Universe a grand tour of modern science Phần 4 ppsx

... and improvements of sea defences against tsunamis—the great ‘tidal waves’ that often accompany earthquakes. City by city, district by district, experts calculate the risks of damage and casualties ... potential energy of a stream about to go over a waterfall. The energy associated with a certain speed or temperature was greater in a large mass than in a small one, but only in...

Ngày tải lên: 08/08/2014, 01:20

... Feenstra introduced his students to a weed called Arabidopsis thaliana, a relative of mustard. He was following a suggestion made in 1 943 by Friedrich Laibach of Frankfurt, that arabidopsis was a handy plant ... Toronto With offices in Argentina Austria Brazil Chile Czech Republic France Greece Guatemala Hungary Italy Japan Poland Por tugal Singapore South Korea Switzerland Thail...

Ngày tải lên: 08/08/2014, 01:20

... satellites. They have masses a few times greater than the Sun’s, and nowadays they are called microquasars. The black hole idea was thus available, ready made, for explaining the quasars and active galaxies ... are also seasonal differences in the uptake and release of the gas by seawater. The asymmetry results in a yearly wave in the graph of global carbon dioxide, as measured at Mau...

Ngày tải lên: 08/08/2014, 01:20

... those back together, abolishing the Atlantic Ocean, and the job is half-done. East of Africa it’s trickier, because Antarctica, India and Australia could fit together in old Gondwana-Land in various ... called them the Altaids, after the magnificent Altai mountain range that runs from Kazakhstan to China. ‘The Tethysides and the Altaids cover nearly a half of the entire continent of E...

Ngày tải lên: 08/08/2014, 01:20

... proteins, and animals make greater use of this versatility than plants do. Another is that plants, being stationary, need a wider range of defences than animals that can run away from danger. In comparison ... in our own backyard, at the oldest stars of the Milky Way Galaxy itself, and at nearby galaxies. Billions of years from now, the Magellanic Clouds and the Andromeda Galaxy may...

Ngày tải lên: 08/08/2014, 01:20

... Berkeley announced another walker, around 5.5 million years old, found in Ethiopia. He called it Ardipithecus ramidus kadabba, where kadabba meant ‘basal family ancestor’ in the Afar language of the ... widespread changes in the Atlantic reaching to South America and West Africa, already correlated with solar variations by other scientists. Farther afield, reductions of rainfall in East A...

Ngày tải lên: 08/08/2014, 01:20

... y obvious way to establish that one scenario rather than another was what actually happened. Also lacking is clear knowledge about what the planet was like at the time. It was certainly not a tranquil ... peculiar monotremes of Australia,’ she said. ‘The mammals that really matter had a northern origin, as we see in Mongolia.’ I Puzzles of ever-changing geography Mammals are hairy and...

Ngày tải lên: 08/08/2014, 01:20

... possibility of retreat as well as advance, remains a valid basis for thinking generally about co-evolution and its weaponr y. Hamilton’s idea of sex as a means of sharing out 539 plant diseases P otatoes ... large plates account for 94 per cent of the Earth’s surface. In descending order of size they are the Pacific, African, Eurasian, Indo-Australian, North American, Antarctic...

Ngày tải lên: 08/08/2014, 01:20

... search for sparticles at Fermilab near Chicago, begun in 1996, concluded only that a gluino, if it exists at all, must be at least as heavy as an atom of lead. That was beyond the capacity of ... the surface. During a total eclipse it appears as the streaky corona that gives the atmosphere its technical name. Telescopes called coronagraphs use a central mask to create an artificial...

Ngày tải lên: 08/08/2014, 01:20

... Kurile Islands, Kamchatka in eastern Russia, and thence via the Aleutian Islands to Alaska. 7 04 volcanic explosions Aspects of the scenario are still debated. Especially uncertain is how all of these cells ... 2000 Valtaoja: personal communication, 2002 Brain images Landau: W.M. Landau et al., Transactions of the American Neurological Association, vol. 80, pp. 125–9, 1955 Scandinavian...

Ngày tải lên: 08/08/2014, 01:20