[lgarfiel@students.depaul.edu: Re: [UFO Chicago] CEO's Report for January 24th, 2002]

Peter A. Peterson II pedro@tastytronic.net
Fri, 25 Jan 2002 17:00:40 -0600

Larry's "reply-all" must have somehow gotten compressed to just

----- Forwarded message from Larry Garfield <lgarfiel@students.depaul.edu> -----

Compression occurs when an action is taken on an entity such that it
occupies less volume with respect to its environment than the normal
baseline volume occupied by a given entity within the same environment.


When you squeeze a sponge, it is being compressed, as it occupies fewer
cubic centimeters than it did previously in its baseline state (before
you started pressing on it).

When you make more efficient use of a plastic mold you are not
compressing it.  Neither the mold itself nor the products (plastic
Barbie torso) are occupying less spatial volume than their previous

In the electronic world, the volume an object takes up is the number of
bits it uses, not its physical volume.  A 10 KB file is not compressed
by transferring it from a 5.25" floppy to a 3.5" floppy, even though it
takes up considerably less physical space.  Information is not matter. 
Matter is the medium within which information exists, and changing the
medium in which a given bit is stored does not inherently compress it. 

Placing the same abstracted stream of bits into a physical medium does
not itself compress the data.  Therefore, changing from one physical
medium to another does not itself compress the data.  Therefore,
switching from a CAV to CLV-based laser disks is not compression,
because the bits themselves are still the same bits.  The physical media
is merely being used less efficiently.

Removing characters from a text string is altering the abstracted stream
of bits, in such a way that the same data is representable in fewer
bits.  However, the relevant data itself is not being altered, only the
"padding" data.  So whether white space trimming counts as compression
is subject to debate.  Of course, a similar philosophy is used behind
most audio compression codecs, that is, removal of "non-critical"
portions of the data, and I don't believe anyone questions whether or
not mp3 and ogg are compressed audio.

So perhaps we must alter our definition of compression, such that an
entity when compressed must also alter its actual nature in the
process.  To be useful in electronic terms, it must also be a reversible
process, although that is not strictly necessary.  (An old car is
compressed into a small cube, an irreversible process but distinctly a
form of compression.)

So by that definition, white space trimming is not a form of
compression, because the data's actual nature is not altered, that is,
it can still be run through a compiler/interpreter without alteration
and it will be read properly.  Compressed digital audio (mp3, ogg, etc.)
is compressed, because the actual nature of the entity (bits) is altered
and the end results occupies fewer bits than the initial baseline state.

And thus we have seen the definition and explication of the
philosophical concept of compression.

Larry Garfield

Do you have a PalmOS Organizer?  Click here to add me to your address

-- "If at first you don't succeed, skydiving isn't for you." :-)

----- End forwarded message -----

robotfindskitten.org -- free zen simulation 
xy003.net -- free rock opera
peterpeterson.com -- free skates sharpened and repaired