The Symbol of Tai Chi

Often known as the yin-yang symbol, this is in fact the Tai Chi symbol. Yin and Yang embody the teachings of Chinese philosophy and Tai Chi: the teachings of harmony and balance. For everything that exists, there is an opposite however there is a little yin in yang and a little yang in yin just as there is a little light in night (stars) and a little dark in day (shadows).


Yin is the calm, white side of the yin-yang symbol;
Yang is the active, black side.


However, contrary to popular belief, Yin, the white side, is symbolic of night, darkness, and the moon while Yang, the black side, is symbolic of day, light, and the sun.

Image: http://taoism.about.com/od/visualsymbols/ig/Taoist-Symbols/Yin-Yang-Symbol.--jj.htm
Source: Tai Chi for Arthritis Handbook by Dr. Paul Lam (p. 54) & in class lecture