Category Archives: science

Beer Is a Rich Source of Silicon and May Help Prevent Osteoporosis

Posted on by
1

dvorak.org: Beer Is a Rich Source of Silicon and May Help Prevent Osteoporosis

A new study suggests that beer is a significant source of dietary silicon, a key ingredient for increasing bone mineral density. Researchers from the Department of Food Science & Technology at the University of California, Davis studied commercial beer production to determine the relationship between beer production methods and the resulting silicon content, concluding that beer is a rich source of dietary silicon.

Les etudes, ca vaut ce que ca vaut, mais je m’efforce de pointer vers celles qui font mon affaire 😉

P.S. Pas mal le choix de photo sur dvorak.org pour accompagner l’article. La majorite des commentaires parlent d’un autre type de silicone 😉

Posted on by
Reply

likecool.com: Mission to the edge of Space

“The mission, Red Bull Stratos, will take renowned athlete Felix Baumgartner to at least 120,000 feet above the earth, to the very edge of Space.

From there, he will attempt a stratospheric free fall jump – the longest in the history of man – and hopefully will become the first human to break the speed of sound with his own body.

Mach > 1.0? Outch, ca risque de faire mal.

APOD: Eclipses in the Shade

Posted on by
Reply

APOD: Eclipses in the Shade

Explanation: Eclipses are everywhere in this shady scene. The picture was taken on the Indian Ocean atoll island of Ellaidhoo, Maldives, on January 15, during the longest annular solar eclipse for the next 1,000 years. Tall palm trees provided the shade. Their many crossed leaves created gaps that acted like pinhole cameras, scattering recognizable eclipse images across the white sands of a tropical garden near the beach. From this idyllic location near the centerline of the Moon’s shadow track, the ring of fire or annular phase of the eclipse lasted about 10 minutes and 55 seconds.

APOD: The Mysterious Voynich Manuscript

Posted on by
Reply

APOD: The Mysterious Voynich Manuscript

Explanation: The ancient text has no known title, no known author, and is written in no known language: what does it say and why does it have many astronomy illustrations? The mysterious book was once bought by an emperor, forgotten on a library shelf, sold for thousands of dollars, and later donated to Yale. Possibly written in the 15th century, the over 200-page volume is known most recently as the Voynich Manuscript, after its (re-)discoverer in 1912. Pictured above is an illustration from the book that appears to be somehow related to the Sun. The book labels some patches of the sky with unfamiliar constellations. The inability of modern historians of astronomy to understand the origins of these constellations is perhaps dwarfed by the inability of modern code-breakers to understand the book’s text. Can the eclectic brain trust of APOD readers make any progress? If you think you can provide any insight, instead of sending us email please participate in a fresh online discussion. The book itself remains in Yale’s rare book collection under catalog number “MS 408.”

APOD: Dark Sand Cascades on Mars

Posted on by
Reply

APOD: Dark Sand Cascades on Mars

Explanation: They might look like trees on Mars, but they’re not. Groups of dark brown streaks have been photographed by the Mars Reconnaissance Orbiter on melting pinkish sand dunes covered with light frost. The above image was taken in 2008 April near the North Pole of Mars. At that time, dark sand on the interior of Martian sand dunes became more and more visible as the spring Sun melted the lighter carbon dioxide ice. When occurring near the top of a dune, dark sand may cascade down the dune leaving dark surface streaks — streaks that might appear at first to be trees standing in front of the lighter regions, but cast no shadows. Objects about 25 centimeters across are resolved on this image spanning about one kilometer. Close ups of some parts of this image show billowing plumes indicating that the sand slides were occurring even when the image was being taken.

Disable JavaScript in Acrobat

Posted on by
2

grc.com: Security Now! Transcript of Episode #231: Mega Security Update & CES Observations

Steve: The one thing I would reiterate saying, and I imagine people have probably already done this if they’re going to, but I have to say it again, is disable JavaScript in Acrobat, that is, in the Acrobat Reader. There just is no need for scripting. I mean, we understand there’s a need for scripting on web pages because it’s being actively used by more and more websites, with it being a mixed blessing. But there’s just no need for scripting in a PDF document.

En passant, je viens justement d’installer une nouvelle version d’acrobat… et il a remis a “on” le javascript. 🙁

Aussi interessant dans cet episode (evidemment aussi disponible en audio):

Steve: And the Verbatim Corporate Secure FIPS Edition. Now, FIPS is the National Institute of Standards and Technology, NIST. That’s its federal security rating system. These devices have all received the FIPS 140-2 Level 2 certificate which validates devices as being secure for use with sensitive government data. And…

Leo: That’s pretty good. I’d take…

Steve: …they are completely hackable.

Leo: Oops.

Steve: They’ve got hardware AES-256 encryption in the key. So they’re not inexpensive. But get a load of this, Leo. You use some software that comes with a key, which of course prompts you for your password. You put your password in. And it does some mumbo jumbo with your password, whatever it is it does. But every single one of them, no matter what your password was, sends the same key string into the AES-256 cipher engine.

Leo: You’d think something at FIPS, at NIST, might have noticed.

Steve: Uh, yes. In fact, embarrassed by this, NIST has said that they will be considering whether they should make changes to their validation process because the USB drives in question met all their criteria.

Leo: Oh, boy.

Steve: So once again, so it’s true that if, as a user, you did not put the right passphrase in, the software would say, oh, sorry, that’s the wrong passphrase. But a security company reverse-engineered the software, wondering what was going on inside. And what they discovered was that there was a fixed key.

Steve: Well, yeah. And what boggles my mind is, again, our listeners understand this. You take and hash the passphrase with a secure hash, and that’s what you use as the key. This is not hard. I mean, that’s all there is to it. In which case the key would be derived from the passphrase through a secure hash and, bang, you’ve got it. I mean, sure, you want to put minimum security requirements on the length of the passphrase and all those things, and it wants to be nonguessable because it would be prone to a brute-force attack, blah blah blah, all the things we know about. But the idea that the passphrase isn’t being used to generate the key, but that the key is fixed, that’s just, I mean, actually it’s a really good lesson because it demonstrates that just saying AES-256 means nothing.

Female teachers transmit math anxiety to female students

Posted on by
Reply

arstechnica.com: Female teachers transmit math anxiety to female students

Teachers with high math anxiety were shown to have a significant effect on the math achievement and stereotypes of their female students. Girls with anxious teachers scored lower on math achievement tests at the end of the year than girls with more confident teachers—the more anxious the teacher, the more likely girls were to confirm the stereotype that girls have less math ability when they took the year-end tests.

Doit-on traduire “Teachers with high math anxiety” par “professeurs incompetents” par hasard?

Via: dvorak.org: Why can’t girls learn math? Because our teachers don’t know math!

A Geek Funeral

Posted on by
Reply

Slashdot: A Geek Funeral

For my recently departed brother (long illness, don’t smoke!), I thought this nice SPARCstation would be a cool place to spend eternity. Yes, he’s really in there (after cremation). I kept the floppy drive cover but for space reasons removed the floppy drive, hard drive, and most of the power supply. I left behind the motherboard and power switch and plugs to keep all openings covered. The case worked quite well at his memorial party. His friends and family were able to leave their final good-byes on post-notes.