The difference between sunlight and sundial

Different structures have different functions.

1. Different in structure: "sundial" refers to a time measuring instrument used by ancient humans to measure time through the shadow of the sun. Dials made of sundial hands and dials are called "dial surfaces", which should be tilted at a certain inclination according to the local latitude, so that the dial surfaces are parallel to the equatorial plane. The scales on the dial are divided into twelve points, namely Zi, Ugly, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu and Hai. The standard watch stands upright on the flat ground to measure the shadow of the sun, which is called a watch; The rigid plate used to measure the length of the surface shadow in the direction of due south and due north is called Gui. When the sun shines on the watch, the shadow of the watch appears on Guiyu. According to the direction and length of the shadow, the time can be read.

2, the role is different: the sundial is an instrument for observing the time of the sun shadow, you can judge which time of the day you are in according to the shadow of the sundial needle. Guibiao has always been one of the most important astronomical instruments in ancient China. It consists of a vertical "observation" and a horizontal "GUI". Solar terms are determined by the length of the noon sun projection on the GUI.