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The spherical shape of the Earth was known and measured by astronomers, mathematicians, and navigators from a variety of literate ancient cultures, including the Hellenic World, and Ancient India. Greek ethnographer Megasthenes , c. 300 BC , has been interpreted as stating that the contemporary Brahmans of India believed in a spherical Earth as ...
Cenosphere formed from coal combustion, magnified 400×. A cenosphere or kenosphere is a lightweight, inert, hollow sphere made largely of silica and alumina [1] and filled with air or inert gas, typically produced as a coal combustion byproduct at thermal power plants.
Geodesic polyhedra are a good approximation to a sphere for many purposes, and appear in many different contexts. The most well-known may be the geodesic domes, hemispherical architectural structures designed by Buckminster Fuller, which geodesic polyhedra are named after. Geodesic grids used in geodesy also have the geometry of geodesic polyhedra.
Curved into eyelike spheres, the material reflects X-rays and is packed into telescopes.These crustaceans have inspired other inventions as well, such as microchips and the Lobster Eye X-ray ...
The sum of the angles of a spherical triangle is not equal to 180°. A sphere is a curved surface, but locally the laws of the flat (planar) Euclidean geometry are good approximations. In a small triangle on the face of the earth, the sum of the angles is only slightly more than 180 degrees. A sphere with a spherical triangle on it.
A Klerksdorp sphere. It is 3 to 4 centimetres (1.2 to 1.6 in) in maximum diameter and 2.5 centimetres (0.98 in) in thickness. Klerksdorp spheres are small objects, often spherical to disc-shaped, that have been collected by miners and rockhounds from 3-billion-year-old pyrophyllite deposits mined by Wonderstone Ltd., near Ottosdal, South Africa.
Three prehistoric Scottish carved stone balls, in Kelvingrove Art Gallery and Museum, Glasgow. In archaeology, a stone ball or petrosphere (from Greek πέτρα (petra), "stone", and σφαῖρα (sphaira), "ball") is the name for any spherical man-made object of any size that is composed of stone.
This method of globe making was illustrated in 1802 in an engraving in The English Encyclopedia by George Kearsley. Modern globes are often made from thermoplastic. Flat, plastic disks are printed with a distorted map of one of the Earth's hemispheres. This is placed in a machine which molds the disk into a hemispherical shape.