The Tai Chi symbol was used by the Taoist dated back to the 14th century BC, and possibly earlier. The theory of Tai Chi could be explained by the fact that when the universal was created, there was complete emptiness. When matters were created, two opposite but complimentary forces were formed. They were the Yin and Yang which formed the basic theory of Tai Chi. Yin means negative energy, or darkness, or the moon, whereas Yang means positive energy, or brightness, or the sun. The round circle of the symbol represent the Universe. The white segment represents Yang and the dark segment represents Yin. So are the small white and dark dots. The white dot is engulfed into the dark segment and the black dot into the white segment meaning that Yin and Yang are co-existent and complimentary with each other. It also mean that inside Yin there is Yang, while inside Yang there is Yin. The wavy line of separation between the two symmetrical halves suggests mutual accommodation, or flow or exchange between the two halves. It can also mean that Yin and Yang are not separable and should be continuously embracing each other to maintain balance of the universe.