Discipline: Science
This paper shows geometrically the diurnal motion of the sun in the tropics, especially during solstices. It is shown that while daytime is longest during summer solstice, in the tropics the sun is not found at its highest point on the same day. Unlike other regions, the noontime tropical sun shifts between north and south in the course of a year. This paper also presents a method for calculating the lengths of daytime and nighttime, and for calculating when a tropical sun would be at the zenith.