Description
The celestial sphere with its celestial coordinate system is a key component of a time and date telling Calendar-Clock. The celestial sphere is a mathematical object with a mathematical surface. For the virtual, 3-D Calendar-Clock, I have modified the celestial sphere without changing it’s essential nature or orientation in space. I have “cut off” (or made invisible) the north and south ends of the celestial sphere, so you can see both inside and outside the celestial sphere, leaving the so called celestial ring. I have also given the celestial sphere or ring a fixed but variable diameter of two time the distance from the center of the earth to the center of the Sun. So the Sun is always located somewhere on the surface of the celestial sphere, and somewhere along the ecliptic which is one of the two main coordinate circles (the other is the celestial equator) marked on the surface of the celestial sphere. The circle of the ecliptic is tilted 23.5º relative to the celestial equator, and where the two circles intersect on the celestial sphere mark the two equinoctial nodes, which are used to mark and measure a seasonal year. The celestial meridian passing through the ascending node also marks 0º right ascension.