The Grandmaster 《一代宗師》, Opera Scene
Here's the rest of that kungfu fight scene.
The song is a prelude in a fight scene, between the 2 main characters, in a friendly fight. The girl is a master of the Bagua Palm fighting style, and the guy is master of Wing Chun fist.
Baguazhang (trigram palm) (八卦掌) is one of the three main Chinese martial arts of the northern style. (the other 2 are Taiji (太極) and Xingyi (形意).) Baguazhang means “eight trigram palm” referring to the trigrams of the Yijing (I Ching), one of the canons of Taoism.
Wing Chun (詠春) is a southern China style of martial arts, a more practical style.
Here's the best scene.
What Does Bagua, Taiji Mean?
The bagua (Chinese: 八卦; literally “eight symbols”) are eight trigrams used in Taoist cosmology to represent the fundamental principles of reality, seen as a range of eight interrelated concepts. Each consists of three lines, each line either “broken” or “unbroken,” representing yin or yang, respectively. Due to their tripartite structure, they are often referred to as “trigrams” in English.
Taiji (philosophy), quote:
Taiji (simplified Chinese: 太极; traditional Chinese: 太極; pinyin: tàijí; literally “great pole”) is a Chinese cosmological term for the “Supreme Ultimate” state of undifferentiated absolute and infinite potentiality, contrasted with the Wuji (無極, “Without Ultimate”).
Here's the trigrams in Unicode: ☰ ☱ ☲ ☳ ☴ ☵ ☶ ☷ and here's the taichi ☯.
Here's a verse describing the Bagua:
The Limitless (Wuji) produces the delimited, and this is the Absolute (Taiji).
The Taiji produces two forms, named yin and yang.
The two forms produce four phenomena, named lesser yin, great yin (taiyin also means the Moon), lesser yang, great yang (taiyang also means the Sun).
The four phenomena act on the eight trigrams (bagua), eight eights are sixty-four hexagrams.
Note that the trigrams is inherently a binary system. You have 3 lines, each line has 2 states. So, 2^3 = 8 possible combination. And, if you have 6 bars, you have 2^6=64 possible combinations, as is mentioned in the verse.
Exercise 1: look at South Korean flag. It has 4 of the 8 trigrams. Find a description of why those 4.
Exercise 2: Gottfried Leibniz (1646 to 1716), inventor of calculus and father of computer, said that “hexagrams a base for claiming the universality of the binary numeral system.”. Why?