Become a fan of Slashdot on Facebook
mikejuk writes "The Goldbach conjecture is not the sort of thing that relates to practical applications, but they used to say the same thing about electricity. The Goldbach conjecture is reasonably well known: every integer can be expressed as the sum of two primes. Very easy to state, but it seems very difficult to prove. Terence Tao, a Fields medalist, has published a paper that proves that every odd number greater than 1 is the sum of at most five primes. This may not sound like much of an advance, but notice that there is no stipulation for the integer to be greater than some bound. This is a complete proof of a slightly lesser conjecture, and might point the way to getting the number of primes needed down from at most five to at most 2. Notice that no computers were involved in the proof — this is classical mathematical proof involving logical deductions rather than exhaustive search."
Hugh Pickens writes "Although a fully operation city with no people sounds like the setup for a dystopian sci-fi novel, the Boston Globe reports that the Center for Innovation, Testing and Evaluation will develop a $1 billion scientific ghost town near Hobbs, New Mexico to help researchers test everything from intelligent traffic systems and next-generation wireless networks to automated washing machines and self-flushing toilets on existing infrastructure without interfering in everyday life. Bob Brumley, senior managing director of Pegasus Holdings, says the town will be modeled after the real city of Rock Hill, South Carolina, complete with highways, houses and commercial buildings, old and new. Unlike traditional cities, City Labs will start with its underground 'backbone' infrastructure that will allow the lab to monitor activity throughout the 17-mile site. Since nobody lives in the Center's buildings, computerized systems will mimic human behavior such as turning thermostats up and down, switching lights off and on, or flushing toilets. The Center's test facilities and supporting infrastructure may require as much as 20 square miles of open, unimproved land where the controlled environment will permit evaluation of the positive and negative impacts of smart grid applications and integration of renewable energies for residential, commercial and industrial sectors of the economy. 'It's an amusement park for the scientists,' adds Brumley."
Nancy_A writes "An engineer has proposed — and outlined in meticulous detail — building a full-sized, ion-powered version of the starship Enterprise. The ship would be based on current technology, and would take about 20 years to construct, at a cost of roughly $1 trillion. 'We have the technological reach to build the first generation of the spaceship known as the USS Enterprise – so let's do it,' writes the curator of the Build The Enterprise website, who goes by the name of BTE-Dan."
Hugh Pickens writes "Dr James Hansen, director of the NASA's Goddard Institute for Space Studies, who first made warnings about climate change in the 1980s, writes in the NY Times that he was troubled to read a recent interview with President Obama in Rolling Stone in which he said that Canada would exploit the oil in its vast tar sands reserves 'regardless of what we do.' According to Hansen 'Canada's tar sands, deposits of sand saturated with bitumen, contain twice the amount of carbon dioxide emitted by global oil use in our entire history. If we were to fully exploit this new oil source, and continue to burn our conventional oil, gas and coal supplies, concentrations of carbon dioxide in the atmosphere eventually would reach levels higher than in the Pliocene era, more than 2.5 million years ago, when sea level was at least 50 feet higher than it is now.' Hansen says that instead of placing a rising fee on carbon emissions to make fossil fuels pay their true costs, leveling the energy playing field, the world's governments are forcing the public to subsidize fossil fuels with hundreds of billions of dollars per year."
An anonymous reader writes "In the next decade, our brains are going to become optimized for information browsing, says best-selling author Nicholas Carr. According to Carr, while the genetic nature of our brains isn't being changed by the Internet at all, our brains are adapting 'at a cellular level' and are weakening modes of thinking we no longer exercise. Therefore, in 10 years, if human beings are using the Internet even more than they do today, says Carr, "our brains will be even more optimized for information browsing, skimming and scanning, and multitasking — fast, scattered modes of thought — and even less capable of the kinds of more attentive, contemplative thinking that the net discourages."" While Carr isn't making a case for Lamarckian evolution, the argument here seems weak to me; the same kind of brain change could be attributed to books, or television, or the automobile, couldn't it?
An anonymous reader writes "Traditional methods of producing pure hydrogen are either extremely expensive or release lots of carbon dioxide into the atmosphere. Now, scientists at Brookhaven National Laboratory have developed an electrocatalyst that addresses one of these problems by generating hydrogen gas from water cleanly and with drastically more affordable materials. Goodbye platinum; hello nickel and ammonia."
astroengine writes "Vesta, the second largest object in the main asteroid belt, has an iron core, a varied surface, layers of rock and possibly a magnetic field — all signs of a planet in the making, not an asteroid (abstract). This is the conclusion of an international team of scientists treated to a virtual front row seat at Vesta for the past 10 months, courtesy of NASA's Dawn robotic probe. Their findings were presented during a NASA press conference on Thursday. As to why Vesta never made it to full planethood, scientists point to Jupiter. When the giant gas planet formed, nearby bodies such as Vesta found their orbits perturbed. 'Jupiter started to act like a spoon in a pot, stirring up the asteroid belt and the asteroids started bumping into one another,' said Dawn lead scientist Christopher Russell. 'If they're just out there gently orbiting and everything is going smoothly, then without Jupiter in the picture, they would gather mass and get bigger and bigger and bigger. But with Jupiter there, stirring the pot, then the asteroids start bumping into one another and breaking apart, so nothing grew in that region, but started to shrink.'"
MrSeb writes "Chinese physicists are reporting that they've successfully teleported photonic qubits (quantum bits) over a distance of 97 kilometers (60mi). This means that quantum data has been transmitted from one point to another, without passing through the intervening space. It's important to note that the Chinese researchers haven't actually made a photon disappear and reappear 97 kilometers away; rather, they've used quantum entanglement to recreate the same qubit in a new location, with the same subatomic properties as the original qubit. The previous record for transmitting entangled qubits was 16 kilometers, performed by another Chinese team back in 2010 — and perhaps most excitingly, the researchers seem confident that their system will scale up from 97km to distances capable of reaching orbital satellites, at which point we'll actually be able to build a global quantum network for all of our cryptographic needs."
An anonymous reader writes with news that the European Space Agency has lost contact with its Envisat environmental satellite mere weeks after celebrating a full decade in orbit. Engineers have spent the last month trying to re-establish contact, and will continue to do so for another two months. "With ten sophisticated sensors, Envisat has observed and monitored Earth’s land, atmosphere, oceans and ice caps during its ten-year lifetime, delivering over a thousand terabytes of data. An estimated 2500 scientific publications so far have been based on this information, furthering our knowledge of the planet." The ESA was hoping Envisat would stay operational for another two years, until Sentinel satellites from the Global Monitoring for Environment and Security initiative became operational.
bonch writes "22 percent of California eighth-graders passed a national science test, ranking California among the worst in the U.S. according to the 2011 National Assessment of Educational Progress. The test measures knowledge in Earth and space sciences, biology, and basic physics. The states that fared worse than California were Mississippi, Alabama, and a tie between the District of Columbia and Hawaii. 'Nationally, 31 percent of eighth-graders who were tested scored proficient or advanced. Both the national and state scores improved slightly over scores from two years ago, the last time the test was administered.'"
Zothecula writes "SpaceX and Bigelow Aerospace have joined forces in an attempt to woo international customers looking to enjoy some extended periods of microgravity. The joint marketing effort will push trips to orbiting Bigelow habitats on SpaceX's Dragon spacecraft using the Falcon launch vehicle. 'Bigelow's BA 330 space module would be designed to provide 330 cubic meters of usable volume, which is about the size of a two-bedroom apartment. The BA 330 could accommodate up to six astronauts, depending on how cozy they plan to get. Two or more BA 330 modules could be connected together in orbit for lease by national space agencies, companies or universities, according to Bigelow Aerospace.'"
ananyo writes "Evidence is mounting that research is riddled with positive bias. Left unchecked, the problem could erode public trust, argues Dan Sarewitz, a science policy expert, in a comment piece in Nature. The piece cites a number of findings, including a 2005 paper by John Ioannidis that was one of the first to bring the problem to light ('Why Most Published Research Findings Are False'). More recently, researchers at Amgen were able to confirm the results of only six of 53 'landmark studies' in preclinical cancer research (interesting comments on publishing methodology). While the problem has been most evident in biomedical research, Sarewitz argues that systematic error is now prevalent in 'any field that seeks to predict the behavior of complex systems — economics, ecology, environmental science, epidemiology and so on.' 'Nothing will corrode public trust more than a creeping awareness that scientists are unable to live up to the standards that they have set for themselves,' he adds. Do Slashdot readers perceive positive bias to be a problem? And if so, what practical steps can be taken to put things right?"
sciencehabit writes "A team of American researchers has discovered a small trove of ancient Mayan texts in a surprising place. In a paper published online today in Science, researchers report finding Mayan astronomical tables and other texts painted and incised on the walls of a 1200-year-old residential building at the site of Xultún in Guatemala. The newly discovered astronomical tables are at least 500 years older than those preserved in the Maya codices, giving researchers a new glimpse of science at the height of the Maya civilization. 'I think we are all astonished by this find,' says Stephen Houston, an archaeologist at Brown University who was not part of the team."
ericjones12398 writes "The Food and Drug Administration is proposing that manufacturers of X-ray machines and CT scanners do more to protect children from radiation exposure. If companies don't take steps to limit X-ray doses, the agency may require a label on their new equipment recommending it not be used on children. X-rays and CT scans can provide doctors with lots of useful information. But the radiation that creates the helpful images also increases a person's risk for cancer. There's been an explosion in the use of imaging tests. And rising radiation doses, particularly from CT scans, have drawn concern. The cancer risk increases with the dose of X-rays received during a person's lifetime, so kids' exposure is particularly important. It's also the case that children are more sensitive to X-ray damage. The FDA is also telling parents to speak up. If a doctor orders a test or procedure that uses X-rays, parents shouldn't be afraid to ask if it's really necessary. Also, it doesn't hurt to ask if there's an acceptable alternative, such as ultrasound or MRI, that doesn't rely on X-rays."
sciencehabit writes "A new study suggests that, by disrupting your body's normal rhythms, your alarm clock could be making you overweight. The study concerns a phenomenon called 'social jetlag.' That's the extent to which our natural sleep patterns are out of synch with our school or work schedules. When we wake up earlier than we're supposed to — or spend all weekend sleeping in and then get up at 6 am on Monday — it makes our body feel like it's spending the weekend in one time zone and the week in another. For people who are already on the heavy side, greater social jet lag corresponds to greater body weight."