View
214
Download
1
Tags:
Embed Size (px)
Citation preview
Is It Live, or Is It Fractal?
Bergren ForumSeptember 3, 2009
Addison Frey, Presenter
Chaos Under Control: The Art and Science of Complexity
David Peak, Physics Department, Utah State University, Logan, UT 84322-4415([email protected])andMichael Frame, Mathematics Department, Union College, Schenectady, NY 12308([email protected])
W.H. Freeman, Publishers1994ISBN 0-7167-2429-4
What Is a Fractal?
• Many fractals are “self-similar” (or nearly so).– But what is “self-similar”?
What Is a Fractal?• Many fractals are “self-similar” (or nearly so).
– But what is “self-similar”?
A self-similar object is exactly or approximately similar to a part of itself (i.e. the whole has the same shape as one or more of the parts).
What Is a Fractal?
• Many fractals are “self-similar” (or nearly so).– But what is “self-similar”?– Example:
What Is a Fractal?
• Many fractals are “self-similar” (or nearly so).– But what is “self-similar”?– Example:
What Is a Fractal?
• Many fractals are “self-similar” (or nearly so).– But what is “self-similar”?– Example:
But a square is not a fractal!
What Is a Fractal?
• Many fractals are “self-similar” (or nearly so)• A fractal has a fine structure at arbitrarily
small scales.
What Is a Fractal?• Many fractals are “self-similar” (or nearly so)• A fractal has a fine structure at arbitrarily small
scales.– Example:
What Is a Fractal?• Many fractals are “self-similar” (or nearly so)• A fractal has a fine structure at arbitrarily small
scales.– Example:
What Is a Fractal?
• Many fractals are “self-similar” (or nearly so)• A fractal has a fine structure at arbitrarily small scales.• A fractal has a Hausdorff dimension greater than its
Euclidean dimension
What Is Hausdorff Dimension?
Example:
What Is Hausdorff Dimension?
Example:
What Is Hausdorff Dimension?
Example:
What Is Hausdorff Dimension?
Example:
What Is Hausdorff Dimension?
Example:
What Is Hausdorff Dimension?
Example:
What Is Hausdorff Dimension?
Example:
What Is Hausdorff Dimension?
Example:
What Is Hausdorff Dimension?
Example:
WARNING!
WARNING!
LOGARITHMS AHEAD!
What is the Hausdorff dimension of the Sierpinski carpet?
What is the Hausdorff dimension of the Sierpinski carpet?
What is the Hausdorff dimension of the Sierpinski carpet?
Fractals in Nature
Fractals in Nature
Fractals in Nature
Canacadea Creek, Alfred
James Cahill
Process
• Box Counting Method– Place object in a single large box that leaves little
to no extra space on the ends.– Apply a grid with smaller boxes over object, and
count the number of boxes the object is in.– Repeat the second step with increasingly
increasingly smaller boxes, and least twice more.
James Cahill
The Math
• The number of boxes = N• The scale factor (s) = Big box / Little box• Plot graph with log(N) on the y-axis and log(s)
on the x-axis.• Create a best-fit line of the points. The slope
of that line is the dimension of the object.
James Cahill
N=1
S=1
N=17
S=11.02
N=38
S=20.84
James Cahill
N=116S=60.8
James Cahill
The Creek is 1.166 Dimensional
James Cahill
• The box counting method is a slow, painstaking, but all together fairly accurate way to find the dimensions of natural objects. The idea behind it is that we take and average of the smaller and larger N values, and hope that it smoothes out any wrinkles in the results. Unlike mathematical fractals like the Sierpinski Gasket, our rivers and cracks lose definition at high magnification, so there comes a point when smaller S values are completely pointless, as the boxes are smaller than the thickness of the line we are examining.
Concludatory
James Cahill
What Is a Fractal?• Many fractals are “self-similar” (or nearly so)• It has a fine structure at arbitrarily small scales.• It has a Hausdorff dimension greater than its Euclidean dimension• It has a simple and recursive definition.
What Is a Fractal?• Many fractals are “self-similar” (or nearly so)• It has a fine structure at arbitrarily small scales.• It has a Hausdorff dimension greater than its Euclidean dimension• It has a simple and recursive definition.
Example (A Deterministic Approach):
Generating the Sierpinski Gasket (Deterministic Approach)
Generating the Sierpinski Gasket (Deterministic Approach)
Generating the Sierpinski Gasket (Deterministic Approach)
Generating the Sierpinski Gasket (Deterministic Approach)
Generating the Sierpinski Gasket (Deterministic Approach)
Generating the Sierpinski Gasket (Deterministic Approach)
Generating the Sierpinski Gasket (Deterministic Approach)
Generating the Sierpinski Gasket (Deterministic Approach)
Generating the Sierpinski Gasket (Deterministic Approach)
Generating the Sierpinski Gasket(Random Approach)
0.Start with the point 1.Randomly choose one of the following:
a.b.c.
2.Plot3.Let 4.Go back to Step 1
Generating the Sierpinski Gasket(Random Approach)
Generating the Sierpinski Gasket(Random Approach)
Generating the Sierpinski Gasket(Random Approach)
Generating the Sierpinski Gasket(Random Approach)
Generating the Sierpinski Gasket(Random Approach)
A Maple Leaf
A Tree
Jarrett Lingenfelter
A Tree
Jarrett Lingenfelter
A Tree
Jarrett Lingenfelter
A Tree
Jarrett Lingenfelter
A Tree
Jarrett Lingenfelter
A Tree
Jarrett Lingenfelter
A Tree
Jarrett Lingenfelter
Another Tree
Another Tree
Another Tree
WARNING!
WARNING!
TRIGONOMETRY AHEAD!
Another Tree(Random Approach)
0. Start with the point 1. Randomly choose one of the following:
a.b.c.d.e.f.
2. Plot3. Let 4. Go back to Step 1
Another Tree(Random Approach)
Another Tree(Random Approach)
Another Tree(Random Approach)
Another Tree(Random Approach)
Another Tree(Random Approach)
Another Tree(Second Attempt)
Another Tree(Second Attempt)
Another Tree(Second Attempt)
Another Tree(Second Attempt)
Another Tree(Second Attempt)
Another Tree(With Some Fruit)
A fractal landscape created by Professor Ken Musgrave (Copyright: Ken Musgrave).
A fractal planet.
Is It Live, or Is It Fractal?