Thunder AKA The Arousing
This trigram is the symbol of enlightenment in the bottom position of a hexagram, and awareness when in the top position of a hexagram. Also linked to the concept of newness, shock, etc. One of the six 'mixed' trigrams, symbolic of the interaction of degrees of yin and yang.
The roots of this symbol are at the level of the 4096 dodecagrams that make-up the 'meaning space' of the I Ching. The 'pure' dodecagram that is compressed into a hexagram that is then compressed into this trigram is:
Compressed into a hexagram we have:
This is then compressed into the trigram of thunder. The overall focus in 19 is on 'new' rules or more so the bending or breaking of the norm - thus the 'low' approach the high without fear and the high defer to the low. As such the mind approaches the universe and the universe defers by revealing aspects.
In the IDM template it is representative of expansive binding and thus an overall bias to making distinctions through the determination of dynamic relationships between inner and outer. In the realm of emotions this trigram is linked to 'surprise'.
In the Myers-Briggs/Keirsey systems of persona classification it is linked to XNTP/Engineers and is mostly concerned with solution seeking through relational analysis. (e.g. Inventors, Architects, Philosophers)
In Chinese Five-Phase theory, Thunder is linked to the concept of WOOD and so to the concept of PRODUCTION through the 'new', the 'raw', the sudden manifestation of something ready for use.
The numeric link is to complex numbers (transitions, transcendence and transformations). The Peircean Category is Thirdness as Active/Explicit MEDIATION.