Yin Yang and Taiji — Origin, Meaning, Symbol, and Utilization
Yin Yang, which evolved out of Taiji, is a simple ancient Chinese philosophical idea widely applied in astrology, calendar, religion, traditional medicine, Feng Shui, and other traditions and customs.
Introduction to Yin Yang Symbol or the Taijitu.
What Are the Yin and Yang Meanings?
What Are the Flow and Relationships of Yin and Yang?

What Is Taiji?
Taiji was the original state of the cosmos when the universe was believed to be undifferentiated and the oneness.
With the constant movement of Taiji, it evolves out of the Yin and Yang.
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Yin is about contracting energy, which is downward, passive, dark, accumulated, introverted, feminine, and quiet.
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Yang is about releasing energy, representing upward, active, bright, expand, exocentric, masculine, and lively.

Everything in the world has both sides: constant motion and mutual transformation.
The motions of Yin and Yang generate the Greater Yin, Lesser Yin, Greater Yang, and Lesser Yang.
They are the Four Images, whose transformations formed the Five Elements (Metal, Wood, Water, Fire, and Earth) or Five Phases theory.
Click to Read More About the Four Images, Five Elements Theory
Therefore, Taiji is considered the Supreme Ultimate, the origin of everything, and the Dao from Daoism (or Taoism) Philosophy.

Introduction to Yin Yang Symbol or the Taijitu.
Yin Yang Symbol or Taijitu, or Tai Chi Diagram, had different origins and versions in history.
Yin Yang and Taiji in Cosmology
As a cosmological term, the Yin Yang Symbol or Taijitu is the orbit of the sun's movement in a year.
In the Chinese Calendar, the 24 Solar Terms correspond to the sun's movement.
The lengths of the shadow of the ancient sundial on noontime of each Solar Term day formed the S-shaped curve in the middle.

The two colors represent day and night.
There are cloudy and rainy days in the daytime, hence the black dot on the white side.
At night, there are bright lights of the moon and stars, represented by the black dot on the black side.
