; Date: Sun, 17 Jun 2007 19:49:08 -0400 ; From: Jim Muth ; Subject: [Fractint] FOTD 18-06-07 (Siegel-Disk Fractal [7]) ; Id: <1.5.4.16.20070617195403.2a7f5ec0@pop.mindspring.com> ; --------- ; ; FOTD -- June 18, 2007 (Rating 7) ; ; Fractal visionaries and enthusiasts: ; ; Today's image of a Julia set shows a Siegel disk fractal. My ; math encyclopedia implies it is the only Siegel disk fractal, ; though it is obvious that a mirror image fractal exists at ; C=-0.390541+0.586788i. The Siegel disks are the flat but ; irregular concentric rings filling the 'inside' part of the ; Julia set. They were made visible by the 'bof60' inside fill. ; ; These rings are actually the limiting case of spiral arms that ; have tightened to infinity, where they will take an infinity of ; revolutions to converge an infinitesimal bit closer to the ; central point. The spiral arms have become true closed curves, ; just as the circumference of a circle of infinite radius on a ; flat plane becomes a true straight line. ; ; I know of no special significance in fractals that contain ; Siegel disks, though I feel that there must be something of ; value in them. Why else would they have earned an entry in the ; math encyclopedia? One thing certain is that today's fractal ; contains some interesting sub-images. If I find anything of ; unusual worth, I'll post it as tomorrow's FOTD. ; ; I rated today's image at a 7 for its mathematical interest. The ; name I gave it -- "Siegel Disk Fractal" -- is its description. ; The calculation time of 37 seconds is true on the P2000 machine. ; On the P200 it would take about 2 minutes. ; ; On the FOTD web site, however, the image has already been ; rendered, and is posted for instant viewing. To see today's ; image as well as many past images, direct your browser to: ; ; ; ; and enjoy the enigmatic Siegel disks. ; ; With a high temperature of 88F 31C here at Fractal Central, and ; with the sunshine dimmed by haze, Sunday was too summery to be ; considered perfect. But it was good enough to satisfy those who ; had planned Father's Day outings. At the same time, the indoor ; climate was good enough to please the fractal cats. ; ; And the work was slow enough to give me a restful day, which is ; all I can ask for on a Sunday. The next FOTD will appear in 24 ; hours on the same mailing lists and on the FOTD web site. Until ; then, take care, and be alert for flying Siegel-disc saucers. ; ; ; Jim Muth ; jamth@mindspring.com ; jimmuth@aol.com ; ; ; START PARAMETER FILE======================================= SiegelDisk_Fractal { ; time=0:00:37.41-SF5 on P4-2000 reset=2004 type=julia passes=1 center-mag=0/0/0.9363296 params=-0.390541/-0.586788 float=y maxiter=1500 bailout=4 inside=bof60 logmap=yes symmetry=origin periodicity=no colors=000K75Y35k05yiJiaNUUQV`YWgdXnkXtrZhe_YTaNGb\ C4cT8dhCexFbiR_WbXInU4y`DjgLXnUIta4_lDGvMN4J_EDlO7\ Sfublwmrxo_cpIKtVBwg2dMAN1IO7IPCIQHIQ9VQ2fGHU6WIWS\ StP`lNfeLlZJrSIwbGhmFUxEFszZEiZ7Yb1NegdA_YGTSMMMSF\ GXGO_2kLGWbHceJYEIdT6d89fHChQFjZ4Qn9YkDdiKlsoJmYYj\ IJuHTpHbkeDaXPcP`eNl1LkCKkNIkYzpOjnVWlagxH`tOUqVNn\ a5mvBlnb`5XcFSfPMiZTd5QfFNhPKjZq07gCHZOQQ_ZkIz`SsR\ am62fCKiERhFYhGdgY0mrahanrVmnOljMtiJohh61ZKGQYUEkX\ GkbSm05I4MMkKViIch9KOCUVFbaTXaNdd_Y6TbJNgWL42KFDJQ\ NI`YJjXIk_IkbHkemYCXdShKQVYZIKtajORkYogIYiV8GlBOjD\ WiFchY8D5fTBi`ya7bfQ0Iv6SqCals1`_PdmvEXpTgyaUrdx5V\ _JGVRNQYULd`aGyD2FFIPGXZsMsfVoUck5PsB`mADfVqsOnmrJ\ 7eTKTbW5NY9WaDcdkUr7jiAkhCkhFkg4wjBqhG7UHIYHS`Had7\ F_BQbE`e5`78cHBfQEiZ_VgQcg9t5DoPOa6jKQbRVWYZOdcHk9\ HkR9ciCfhFiguuxgqrUnleDviVQEH`GXdDBkFUiXFkTOjPWiLc\ h4mp9lmDkjvCckQ1cWCW`Nb8L } ; END PARAMETER FILE========================================= ; ;