1434: The Year a Chinese Fleet Sailed to Italy and Ignited the Renaissance. Gavin Menzies. Читать онлайн. Newlib. NEWLIB.NET

Автор: Gavin Menzies
Издательство: HarperCollins
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Жанр произведения: Историческая литература
Год издания: 0
isbn: 9780007280292
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as I can vouch from my experience in 1969 on the staff of Admiral Griffin’s Far East Fleet.

      There are chapters giving practical advice on using trigonometry to determine heights of buildings, hills, trees, and towns on cliffs, and the circumference of walled cities, the depth of ravines, and the breadth of river estuaries.

      No fewer than ninety-five mathematical treatises of the Song dynasty are mentioned, some on such specialized subjects as the Chinese remainder theorum and cryptoanalysis—the use of mathematics to break codes. There are mathematical methods for calculating the area and volume of circles, spheres, cones, pyramids, cubes, and cylinders and for determining magic numbers and constructing magic squares, and the principles of square-root extraction and negative numbers. It was lucky Zheng He had a prodigious memory—he could recite the entire Koran by heart in Arabic at the age of eleven.

      Even “Pascal’s” triangle was included in the Yongle Dadian—centuries before Pascal. The Chinese have always been practical. Mathematics was applied to surveying and cartography. By the Eastern Han dynasty (A.D. 25–A.D. 220), Chinese surveyors were using compass and squares, plumb lines and water levels. By the third century they were using the trigonometry of right-angle triangles, by the fourteenth century the Jacob’s staff to mea sure heights and distances.

      One could carry out a similar exercise for military machines available to Zheng He and how these had been developed over the centuries. The Yongle Dadian included details on how to build mortars, bazookas, cannons, rocket-propelled missiles, flamethrowers, and all manner of gunpowder bombs. This vast encyclopedia was a massive collective endeavor to bring together in one place Chinese knowledge gained in every field over thousands of years. Zheng He had the immense good fortune to set sail with priceless intellectual knowledge in every sphere of human activity. He commanded a magnificent fleet—magnificent not only in military and naval capabilities but in its cargo—intellectual goods of great value and sophistication. The fleet was the repository of half the world’s knowledge.

      Notes Chapter 2