dimanche 20 février 2011

Cosmic census finds crowd of planets in galaxy

WASHINGTON (AP) — Scientists have estimated the first cosmic census of planets in our galaxy and the numbers are astronomical: at least 50 billion planets in the Milky Way.

At least 500 million planets in the Milky Way are in the not-too-hot, not-too-cold zone where life could exist, scientists announced Saturday. The numbers were extrapolated from the early results of NASA's planet-hunting Kepler telescope.

Kepler science chief William Borucki says scientists took the number of planets they found in the first year of searching a small part of the night sky and then made an estimate on how likely stars are to have planets. Kepler spots planets as they pass between Earth and the star it orbits.

So far Kepler has found 1,235 candidate planets, with 54 in the Goldilocks zone, where life could possibly exist. Kepler's main mission is not to examine individual worlds, but give astronomers a sense of how many planets, especially potentially habitable ones, there are likely to be in our galaxy. They would use the one-four-hundredth of the night sky that Kepler is looking at and extrapolate from there.

Borucki and colleagues figured one of two stars has planets and one of 200 stars has planets in the habitable zone, announcing these ratios Saturday at the American Association for the Advancement of Science annual conference in Washington. And that's a minimum because these stars can have more than one planet and Kepler has yet to get a long enough glimpse to see planets that are further out from the star, like Earth, Borucki said.

For example, if Kepler were 1,000 light years from Earth and looking at our sun and noticed Venus passing by, there's only a one-in-eight chance that Earth would also be seen, astronomers said.
To get the estimate for the total number of planets, scientists then took the frequency observed already and applied it to the number of stars in the Milky Way.

For many years scientists figured there were 100 billion stars in the Milky Way, but last year a Yale scientist figured the number was closer to 300 billion stars.
Either way it shows that Carl Sagan was right when he talked of billions and billions of worlds, said retired NASA astronomer Steve Maran, who praised the research but wasn't part of it.

And that's just our galaxy. Scientists figure there are 100 billion galaxies.
Borucki said the new calculations lead to worlds of questions about life elsewhere in the cosmos. "The next question is why haven't they visited us?"
And the answer? "I don't know," Borucki said.

samedi 19 février 2011

Speaking 2 languages may delay getting Alzheimer's

Mastering a second language can pump up your brain in ways that seem to delay getting Alzheimer's disease later on, scientists said Friday.

Never learned to habla or parler? While the new research focuses mostly on the truly long-term bilingual, scientists say even people who tackle a new language later in life stand to gain.

The more proficient you become, the better, but "every little bit helps," said Ellen Bialystok, a psychology professor at York University in Toronto.
Much of the study of bilingualism has centered on babies, as scientists wondered why simply speaking to infants in two languages allows them to learn both in the time it takes most babies to learn one. Their brains seem to become more flexible, better able to multitask. As they grow up, their brains show better "executive control," a system key to higher functioning — as Bialystok puts it, "the most important part of your mind."

But does that mental juggling while you're young translate into protection against cognitive decline when you're old?
Bialystok studied 450 Alzheimer's patients, all of whom showed the same degree of impairment at the time of diagnosis. Half are bilingual — they've spoken two languages regularly for most of their lives. The rest are monolingual.

The bilingual patients had Alzheimer's symptoms and were diagnosed between four and five years later than the patients who spoke only one language, she told the annual meeting of the American Association for the Advancement of Science.

Being bilingual does nothing to prevent Alzheimer's disease from striking. But once the disease does begin its silent attack, those years of robust executive control provide a buffer so that symptoms don't become apparent as quickly, Bialystok said. "They've been able to cope with the disease," she said.
Her work supports an earlier study from other researchers that also found a protective effect.

What is it about being bilingual that enhances that all-important executive control system?
Both languages are essentially turned on all the time, but the brain learns to inhibit the one you don't need, said psychology professor Teresa Bajo of the University of Granada in Spain. That's pretty constant activity.

That's not the only area. University of British Columbia psychologist Janet Werker studies infants exposed to two languages from birth to see why they don't confuse the two, and says bilingual babies learn very early to pay attention better.

Werker tested babies in Spain who were growing up learning both Spanish and Catalan. She showed the babies videos of women speaking languages they'd never heard — English and French — but with the sound off. By measuring the tots' attention span, Werker concluded that babies could distinguish between English and French simply by watching the speakers' facial cues. It could have been the different lip shapes.

"It looks like French people are always kissing," she joked, while the English "th" sound evokes a distinctive lip-in-teeth shape.
Whatever the cues, monolingual babies couldn't tell the difference, Werker said Friday at the meeting.

But what if you weren't lucky enough to be raised bilingual? Scientists and educators know that it becomes far harder to learn a new language after puberty.
Partly that's because adults' brains are so bombarded with other demands that we don't give learning a new language the same attention that a young child does, Bialystok said.

At the University of Maryland, scientists are studying how to identify adults who would be good candidates to master a new language, and then what types of training are best. Having a pretty strong executive control system, like the lifelong bilinguals have, is among the good predictive factors, said Amy Weinberg, deputy director of the university's Center for Advanced Study of Language.

But people don't have to master a new language to benefit some, Bialystok said. Exercising your brain throughout life contributes to what's called cognitive reserve, the overall ability to withstand the declines of aging and disease. That's the basis of the use-it-or-lose-it advice from aging experts who also recommend such things as crossword puzzles to keep your brain nimble.

"If you start to learn at 40, 50, 60, you are certainly keeping your brain active," she said.


jeudi 17 février 2011

« Paris, avant-après »

Georges Eugène Haussmann (né le 27 mars 1809 à Paris, mort le 11 janvier 1891 à Paris), couramment appelé le « baron Haussmann », a été préfet de la Seine du 23 juin 1853 au 5 janvier 1870. À ce titre, il a dirigé les transformations de Paris sous le Second Empire en élaborant un vaste plan de rénovation.

Comment Haussmann a métamorphosé Paris : un face à face inédit entre les photos de Charles Marville avant les transformations du baron Haussmann et autant de photos du Paris contemporain, prises au même endroit et sous le même angle. Une expo à voir à l'Académie d'architecture, 9 place des Vosges à Paris.

Ici, on assiste à l’achèvement du percement de l’avenue de l'Opéra (1877). Les immeubles vus au premier plan seront bientôt démolis et remplacés par les immeubles que l’on voit sur la photo suivante, aux belles façades haussmanniennes. © Les Editions du Mécène

Avenue de l’Opéra - Vues prises au niveau de la rue d’Antin. © Les Editions du Mécène

mercredi 16 février 2011

Stefano Benni – Bar sport duemila

"Il bar Fico"

La cordialità degli avventori del Bar Fico è entustiasta ed esibita in modo perfino sospetto. Chi entra, urla di gioia al cospetto del conoscente, come se non lo vedesse da dieci anni, mentre lo ha lasciato la sera prima.

E tutto un fiorire di pacche sulle spalle e virili toccate di coglioni tra gli uomini, di trilli e bacetti sodali tra le donne. Mentre si saluta e si bacia il primo conoscente, già con la mano si fa un cenno al secondo e si strizza l'occhio al terzo. Per uno strano contrappunto, queste espressioni di affetto e cameratismo vengono per lo piu' accompagnate da spiritosi epiteti quali "brutto bastardo!", "eccoti qua, vecchia checca!" oppure "stronza, dov'eri finita?" o "troia, che sorpresa!".

Lo scopo di questo Gran Teatro della cordialità è naturalmente segnalare il proprio arrivo e parimenti mostrare quanta gente si conosce. Guai a chi, entrando in un Bar Fico, va direttamente alla cassa e non saluta, né viene salutato da qualcuno. Chi è? Un rappresentante di mentine, un rapinatore o peggio, un non-Vip che vuole inserirsi a tradimento?

Il vero habitué del Bar Fico poi, non solo saluta fragorosamente, ma piange di commozione, stritola mani, bacia sensualmente, dopodiché si apparta in un angolo con un conoscente esternandogli l'odio per tutti i presenti, l'insofferenza per queste recite smancerose, e la noia di doversi recare li' tutte le sere, mentre nei bar di Manhattan o di Marbella c'è tutta un'altra atmosfera.