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Math

Major Advances In Knot Theory 230

Posted by kdawson from the if-it's-not-theory-then-it-must-be-practice dept.
An anonymous reader sends us to Science News, which is running a survey of recent strides in finding an answer to the age-old question: How many ways are there to tie your shoelaces? "Mathematicians have been puzzling over that question for a century or two, and the main thing they've discovered is that the question is really, really hard. In the last decade, though, they've developed some powerful new tools inspired by physics that have pried a few answers from the universe's clutches. Even more exciting is that the new tools seem to be the tip of a much larger theory that mathematicians are just beginning to uncover. That larger mathematical theory, if it exists, may help crack some of the hardest mathematical questions there are, questions about the mathematical structure of the three- and four-dimensional space where we live. ... Revealing the full ... superstructure may be the work of a generation."

Comment Re:One arm, OK. But TWO??!!! (Score 1) 124

by Jump (#23648327) Attached to: Spitzer's 5-Gigapixel Milky Way
Not seeing all 4 arms in infrared light is not new. In fact this has been known for a long time and it just means that those stellar arms are not density waves in the stellar disk. However, they are seen in the distribution of molecular clouds. Basically this means that the Milky Way has two overlapping spiral pattern: a stronger 2-armed mode which is in stars and gas, and another 4-armed mode which is only seen in gas. The 4-arm mode is weaker (as expected from theory) and extends over a smaller radius range. So not all studies will find 4 arms. In the optical, that is seen by eye from the distance, our Galaxy would look 4-armed, because those weaker arms are still hosts of star formation. But in infrared, many galaxies look different, because in this waveband we see mostly the older stellar population.
Unix

The Birth of vi 459

Posted by Zonk from the please-keep-emacs-trolling-to-a-minimum dept.
lanc writes "Bill Joy, co-founder of Sun, tells the story of how he wrote the vi editor. The article at The Register delves into his motives, who instigated the project, and some of the quirks of leaving a 'gift to mankind'. From the piece: '9600 baud is faster than you can read. 1200 baud is way slower. So the editor was optimized so that you could edit and feel productive when it was painting slower than you could think. Now that computers are so much faster than you can think, nobody understands this anymore. The people doing Emacs were sitting in labs at MIT with what were essentially fibre-channel links to the host, in contemporary terms. They were working on a PDP-10, which was a huge machine by comparison, with infinitely fast screens. So they could have funny commands with the screen shimmering and all that, and meanwhile, I'm sitting at home in sort of World War II surplus housing at Berkeley with a modem and a terminal that can just barely get the cursor off the bottom line.'"
Security

Submission + - Fingerprinting the World's Mail Servers

Submitted by
ttul
ttul writes: "This O'Reilly SysAdmin Article describes some work done by mod_perl author Stas Bekman and his colleagues at anti-spam software company MailChannels to fingerprint the world's publicly visible email servers. Interesting results from the survey? Open source options like Sendmail and Postfix are still firmly in the lead after all these years, but commercial services like Postini are catching up fast. The article goes into some detail on how email servers can be fingerprinted despite attempts by sysadmins to cloak their identity."
Power

Submission + - Offshore Wind Farms are set to battle bad storms

Submitted by
abramsv
abramsv writes: "New floating wind farms are located off Denmark's West coast in the North Sea, which is considered to be one of the roughest stretches of water in the world — 8 to 10 meter waves are expected at the site... Based on data determining that average wind speeds at sea are higher than on land, the modern offshore wind farms promise to be exceptionally energy efficient — but it still remains to be seen whether or not these long-bladed Goliaths will survive the harshest of North Sea storms."
Power

Submission + - High altitude wind farms?

Submitted by Anonymous Coward
An anonymous reader writes: Why plant a rotor on the ground to generate electricity in fickle, turbulent surface winds? Here is a possible green-friendly solution that is far above any other in reality as well as in concept:

From the site: "Here we are with very high gasoline prices, now starting to pay real attention to global warming, and seriously considering nuclear fission, with all its dangers from both accident and terrorist attack, as the best potential solution. And yet the energy we need is only a few miles above us in tremendous quantity, it is clean, non global warming energy, potentially more economical than nuclear, and we are ignoring it."

A flying wind farm might just be the way to go to lower our reliance such energy producing staples as fossil fuels and their immediate pollution, the admittedly intermittent production from solar or ground-level winds, and the long-term storage concerns of nuclear waste.
Space

How a Pulsar Gets Its Spin 63

Posted by Zonk from the how-the-pulsar-got-its-spin-back dept.
brian0918 writes "Until now, the assumption has been that the rapid spin of a pulsar comes from the spin of the original star. The problem was that this only explained the fastest observed pulsars. Now, researchers at Oak Ridge have shown that the spin of a pulsar is determined by the shock wave created when the star's massive iron core collapses. From the article: 'That shock wave is inherently unstable, and eventually becomes cigar-shaped instead of spherical. The instability creates two rotating flows — one in one direction directly below the shock wave and another, inner flow, that travels in the opposite direction and spins up the core. The asymmetrical flows establish a 'sloshing' motion that accounts for the pulsars' observed spin velocities from once every 15 to 300 milliseconds.'"
Red Hat Software

Submission + - No more Fedora Core, Extras

Submitted by
netbuzz
netbuzz writes: ""It's time to bite the bullet," says Red Hat engineer and Fedora Project board member Bill Nottingham. "Starting with Fedora 7, there is no more Core, and no more Extras;
there is only Fedora. One single repository, built in the community
on open source tools, assembled into whatever spins the Fedora community
desires." There are 28 new features being targeted for the release, which can be seen at http://fedoraproject.org/wiki/Releases/7/Features.

Finally, Nottingham says of Fedora 7: "Name TBD, but probably not 'Bride of Zod'."

http://www.redhat.com/archives/fedora-devel-list/2 007-January/msg00091.html"
United States

Submission + - Military to forecast global wars with new computer

Submitted by
John Keller
John Keller writes: "Scientists at the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, Va., are asking industry for ideas on how to develop an advanced computer system called the Integrated Crisis Early Warning System (ICEWS) that is able to predict global wars and other political instability. The goal is to develop a system to monitor, assess, and forecast crises throughout the world to support decisions on how to allocate resources to mitigate them, officials say. The ICEWS will provide military commanders with a powerful capability to anticipate and respond to worldwide political crises and track their success in near-real time.

URL of this story is: http://mae.pennnet.com/display_article/281403/32/N EWS/none/none/DARPA-kicks-off-program-to-develop-a dvanced-computer-system-to-forecast-global-wars-an d-other-political-instability/"
Quickies

Submission + - Sleep Disturbances associated with suicide

Submitted by brainvoid
brainvoid writes: In the first known report of its kind, a study published in the January 1st issue of the journal SLEEP finds that sleep disturbances are common among suicide attempters, and that nightmares are associated with suicidality.
The study, conducted by Nisse Sjöström, RN, and colleagues of Sahlgrenska University Hospital in Göteborg, Sweden, focused on 165 patients between the ages of 18-68, who were admitted to medical units or psychiatric wards at Sahlgrenska after a suicide attempt. It was discovered that 89 percent of subjects reported some kind of sleep disturbance. The most common complaint was difficulties initiating sleep (73 percent), followed by difficulties maintaining sleep (69 percent), nightmares (66 percent) and early morning awakening (58 percent). Nightmares were associated with a five-fold increase in risk for high suicidality.

http://www.medicalnewstoday.com/medicalnews.php?ne wsid=59937

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