yanom writes "I'm currently a high school student using my TI-84 for mathematics courses. It has all the functionality I need (except CAS), but saying that the hardware is dated is putting it nicely. Waiting 4-5 seconds for a simple function to be graphed on its 96x64 screen just makes me want to hurl it at the wall. Recently, I've begun to notice the absurdity of doing my math homework on a 70's era microchip when I have an i7 machine with Linux within arm's reach. I've begun looking for software packages that could potentially replace the graphing calculator's functionality, including Xcas and Maxima, but both lack what I consider basic calculator functionality — xcas can't create a table of values for a function, and maxima can't use degrees, only radians. So, does anyone know of a good software package to replace my graphing calculator (and maybe provide CAS to boot)?"
Catch up on stories from the past week (and beyond) at the Slashdot story archive
ananyo writes "DNA strands can be coaxed to fold up into shapes in a matter of minutes, reveals a study published in Science (abstract). The finding could radically speed up progress in the field of DNA origami. DNA origami involves using short DNA strands to hold a longer, folded strand in place at certain points, like sticky tape. Until now, assembling the shape has involved heating the DNA and allowing it to cool slowly for up to a week. But researchers at the Technical University of Munich in Germany have worked out that for most of the cooling period, nothing happens. But when a crucial temperature is reached, the whole structure forms suddenly. The researchers now aim to design nanostructures with optimal folding temperatures close to 37 C, the temperature at which mammalian cell cultures are grown, so that DNA machines could one day be used in biological settings."
Press2ToContinue writes "According to a NASA news release, 'Twin lunar-orbiting NASA spacecraft that have allowed scientists to learn more about the internal structure and composition of the moon are being prepared for their controlled descent and impact on a mountain near the moon's north pole at about 2:28 p.m. PST (5:28 p.m. EST) Monday, Dec. 17. Ebb and Flow, the Gravity Recovery and Interior Laboratory (GRAIL) mission probes, are being sent purposely into the lunar surface because their low orbit and low fuel levels preclude further scientific operations. The duo's successful prime and extended science missions generated the highest resolution gravity field map of any celestial body. The map will provide a better understanding of how Earth and other rocky planets in the solar system formed and evolved. Both spacecraft will hit the surface at 3,760 mph (1.7 kilometers per second). No imagery of the impact is expected because the region will be in shadow at the time.' That's too bad; observing the impacts could provide valuable feedback. For example, a spectrographic analysis of the impact dust cloud could reveal additional density and compositional element information for the lunar polar surfaces." Emily Lakdawalla at the Planetary Society has more information about the violent end to GRAIL's mission. If the probes were going to hit the surface of the Moon vertically, they would probably leave a crater about 3 or 4 meters in diameter. However, they are actually coming in at a very slight angle: 1.5 degrees from the horizontal, though the mountain itself has a 20-degree slope. Despite the darkness at the impact site, NASA will attempt to monitor the crashes using the Lunar Reconnaissance Orbiter.
illtud writes "It appears that the Metropolitan Police in London have been recording the frequency of the mains supply for the past 7 years. With this, they claim to be able to pick up the hum from any digital recording and tell when the recording was made. From the article: 'Comparing the unique pattern of the frequencies on an audio recording with a database that has been logging these changes for 24 hours a day, 365 days a year provides a digital watermark: a date and time stamp on the recording.'"
New submitter stonetony writes with this excerpt from the BBC: "A team of 12 scientists and engineers has begun work at remote Lake Ellsworth. They are using a high-pressure hose and sterilised water at near boiling point to blast a passage through more than two miles of ice. The aim is to analyse ice waters isolated for up to 500,000 years. The team of 12 scientists and engineers is using sterilised water at near boiling point to blast a passage through the ice to waters isolated for up to half a million years. The process of opening a bore-hole is expected to last five days and will be followed by a rapid sampling operation before the ice refreezes."
ananyo writes "A controversial paper published in Nature argues that enigmatic fossils regarded as ancient sea creatures were actually land-dwelling lichen. If true, that would suggest life on land began 65 million years earlier than researchers now estimate. The nature of fossils from the Ediacaran period, some 635 million–542 million years ago, has been fiercely debated by palaeontologists. But where others envisage Ediacaran sea beds crawling with archaic animals, Gregory Retallack, a geologist at the University of Oregon in Eugene, sees these sites in southern Australia as dry, terrestrial landscapes dotted with lichens. He proposes that rock in the Ediacara Member in South Australia — where palaeontologist Reginald Sprigg first discovered Ediacaran fossils in 1947 — represents ancient soils, and presents new geological data. Among other lines of evidence, Retallack argues that the rock's red colour and weathering pattern indicate that the deposits were formed in terrestrial — not marine — environments (abstract). Others strongly disagree."
An anonymous reader writes "Researchers have found conclusive evidence for the first time that humans have been making cheese since the 6th millennium BC."
AbsoluteXyro writes "NASA's Cassini orbiter, which has been dutifully exploring the Saturn system since 2004, has captured images of the first river ever observed on another world — and it's a biggun. 200 miles of flowing hydrocarbons meandering down a valley in the north polar region of Saturn's moon Titan, emptying into the awesomely named Kraken Mare — itself a body of liquid roughly the size of the Mediterranean Sea back on Earth. But don't think of going for an extraterrestrial skinny dip quite yet, temperatures on Titan average a brutally cold 290 degrees below zero (Fahrenheit)."
Hugh Pickens writes "According to NASA, a pair of asteroids — one just over three miles wide — passed Earth Tuesday and early Wednesday, avoiding a potentially cataclysmic impact with our home planet. 2012 XE5, estimated at 50-165 feet across, was discovered just days earlier, missing our planet by only 139,500 miles, or slightly more than half the distance to the moon. 4179 Toutatis, just over three miles wide, put on an amazing show for astronomers early Wednesday, missing Earth by 18 lunar lengths, while allowing scientists to observe the massive asteroid in detail. Asteroid Toutatis is well known to astronomers. It passes by Earth's orbit every four years and astronomers say its unique orbit means it is unlikely to impact Earth for at least 600 years. It is one of the largest known potentially hazardous asteroids, and its orbit is inclined less than half-a-degree from Earth's. 'We already know that Toutatis will not hit Earth for hundreds of years,' says Lance Benner of NASA's Near Earth Object Program. 'These new observations will allow us to predict the asteroid's trajectory even farther into the future.' Toutatis would inflict devastating damage if it slammed into Earth, perhaps extinguishing human civilization. The asteroid thought to have killed off the dinosaurs 65 million years ago was about 6 miles wide, researchers say. The fact that 2012 XE5 was discovered only a few days before the encounter prompted Minnesota Public Radio to poll its listeners with the following question: If an asteroid were to strike Earth within an hour, would you want to know?"
Koreantoast writes "After failing on numerous occasions, North Korea has finally put a satellite in orbit. But according to US officials, it is now 'tumbling out of control.' This is bad news, and more bad news, covered in a double layer of extra bad news. From the article: 'According to US officials, it appears that North Korea's new satellite has failed to achieve a stable orbit and is now "tumbling out of control." The greatest danger is the threat of it colliding with another satellite, adding to the growing debris field around the earth.' A separate Gizmodo article provides links for tracking the current location of the satellite."
GNUman writes "Wired has an article about using videogames to get kids into engineering, starting with Kerbal Space Program, a indie physics-driven sandbox where you build your own spaceship and explore space. I have had much fun with this game the past year and I have actually learned a bit of rocket engineering and orbital mechanics while at it. The article also mentions Minecraft, World of Goo, Amazing Alex, Patterns, Banjo Kazooie: Nuts and Bolts, Fantastic Contraption and SpaceChem. I really like the idea of games that are great fun while fostering creativity and even learning in the process. What games would you add to this list?"
The Bad Astronomer writes "Using Hubble Space Telescope, astronomers have spotted seven galaxies that are all over 13 billion light years away... including one that appears to be a record breaker at a staggering 13.3+ billion light years distant. That one is seen as it was only 380 million years after the Big Bang. This observation reaches into the era of the young cosmos when stars were first forming, and allows astronomers to better understand what the Universe was like back then — a time we know very little about."
gbrumfiel writes "For years, physicists have been on the hunt for a material so weird, it might as well be what unicorn horns are made of. Topological insulators are special types of material that conduct electricity, but only on their outermost surface. If they exist, and that's a real IF, then they would play host to all sorts of bizarre phenomenon: virtual particles that are their own anti-particles, strange quantum effects, dogs and cats living together, that sort of thing. Now three independent teams think they've finally found the stuff that the dreams of theoretical physicists are made of: samarium hexaboride."
dstates writes "Retraction Watch reports that fake reviewer information was placed in Elsevier's peer review database allowing unethical authors to review their own or colleagues manuscripts. As a result, 11 scientific publications have been retracted. The hack is particularly embarrassing for Elsevier because the commercial publisher has been arguing that the quality of its review process justifies its restrictive access policies and high costs of the journals it publishes."
Hugh Pickens writes writes "A suspected terrorist has been taped planning a deadly attack and the police want to use this evidence in court, or someone has been captured on CCTV threatening an assault. Increasingly, recordings like these are playing a role in criminal investigations, but how can the police be sure that the audio evidence is genuine and has not been cleverly edited? Now Rebecca Morelle writes on BBC that a technique known as Electric Network Frequency (ENF) analysis is helping forensic scientists separate genuine, unedited recordings from those that have been tampered with and the technique has already been used in court. Any digital recording made near an electrical power source will pick up noise from the grid that will be embedded throughout the audio. This buzz is an annoyance for sound engineers trying to make the highest quality recordings, but for forensic experts, it has turned out to be an invaluable tool in the fight against crime. Due to unbalances in production and consumption of electrical energy, the ENF is known to fluctuate slightly over time rather than being stuck to its exact set point so if you look at the frequency over time, you can see minute fluctuations and the pattern of these random changes in frequency is unique over time providing a digital watermark on every recording. Forensic Scientist Philip Harrison has been logging the hum on the national grid in the UK for several years. 'Even if [the hum] is picked up at a very low level that you cannot hear, we can extract this information,' says Dr. Harrison. 'If we have we can extract [the hum] and compare it with the database, if it is a continuous recording, it will all match up nicely.'"
pigrabbitbear writes "Farming, logging, and strip mining has long altered much of the Amazon rainforest, with slash-and-burn land-clearing techniques turning large portions of the forest into patchworks of pastures, second-growth forest, and degraded land. Now, rural people are increasingly moving to booming Amazonian cities; paradoxically, the land they're leaving behind is being ravaged by wildfires. A new paper published in PNAS shows that in the Peruvian Amazon, land use changes and depopulation have let large wildfires fly through converted land. It puts a damper on those optimistic that the urbanization of the Amazon may allow parts of the forest to recover, by centralizing populated areas and leaving old converted land to be slowly gobbled up by the encroaching forest."
sciencehabit writes "A SARS-like virus discovered this summer in the Middle East may infect more than just humans. The pathogen, a close cousin to the one that caused the 2002 to 2003 SARS outbreak, may also be able to infect cells from pigs and a wide range of bat species, researchers report today (abstract). The findings may help public health officials track the source of the outbreak and identify the role of wild animals and livestock in spreading the virus, researchers say."
gbrumfiel writes "Those hoping to laser their way out of the energy crisis will have to wait a little longer. The U.S. government has unveiled its new plan for laser fusion, and it's not going to happen anytime soon. It all comes down to problems at the National Ignition Facility (NIF), the world's most powerful laser at Lawrence Livermore Lab in California. For the past six years researchers at NIF have been trying to use the laser to spark a fusion reaction in a tiny pellet of hydrogen fuel. Like all fusion, it's tougher than it looks, and their campaign came up short. That left Congress a little bit miffed, so they asked for a new plan. The new plan calls for a more methodical study of fusion, along with a broader approach to achieving it with the NIF. In three years or so, they should know whether the NIF will ever work."
dsinc sends this quote from an AP report about the U.S. Air Force's X-37B spaceplane: "The Air Force launched the unmanned spacecraft Tuesday hidden on top of an Atlas V rocket. It's the second flight for this original X-37B spaceplane. It circled the planet for seven months in 2010. A second X-37B spacecraft spent more than a year in orbit. These high-tech mystery machines — 29 feet long — are about one-quarter the size of NASA's old space shuttles and can land automatically on a runway. The two previous touchdowns occurred in Southern California; this one might end on NASA's three-mile-long runway once reserved for the space agency's shuttles. The military isn't saying much, if anything, about this new secret mission. In fact, launch commentary ended 17 minutes into the flight. But one scientific observer, Harvard University's Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics, speculates the spaceplane is carrying sensors designed for spying and likely is serving as a testbed for future satellites."
Hugh Pickens writes writes "RIA Novosti reports that Kazakhstan and Russia are in talks over returning the city of Baikonur to Kazakhstan — the site of the first Soviet rocket launches and Russia's most important space launch center. Baikonur, built in Kazakhstan in the 1950s, is the main launch facility for the current generation of Russian rockets and was leased by Russia from Kazakhstan under an agreement signed in 1994 after the collapse of the Soviet Union. 'Today both nations' governments have decided to set up a new intergovernmental commission for the Baikonur complex to be headed up by first or other deputy prime ministers,' said Talgat Musabayev, head of Kazakhstan's space agency. At issue is control over Baikonur and the rent Russia pays Kazakhstan to use the facility, a subject of ongoing dispute between the two nations ever since Kazakhstan gained independence from the USSR. Earlier this year, Kazakhstan blocked Russia from launching several rockets from Baikonur in a dispute over a drop zone for debris and Kazakhstan insisted this must be covered by a supplement to the main rental agreement signed in Astana in 2004, extending Russia's use of the space center's facilities until 2050. Russia pays an annual fee of approximately $115 million to use the space center, which currently has the world's busiest launch schedule, as well as $50 million annually for maintenance. Russia and Kazakhstan are working to build a new space launch facility at Baikonur, called Baiterek, to launch Angara carrier rockets capable of delivering 26 metric tons of payload to low-Earth orbits but Russia intends to eventually withdraw from Baikonur and conduct launches from the Plesetsk Cosmodrome, an operating spaceport about 500 miles north of Moscow — and the unfinished Vostochny Cosmodrome in the Russian Far East."