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The spheres thus moved with a "natural nonviolent motion". [33] The mover's power diminished with increasing distance from the periphery so that the lower spheres lagged behind in their daily motion around the Earth; this power reached even as far as the sphere of water, producing the tides. [34] [35]
In Greek antiquity the ideas of celestial spheres and rings first appeared in the cosmology of Anaximander in the early 6th century BC. [7] In his cosmology both the Sun and Moon are circular open vents in tubular rings of fire enclosed in tubes of condensed air; these rings constitute the rims of rotating chariot-like wheels pivoting on the Earth at their centre.
The seven heavens and the sublunar spheres, from an engraving of Albertus Magnus' Philosophia naturalis.. Plato and Aristotle helped to formulate the original theory of a sublunary sphere in antiquity, [4] [missing long citation] the idea usually going hand in hand with geocentrism and the concept of a spherical Earth.
The Middle Ages broadly inherited the concept of the four elements of earth, water, air and fire arranged in concentric spheres about the earth as centre: [3] as the purest of the four elements, fire - and the sphere of fire - stood highest in the ascending sequence of the scala naturae, and closest to the superlunary world of the aether. [4]
Visualization of a celestial sphere. In 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 can be conceived as being projected upon the inner surface of the celestial sphere, which may be centered on Earth or the observer.
S 3: a 3-sphere is a sphere in 4-dimensional Euclidean space. Spheres for n > 2 are sometimes called hyperspheres. The n-sphere of unit radius centered at the origin is denoted S n and is often referred to as "the" n-sphere. The ordinary sphere is a 2-sphere, because it is a 2-dimensional surface which is embedded in 3-dimensional space.
The four spheres (for which most of the other spheres are a subtype of) are the atmosphere, the biosphere, the hydrosphere and the geosphere. Earth's ecosphere lies it self within the heliosphere (the Sun's astrosphere). [4] Listed roughly from outermost to innermost the named spheres of the Earth are:
They were believed to explain the motions of the four terrestrial elements: Earth, Water, Air, and Fire. In modern texts and in Earth system science , geosphere refers to the solid parts of the Earth ; it is used along with atmosphere , hydrosphere , and biosphere to describe the systems of the Earth (the interaction of these systems with the ...