July 1, 1997: Whirlygig June 30 July 2 1997 FOTD Home


Fractal visionaries:

What is the most reliable medium for long-term storage of digital data?  In other words, where does one store those glorious fractals with the assurance that they will still be there in five or ten years?

I'm no longer so certain.

I have just tried to recover about 350 old images that I thought were safely stored away on a SyQuest 88mb cartridge.  I had intended on recoloring them and bringing them up to my present standards, but when I tried to read the cartridge, I discovered that the fractals had vanished.  I even tried the cartridge in three other drives.  No luck.  The cartridge had lost its format; the pictures were gone.

I am not totally out of luck, however, because I still have two copies of the parameter files safely stored away on good old (sometimes) reliable 1.44mb floppy disks.  Of course, this means a couple hundred hours of redraw time, but eventually I'll have the original fractals once again in my possession.

The reason for the disappearance of the fractals will likely never be known for certain, but I have a pretty good idea what happened.  The cartridge was stored on a shelf located about one foot, through a wall, from a television antenna ground wire.  I believe that the antenna was struck by lightning recently, and I suspect that the magnetic field associated with the surge of the discharge through the ground wire was so strong that it damaged the cartridge.  The fact that several blank but formatted cartridges on the same shelf also have lost their formats would lend credence to my suspicion.  So don't store your digital data near lightning rods.

(Five-thousand years ago, the Egyptians had an archiving technology that has lasted until this day, and may last five-thousand years more.  They carved their data in stone.  Today, we can't even preserve data for five years.  This is some progress.  Of course, we have much more data than the Egyptians ever dreamed of, but perhaps that is part of the problem.) :-)

I remember seeing a thread in this group a few weeks ago about the most reliable long-term storage medium -- something about a medium immune to magnetic disruption.  I've still got those letters filed away, so when I finish here, I'll see what I can turn up.

Now it's time for today's fractal -- a different type of image.  This one is notable in that it consists entirely of trapped points.  If the inside fill were set to 0, the result would be a blank screen.  The fractal itself is the inside of a Julia set that just misses an area of chaos, but comes close enough for the nearby chaos to do strange things to the blank interior -- things which the proper fill option can reveal.

Those with a bit of idle time might try different fill options -- they all give interesting results.  Changing the maxiter and/or the periodicity also changes the image.  Of course, the finished product has been posted to a.b.p.f. and a.f.p.

Tomorrow, perhaps I'll get back to those way-out oblique planes.  We'll see when the time comes.

Jim Muth

START 19.6 PAR FILE=========================================

Whirlygig          { ; time=0:00:48.99-SF5 on P4-2000
  reset=1960 type=formula formulafile=basicer.frm
  formulaname=JulibrotInvZ passes=1 center-mag=0.170\
  172/0.452708/2.69095 params=1.1/0/0/1/0/0 float=y
  maxiter=125 bailout=100 inside=bof61
  logmap=yes periodicity=10
  kotnptoquqrussvttvvuwxvwy }

frm:JulibrotInvZ {; Jim Muth
z=pixel, c=p2+(pixel*p3):
|z| <= 100 }

END 19.6 PAR FILE===========================================