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marți, 6 noiembrie 2012

Pristine moon crater could help unlock secrets of impacts

Scientists trying to understand the evolution of impact craters on Earth and other rocky bodies have found a good case study on the moon.

Researchers are focusing on Linne Crater, which lies in the moon's Mare Serenitatis region. Linne is just 1.4 miles (2.2 kilometers) wide, but it's extremely young — having formed just 10 million years or so ago — and beautifully preserved.

Surprising 'Mini' Supermassive Black Hole Found in Unlikely Home

Using NASA's Chandra X-Ray space telescope, astronomers have discovered one of the smallest supermassive black holes in middle of an unlikely host galaxy.

The little monster was spotted in NGC 4178, a spiral galaxy about 55 million light-years from Earth that is quite flat and lacks a concentration or bulge of stars at its center.

Theoretical models had predicted that bulges are necessary for supermassive black holes to form and grow. But the new observations from NGC 4178 and four other bulgeless galaxies where black holes have previously been found challenge these assumptions and suggest more than one mechanism is at work in forming supermassive black holes. Researchers have speculated that these behemoths could feed on the disks of galaxies or the haloes of mysterious dark matter that surround galaxies instead of a cluster of stars at the center.

The secrets of a lost city

VAST stacks of sandstone loom over the arid valley of Wadi Musa like giant handfuls of sun-baked clay. But even in this parched landscape, there are places where the sun casts no light.

Walls 200m high keep the Siq permanently cast in shadow  - it's as though the long, narrow canyon passes through the dark heart of the mountain itself. Utterly silent at dawn, there is not even a bird's chirrup to accompany solitary footsteps along its patchwork floor of rock and sand.

Marile biblioteci antice pierdute ale omenirii

Lumea a uitat, s-a inecat profund in jurnalismul cotidian, in uriasul spatiu al www-ului. Intr-o era digitala cine mai citeste, cine mai frunzareste cartile, cine le mai cauta, cine le mai acorda atentie?

Anticariatele au disparut, librariile s-au transformat in mici capuse intelectuale (exista si exceptii, desigur) care profita din plin de noua era media si de descoperirea marketing-ului agresiv, a targetarii pietei, a consumului, a trend-ului, etc.

Totul a devenit minimalist, totul se face la comanda de parca cartea insasi ar fi un produs ordinar, unul despre care s-ar putea spune ca exista cerere si oferta. De la marile colectii la best-seller, de la cartile pentru copii la aceasta tendinta moderna adolescentina spre vampirism, licantropism, vrajitorie si altele asemenea, cartile se publica in tiraje imense pentru ca sunt citite de mase.