411 REFERENCE · Wikibooks
Fractals/Iterations in the complex plane/critical orbit
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Definition
Forward orbitWikipedia: orbit (dynamics) of a critical pointWikipedia: Complex quadratic polynomial - Critical pointMandelOrbits - A visual real-time trace of Mandelbrot iterations by Ivan Freyman is called a critical orbit.
Importance
Critical orbits are very important because every attracting periodic orbitWikipedia: Periodic points of complex quadratic mappings attracts a critical point, so studying the critical orbits helps us understand the dynamics in the Fatou set.M. Romera, G. Pastor, and F. Montoya: Multifurcations in nonhyperbolic fixed points of the Mandelbrot map. Fractalia 6, No. 21, 10-12 (1997)Burns A M: Plotting the Escape: An Animation of Parabolic Bifurcations in the Mandelbrot Set. Mathematics Magazine, Vol. 75, No. 2 (Apr., 2002), pp. 104-116
Khan Academy: Mandelbrot Spirals 2
This orbit falls into an attracting periodic cycle.
Shape
Relation between shape types and dynamics:
n-th arm spiral: attracting or repelling n-periodic orbit ( cycle)
closed curve: Siegel disc ( rotation)
n-th arm star = period n parabolic root
The shape of critical orbit can show the type of dynamics and the period
Level sets
Points of critical orbit ( including crirital point and fixed point = finite attractor) are on the level curves like notes on the musical staff ( dots on curves) .
How to compute attracting radius (AR) to get such effect ?
Code
"https://github.com/conanite/rainbow/blob/master/src/arc/rainbow/spiral.arc
This software is copyright (c) Conan Dalton 2008. Permission to use it is granted under the Perl Foundations's Artistic License 2.0.
This software includes software that is copyright (c) Paul Graham and Robert Morris, distributed under the Perl Foundations's Artistic License 2.0.
This software uses javacc which is copyright (c) its authors
"
(def plot (plt c)
(with (z 0+0i
n 0
repeats 0)
(while (and (small z) (< n 10000) (< repeats 1000))
(assign n (+ n 1)
z (+ c (* z z))
repeats (if (apply plt (complex-parts z))
(+ repeats 1)
0)))))
images
images of critical orbitsat commons
by Mike CroucherComplex Power Towers (Or ‘mucking around with Mathematica’) by Mike Croucher
Chris King /DarkHeart by Chris King
Kerry Mitchel: cardioid-boundary-orbits
Visualizing Escape Paths in the Mandelbrot Set by Anne M. Burns
Stefan Zenker
lists
critical orbits
Lori GardiThe Mandelbrot set and the fractal nature of light, the Universe, and everything by
The Mandelbrot Set as a Quasi-Black Hole by Lori Gardi
Mandelbrot Z Orbits by Stefan Bion
Plot the orbits from the list by Stefan Bion
images by Conan written in Rainbow
intro
examples
Mandelbrot Sequences and Orbits by Stefan Forcey
Moiré interferences in the map of orbits of the Mandelbrot Set by P. Alcover Published 2017
programs
Geogebra (interactive)
Mandelbrot Iteration Orbits by Ben Sparks
Mandelbrot kümesi by Hüseyin KAVAK
Java Script by Stefan Forcey
videos
Mandelbrot Set as a Vortex Generator by Fractal Woman
See also
Spreading points on a disc Alexandre Devert blogcodeproject: Fractals-in-theory-and-practice
References