Johnald's Fantastical Daily Link Splurge |
- In Your Face: Close-Up Look at Doomed Comet
- How Rockets Realign Ice Crystals
- To Talk With Aliens, Learn to Speak With Dolphins
- Obama’s 2012 Budget Proposes Pains, Gains for Science
- Sex Discrimination in Science Continues, But Reasons Unclear
- ‘Magnetricity’ Created in Crystals of Spin Ice
- Spacecraft Seeks Doomed Comet for Valentine’s Day Rendezvous
| In Your Face: Close-Up Look at Doomed Comet Posted: 15 Feb 2011 02:06 PM PST
NASA's Stardust-Next spacecraft flew past Comet Tempel 1 at 8:38 Pacific time Monday night, snapping photos as it sped by. In 2005, the Deep Impact probe blew a crater into Tempel 1 with an 800-pound metal slug. Since then, Tempel 1 has completed an orbit around the sun, losing ice and other material to the sun's hot glare along the way. The new images will give astronomers new insight into how a comet is slowly destroyed by the sun. "This is something we've never been able to see before," said principal investigator Joe Veverka of Cornell University in an interview on NASA TV during the flyby. "We know every time a comet comes close to the sun, it loses material. But we don't know where those changes occur." Stardust-Next, which originally launched as "Stardust" in 1999, swooped within 124 miles of Tempel 1's icy, dirty core at about 24,300 miles per hour. The spacecraft took a total of 72 science images, 46 as it approached and 26 as it receded from the comet. As it approached, it snapped pictures once every 6 seconds.
The new images started arriving at NASA's Jet Propulsion Lab in Pasadena, California, about three hours after the spacecraft made its closest approach. Each image took 15 minutes to download. The Stardust crew wanted to download the five closest images first, but an unknown error sent the photos in the order in which they were taken. The astronomers had to wait until 6 a.m. Tuesday Pacific time to get the good stuff. Luckily, the images were everything the science team hoped for. "If you ask me, was this mission 100 percent successful, in terms of the science? I would have to say no," Veverka said in a press conference Feb. 15. "It was 1,000 percent successful!" Stardust-Next shot photos of new terrain that had never been seen before, as well as areas on Tempel 1 that had been covered by Deep Impact. The images showed that several regions changed significantly over the past five years. One of the most interesting areas looks like a blanket of material that erupted from beneath the comet's surface and flowed downhill. That flow is now receding due to erosion, Veverka said. "It goes much against the idea that [comets are] just icy dirtballs where nothing has happened since their formation," Veverka said. "Apparently a lot of things have happened." The spacecraft also found the crater Deep Impact blew in the comet's surface. Deep Impact never saw its handiwork, because the crater was obscured by all the dust and ice kicked up in the impact. "That created a lot of mystery, and it also helped create this mission," said Stardust-Next co-investigator Pete Schultz of Brown University. The crater is about 150 meters (492 feet) across, and has a small central mound. It looks as if the cloud of material Deep Impact excavated fell back to the surface. "The surface of the comet where we hit is very weak. It's fragile," Schutlz said. "The crater partly healed itself." Flying close to a comet is a risky business. Comets spew jets of gas and dust from beneath their surfaces, which act as little rocket thrusters, making the comet's position hard to predict. In the final 16 hours, the spacecraft has to navigate on its own — signals from Earth would be too slow to direct last-second turns. And for five minutes before and after closest approach, Stardust-Next had to roll on its side to make sure the cameras were pointing straight at the comet's heart, a maneuver that could have temporarily cut off communication with Earth. The spacecraft also has to fly through the hailstorm of the comet's coma, where clumps of dirt and ice collide and come apart. Co-investigator Don Brownlee of the University of Washington compared the spacecraft's flight to a B-17 in World War II flying through flak. Stardust-Next's instruments recorded about 5,000 dust strikes during the flyby, about 12 of which were large enough — a millimeter across — to pierce the spacecraft's main shield. But Stardust-Next is a flyby veteran. The spacecraft has traveled a total of 3,525,327,446 miles since its 1999 launch, It visited asteroid Annefrank in 2002 and comet Wild 2 (pronounced "willed two") in 2004. Stardust caught particles from Wild 2's cloudy coma in an instrument that resembled a catcher's mitt, and in 2006 sent them back to Earth, where they are still being analyzed. The flyby went without a hitch, the Stardust team said. The spacecraft was in almost the perfect position to photograph the comet when it arrived, and only had to roll half-a-degree to adjust its cameras. The spacecraft's near-perfect performance is particularly impressive considering its age. The 12-year-old probe was put together from recycled parts cribbed from the Voyager mission of the 1970s, the Galileo spacecraft in 1989 and the Cassini probe in 1997. Reusing an already recycled spacecraft makes this mission space science on a shoestring, said Ed Weiler, NASA associate director for the science mission directorate. The extended mission, from after the Wild 2 samples returned to Earth until today, cost about $29 million. It would have cost about $500 million to start from scratch. But Tempel 1 will be Stardust's last stop. The spacecraft is running on fumes. It will continue to take photos of the comet over it shoulder for another week or two, until its fuel runs out. Then it will at last retire into the blackness of space. Images: NASA/JPL-Caltech/Cornell. Animation: Dave Mosher/Wired.com. See Also: |
| How Rockets Realign Ice Crystals Posted: 15 Feb 2011 12:00 PM PST
As the rocket carrying the sun observer climbed into orbit, it produced shock waves that destroyed a small splotchy-shaped rainbow and created a new, never-before-seen form of ice halo. Ice halos are rings and arcs of light that appear when sunlight is deflected through ice crystals. On the morning of Feb. 11, 2010, when SDO launched from Cape Canaveral, hexagonal plate-shaped ice crystals drifting downward created a sundog, a fragment of a rainbow that can often be found on either side of the morning sun on chilly days. As SDO passed the sundog, it erased it. Shortly after, a column of white light appeared next to the rocket and followed it into the sky. Astronomers knew what happened to the sundog: Shock waves from the rocket destroyed the alignment of ice crystals, which in turn destroyed the rainbow. But the white column was a mystery. "We'd never seen anything like it," said retired physicist and atmospheric-optics expert Les Cowley in an explainer at Science@NASA. Now, a year later, Cowley and retired physicist Robert Greenler of the University of Wisconsin–Milwaukee think they know what happened. Rather than scrambling the ice crystals, the shock wave from the rocket organized them into an array of tiny spinning tops. The hexagonal ice crystals are tilted between 8 and 12 degrees, Cowley said. The crystals then wobble in an ordered, precise motion so that an imaginary line running through their center traces out a cone shape. This motion, called precession, shows up in a variety of spinning bodies, from toy tops to planets. "This could be the start of a new research field — halo dynamics," Cowley said. Cowley and Greenler's simulations show that the white column that followed SDO to orbit was part of a larger oval that would have surrounded the ascending rocket if the crystals and shock waves had covered a wider range. Via Science@NASA Image: Science@NASA. Video: Anna Herbst of Bishop, California. See Also: |
| To Talk With Aliens, Learn to Speak With Dolphins Posted: 15 Feb 2011 10:00 AM PST
The Kepler Space Telescope announced a new bonanza of distant planets this month, reconfirming that solar systems, some possibly hosting life, are common in the universe. So if humanity someday arrives at an extraterrestrial cocktail party, will we be ready to mingle? At the Wild Dolphin Project in Jupiter, Florida, researchers train for contact by trying to talk with dolphins. Behavioral biologist Denise Herzing started studying free-ranging spotted dolphins in the Bahamas more than two decades ago. Over the years, she noticed some dolphins seeking human company, seemingly out of curiosity. "We thought, 'This is fascinating, let's see if we can take it further,'" Herzing said. "Many studies communicate with dolphins, especially in captivity, using fish as a reward. But it's rare to ask dolphins to communicate with us."
Dolphins have large, sophisticated brains, elaborately developed in the areas linked to higher-order thinking. They have a complex social structure, form alliances, share duties and display personalities. Put a mirror in their tank and they can recognize themselves, indicating a sense of self. When trained, they have a remarkable capacity to pick up language. At the Dolphin Institute in Hawaii, Louis Herman and his team taught dolphins hundreds of words using gestures and symbols. Dolphins, they found, could understand the difference between statements and questions, concepts like "none" or "absent," and that changing word order changes the meaning of a sentence. Essentially, they get syntax. Easier Language Through Math Laurance Doyle of the SETI Institute in Mountain View, California, also studies animal communication in preparation for extraterrestrial contact. Doyle uses information theory — a branch of math that analyzes the structure and relationships of information — to analyze radio signals, hoping to better detect intelligence in space. "Information theory is an example of an intelligence filter we can use to sift the signals we get from space," Doyle said. "Otherwise, we might miss them." Using information theory it's possible to separate binary code from random 0s and 1s, for examples. By analyzing dolphin sounds, it's possible to know that adults send information when they whistle, but not babies. Like human babies, they just babble until they've learned language. Information theory also shows that humpback whales have rules of grammar and syntax. "At SETI meetings we always ask 'Are we alone?'" Doyle said. "No, we're not alone. There are many animals communicating right here that we don't understand." Doyle is interested in applying information theory to bees. Social bees are capable of complex group decisions, it seems, but their intelligence is a product of the hive. He also plans to study the communication between trees, because they share information about pests and threats via chemicals. "Who knows? Brains might not be necessary," Doyle said. Some tantalizing studies even suggest dolphins share their own language (see sidebar, "Easier Language Through Math"). All are qualities we'd hope to see in an alien, and no daydream of contact is complete without some attempt at communication. Yet with dolphins, our attempts have involved teaching them to speak our language, rather than meeting in the middle. Herzing created an open-ended framework for communication, using sounds, symbols and props to interact with the dolphins. The goal was to create a shared, primitive language that would allow dolphins and humans to ask for props, such as balls or scarves. Divers demonstrated the system by pressing keys on a large submerged keyboard. Other humans would throw them the corresponding prop. In addition to being labeled with a symbol, each key was paired with a whistle that dolphins could mimic. A dolphin could ask for a toy either by pushing the key with her nose, or whistling. Herzing's study is the first of its kind. No one has tried to establish two-way communication in the wild. "This is an authentic way to approach this, she's not imposing herself on them," said Lori Marino, the Emory University biologist who, with Hunter College psychologist Diana Reiss, pioneered dolphin self-recognition studies. "She's cultivated a relationship with these dolphins over a very long time and it's entirely on their terms. I think this is the future of working with dolphins." For each session, the researchers played with the dolphins for about half-an-hour, for a total of roughly 40 hours over the course of three years. They reported their findings of this pilot study in the December issue of Acta Astronautica. Herzing's team found that six dolphins, all young females, were interested in the game, and would come to play when the game was on. Young males were typically less social and less interested in humans. "This is when the females have a lot of play time," Herzing said, "before they are busy being mothers." To Herzing's surprise, some of her spotted dolphins recruited bottlenose dolphins, another species, to the game. This shows their natural curiosity, Herzog zaid. In the wild, dolphins communicate across cetacean species lines, coordinating hunting with other dolphins and even sharing babysitting duties. Herzing found the study sessions were most successful when, before playing, the humans and dolphins swam together slowly and in synchrony, mimicked each other and made eye contact. These are signs of good etiquette among dolphins. Humans also signal their interest in someone with eye contact and similar body language. Perhaps these are universal — and extraterrestrial — signs of good manners. Before we hope to understand extraterrestrials, then, perhaps we should practice with smart animals right here on Earth. Astronomer Laurance Doyle of the SETI Institute was struck by this thought at a recent conference. "From the way the presenter was speaking, I thought he was going to announce that he had found a signal of extraterrestrial intelligence," Doyle said. "We've been waiting for this for years, but I thought, 'We're not ready!' We can't even speak to the intelligent animals on Earth." Image: Two Atlantic spotted dolphins in the wild. (Ricardo Liberato) See Also:
Citations: "SETI meets a social intelligence: Dolphins as a model for real-time interaction and communication with a sentient species." By Denise L. Herzing. Acta Astronautica, Vol. 67 December 2010. "Information theory, animal communication, and the search for extraterrestrial intelligence." By Laurance R. Doyle, Brenda McCowan, Simon Johnston and Sean F. Hanser. Acta Astronautica, Vol. 68, February-March 2011. |
| Obama’s 2012 Budget Proposes Pains, Gains for Science Posted: 15 Feb 2011 08:38 AM PST
President Obama sent the research community a valentine of sorts in his proposed 2012 federal budget. Sent to Congress on Feb. 14, the budget was a pledge to fight for increased investment in research and education even as the president committed to belt-tightening for most segments of federal spending.
Many R&D programs would see expanded or new funding to meet a number of administration goals, said presidential science adviser John Holdren, including:
To pay for those priorities, Holdren says, agencies were asked to make the painful determination of which programs were underperforming or of lower priority to the president's national objective "to out-innovate, out-educate and out-build the rest of the world." "I think it is especially encouraging to have a president who really supports R&D and education," says Albert Teich, who directs science and policy programs at the American Association for the Advancement of Science in Washington, D.C. "You wish every president saw things this way. What's discouraging, of course, is that we face this huge deficit. And not everybody in Congress is going to agree with the president's priorities. So there's bound to be fights over it." How big a tussle? "That's the question of the hour. And for the answer, I think you should ask the IBM computer on Jeopardy this week," Teich says.
This "zero-sum game" for federal R&D budgeting is novel, Teich notes. It is also virtually impossible to achieve, he adds, since a host of different congressional committees are responsible for eventually drafting the spending bills that will determine how money will be apportioned for individual agencies. And they don't coordinate their spending plans to allow such a finely balanced ledger. Who would feel the pain — or gain — varies considerably. For instance, the Department of Education has been slated for a whopping 33.5 percent increase. But owing to its relatively small R&D component, this boost would amount to a rather paltry $124 million. Some $80 million of that boost would pay for research into developing better science, engineering and math teachers. The president has stated a goal of increasing their numbers by 100,000 within a decade. Among agencies slated to experience a big dip in R&D funding, none stands to hurt more, in dollar terms, than the Department of Defense. The administration has targeted its programs for a nearly $5 billion drop. Part of the cutbacks would be made possible by terminating several major weapons systems that the administration claims "are experiencing significant development problems, unsustainable cost growth, or are not suited for today's security challenges." The U.S. Department of Agriculture, slated for a 19 percent R&D decrease, would kill all spending on research grants that Congress had initially earmarked for funding and would cancel $224 million in construction funds. These adjustments would not only allow for some overall savings, but also free up a little money to boost spending for research on human nutrition, obesity reduction, food safety, climate change and crops that could be used to produce biofuels. Below are summaries of the budget's effects on the following areas of R&D:
Basic research R&D funding within the National Science Foundation would increase by some 16 percent under the proposed budget. "In these challenging fiscal times, when difficult financial choices have to be made to return our nation to solid financial footing, this budget request reflects the confidence that the president is placing in NSF as an agency," said Subra Suresh, the agency's director. Much of the money is designated for interdisciplinary research and training, with an emphasis on clean-energy initiatives, cyberinfrastructure and other programs such as robotics for health care and for deep-sea exploration. Research grants to non-NSF scientists might see a 27.8 percent increase over FY 2010 spending, including boosting the number of faculty career grants and graduate research fellowships. More than $998 million is slated for the Science, Engineering and Education for Sustainability portfolio, which would invest in research on clean energy, climate change and rapid response to extreme events. A new National Robotics Initiative would receive $30 million in the next fiscal year, and another $117 million would launch a Cyberstructure Framework for 21st Century Science and Engineering, to ensure internet and computer access to schools and the public. Several interdisciplinary programs, such as BioMaPS, (which is geared towards clean energy), and Science and Engineering Beyond Moore's Law (which focuses on research into efficient computing, data storage and communication) also may receive hefty funds. Almost $200 million could go to research into advanced manufacturing, which includes robotics programs, nanomanufacturing and sensor-based "smart" manufacturing. Earth and climate The budget proposes nearly $5.5 billion for the Commerce Department's National Oceanic and Atmospheric Administration, the second year in a row that the president has requested a significant uptick from the $4.86 billion NOAA received in FY 2010. Most of that increase would go to develop satellites vital for weather forecasting, said Monica Medina, the agency's principal deputy undersecretary for oceans and atmosphere. For instance, the proposed budget asks for $1.07 billion for the planned Joint Polar Satellite System, the next generation of polar-orbiting satellites. Also on the administration wish list: several climate initiatives, including $4.7 million to improve measurements of fossil fuel emissions nationwide and $2 million for improving the quality of weather forecasts as they relate to clean-energy projects. After the Deepwater Horizon oil spill last year, NOAA is asking for $2.9 million for research into such spills, plus a host of initiatives to assist coastal communities that depend on fishing. Overall, the budget would give NOAA $737 million to fund R&D programs on climate, weather and the study of ecosystems. The U.S. Geological Survey would see an essentially flat budget of $1.12 billion. That would, however, include a $48 million increase so that USGS could assume sole management of the Landsat series of Earth-observing satellites, orbiters it had jointly managed with NASA. Space and planetary research NASA's R&D budget would decline by 2.2 percent, to $9.8 billion, under the President's proposed budget. "It's difficult fiscal times and we had to make very difficult fiscal choices," NASA Administrator Charles Bolden said at a press briefing on Feb. 14. NASA's successor to the Hubble Space Telescope, the James Webb Space Telescope, which an independent panel recently found had a minimum construction overrun of $1.5 billion, is now funded separately from other astrophysics missions, as the panel had suggested [SN Online: 11/11/10]. Under the president's plan, the James Webb would receive $374 million in 2012, which Bolden said would stabilize the mission but not stem the overrun. A new, later launch date for the telescope, which only a year ago was targeted for 2014, won't be announced until the summer. Rick Howard, program director for the telescope at NASA in Washington, D.C., said it was unlikely to be launched before 2016 due to funding constraints. As many astronomers had feared, money for the Webb telescope appears to have come at the expense of other astrophysics projects. For instance, the president's proposed budget includes no money for the Wide Field Infrared Survey Telescope, recommended as the top astrophysics space mission by a recent National Academy of Science panel. The telescope would search for extrasolar planets and dark energy, the mysterious entity that is thought to be accelerating the expansion of the universe. Although only three more flights of the space shuttle fleet are scheduled before it's retired, funding for a new vehicle that would take astronauts beyond low-Earth orbit — perhaps to a near-Earth asteroid — and a heavy-lift rocket that would launch that vehicle are slated to remain at roughly the current year's level. That's a 1.3 percent decline after inflation. "We're going to have to make some small steps; we're going to have to move incrementally," Bolden said. Funding for NASA's earth science programs would decline from $1.802 billion in fiscal 2011 to $1.797 billion in fiscal 2012. The cuts would slow development of future missions such as the third generation of the Orbiting Carbon Observatory and a satellite that would monitor changes in Earth's temperature. Energy sciences The Department of Energy's budget favors renewable technologies at the expense of fossil fuels. Funding for programs administered by its Office of Science would climb to $5.4 billion, a two-year increase of 6.2 percent. Funding for renewable energy technology would climb a whopping 70 percent. Within renewable R&D programs, only those focused on hydrogen would take a hit — of about $70 million, representing a 40 percent cut. The new budget plan proposes $550 million for ARPA-E, which invests in high-risk, high-reward energy research. DOE would also double to six the number of Energy Innovation Hubs. These are cross-disciplinary collaborations that Secretary of Energy Steven Chu calls the "Apollo Projects of our time." The new hubs would focus on smart-grid technologies, critical materials such as rare-earth elements and energy storage and batteries. At a press briefing Feb. 14, Chu said he expects the United States will soon lead the nuclear market in developing small modular reactors, an as-yet-unproven technology highlighted in the $380 million devoted to nuclear R&D. To encourage the building of more large nuclear power facilities, his agency is requesting a budget increase for loan guarantees for electric utilities — from $18 billion to $36 billion. The president has issued a goal of putting 1 million electric cars on the road by 2015. In addition to $580 million for advanced-vehicle research, the current $7,500 tax credit for electric cars would become an instant rebate at the point of sale. DOE would also boost tax credits and grants to improve the energy efficiency of commercial and residential buildings, including $100 million designated for state and municipal facilities. To help offset these costs, management expenses have been reduced across DOE programs, to the tune of $45 million. But the big cuts are in fossil fuels, where $418 million will be saved by zeroing out a dozen research programs — from clean coal research to fuel cells. Carbon storage and capture research would survive, receiving an increase of funding to $184 million. The president also repeats his call to end subsidies for the fossil fuel industry. An unpopular idea in Congress, it could save some $3.6 billion. Biomedical research Research spending budgeted for the Department of Health and Human Services — almost all of which goes to the National Institutes of Health — is $32.3 billion, a marginal decrease from the current year. NIH research would continue to place strong emphasis on the use of genomics and biotechnology to take on Alzheimer's disease, cancer, diabetes, obesity, autism and other ailments. NIH also proposes a new addition, the National Center for Advancing Translational Sciences, which would aim to shepherd laboratory findings as they are "translated" into drugs and diagnostics for practical use. "There's been a great deluge of scientific discoveries that point toward new therapeutics," says NIH Director Francis Collins. "This is a new arrival on the NIH stage." Technology and environment The president would allocate $1.001 billion for research within the Commerce Department's National Institute of Standards and Technology. The gain represents a projected one-year jump of 7.2 percent. "From NIST's perspective, this is a historic budget request," says NIST Director Patrick Gallagher. "It really reflects some strong White House leadership to make some very difficult priority-setting in a tough climate." Roughly $678.9 million would fund a diverse set of in-house research priorities, including a strong emphasis on manufacturing. That includes funding boosts in nanomanufacturing, biomanufacturing, clean manufacturing and advanced robotics. The proposed budget also looks outward, encouraging collaborations with private industry. One new NIST program — the Advanced Manufacturing Technology Consortia — would receive $12.3 million to identify problems in particular industries, and work with private firms to find a solution. A pilot program that targets semiconductors has been operating successfully for several years, Gallagher says. "It's a very powerful approach, where industry is directly cost-sharing and working on a common research agenda," he says. "I think it's particularly noteworthy that it [the increase] is occurring in a time when the administration is also proposing a fiscally responsible budget," said Gallagher. The Environmental Protection Agency's proposed research budget would sag 3.2 percent from the current fiscal year, but would boost the Science to Achieve Results (STAR) program of grants to scientists in academic institutions. These increases would be offset by cuts in some of the agency's other research areas, such as those affecting homeland security. Research at EPA is getting a bit of a shakeup for a more integrated approach, looking at issues systemically rather than focusing as much on individual chemicals or problems. "Even our scientists can get more efficient," quipped EPA Administrator Lisa P. Jackson when presenting the EPA budget proposal. —With additional reporting by the Science News staff Image: The Obama administration's proposed budget for fiscal year 2012 includes big increases for research in clean energy, environmental science and science education. (T. Dube/ScienceNews) See Also: |
| Sex Discrimination in Science Continues, But Reasons Unclear Posted: 15 Feb 2011 06:45 AM PST
By Kate Shaw, Ars Technica Today, more than half of all PhDs in the life sciences are awarded to women, compared to a measly 13 percent bestowed upon women in 1970. However, women still lag far behind men in full professorships and tenure track positions in math-intensive fields.
Is it harder for women to publish?Getting research published is a must for scientists, and is essential for getting hired and moving up the ranks in all scientific professions. Critics have claimed that men have an advantage in the reviewing and publishing processes, and that this bias may account for the dearth of females in tenured positions. However, after reviewing several studies in this area, Ceci and Williams conclude that this just doesn't seem to be the case. Studies of publication rates in Nature Neuroscience, Cortex, and Journal of Biogeography, among others, found no evidence of sex discrimination. When men and women with similar resources are compared, there is no evidence for publication differences between the sexes. However, there are some factors that affect women at a disproportionately high rate and may cause biases in the publication process. For example, women are more likely to work at teaching-intensive colleges and therefore lack the time and resources to produce frequent and high-quality research for publication. When the type of institution, the scientist's funding, the teaching load, and the research assistance are taken into account, there is no difference in publication rates for men and women. It seems that the critical factor isn't sex, but instead access to resources, an area in which women may lag behind men.
Are women at a disadvantage when applying for grants?Another commonly-cited issue is that it is harder for female scientists to get funding for their work than it is for male scientists. Some studies, such as a very influential 1997 Nature publication by Wenneras and Wold, have found that grant review panels are more likely to fund males over females. This study found that women needed to be "2.5 times more productive" than men to be funded by the Swedish Medical Research Council in 1995. However, this study has been challenged based on methodological and conceptual issues, and further studies have mostly been unable to replicate this level of bias. In fact, where biases have been found, advantages often go to the women; a 1996 study of females funded by a UK panel found they have published just 11.2 papers on average, while the funded males had published an average of 13.8 papers. Large scale analyses of grant review in the past 30 years at NSF, NIH, the US Department of Agriculture, and the Australian Research Council have not found any evidence of sex discrimination. Research does suggest that, before the 1980s, it was more difficult females to get grants than it was for males. However, most research agrees that the playing field has evened out in terms of funding in the last few decades. Does hiring occur without regard to gender?Finally, Ceci and Williams examined the interviewing and hiring process at research institutions. A very famous 1999 study distributed mock CVs to 238 psychologists who were reviewing possible hires for assistant professor and tenure track positions. For the assistant professor job, the reviewers tended to rate CVs with male names more highly than identical CVs with female names (although this effect disappeared for the tenure track job). This finding, as well as similar results in other studies, suggested to many that females may be at a disadvantage when applying for some scientific positions. However, since 2000, there is little evidence that females face more hurdles than men in the hiring process. In fact, some studies have shown that women get interviewed and are offered tenure-track jobs at a slightly higher rate than males. What is evident, however, is that females tend to make different choices than men when applying for and accepting jobs. Here, Ceci and Williams argue, is where much of the scientific gender gap arises. About 80 percent of both male and female graduate students believe that working full-time is "important" or "extremely important." However, nearly a third of women believe that working part-time for a period is "important" or "somewhat important," compared to just 9 percent of men. In the UK, females are almost twice as likely as men to work part-time for at least some length of time. So, while females have similar aspirations as men, they seem to make different choices when it comes to employment. Asking different questionsInstead of debating whether women are being discriminated against in publication, grant review, and hiring, Ceci and Williams argue that we should concentrate on more current causes of female underrepresentation in the sciences. The important question to address now is whether women on the academic track are making personal choices that promote happiness and satisfaction, or whether their careers are constrained by biology and societal obligations. The authors suggest that there are three main contributors to this unde-representation: career preferences, family choices, and ability differences. Women tend to chose careers in which they are "helping people," such as working at teaching-intensive institutions, at a greater rate than men do. Additionally, fertility and lifestyle choices affect women's careers at a disproportionately high rate when compared to men. In terms of ability differences, far fewer women than men appear in the top one percent of standardized math results, such as SAT and GRE scores. The authors cite this last fact without venturing into the complicated reasons behind the phenomenon, except for stating that it is "potentially influenced by both socialization and biology." So, women in scientific fields — especially math-intensive ones — seem to be at a disadvantage due both to free choices and various constraints. According to the authors, however, discrimination in publication, grant review, and hiring do not seem to be among those constraints. As a start, Ceci and Williams suggest exposing young women to successful role models in science and math-intensive fields and giving them more information about career opportunities. Furthermore, they advocate changing the tenure system slightly so that there are fewer disincentives for women to have families and children. As a model, the authors cite UC Berkeley's "Family Edge" program, which provides child care and urges reviewers to ignore family-related gaps in employment and productivity. While more work clearly needs to be done on clarifying the causes of women's underrepresentation in the sciences (especially in math-intensive fields) the review strongly suggests that discrimination isn't the cause, and that we need to "redirect our energies" toward more pertinent questions. Image: Flickr/juan.barredo. Source: Ars Technica. Citation: "Understanding current causes of women's underrepresentation in science." Stephen J. Ceci and Wendy M. Williams. Proceedings of the National Academies of Science, published online Feb. 7, 2011. DOI: 10.1073/pnas.1014871108 See Also: |
| ‘Magnetricity’ Created in Crystals of Spin Ice Posted: 14 Feb 2011 03:05 PM PST
Electricity has a new little sister: magnetricity.
In magnets, poles always come in pairs. No matter how many times you cut a magnet in half, down to the atoms themselves, each piece will always have a north and a south — a dipole. But the magnetic molecules that make up a crystalline material called spin ice are arranged in triangular pyramids that prevent them from lining up comfortably with all of their poles pointing in the same direction. In an awkward compromise, each pyramid tends to have two magnets pointing inward and two pointing outward. In 2009 Steven Bramwell of the University College of London found that sometimes a molecule squirms and flips. Two poles, a north and a south, are born. The molecule itself stays put, but these ghostly poles, which aren't actually attached to a physical object, can move around independently of each other as chain reactions of flipping molecules carry them from pyramid to pyramid. "Eventually they get so far apart that they lose all memory of each other," says Bramwell. "The dipole splits in half and becomes two monopoles."
Some scientists have questioned the use of the term monopole for a phenomenon that exists only inside spin ice. This term traditionally refers to cosmic monopoles thought to be created during the Big Bang and first theorized by Paul Dirac in 1931. "A real monopole would be a magnetic charge that would exist in a vacuum," says Michael Bonitz, a physicist at the Institute for Theoretical Physics and Astrophysics in Kiel, Germany. "What they have is a complicated condensed matter system." Within the confines of the spin ice, though, these wandering poles do behave much like monopoles. The poles have magnetic charge that closely agrees with theoretical predictions and interact with each other according to the same law that governs the interaction of electric charges, Coulomb's Law. Using brief magnetic pulses, Bramwell and his team have now developed a way to trigger currents of these magnetic charges — "magnetricity" — that last for minutes. "We apply a magnetic field to create magnetic charges and get them all going the same direction," says Sean Giblin, a physicist at the Rutherford Appleton Laboratory in Oxfordshire, England, and a co-author of a paper published online Feb. 13 in Nature Physics. These currents have revealed new similarities between magnetic and electric charges. The creation and slow dissipation of new magnetic charges follows the exact same principles that govern charged particles in solutions — such as ions in battery electrolytes. The way that the spin ice stores magnetic charge is also similar to the way existing devices called capacitors store electric charge. So Bramwell's pie-in-the-sky dream is for magnetricity to someday spawn a new technology called "magnetronics." But he admits it may take a while to get there, especially because these currents appear only in crystals kept close to absolute zero.
Image: Currents of magnetricity are born when north poles and south poles split up and move around independently of each other. (Courtesy Steven Bramwell) Video: When a molecule of spin ice flips, it creates two magnetic poles in neighboring pyramids that can be carried away from each other as other molecules flip. (Steven Bramwell/Vimeo) See Also: |
| Spacecraft Seeks Doomed Comet for Valentine’s Day Rendezvous Posted: 14 Feb 2011 12:00 PM PST
Late Monday night, NASA's Stardust-NExt spacecraft will make a close flyby of the comet Tempel 1, destined for fiery destruction by the sun. This will be the second comet rendezvous for Stardust-NExT, which caught dusty bits of comet Wild 2 in 2004 and sent them back to Earth. It will also be the second encounter with a spacecraft for Tempel 1, which collided with the Deep Impact probe in 2005. Combined with Deep Impact's visit, the Stardust-NExT flyby will give astronomers their first view of a complete cometary circuit around the sun, and the best picture yet of how the sun devours a comet. "We know that comets lose material," said astronomer Joe Veverka of Cornell University, principal investigator of the Stardust-NExT mission, in a recent press conference. "But the question is, how does the surface change, and where does the surface change?" At closest approach, Stardust-NExT will come within 120 miles of the comet's core. Astronomers hope to get a good look at the scars Deep Impact left behind, and to map some uncharted territory on the comet's dusty, icy surface. Of particular interest are parts of the surface that look like they're layered like a stack of pancakes. Another intriguing spot is a large plateau that looks like material flowed across it in the recent past. The flyby will air live on NASA TV from 11:30 pm Eastern time on Feb. 14 to 1 am Eastern time on Feb. 15. The spacecraft is expected to make its closest approach at 11:37, although confirmation won't reach Earth until 11:56. But if you don't want to stay up that late, we'll have a re-cap tomorrow. Image: Comet Tempel 1 immediately after its brief, explosive relationship with Deep Impact. Credit: NASA See Also: |
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