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The Tetrahedral hypothesis is an obsolete scientific theory attempting to explain the arrangement of the Earth's continents and oceans by referring to the geometry of a tetrahedron. Although it was a historically interesting theory in the late 19th and early 20th century, it was superseded by the concepts of continental drift and modern plate tectonics. ==Theory== This idea, described as ‘"ingenious" by geologist Arthur Holmes, is now of historical interest only, being finally refuted by that same Holmes (see reference 7). It attempted to explain apparent anomalies in the distribution of land and water on the Earth's surface: *More than 75% of the Earth's land area is in the northern hemisphere. *Continents are roughly triangular. *Oceans are roughly triangular. *The north pole is surrounded by water, the south pole by land. *Exactly opposite the Earth from land is almost always water. *The Pacific Ocean occupies about one third of the Earth's surface. To understand its appeal, consider the "regular solids": the sphere and the 5-member set of Platonic Solids. The solid with the lowest number of sides is the tetrahedron (four equilateral triangles); progressing through the hexahedron or cube, the octahedron, the dodecahedron and the icosahedron (20 sides), the sphere can be considered to have an infinite number of sides. All six regular solids share many symmetries. Now, for each regular solid, we may relate its surface area and volume by the equation: : where'' k'' is a characteristic of each solid, ''V'' its volume, and ''A'' its area. As we traverse the set in order of increasing number of faces, we find that k increases for each member; it is 0.0227 for a tetrahedron and 0.0940 for a sphere. Thus the tetrahedron is the regular solid with the largest surface area for a given volume, and makes a reasonable endpoint for a shrinking spherical Earth. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Tetrahedral hypothesis」の詳細全文を読む スポンサード リンク
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