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by shawn 2830 days ago
Davinci pointed out that a tree’s thickness is constant if you slice it in a semi circle. https://fractalfoundation.org/OFC/leonardotree1.jpg

That is, if you face a tree and draw a circle with your arm, and add up all the thicknesses your fingers intersect, the total will always be the same.

https://www.insidescience.org/news/uncovering-da-vincis-rule...

2 comments

That second link you gave puts it very well:

> In other words, if a tree’s branches were folded upward and squeezed together, the tree would look like one big trunk with the same thickness from top to bottom.

Absolutely fascinating!

In forestry, they teach that as "pipe model". I am unable to track down how long that observation has been known in forestry, but I found this 1964 paper that attempts to build on the observation (already known in 1964) and build a theory.

https://www.ncbi.nlm.nih.gov/pubmed/29370362

The modern understanding is that the pipe model holds only approximately.

It's kinda nice, how you can take a bunch of metal wires to make a tree trunk, and start separating them and folding them into branches, and separating and folding into smaller branches, and this can give pretty realistic looking trees.

https://diyjoy.com/wp-content/uploads/2016/06/WireTree.jpg

https://www.thisiscolossal.com/2014/10/dense-wire-tree-sculp...

https://www.youtube.com/watch?v=g0tj_ZLpv80