This drawing clearly shows what are "fractals". They are figures which in their parts resemble, or have the same structure, as the whole figure.

A river delta (Lena river)

A river delta (in this case: Lena river) has a tree-like shape

Tree of knowledge2

Knowlede is said to have a tree-like structure. This has been first noticed in the Bible, where Eve asked Adam to eat an apple from the tree of knowledge.

A tree

A tree

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