Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. 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 Although it was a historically interesting theory in the late 19th and early 20th century, it was superseded by the concepts of continental drift and modern plate tectonics. By 1915 German Alfred Wegener (1880â€“1930) had proposed in his continental drift theory that land masses moved great distances over the Earth''s history. Wegener was also at first met with hostile reactions. By the mid 1920s the same Holmes developed theories on what could cause the drift. The plate tectonics theory is now generally accepted to explain the dynamic nature of the Earth''s surface; the tetrahedral shape plays no special role in modern theories.