دانلود کتاب T. Rex and the Crater of Doom

Sixty-five million years ago a gigantic comet or asteroid as big as Mount Everest slammed into the Yucatan Peninsula, creating an explosion on impact equivalent to the detonation of a hundred million hydrogen bombs. It produced a cloud of roiling debris that blackened the sky for months as well as other geologic disasters--and triggered the demise of Tyrannosaurus rex. We know what happened largely because Walter Alvarez--synthesizing the findings of experts from a variety of scientific fields--has written a gripping story of the decades-long search for the cause of the dinosaurs' extinction. Painstakingly assembling clues from the Italian Apennines and the depths of the Pacific and presenting them with the excitement of a great novel, T. rex and the Crater of Doom is a book of undeniable importance and irresistible appeal by a major figure in contemporary science. ''Engaging and witty. Read Alvarez for and excellent account of how scientists pose questions and seek to solve them.''--Scientific American ''First-rate...Alvarez provides the up-close tale of the comet or asteroid that wiped out the dinosaurs.''--San Francisco Chronicle