What is the difference between a sundial and a sundial?

1, sundial

"sundial" refers to a time measuring instrument used by ancient humans, which measures time through the shadow of the sun. Dials made of sundial hands and dials are called "dials" and should be tilted at a certain inclination according to local latitude, so that the dials 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.

2, standard table

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.

Second, the role is different.

1, sundial

The sundial is an instrument for observing the shadow of the sun and timing. According to the shadow of the sundial needle, you can judge what time of day it is.

2, standard table

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.

Extended data

Classification of sundials

There are all kinds of sundials in the world, which can be divided into three types according to the placement of the surface: horizontal, straight and oblique.

The most common horizontal sundial is the horizontal sundial, whose surface is strictly horizontal, and the angle between the surface and the pointer is the local geographical latitude, which is suitable for low latitude. Horizontal sundials are not only easy to manufacture and install, but also have strong ornamental value, and are suitable for being placed in parks, squares and schools.

Vertical sundials are placed perpendicular to the ground level and can be divided into vertical south sundials, vertical north sundials and vertical east-west sundials. There are two kinds of hands: those perpendicular to the surface and those not perpendicular to the surface. The inclination of the latter's hand is usually equal to the local geographical latitude. Vertical south sundial is more suitable for middle latitude.

Oblique sundials can be divided into equatorial sundials and polar sundials. The equatorial sundial is the simplest and most common sundial in the world. Its surface is parallel to the equatorial plane, the scales on the dial are equally divided, the pointer points to the north pole, and the elevation angle of the pointer is the local geographical latitude.