The celestial sphere has the Earth at the centre and all the objects in the sky situated on the sphere at infinite distance. Positions of the objects are described by two coordinates, which could be azimuth and elevation, or, in geocentric coordinates, declination and hour-angle.
celestial globe is a physical model of celestial sphere
The stars in the Ptolemaic model of the universe move on or are attached to a celestial sphere.
The celestial sphere is a sphere, which contains the sky and encompasses the entire earth and has earth as the center of the solar system. While we know this not be true the model does allow for a more convient way to view what is around us. So basically the model makes it easier for us to see constellations, asterisms, planets and stars in easy to understand model. That is why it is a model and not a 100% accurate figure.
celestial sphere . . . ?
i have no idea this website doesnt make sense
Ball, globe, or sphere.
A sphere could be used as a three dimensional model of the earth.
For some purposes, especially explaining the apparent motion of the stars, the actual distances are not relevant, so the celestial sphere is still a useful model in such cases.
Archaic models are studied only to understand the evolution of human thought.
I don't know for sure, but it looks identical to a Celestial Globe, which was an ancient navigation tool used by sailors. Also known as an armillary sphere (variations are known as spherical astrolabe, armilla, or armil), this was a model of the celestial sphere that present the stars in relation to the earth. Link illustrates what the Celestial Globe looked like. It did have a globe mounted in the center of several rings. http://en.wikipedia.org/wiki/Armillary_sphere
According to Aristotle the Universe is a sphere and Earth is at the centre.
The Earth was the center of the universe and the "heavenly bodies", such as the moon, sun, planets and stars, rotated in their own spheres around the Earth in a pattern. The order of spheres from Earth outward are:MoonMercuryVenusMarsJupiterSaturnFixed starsSphere of Prime Mover