Where is the Sun?
Lie down on the platform and place your head in the depression at the top. Observe the equinox and solstice lines. From this position, the winter solstice line represents the path of the Sun on the shortest day of the year. The Sun rises much later and is farthest from the East. At noon, the sun is relatively close to the horizon; its rays are oblique which means that the heat energy from its rays is weaker.
As winter progresses, the elevation of the Sun increases. On the day when the vernal equinox occurs, the Sun rises exactly due East, and follows the line traced by the central circumference. Day and night last an equal length of time (12 hours), which gave rise to the term 'equinox', which is derived from the Latin word aequinoctium, or 'night equal (to day)'. As spring progresses, the Sun rises earlier and sets later each day until the summer solstice, when there are more hours of daylight. On this day the Sun's trajectory follows the upper circumference, the one that is largest.
Over the three summer months that follow, the cycle is reversed: the Sun follows a path that gets shorter each day, until the autumnal equinox. The line traced is identical to that followed in the spring.