Math 125 (Fractals and Chaos) Fall 2006

Daily Schedule

(See below for some useful web sites)

# Date Topics Homework
1 F 9/8 Introduction Reading: Prologue and The butterfly effect
2 M 9/11 The k-th stage of the Koch curve has length (4/3)^k. The Koch curve itself is infinitely long. Questions to think about: (1) How can an infinitely long curve fit into a finite amount of space? (2) If you start walking on the Koch curve, can you reach the other end?
3 W 9/13 The Sierpinski carpet. The k-th stage has area (8/9)^k. The carpet itself has area 0. Also the Menger sponge. -
4 F 9/15 Self-similar sets. The numbers N of smaller copies making up the whole and the scale factor r -
5 M 9/18 Fractal (self-similarity) dimension HW 1 (due M 9/25)
6 W 9/20 Introduction to iteration. Terminology: initial value, orbit, fixed point, cycle -
7 F 9/22 Find fixed points algebraically by solving f(x) = x for x. -
8 M 9/25 Repelling and attracting fixed points. Four ways to visualize iteration (list of numbers, number line with arrows, time series, histogram). Chaos. -
9 W 9/27 More on chaos. Some properties of chaos: (1) repelling periodic points are everywhere, (2) it has sensitive dependence on initial conditions (the butterfly effect), and (3) it is transitive (almost all points travel everywhere) Homework 2 (due 10/3).
- - The small pendulum demonstrates chaos. -
10 F 9/29 Iteration with a spreadsheet. (handout) Measuring boarders and coastlines. Reading: Gleick: "Nature's ups and downs"
11 M 10/2 Measuring the length of the coastline of Great Britain, also measuring the length of a straight line, a curved line, and the Koch curve. Homework 4 (due 10/13)
12 W 10/4 The ruler dimension Homework 3 (due 10/11)
- - - Homework 5 (practice with logs and exponents; due 10/16)
14 F 10/6 [No class] -
15 W 10/11 - HW 6 (Find the ruler dimension of the Koch curve)
16 F 10/13 [no class] -
17 M 10/16 Introduction to Boston University's iteration applet -
18 W 10/18 Video "Chaos, fractals and dynamics" -
19 F 10/20 Box dimension -
20 M 10/23 HW 7 done in class Test 1 handed out. Topics: up through HW 5.
- - - -
21 W 10/25 Random Koch curves and Sierpinski triangles, fake landscapes HW 9: Draw a random Koch curve. (Do with someone else, one tossing the coin, the other drawing) (Due 11/1)
22 F 10/27 HW 8 done in class (due before beginning of class 11/1) -
23 M 10/30 Introduction to the complex numbers: addition, subtraction, multiplication, division -
24 W 11/1 How HW 7 and HW 8 together lead to the orbit diagram -
25 F 11/3 More on complex numbers: graphing, representing in polar coordinate form. Multiplication of complex numbers is adding the angles and multiplying the distances. Homework 10 (due 11/8)
26 M 11/6 Iterating z^2 + c using complex numbers. Terminology: prisoners, escapees. -
27 W 11/8 Reading: Gleick: "Universality" Homework 11 ("Lab 3"): Windows in the orbit diagram of the family cx(1-x).
28 F 11/10 (con't) -
29 M 11/13 - -
30 W 11/15 Period doubling. The orbit diagram is a fractal. HW 13 (the first one numbered 13--examples of self-similar fractals with increasing fractal dimension). The curves become "rougher"
- - The map x -> rx(1-x) is essentially the same as x-> x^2 + c. The former is related to polulation growth in a limited environment; the latter is used for the Mandelbrot set and its Julia sets. -
- - Test II handed out (on HW 6-10) pdf version of test, without pictures
31 F 11/17 For f(z) = z^2 the motion on the unit circle is chaotic Test II due
32 M 11/20 - -
33 M 11/27 Introduction to Julia sets Reading: Gleick "Images of chaos"
34 W 11/29 (con't) -
35 F 12/1 Homework 13 (the second one numbered 13) "A tour of Julia sets" Finish the second HW 13 by 12/8
36 M 12/4 [go over test] -
37 W 12/6 The Mandelbrot set Reading: Gleick "A geometry of nature", "Images of chaos"
38 F 12/8 - Second version of test II
- - - HW 14: Exploring the Mandelbrot set
39 M 12/11 - -
40 W 12/13 The sound of iteration (demo) All homework (except numbers 13, 14) is due at 5pm today.
- - Can chaos authenticate Pollock's paintings? http://www.phys.unsw.edu.au/PHYSICS_!/FRACTAL_EXPRESSIONISM/fractal_taylor.html ; http://www.sciencedaily.com/releases/2006/12/061204123447.htm -
- - The Lorenz attractor: http://www.sat.t.u-tokyo.ac.jp/~hideyuki/java/Attract.html -
- - Fractals and the 12c. pulpit of Ravello Catherdral: http://www.christianhubert.com/hypertext/fractals.html -
- - Fractals in nature: http://www.ba.infn.it/~zito/project/nfractals.html -
- - The dinosaurs live on! -


Some useful web sites