• cosmological model of concentric (or homocentric) spheres, developed by Eudoxus, Callippus, and Aristotle, employed celestial spheres all centered on the...
    8 KB (875 words) - 11:25, 16 February 2025
  • Thumbnail for Concentric objects
    circles (any line through the center), spheres, cylinders, conic sections, and surfaces of revolution. Concentric objects are often part of the broad category...
    9 KB (895 words) - 21:44, 19 August 2024
  • Thumbnail for Celestial spheres
    student Eudoxus developed a planetary model using concentric spheres for all the planets, with three spheres each for his models of the Moon and the Sun and...
    44 KB (5,795 words) - 15:07, 22 April 2025
  • Thumbnail for John Cleves Symmes Jr.
    spheres". Ultimately, Symmes was to simplify his theory, abandoning the series of concentric inner spheres, and teaching "only one concentric sphere (a...
    29 KB (3,142 words) - 22:51, 30 May 2025
  • Thumbnail for Hallin's spheres
    three concentric spheres: consensus, legitimate controversy, and deviance. In the sphere of consensus, journalists assume everyone agrees. The sphere of...
    9 KB (1,077 words) - 09:40, 9 February 2025
  • Thumbnail for Paradiso (Dante)
    symbolises theology. In the poem, Paradise is depicted as a series of concentric spheres surrounding the Earth, consisting of the Moon, Mercury, Venus, the...
    40 KB (4,852 words) - 08:40, 25 May 2025
  • polyhedron are congruent. A convex regular polyhedron has all of three related spheres (other polyhedra lack at least one kind) which share its centre: An insphere...
    32 KB (3,128 words) - 14:50, 8 June 2025
  • Thumbnail for Celestial sphere
    astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky...
    18 KB (2,222 words) - 22:16, 8 June 2025
  • Thumbnail for Spherinder
    stereographic projection as two concentric spheres, in a similar way that a tesseract (cubic prism) can be projected as two concentric cubes, and how a circular...
    6 KB (834 words) - 05:38, 5 May 2025
  • mathematical astronomy, his fame is due to the introduction of the concentric spheres, and his early contributions to understanding the movement of the...
    23 KB (2,854 words) - 21:23, 19 April 2025
  • structuring of the cosmos into concentric spheres, with the Earth at the centre and celestial spheres around it. The terrestrial sphere was made of four elements...
    49 KB (6,445 words) - 21:26, 16 February 2025
  • Thumbnail for Spherical shell
    between two concentric spheres of differing radii. The volume of a spherical shell is the difference between the enclosed volume of the outer sphere and the...
    2 KB (288 words) - 19:06, 21 February 2025
  • astronomer to present the concentric spheres model as an alternative to the Ptolemaic system, with the planets borne by geocentric spheres. Another original aspect...
    7 KB (694 words) - 20:59, 4 May 2025
  • Thumbnail for Spherical conic
    based on concentric spheres and quadratic cones is called a conical or sphero-conical coordinate system. When restricted to the surface of a sphere, the remaining...
    12 KB (1,056 words) - 02:30, 20 January 2025
  • Thumbnail for Geocentric model
    rotating spheres surrounding the Earth, all concentric with it. (The number is so high because several spheres are needed for each planet.) These spheres, known...
    74 KB (8,585 words) - 04:09, 26 May 2025
  • Thumbnail for Fixed stars
    based on (conceptual) concentric spheres centered on Earth, and by 360 BC Plato claimed in his Timaeus that circles and spheres were the preferred shape...
    49 KB (6,369 words) - 20:31, 24 May 2025
  • Thumbnail for Luneburg lens
    profiles, the lens will form perfect geometrical images of two given concentric spheres onto each other. There are an infinite number of refractive-index...
    16 KB (2,104 words) - 01:36, 20 January 2025
  • Thumbnail for Hollow Earth
    two inner concentric shells and an innermost core. Atmospheres separate these shells, and each shell has its own magnetic poles. The spheres rotate at...
    40 KB (5,098 words) - 21:16, 29 May 2025
  • Thumbnail for Polycystine
    spicules, but in others it forms more elaborate lattices, such as concentric spheres with radial spines or sequences of conical chambers. Two of the orders...
    3 KB (183 words) - 13:09, 25 October 2024
  • Thumbnail for Firmament
    cosmology or the Greek notion of the surrounding of the Earth by seven concentric spheres: one for the sun, one for the moon, and one for each of the five other...
    28 KB (3,515 words) - 13:43, 25 May 2025
  • Thumbnail for Historical models of the Solar System
    an unrolled sphere in between, increasing the number of spheres needed well above Eudoxus'. Historians are unsure about how many spheres Aristotle thought...
    65 KB (7,773 words) - 17:13, 24 May 2025
  • regularity is that the Platonic solids all possess three concentric spheres: the circumscribed sphere that passes through all the vertices, the midsphere that...
    53 KB (5,642 words) - 21:32, 1 June 2025
  • Thumbnail for Girolamo Fracastoro
    or Concentric spheres in an attempt to bring it back to the scientific sphere. It was criticised by Christopher Clavius, since Homocentric Spheres could...
    14 KB (1,606 words) - 15:07, 26 May 2025
  • forces and viscous forces. For simplicity, consider the example of two concentric spheres that rotate about a common axis with slightly different angular velocity...
    4 KB (718 words) - 11:14, 7 September 2024
  • series of concentric spheres each including a hierarchical organization of spirits in a setting more earth-like than theocentric. The spheres become gradually...
    5 KB (581 words) - 01:15, 26 December 2024
  • Thumbnail for Stellar engine
    galaxy. A class-B stellar engine consists of two concentric spheres around a star. The inner sphere (which may be assimilated with a Dyson shell) receives...
    11 KB (1,346 words) - 16:03, 28 May 2025
  • Thumbnail for Klerksdorp sphere
    (Klerksdorp spheres), and layers at multiple horizons within thin beds of carbonaceous shale or slate, which is locally called wonderstone. Klerksdorp spheres are...
    15 KB (1,797 words) - 07:57, 5 April 2025
  • Concentric hypertrophy is a hypertrophic growth of a hollow organ without overall enlargement, in which the walls of the organ are thickened and its capacity...
    2 KB (198 words) - 01:04, 22 June 2022
  • Thumbnail for Machine
    move in a way that the trajectories of points in the system lie on concentric spheres. The rotational axes of hinged joints that connect the bodies in the...
    57 KB (6,399 words) - 01:32, 4 May 2025
  • the Couette flow between rotating colinear cylinders or rotating concentric spheres. In the case of a system which is not rotating uniformly, such as...
    3 KB (503 words) - 17:58, 31 December 2024