should be able to explore the mysterious dark energy that makes up most of the energy of the universe.
He adds that any "argument for using astronauts to service satellite observatories is now out of date" because the new research tools "are not in low Earth orbits like Hubble, but at L2."
Weinberg closes with this: "The only technology for which the manned space flight program is well suited is the technology of keeping people alive in space. And the only demand for that technology is in the manned space flight program itself."
Physics Today: IBM researchers demonstrated a radio-frequency graphene transistor with the highest cut-off frequency achieved so far for any graphene device—100 billion cycles/second (100 gigahertz).
The high frequency record was achieved using wafer-scale, epitaxially grown graphene using processing technology compatible to that used in advanced silicon device fabrication.
"A key advantage of graphene lies in the very high speeds in which electrons propagate, which is essential for achieving high-speed, high-performance next generation transistors," said T. C. Chen, vice president of science and technology, IBM Research. "The breakthrough we are announcing demonstrates clearly that graphene can be utilized to produce high performance devices and integrated circuits."
Graphene is a single atom-thick layer of carbon atoms bonded in a hexagonal honeycomb-like arrangement. This two-dimensional form of carbon has unique electrical, optical, mechanical, and thermal properties, and its technological applications are being explored intensely.
Uniform and high-quality graphene wafers were synthesized by thermal decomposition of a silicon carbide (SiC) substrate. The graphene transistor itself utilized a metal top-gate architecture and a novel gate insulator stack involving a polymer and a high dielectric constant oxide. The gate length was modest, 240 nanometers, leaving plenty of space for further optimization of its performance by scaling down the gate length.
The frequency performance of the graphene device already exceeds the cut-off frequency of state-of-the-art silicon transistors of the same gate length (~ 40 GHz).
ScienceNOW: Have you ever noticed that the first gunslinger to draw his gun in a movie is invariably the one to get shot?
Nobel prize–winning physicist Niels Bohr did, once arranging mock duels to test the validity of this cinematic curiosity.
Following Bohr's example, researchers have now confirmed that people move faster if they are reacting to another person's movements than if they are taking the lead themselves.
NYTimes.com: Wind could replace coal and natural gas for 20% to 30% of the electricity used in the eastern two-thirds of the US by 2024, according to a study released by the US Department of Energy.
But doing so would require a reorganization of the power grid and a significant increase in costs. And it would have only a modest impact on cutting emissions linked to global warming, the study found.
msnbc.com: Supercomputing has helped astrophysicists create massive models of the universe, but such simulations remain out of reach for many in the US and around the world.
To compensate, groups around the world—such as the University of Chicago and CERN in Switzerland—are developing ways in which different research groups can contribute and see the results of supercomputer simulations in real-time by streaming the results over the internet.
One of the first tests of such a system occurred last week in which scientists in Portland, Oregon, watched a Chicago-based simulation of how ordinary matter and mysterious dark matter evolved in the early universe.
NYTimes.com: Freestyle aerialists, skiers that hurtle off a curved ramp at 30 miles per hour, soaring six stories in the air while doing three back flips and up to five body twists, are not actually throwing caution to the winds. It is not fate that plops them down at the end of their jumps, more or less upright and safe, in a cloud of powdery snow. It is physics, and plenty of preparation.
"The forces are pretty simple," said Adam Johnston, a physics professor at Weber State University in Ogden, Utah.
"There's the force of the ramp on his skis, and the force of gravity on him," Johnston said, after Ryan St. Onge, the reigning world champion in men's aerials, zipped down a steep inrun, leaned back as he entered the curved ramp until he was nearly horizontal, and flew off at a 70-degree angle.
But it is enough to create torque that sends St. Onge somersaulting backward as he takes to the air, arcing toward a landing on a steep downslope that the skiers and coaches have chopped and fluffed for safety.
"Once he's in the air, the only force on him is gravity," Johnston said. "You could trace his center of mass as a perfect parabola through the whole thing. From the physics point of view, that's one of the beautiful things."
New Scientist: Two crystals identical in appearance and chemical formula—and even with the same crystal symmetry—turn out to differ wildly in their capacity for storing hydrogen, much to the surprise of the chemists who made them.
The finding hints that there may be a previously unknown class of crystals that would be useful for gas storage or catalysis.
Related link
An unusual case of symmetry-preserving isomerism
Nature News: The internet is struggling to keep up with the ever-increasing demands placed on it. Freelance writer Katharine Gammon looks at ways to fix it.
Wired.com: New papers based on the first seven years of data taken by NASA's Wilkinson Microwave Anisotropy Probe (WMAP) have been posted to arXiv (see list below).
The data have helped researchers calculate the most accurate determination yet of the age of the cosmos. Moreover, WMAP directly detected primordial helium gas for the first time, and has discovered a key signature of inflation, the leading cosmological model of how the universe developed from its earliest beginnings.
The data also provide new evidence that the mysterious entity speeding up the expansion of the universe resembles Einstein's cosmological constant, a factor he inserted but later removed from his theory of general relativity.
In addition, the data reveal that theorists don't have the right model to explain the hot gas that surrounds massive clusters of galaxies.
Related links
1. Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Are There Cosmic Microwave Background Anomalies?
2. Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Sky Maps, Systematic Errors, and Basic Results
3. Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Planets and Celestial Calibration Sources
4. Variograms of the Cosmic Microwave Background Temperature Fluctuations: Confirmation of Deviations from Statistical Isotropy
5. Inconsistency between WMAP data and released map
6. Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Power Spectra and WMAP-Derived Parameters
7. Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Galactic Foreground Emission
8. Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
NPR: Airlines are paying extra attention to the weather these days: the weather in space.
That's because more commercial flights are using shortcuts that take them near the North Pole or the South Pole. And in polar regions, flights are vulnerable to cosmic storms that can interfere with communication and navigation systems, or even expose travelers to doses of radiation above usual safety levels.
The Guardian: A global deal to tackle climate change is all but impossible in 2010, leaving the scale and pace of action to slow global warming in coming decades uncertain, according to senior figures across the world involved in the negotiations.
"The forces trying to tackle climate change are in disarray, wandering in small groups around the battlefield like a beaten army," said a senior UK diplomat.
An important factor cited is an impasse within the United Nations organization charged with delivering a global deal, which this week is assessing the pledges made by individual countries by a deadline that passed at the end of January.
BBC News: The world's first large-scale, electronic programmable computer was created to do one job—crack the wartime codes used by the Germans during World War II. Engineers and code-crackers describe life working on Colossus as part of a BBC News series on computer pioneers.
Physics Today:Springtime ozone levels above western North America are rising primarily due to air flowing eastward from the Pacific Ocean, a trend that is most significant when the air originates in Asia.
Such increases in ozone could make it more difficult for the US to meet Clean Air Act standards for ozone pollution at ground level, according to a new international study in Nature. The study analyzed large sets of ozone data captured since 1984.
"In springtime, pollution from across the hemisphere, not nearby sources, contributes to the ozone increases above western North America," said lead author Owen R. Cooper, of the University of Colorado at Boulder. "When air is transported from a broad region of south and east Asia, the trend is largest."
The study focused on springtime ozone in a slice of the atmosphere from two to five miles above the surface of western North America, far below the protective ozone layer but above ozone-related, ground-level smog that is harmful to human health and crops. Ozone in this intermediate region constitutes the northern hemisphere background, or baseline level of ozone in the lower atmosphere. The study was the first to pull together and analyze nearly 100 000 ozone observations gathered in separate studies by instruments on aircraft, balloons and other platforms.
Combustion of fossil fuels releases pollutants like nitrogen oxides and volatile organic compounds, or VOCs, which react in the presence of sunlight to form ozone. North American emissions contribute to global ozone levels, but the researchers did not find any evidence that these local emissions are driving the increasing trend in ozone above western North America.
Cooper and colleagues from from the National Oceanic and Atmospheric Administration's Earth System Research Laboratory in Boulder and eight other research institutes used historical data of global atmospheric wind records and sophisticated computer modeling to match each ozone measurement with air-flow patterns for several days before it was recorded. This approach essentially let the scientists track ozone-producing emissions back to a broad region of origin.
This method is like imagining a box full of 40 000 tiny weightless balls at the exact location of each ozone measurement, said Cooper. Factoring in winds in the days prior to the measurement, the computer model estimates which winds brought the balls to that spot and where they originated.
When the dominant airflow came from south and east Asia, the scientists saw the largest increases in ozone measurements. When airflow patterns were not directly from Asia, ozone still increased but at a lower rate, indicating the possibility that emissions from other places could be contributing to the ozone increases above North America.
The study used springtime ozone measurements because previous studies have shown that air transport from Asia to North America is strongest in spring, making it easier to discern possible effects of distant pollution on the North American ozone trends.
Ozone-measuring research balloons and research aircraft collected a portion of the data. Commercial flights equipped with ozone-measuring instruments also collected a large share of the data through the MOZAIC program, initiated by European scientists in 1994. The bulk of the data was collected between 1995 and 2008, but the team also included a large ozone dataset from 1984.
The analysis shows an overall significant increase in springtime ozone of 14 percent from 1995 to 2008. When they included data from 1984, the year with the lowest average ozone level, the scientists saw a similar rate of increase from that time through 2008 and an overall increase in springtime ozone of 29 %.
"This study did not quantify how much of the ozone increase is solely due to Asia," Cooper said. "But we can say that the background ozone entering North America increased over the past 14 years and probably over the past 25 years."
Wired.com: If we’re going to protect Earth from an asteroid, we need to find the dangerous ones whizzing about in the emptiness of space.
Unfortunately, the US will not complete the survey of large near-Earth objects by 2020 as mandated, but not funded, by Congress in 2005. That’s the conclusion of a new National Resource Council Report, Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies.
NPR: Genetically modified food, vaccines, and synthetic biology are all hot-button issues. But they shouldn't be, according to guest Michael Specter, author of the new book Denialism. He argues that the scariest threat is not science itself, but the reluctance to discuss it.
ScienceNOW: Of all the radioactive isotopes left over from nuclear weapons testing and nuclear power plants, cesium-137 is among the most dangerous. The soft, silvery-white metal has a half-life of 30 years, enters the body quickly, and can trigger cancer even decades after exposure. Removing cesium-137 from the environment has proven difficult, but researchers say they have a promising new way to clean it up: a flexible, porous solid that grabs cesium ions much like a Venus flytrap ensnares its prey.
Related link
Selective incarceration of caesium ions by Venus flytrap action of a flexible framework sulfide Nature Chemistry
Nature: A living cell can be thought of as a building of extremely peculiar architecture, in which the walls are formed by films just a few nanometers thick—the cell membranes.
The diversity and dynamics of membrane shapes are vital for the cell's physiology. One of the biggest challenges in cell biology and biophysics is therefore to understand the molecular mechanisms that enable cell membranes to bend easily and rapidly into highly curved, dynamic shapes. Reporting in the Journal of the American Chemical Society, Y. Yu and coworkers describe a promising synthetic model of membranes that can be used to assess experimentally the combined influence of lipids and proteins on membrane curvature.
Related link
Vesicle budding induced by a pore-forming peptide
Science: In the natural sciences, x-ray crystallography has clarified how the shapes of proteins and related complexes relate to their cellular function, and x-ray scattering has elucidated the structure and dynamics, mechanical properties, and intermolecular interactions of countless materials.
In Science, H. Cui and coworkers report a new twist in the application of x-ray scattering, where synchrotron x-ray irradiation, in addition to its usual role in probing structure, acts as a reversible switch for self-assembly from a disordered to an ordered state of bundled filaments.
Related link
Spontaneous and x-ray–triggered crystallization at long range in self-assembling filament networks
CNET News: The global race to develop clean technology is not just about who can build the best solar parks or wind farms. It is also shaping up as a contest between Chinese-style capitalism and the more market-oriented approach fancied by the US and Europe.
The failure in Copenhagen to agree to replace the Kyoto Protocol with a new global climate treaty when it expires in 2012 has thrown the focus on national measures. And by almost all accounts, the Chinese are coming on strong.
The Chinese government has made clear its intention to dominate this new industry, up and down the value ladder. And in its quest for the prize, it are not burdened by concerns facing its Western counterparts—such as the impact of wind turbines on landscapes, higher energy prices for consumers, or investor returns.
Wired.com: Bill Gates has sunk at least $4.5 million of his personal wealth into geoengineering research.
While it’s only a small chunk of his vast personal fortune, it’s a sign that the founder of Microsoft thinks we should at least be looking into the controversial practice of intentionally altering Earth’s climate on a global scale.
Various: A new study in Science magazine helps explain why the planet didn't warm up dramatically over the course of the past decade, even though the gases that cause global warming increased dramatically.
Scientists have identified a surprising phenomenon in water vapor 10 miles above our heads that explains part of this unexpected pause in warming.
The concentration of water vapor at this altitude has dropped by 10%, triggered by unexplained cooler temperatures at certain high altitudes above the tropics. The study concludes that in the last decade the decline in water vapor slowed the rate of rising temperatures by about 25%, thus partly negating the heat-trapping effect of increasing greenhouse gases such as carbon dioxide and methane.
The recent flattening of temperatures since the year 2000 has added credence to climate-change skeptics, who claim that global warming is not happening. This study increases the likelihood that it is a blip, and warming remains a long-term trend. The researchers do call however for a "closer examination" of the way climate computer models consider water vapor.
A number of publications reported the news, including NPR, the Wall Street Journal, the Guardian.
