Over 500 years ago, Leonardo da Vinci made an interesting observation about trees. He concluded that the total thickness of a tree’s branches at a certain height almost always equals the total thickness of the tree trunk. In other words, as the tree splits into branches, the cross section of the branches remains equal to the cross section of the trunk. This observation holds true for almost all trees. When trees begin to split, they make exact copies of themselves. Scientists believe that there are two reasons for this law of nature. Firstly, this design is ideal for transporting sap through a tree. Secondly, this structure makes a tree more resistant to wind. Artists commonly use Leonardo da Vinci’s rule of nature to design real-looking trees.