response 1 of 51:

Feb 23 19:38 UTC 2001

  The best practical option seems to be high-quality paper.  The jury is
  still out on current digital media -- most of what we use currently
  hasn't been around long enough to form a really good idea of its longevity.

  Still, I'd think that mini-disc would be a comparatively poor choice.
  Even if the data persists, I think you'd have a really hard time finding
  a mini-disc player twenty years from now.  The relative ubiquity of the
  CD standard makes me think that CD-R is probably a better choice, although
  there is disagreement over how long the data on a CD-R is likely to last.

response 5 of 51:

Feb 23 20:47 UTC 2001

Let's not forget the most important question:
1.  How much portability will you need?

MiniDisc is great for remote recording; while it's not quite as good a sound
quality as CD it's a lot smaller & lighter than carrying your PC with the CD
burner around.

Finally, you can easily enough transfer the audio to CD later for longer term
storage.

response 7 of 51:

Feb 24 00:13 UTC 2001

Well, if you want it to last "forever"...

I don't think we have any real data on how long magnetic media is
actually good for.  The best claim I've heard is that 9 track tape might
be good for a hundred years.  The plastic medium isn't the issue - mylar
tape is probably good for thousands of years.  The issue is the magnetic
domains, and the glue that secures the magnetic stuff to the mylar.
Probably the most durable magnetic media made was digital's DECtape;
which recorded fixed sized blocks on really big tape at a very low data
rate.  Of course, finding a working DECtape drive these days may be a
bit of a challenge.

Paper has a good track record for storing data over historical periods
of time.  Unfortunately, paper has its own problems, which are equally
well understood.  These include vulnerability to water, fire, termites,
wasps, ants, &etc.  The paper records we have today are basically of two
forms: stuff dating back to the middle ages that was mostly stored on
purpose, and didn't get recycled, faded, burned, rotted, or otherwise
destroyed.  Most of that is pure luck, and some of what we have is
fragmented or singed.  Experimentally, the reliability of paper records
over periods > 400 years is considerably less than 50%, even under the
most conscientious conditions.  The remaining stuff we have is basically
from archeology - stuff people *did* trash, bury, left in a hole, or
otherwise forgot about, and by some accidental coincidence, it didn't
rot away or get destroyed.  We have a lot of stuff from Egypt because
(a) they wrote a lot, (b) they liked to bury stuff with their friend's
rotting corpses, and (c) they lived in the middle of a desert, so the
cheap burial ground was basically anywhere except right next to the
river.

An even better recording technique than either magnetic tape or ink on
paper is probably punched mylar tape.  Mylar is considerably more
chemically stable than tape and might persist for geologic time.  Holes
in mylar won't fade, are durable and easy to read.  So punched mylar
tape is probably the most practical long-term solution.  Creating a
mylar tape does present some practical problems; probably the simplest
solution is to acquire an ASR-33 or 35.

Storing digital data does require some consideration.  Compression could
be dangerous in that it destroys redundancy in the input data, which
makes it harder to understand.  As long as the data isn't compressed, it
can probably be understood without too much work; after all, computers
in the future will be *much* faster so it may almost be child's play to
decipher audio from a given digital data format.  If you're really
worried, however, you could include an ASCII preamble that describes in
English the format of the audio data that follows.  You definitely don't
need to worry about documenting either ASCII or English; any future data
archeologists worth their salt will know these by heart.  (Unless
they're aliens, in which case they won't care.)

If you want something that lasts *longer* than mylar, well, there
certainly are things...  The big catch is finding something that's
chemically inert, rugged, yet without value.  Gold does well for both
inertness and ruggedness.  Thin plates of stamped gold would be a
perfectly viable way to store data for geological amounts of time.  The
problem is gold is also scarce & valuable - so if any human finds it,
they're much more likely to melt your gold down first, and not ask any
questions later about why anyone would bother stamping little
meaningless marks into gold.  Glass is just as inert, relatively cheap,
but not very rugged.

Engraved rock is a possibility.  Indeed many of our more ancient records
were first recorded in rock.  The major problem was later ages had an
unfortunate tendency to dismantle monuments to use them as a cheap
source of prefabricated stone of *almost* the right size (ie, fine after
some trimming and polishing...) Small hard stones of ugly rock might
work fine.  It turns out that the surface of Venus might be a much
better source of such rock - it's essentially been baked under several
thousand atmospheres worth of acid, which makes it a much harder & more
durable rock than almost everything here on Earth.

response 11 of 51:

Feb 24 03:49 UTC 2001

Sounds like jp2 has made up his mind to use minidiscs no matter what 
anyone says.

response 13 of 51:

Feb 24 04:06 UTC 2001

You don't think jp2 is considering lithic media?

response 15 of 51:

Feb 24 08:29 UTC 2001

(MiniDiscs have *really* come down in price over the past couple of 
years, and have begun challenging DAT tapes as a recording standard
[at least among U.P. radio stations] because of price, ease of use,
and ability to use with a DSB port.)

(FWIW, at both WUPX-FM and WNMU-FM, we use DAT tapes for "long" recordings
[of an hour or more].  WUPX will have MiniDisc technology by the end of
next month, and we're planning to use it for field recordings, reserving
DAT tape for in-studio recordings.  durability of jp2's desired standard
hasn't been a consideration, although I should note that WUPX is in the
process of putting some of those recordings onto CD-R, mostly for ease
of use for our DJs, who *detest* using DAT tapes for 3-5 minute
on-air snippets.)

response 17 of 51:

Feb 24 20:22 UTC 2001

        I was surpised to see professional MiniDisc recorder/players in
a radio station I visted recently.  I quickly made sense.  The old
technology for short recordings (commericials, announcements) was 
cartridge tape.   Considering that a MD now costs near $2.50, it 
does not matter if it can hold more material than the near $5.00 to 
$8 tape cartridge it replaces.  On top of that, tape cartridge 
machines for radio stations require regular maintenance, some daily
(clean heads), some weekly or monthly (align heads).

response 19 of 51:

Feb 24 20:44 UTC 2001

Re #10: I would strongly advise using a digital connection
  between the Minidisc recorder and CD-Recorder (whether
  that's a PC or a stand-alone piece of kit).  Where's the
  sense in recording digitally and then converting back to
  analog, and back to digital?

response 21 of 51:

Feb 25 03:53 UTC 2001

I'd be leery of using anything magnetic, personally.  My personal 
experience has been that floppy disks fail after around 10 to 15 years, 
much less if they're read frequently.  I've also found that 3/4" 
videotape seems to have a useful life of somewhat less than 25 years.  
The adhesive binder seems to fail and let the oxide shed off the tape, 
which both degrades the tape and clogs the heads.  Some types of 
magnetic tape are known to get physically sticky over time, as well, 
with unhappy results when you try to draw it past the heads and 
capstans.

Your best bet may be something no one's brought up yet: Use digital 
media, in an uncompressed format.  Every decade or so, make a new copy 
onto whatever digital media seems best at the time.  This eliminates 
worries about obsolescence *and* degradation.

response 23 of 51:

Feb 26 03:33 UTC 2001

I like the idea of mylar.  I would like it better if you could type on it with
some kind of heat element and thus make a permenent mark on the sheet.  Copper
disk etchings, or better yet, gols etching (isn't that what they used on
Voyager)?