Home Uncategories 達文西樹木法則 "all the branches of a tree at every stage of its height when put together are equal in thickness to the trunk." Da Vinci

達文西樹木法則 "all the branches of a tree at every stage of its height when put together are equal in thickness to the trunk." Da Vinci

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達文西樹木法則 "all the branches of a tree at every stage of its height when put together are equal in thickness to the trunk."   Da Vinci

 Self-similarity. a Representation of the Strahler order of each branch for the tree illustrated in Fig. 4. b The number of branches, their mean length (unit L), area (unit L 2) and diameter (unit L) are plotted as a function of their Strahler order for the 999-year-old tree illustrated in Fig. 4 and in a. Error bars show standard deviations around these means. Solid lines are regression fits on the first 7 ranks. Open symbols connected by dotted lines represent the same quantities when the tree is only 25 years old. c Evolution of the branching ratio R n , length ratio R l and fractal dimension D = lnR n /lnR l during the lifetime of the same tree. Grey bars show the 80% confidence interval for D. d Branch tapering is illustrated by plotting, for each segment, the average distance from the foliages, 
⟨ℓ⟩ Assessment of Leonardo’s rule of area conservation across branching nodes. For each node, the area ratio (i.e. the ratio between the total cross-sectional area of children segments and the parent area) is plotted as a function of the average distance ⟨ℓ⟩⟨ℓ⟩>1.5⟨ℓ⟩>10


In his notebooks, Leonardo da Vinci observed that “all the branches of a tree at every stage of its height, when put together, are equal in thickness to the trunk”. Yet, the mechanisms underlying this Leonardo’s rule are still debated today. One hypothesis is that branches sense wind-induced loads and adjust their diameters to resist fracture, while keeping biomass investments to a minimum.


達文西樹木法則這個是真的，這是達文西在筆記本寫下的，事實上樹還真的是這樣，為什麼樹木會有這樣的規則呢 ?
500年過後，對這類解釋有兩種，第一種為水文，把樹枝看做河流，當河水流分流出去後，分流出去的總水量是一樣的。樹枝也傳送水的，很理所當然。第二種解釋和力學結構有關，樹木這樣生長可以用最少的材料來達成不錯的抗風效果，這是電腦模擬驗證的喔!
  有不符合達文西樹木法則的情況嗎? 有的，可能有以下情況1年輕的樹枝，會大於下方母枝一點面積。2反應木不符合3樹木基部出來萌枝


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