When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Celestial spheres - Wikipedia

    en.wikipedia.org/wiki/Celestial_spheres

    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.

  3. Celestial sphere - Wikipedia

    en.wikipedia.org/wiki/Celestial_sphere

    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.

  4. List of largest cosmic structures - Wikipedia

    en.wikipedia.org/wiki/List_of_largest_cosmic...

    Discovered through gamma-ray burst mapping. Largest-known regular formation in the observable universe. [8] Huge-LQG (2012–2013) 4,000,000,000 [9] [10] [11] Decoupling of 73 quasars. Largest-known large quasar group and the first structure found to exceed 3 billion light-years. "The Giant Arc" (2021) 3,300,000,000 [12] Located 9.2 billion ...

  5. Dynamics of the celestial spheres - Wikipedia

    en.wikipedia.org/wiki/Dynamics_of_the_celestial...

    Johannes Kepler's (1571–1630) cosmology eliminated the celestial spheres, but he held that the planets were moved both by an external motive power, which he located in the Sun, and a motive soul associated with each planet. In an early manuscript discussing the motion of Mars, Kepler considered the Sun to cause the circular motion of the planet.

  6. Solar System belts - Wikipedia

    en.wikipedia.org/wiki/Solar_System_belts

    The Grand tack hypothesis explains how in the Solar System giant planets migrated in unique way to form the Solar System belts and near circular orbit of planets around the Sun. [10] [11] [9] The Solar System's belts are one key parameters for a Solar System that can support complex life, as circular orbits are a parameter needed for the ...

  7. Sublunary sphere - Wikipedia

    en.wikipedia.org/wiki/Sublunary_sphere

    The sublunary sphere was the realm of changing nature. Beginning with the Moon, up to the limits of the universe, everything (to classical astronomy) was permanent, regular and unchanging—the region of aether where the planets and stars are located. Only in the sublunary sphere did the powers of physics hold sway. [3]

  8. Fixed stars - Wikipedia

    en.wikipedia.org/wiki/Fixed_stars

    Anaximander proposed this original (and erroneous) order of the celestial objects above the Earth: first a nearest layer with the fixed stars plus planets, then another layer with the Moon, and finally an outer one with the Sun. To him, the stars, as well as the Sun and Moon, were apertures of "wheel-like condensations filled with fire". [42]

  9. Milky Way - Wikipedia

    en.wikipedia.org/wiki/Milky_Way

    The Milky Way [c] is the galaxy that includes the Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye.