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Idle

Directed Energy Weapon Downs Mosquitos 428

Posted by samzenpus from the two-pound-hammer-and-ten-penny-nail dept.
wisebabo writes "Nathan Myhrvol demonstrated at TED a laser, built from parts scrounged from eBay, capable of shooting down not one but 50 to 100 mosquitos a second. The system is 'so precise that it can specify the species, and even the gender, of the mosquito being targeted.' Currently, for the sake of efficiency, it leaves the males alone because only females are bloodsuckers. Best of all the system could cost as little as $50. Maybe that's too expensive for use in preventing malaria in Africa but I'd buy one in a second!" We ran a story about this last year. It looks like the company has added a bit more polish, and burning mosquito footage to their marketing.

Comment Re:Because... (Score 1) 710

by epiteo (#30626332) Attached to: Thorium, the Next Nuclear Fuel?

the enrichment process is more difficult and costly

What enrichment process? Do you mean the chemical extraction of Thorium? How could that be expensive compared to cost of enriching U-235?
There is only one kind of Thorium (Th-232) when you mine it. Turning it to U-233 requires neutrons but you are supposed to get enough extra of those when you burn the U-233 to make it economical.
Best explanation of the process I have seen: http://www.youtube.com/watch?v=AZR0UKxNPh8

Comment Re:Iron Man's Suit Defies Physics -- Mostly (Score 2, Interesting) 279

by John Carmack (#23266718) Attached to: The Science of Iron Man
Hydrogen peroxide powered rocket packs fly for around 30 seconds, because they have a specific impulse of around 125, meaning that one pound of propellant can make 125 pound-seconds of thrust, meaning that it takes about two pounds of propellant for every second you are in the air. Mass ratios are low for anything strapped to a human, so the exponential nature of the rocket equation can be safely ignored.

A pretty hot (both literally and figuratively) bipropellant rocket could manage about twice the specific impulse, and you could carry somewhat heavier tanks, but two minutes of flight on a rocket pack is probably about the upper limit with conventional propellants.

However, an actual jet pack that used atmospheric oxygen could have an Isp ten times higher, allowing theoretical flights of fifteen minutes or so. Here, it really is a matter of technical development, since jet engines have thrust to weight ratios too low to make it practical. There is movement on this technical front, but it will still take a while.

John Carmack
Idle

Miss Landmine 2008 5

Posted by samzenpus
How do you know that you live in a dangerous place? One sign might be that your country is holding a Miss Landmine pageant. The contestants come from Angola's various provinces and are between 19 and 33. Each woman has a profile that lists not only their ages and favorite colors but also when they were injured and what kind of mine claimed their limbs. All the contestants get help to go back to school or to start a small business and best of all the winner gets a new prosthetic limb. Nike, who is sponsoring the event, says that the pageant proves people with disabilities can still be beautiful and that they would be happy to sponsor next year as well since it only cost half as much as usual.
GNU is Not Unix

Number of GPL v3 projects tops 2,000 116

Posted by CmdrTaco from the i'm-sure-rms-is-very-happy dept.
Da Massive writes "The number of open-source projects that use the GNU General Public License Version 3 has grown to more than 2,000, according to Palamida, which sells software and services for tracking open-source code within a customer's code base. 'Our database now contains over 2,000 projects that are using the GPL v3. "At this rate the GPL v3 is being adopted by 1,000 projects every 4-5 months, and if the trend continues, the license will be used by 5,000 projects by the end of the year," states a recent posting on Palamida's blog.'"
Privacy

Users Know Advertisers Watch Them, and Hate It 243

Posted by kdawson from the someone-to-watch-over-me dept.
Chris Blanc tips an Ars writeup on a survey of consumer attitudes toward targeted advertising. The results of the survey, conducted for TRUSTe, confirm that advertisers are in a tough spot. "[The survey company] randomly selected 1,015 nationally representative adults... Although only 40 percent of the group was familiar with the term 'behavioral targeting,' most users were well aware of the practice. 57 percent reported that they weren't comfortable their activities [were being] tracked for advertising purposes, even if the information couldn't be tied to their names or real-life identities. Simultaneously, 72 percent of those surveyed said that they find online advertising annoying when the ads are not relevant to their needs..."
Education

How Ancient Mechanics Thought About Machines 76

Posted by kdawson from the first-practice-then-theory dept.
friedo writes "The NYTimes has an interesting piece about Prof. Mark Schiefsky, a Harvard classicist with an interest in the history of science. Schiefsky pores over ancient texts in Greek, Latin, and Arabic to decipher the origin of knowledge that's been taken for granted for millennia. For example, a Greek treatise published a generation before Archimedes' proofs of the lever laws explains why, if you were a galley slave, you'd want to work the oars near the center of the ship instead of closer to the hull."
Social Networks

To Search Smarter, Find a Person? 136

Posted by Zonk from the when-the-man's-right-the-man's-right dept.
Svonkie writes "Brendan Koerner reports in Wired Magazine that a growing number of ventures are using people, rather than algorithms, to filter the Internet's wealth of information. These ventures have a common goal: to enhance the Web with the kind of critical thinking that's alien to software but that comes naturally to humans. 'The vogue for human curation reflects the growing frustration Net users have with the limits of algorithms. Unhelpful detritus often clutters search results, thanks to online publishers who have learned how to game the system.'"

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