The infinitely complex… Fractals Jennifer Chubb Dean’s Seminar November 14, 2006 Sides available at
Fractals are about all about infinity… The way they look, The way they’re created, The way we study and measure them… underlying all of these are infinite processes.
Fractal Gallery 3-Dimensional Cantor Set
Fractal Gallery Koch Snowflake Animation
Fractal Gallery Sierpinski’s Carpet Menger Sponge
Fractal Gallery The Julia Set
Fractal Gallery The Mandelbrot Set
Dynamically Generated Fractals and Chaos Chaotic Pendulum
Fractal Gallery Henon Attractor
Fractal Gallery Tinkerbell Attractor and basin of attraction
Fractal Gallery Lorenz Attractor
Fractal Gallery Rossler Attractor
Fractal Gallery Wada Basin
Fractal Gallery
Romanesco – a cross between broccoli and cauliflower
What is a fractal? Self similarity As we blow up parts of the picture, we see the same thing over and over again…
What is a fractal? So, here’s another example of infinite self similarity… and so on … But is this a fractal?
What is a fractal? No exact mathematical definition. Most agree a fractal is a geometric object that has most or all of the following properties… Approximately self-similar Fine structure on arbitrarily small scales Not easily described in terms of familiar geometric language Has a simple and recursive definition Its fractal dimension exceeds its topological dimension
Dimension Topological Dimension Points (or disconnected collections of them) have topological dimension 0. Lines and curves have topological dimension 1. 2-D things (think filled in square) have topological dimension 2. 3-D things (a solid cube) have topological dimension 3.
Dimension Topological Dimension 0 The Cantor Set (3D version as well)
Dimension Topological Dimension 1 Koch Snowflake Chaotic Pendulum, Henon, and Tinkerbell attractors Boundary of Mandelbrot Set
Dimension Topological Dimension 2 Lorenz Attractor Rossler Attractor
Dimension What is fractal dimension? There are different kinds: Hausdorff dimension… how does the number of balls it takes to cover the fractal scale with the size of the balls? Box-counting dimension… how does the number of boxes it takes to cover the fractal scale with the size of the boxes? Information dimension… how does the average information needed to identify an occupied box scale? Correlation dimension… calculated from the number of points used to generate the picture, and the number of pairs of points within a distance ε of each other. This list is not exhaustive!
Box-counting dimension Computing the box-counting dimension… … … … … and so on…
Hausdorff Dimension of some fractals… Cantor Set… Henon Map… 1.26 Koch Snowflake… D Cantor Dust… Appolonian Gasket… Sierpinski Carpet… D Cantor Dust… Boundary of Mandelbrot Set… 2 (!) Lorenz Attractor… 2.06 Menger Sponge…
Thank you!