Other scholars were at work on mathematics. Zhang Heng calculated a value for pi – the ration of the circle’s circumference to its diameter – which matches closely the figure used today.
In the land where earthquakes were a constant treat, he also made the world’s first seismograph to detect and record them.
At about the same time, the Chinese invented a water clock, and made accurate sundials marked off into 100 equals unit.
They calculated correctly the phases of the moon and the length of the solar year, and had system for writing decimal numbers.
Not all Han ideas were quite so scientific and most people shared the traditional belief in the forces of Yin and Yang.
Yin is weak, passive, female and dark, where Yang is strong, active male and bright. One could exist without the other, and all things are in constant state of flux between the two.
The moon is yin, the sun yang; day becomes night but night will place to day. The forces were symbolized by a circle divided into dark and light halves by a curved line, each half containing a spot of the other’s color.
The Han state was run on the principles of Confucius, a Chinese philosopher born about 551 BC.
His code valued an orderly way of life and the advantages of all people knowing their place in the society, but did not cater for spiritual needs. And neither did the native Chinese beliefs – in stern ancestor spirits and nature gods – offer any hope of personal salvation.
So there was a spiritual vacuum and after the 1st century AD the religion of Taoism (or Daoism) moved to fill it.
Chinese: recording Hours and Earthquakes
