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| Sunday, 24 April 2005 |
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Features |  |
| News Business Features Editorial
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Compiled by Vimukthi Fernando Fireworks 268 million miles away This year, NASA is planning a spectacular fireworks display on the Fourth of July. Unfortunately, you'll need a telescope to see it, as the explosions will take place over 268 million miles away. Obviously, this is far from the usual observances of the birth of the USA. But NASA's plans do indeed have something to do with a birth: not just the birth of the United States, but the entire solar system.
Scientists are learning more and more about how planets form in young solar systems. Ten years ago, there were only a handful of stars that we knew had planet-forming disks of gas and dust around them (astronomers call them protoplanetary disks). Now, we know of hundreds, due to a large part to the observations coming down from the Spitzer Space Telescope, an all-infrared observatory launched in 2003. Warm disks of planet-forming material show up bright and clear to a heat-light sensitive telescope, and for the first time, astronomers are able to look at the process of planet formation using large numbers of examples. But the only example we have of a planet-forming disk that really did the right thing (i.e.,formed a stable solar system capable of life) is our own. With so many examples of how planet-forming gets started, it's important to compare the new systems we're discovering to what we must have looked like, a few billion years ago. But there's one inconvenient fact: we've moved on since then. The dust and gas of our protoplanetary disk is long gone, gathered into planets or leaked away into the emptiness of space. Where could we find a sample of the material that was around during the actual formation process of our system? Inside a comet! Comets are a relic of our early solar system. In a way, the leftovers of planet formation - chunks of dirt and ice that never got incorporated into a larger planetary body. Astronomers have been interested in the chemistry of comets for some time now, as being like a time-machine to look back and study the chemistry of our solar systems before the planets even formed. Up until now, we've only been able to study the material near the surface of comets - the stuff blown off in the tail or, more recently, a few near encounters with the icy body itself. But the surface material has been altered over time: blasted by the Sun's heat each time a comet makes its rounds through our solar system. If we want to see a pristine sample of the stuff of our early selves, we've got to dig down. Or even better, blast down! The idea behind the Deep Impact mission is this: send a spacecraft to intercept the comet Tempel-1 and launch some ballistic object at it to carve out a crater deep enough to get down to the pure, unaltered comet material beneath the surface. While that's going on, observe the chemistry of the comet before, during, and after the impact, and study the structure of the crater for clues about how the comet is made up. Deep Impacts strategy may seem rather brutal, but there is actually quite a bit of delicacy involved. The spacecraft has two parts, a fly-by craft and an impactor. The fly-by spacecraft will travel millions of miles out into space to pull up about 536,000 miles away from Tempel-1. On July 3rd, it will release the impactor and train its sensitive cameras toward the surface of the comet. The impactor, as its name suggests, is the bit that will actually hit the comet, an 820 pound bullet of copper and aluminum. But it is far from just a lump of metal; the impactor will have just 24 hours to travel half a million miles and insert itself directly into the path of Tempel 1, a comet only 4 miles across that will be barrelling through space at incredible speeds. When the impactor hits the comet, it should crash into Tempel 1 with speeds around 23,000 miles per hour. The impactor also has to hit the comet on its sunny side, or we wont get a very good view of the crater or the debris that gets blown off. The impactor is actually a mini-spacecraft unto itself, able to steer itself by the stars and alter its path accordingly with its own thrusters. The thrusters aren't hugely strong either; the idea is basically to get the impactor into the orbital path of the comet, and then let the comet plow into it. Watching from a safe distance of 536,000 miles away, the fly-by part of the spacecraft will be constantly sampling the chemistry of the comet, and observing the debris that gets thrown off during the collision. Some of the Earth's largest telescopes will also be pointing up at the celestial fireworks, hoping for a first glimpse inside a comet. What would our expectations be? To begin with, the size and shape of the crater will tell us something about the structure of the comet, whether it's denser in the middle, or if heavy material is spread more evenly throughout the whole body. That data, in turn, will tell us a surprisingly important fact about the processes that were going on in our ancient protoplanetary disk. Were objects allowed to accrete together smoothly over huge spans of time (which would create comets with denser cores with lighter layers of ice deposited on top), or were things being mixed around more, blending heavy and light materials together over shorter timescales? What molecules were present in the early solar system? Many of the protoplanetary disks we're observing now seem to have plenty of water, methane, carbon dioxide and other organic molecules enriching the gas of the disk. Was our chemistry, which ultimately led to life, the same or different? At any rate, on the Fourth of July this year, look up into the sky and give a thought to the more distant fireworks taking place. We've travelled millions of miles to celebrate the beginning of something truly special. - Christian Science Monitor Now its Bomb-Sniffing Polymer Researchers have developed a novel polymer device that can pick up on trace amounts of explosive vapours. The work, described in the journal Nature, could "deliver sensors that can detect explosives with unparalleled sensitivity," its inventors suggest. Aimie Rose and her colleagues at the Massachusetts Institute of Technology used a type of compound known as a semiconducting organic polymer (SOP) in their design. When exposed to laser light, this type of compound subsequently produces its own additional laser light-a process called lasing. Molecules of explosives such as trinitrotoluene (TNT) are deficient in electrons and are attracted to the electron-rich polymer. When they stick to the surface, they interfere with the lasing and the SOP's light output decreases as a result. By measuring the change in lasing, the scientists were able to detect TNT at concentrations as low as five parts per billion. The team also successfully identified dinitrotoluene (DNT) at 100 parts per billion in just one second of detection time. The detector is relatively immune to interference, the researchers report, noting that no response was recorded in the presence of molecules such as benzene or naphthalene. SOPs had previously been used to locate buried land mines; the new design, however, offers a 30-fold increase in sensitivity over previous ones. Happy people are healthier The song "Don't Worry, Be Happy," could double as sound medical advice, the results of a new study suggests. Whereas previous research had linked depression with an increased incidence of health problems, the new findings reveal that people who report more everyday happiness are healthier overall than their less joyous counterparts in a number of key ways. In particular, happy men experienced lower heart rates throughout the day, indicating good cardiovascular health. Andrew Steptoe and his colleagues at University College London studied the emotional and physical well-being of more than 200 middle-aged Londoners recruited for the Whitehall II psychobiology study in the mid-1980s. The participants underwent stress tests, along with blood pressure and heart rate monitoring, and they were asked to record their feelings of happiness throughout their daily lives. The team found that those people who reported feeling happier more often also had on average lower levels of the stress hormone cortisol, which is linked with hypertension and type II diabetes, than did people who recounted fewer moments of joy. In addition, content subjects performed better under stressful conditions in a laboratory task and showed fewer ill aftereffects. Following the assignment, they exhibited lower levels of a blood protein called fibrinogen, which at high levels can indicate potential cardiovascular problems. The findings are published online this week by the Proceedings of the National Academy of Sciences. Making coal power environment friendly Students from Clarkson University have designed an innovative and efficient method for removing and storing carbon dioxide emitted in coal-fired power plant flue gas. "Coal-fired power plants generate 51 per cent of the energy used in the U.S. today," said Brian Malone, a senior civil engineering major at Clarkson.
"But these power plants have also been proven to be the major contributor of greenhouse gas emissions, primarily carbon dioxide. Our challenge was to develop an economical and effective carbon sequestration system that can be implemented as an additional process in present flue gas treatment." Malone and five other students, all members of the Clarkson University Remedial Engineering (CURE) team developed the system as part of an international collegiate competition. Earlier this month the Clarkson team won first place at the 15th Annual Environmental Design Contest at New Mexico State University. The competition, sponsored by WERC: A Consortium for Environmental Education and Technology Development, challenges student teams to develop novel and innovative solutions for real-world environmental problems that have been submitted by various companies and government institutions. Thirty-three teams from the U.S., Canada and China participated in this year's competition. The CURE team designed a process utilising steel slag from the steel manufacturing industry that can be implemented into an already functioning coal-fired power plant. Labour, health, safety and economic considerations have been incorporated into the process design. "Their solution is a highly creative one," said Stefan Grimberg, professor of Civil and Environmental Engineering and team advisor. "Their process uses steel slag, which is a byproduct of the steel manufacturing process and has very little market value, to extract the carbon dioxide. The result is the production of calcium carbonate (limestone) and hydrated slag, both of which can be sold and used by other industries. So the students have used a waste product to solve their problem and the resulting products have considerable market value." The Clarkson team is composed of graduate student William Guerra of Utica, N.Y.; seniors Chase Gerbig of Honeoye Falls, N.Y.; Christopher Kennedy of Pittsford, N.Y.; Brian Malone of Underhill, Vt.; Brian Murray of Victoria, British Columbia; Jordan Winkler of Colchester, Vt.; and Andrew Zamurs of Slingerlands, N.Y. The WERC consortium comprises New Mexico State University, the New Mexico Institute of Mining and Technology, the University of New Mexico, Dino College, Los Alamos and Sandia National Laboratories. Intelligent ANTS - fiction no longer by Robert C. Cowen The cartoon superheroes were frustrated. They confronted a menacing robot that quickly repaired any damage they inflicted. It was made up of a swarm of microscopic robots - so-called nanobots - that could change its function and shape at will. Suddenly the swarm became fluid and flowed away. That cartoon scenario may seem entertaining. But the reality is startling. Engineers at the National Aeronautics and Space Administration want to pull off a similar trick. They are testing a robot that they hope to shrink to nanobot size and eventually form what NASA calls "autonomous nanotechnology swarms" (ANTS). The researchers aim to give ANTS enough artificial intelligence to make smart decisions as well as know intuitively when and how to walk and swarm. NASA invites you to consider the versatility of a nanobot swarm that has "abundant flexibility" to change shape as needed. Descending through the Martian atmosphere, for example, it could form an aerodynamic shield. On the ground, it could become a snake to slither over difficult terrain. It could grow an antenna to send back data on anything interesting it encounters. It also would heal itself if damaged. Human bodies replace damaged cells with new ones, notes Steven Curtis, lead researcher for ANTS, a joint project of Goddard Space Flight Center in Greenbelt, Md., and Langley Research Center in Hampton, Va. "In a similar way, undamaged units in a [nanobot] swarm will join together, allowing it to tolerate extensive damage and still carry on its mission," he says. Prospects like this give vivid meaning to Richard Feynman's 1959 vision of a nanotech world. Units in that world come in 1 to 100 nanometre (billionths of a metre) sizes. It's the world of atoms and molecules and, now, of nanobots. The famous physicist had urged scientists to look into that world for new frontiers: "We have new kinds of forces and new kinds of possibilities, new kinds of effects." That was a dream back then. Now, even though its major payoffs are decades away, nanotechnology already is a big deal. Worldwide government funding of nanotech research reached $3.6 billion last year with some 40 nations joining in, according to National Science Foundation (NSF) figures. For fiscal 2004, the US National Nanotechnology Initiative put up $960 million with states and local government adding roughly another $500 million. United States private industry is estimated to more or less match the federal funding. Nanotech should bring amazing new materials such as carbon-based structures many times stronger than steel. It should transform aspects of medicine, transportation, and environmental monitoring. Yet it is difficult to foresee all its future wonders. Currently, some 475 nanotech-based products such as tennis rackets, bottles, and various instruments already are available. But this brave new world has its risks. "Nanotechnology operates at the very foundation of matter, at the first level of organisation for both living and anthropogenic systems," writes Mihail Roco, who leads the NSF nanotech program, in last month's Environmental Science and Technology journal. There is worldwide concern about - and research into - the possible ecological and health effects of letting loose entities with the ability to produce Dr. Feynman's "new kinds of effects" at that basic material level. While there's no crystal ball to show the nanotech future, you might tune
in to some children's cartoons on TV for a hint of what's to come. |
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| Produced by Lake House |
Deep Impact as the mission is called, when it whoops into the comet
Tempel 1 this summer, the resulting smash will be equivalent to blowing up
4.8 tons of TNT, and is expected to blow a football stadium-sized crater
about 7 storey deep into the dirty ice of the comet. 
