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BioE 202: Aesthetics. The Golden Section – its origin and usefulness in engineering. The Fibonacci Series. Fibonacci Series 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55,… ( add the last two to get the next ) What is the next number? Ratio between numbers. Leonardo Fibonacci c1175-1250.
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BioE 202: Aesthetics The Golden Section – its origin and usefulness in engineering
The Fibonacci Series Fibonacci Series 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55,… (add the last two to get the next) What is the next number? Ratio between numbers Leonardo Fibonacci c1175-1250.
Fibonacci and plant growth Plant branches could be modeled to grow such that they can branch into two every month once they are two months old. This leads to a Fibonacci series for branch counts
Fibonacci’s rabbits Rabbits could be modeled to conceive at 1 month of age and have two offspring every month thereafter. This leads to a Fibonacci series for rabbit counts for each subsequent month
Petals on flowers 3 petals (or sepals) : lily, iris Lilies often have 6 petals formed from two sets of 3 4 petals Very few plants show 4 e.g. fuchsia 5 petals: buttercup, wild rose, larkspur, columbine (aquilegia), orchid 8 petals: delphiniums
Petals on flowers 13 petals: ragwort, corn marigold, cineraria, some daisies 21 petals: aster, black-eyed susan, chicory 34 petals: plantain, pyrethrum 55, 89 petals: michaelmas daisies, Asteraceae family
Ratio of Fibonacci numbers Divide each number by the number before it, we will find the following series of numbers: 1/1 = 1, 2/1 = 2, 3/2 = 1·5, 5/3 = 1·666..., 8/5 = 1·6, 13/8 = 1·625, 21/13 = 1·61538... These values converge to a constant value, 1.61803 39887……, the golden section, Dividing a number by the number behind it: 0·61803 39887..... 1/
The golden section in geometry • The occurrence of the ratio, • The meaning of the ratio • The use of in engineering
Golden Spiral Construction Start with a golden rectangle Construct a square inside Construct squares in the remaining rectangles in a rotational sequence Construct a spiral through the corners of the squares
Golden Spiral Shortcut http://powerretouche.com/Divine_proportion_tutorial.htm
Golden Triangle and Spirals 1 1 1/ 1
Echinacea – the Midwest Coneflower Note the spirals originating from the center. These can be seen moving out both clockwise and anti-clockwise. These spirals are no mirror images and have different curvatures. These can be shown to be square spirals based on series of golden rectangle constructions.
Cauliflower and Romanesque (or Romanesco) BrocolliXCauliflower Note the spiral formation in the florets as well as in the total layout The spirals are, once again, golden section based
Pine cone spiral arrangements The arrangement here can once more be shown to be spirals based on golden section ratios.
Construction: Brick patterns The number of patterns possible in brickwork Increases in a Fibonacci series as the width increases
Phi in Ancient Architecture A number of lengths can be shown to be related in ratio to each other by Phi
Golden Ratio in Architecture The Dome of St. Paul, London. Windsor Castle
Golden Ratio in Architecture Baghdad City Gate The Great Wall of China
Modern Architecture: Eden project The Eden Project's new Education Building
Modern Architecture: California Polytechnic Engineering Plaza
Mathematical Relationships for Phi The Number Phive 50.5 x .5 + .5 = 1.61803399 = phi phive to the power of point phive times point phive plus point phive = phi 1.61803399 2 = 2.61803399 = phi +1 1 / 1.61803399 (the reciprocal) = 0.61803399 = phi - 1 .618033992 + .61803399 = 1
Golden Ratio in the Arts Piet Mondrian’s Rectangles
Dodecahedron This 12-sided regular solid is the 4th Platonian figure
Icosahedron 20-sided solid Note the three mutually orthogonal golden rectangles that could be constructed
Three-dimensional near-symmetry http://www.mathconsult.ch/showroom/unipoly/list-graph.html