How permanent is a CD-ROM??

[christian thompson]

Michael Frankis asked the question: How permanent is a CD-ROM??

There are two answers.

One of which he alluded to, that is, for how long will there be machines
capable of reading CD-ROM.  The answer is obviously dependent on two point:
Technology and Importance of content.  On the technology CDROM will probably
have a long life as the new formats are using the same physical shape, size,
etc., and the read head is only getting smaller and more precise, etc.  That
is, the beam used to read a CDROM is just much broader than the one used to
read a DVD.  And the new experimental disks uses an ever finer beam. So, a
more advanced reader can always be programmed to read an older disk with
larger "holes."  As to the importance of content, if there is a large mass
of valueable material on older CDROMs, then future readers will be
programmed to read them as well as the newer disk formats, such as today's
DVD.

The second question is how long will CD-ROM last?  Well, if properly cared
for, probably as long as paper has. That is, the "stamped" type of CDROM,
not the dye-based ones that one write with their computer.  Yes, it is known
that you subject a CDROM to high heat or water, etc., they will fail.  So,
does paper.

But what happens with the medium fails?  What are they doing with old books
with poor quality paper? The current option many libraries use is to move
the content to newer digital media!

In short, I strongly believe CDROM is a good medium to use, in fact, the
only real archive medium now readily available for digital content.  And I
strongly suspect when that medium fails in the future, we will have created
enough content of value to society that it will be converted to what ever
the newest and best medium is.

Paper is wonderful. And I love my old books; but if the systematics
community is going to meet E. O. Wilson's challenge for documenting life on
earth in the NEAR future, then we will have to accept the best digital media
available. To me that today is the World-Wide-Web and CDROM in combination.
Paper is too costly, too slow to produce, etc.

F. Christian Thompson
Systematic Entomology Lab., ARS, USDA
Smithsonian Institution
Washington, D. C. 20560-0169
(202) 382-1800 voice
(202) 786-9422 FAX
cthompso at sel.barc.usda.gov
visit our Diptera site at www.diptera.org