Upper trigram
☰
Heaven · Qian
Creative force.
FamilyFather
ElementMetal
Hexagram 1 of 64
☰☰ The Creative
Pure initiative — the moment to act with full force.
Lower trigram
☰
Heaven · Qian
Creative force.
FamilyFather
ElementMetal
The image
Heaven above, Heaven below.
Heaven over Heaven: creative force meeting creative force.
That combination is the whole meaning of hexagram 1. Nothing about it is arbitrary — change either trigram and you get a different hexagram with a different reading, which is why the 64 form a system rather than a list.