Can ancient people really know what time it is at a glance at the sun?

It's amazing. Although there were timing tools in ancient times, they were very bulky and inconvenient to move. Therefore, ancient people generally estimated time by watching the sun during the day and the stars at night. Although this time is not very accurate, it can be used, so the ancient time is twelve o'clock rather than accurate to minutes and seconds.

But the clever working people watched the sunrise and sunset, slowly learned to combine timing with the sun and invented the sundial. The sundial was an early time measuring tool. This tool is very simple, consisting of a disk and a needle. The inventor carved a scale on the surface. When the sun shines, the shadow of the pointer will be projected on the surface, and then when the sun rises or sets, the shadow will keep turning, so that people can record the time according to the rotation of the shadow.

Everyone has heard of the sundial. Let me introduce you to a timing instrument with a longer history. This timing instrument also uses the sun to determine the time, and more advanced, it can determine the solar terms. We may not care much about solar terms now, but it was different in ancient times. Solar terms are closely related to planting, which is a major event that affects the country during agricultural civilization.

This tool consists of two parts: watch and GUI. The watch is a vertical body erected at the southern end of Guiyu, which is a ruler lying in the north-south direction. According to historical records, it was just a watch at first, and the approximate time was determined by the movement of the sun and the change of the shadow. In the gradual improvement, GUI was added, which became the standard table we know.

Besides roughly determining the time and judging the solar terms, the standard table can also be used to determine the direction and calculate the calendar, which played an important role in the development of ancient agricultural production. Knowing the sundial and the standard watch, we can't help but marvel at the wisdom of the working people in ancient China.