🚀 go-pugleaf

SproutsRad (sproutsrad@aol.com) wrote:

> One of the things that is confusing, at least for me, is the term
> "information".  With other metrics, say determining mass, one can perform
> a procedure, find a quantity and write it down on a piece of paper.  There
> is less chance for confusing what you have written on the paper with the
> actual mass you have measured.  In measuring "information" it seems easy
> to become confused as to whether the "information" is what you have
> written on the paper or what you have measured.  In another thread here
> John Collier (pljdc@alinga.newcastle.edu.au) noted:

> >Brillouin, _Science and Information Theory, 2nd edition_, Academic
> >Press: 1962, uses the term "bound information" to refer to information
> >that is considered with respect to the physical complexions of the
> >system. He uses "free information" to refer to the mathematical
> >concept that does not respect considerations of physical embodiment, 
> >as used in Shannon theory. 

> This seems like a useful distinction; information on the hoof vs.
> information in a plastic wrap.  (No pejorative on the latter, simply
> driven by the analogy)

So in other words, you're making a distinction between the sum total of
the information embodied in the actual piece of reality (e.g. a cubic
portion of space containing a living cell) vs. an *abstraction* of that
information (e.g. the mass of the cell).  The "sum total" would contain
all information possible about the system; e.g. the position, momentum,
and type of every atom, etc.  "Abstraction" refers to the act of 
disregarding all the information other than the aspects you're looking
for.

So the original question was basically asking, "How much information
about the system which we call a 'living cell' can be abstracted away
before you start losing information that would be necessary to re-create
this system from scratch?" or "Which parts of the information in the
system do we really care about?"

An example of the kind of abstraction I'm refering to:
  "Actual" information: the positions and momenta of all the fundamental
    particles making up all the water molecules in and around the cell.
  Abstraction: Definition of water molecule: "XXXX".  Fill volume Y of
    space with N water molecules of average energy E.

The abstraction in this example probably contains enough information to
be able to re-create the right set of water molecules needed to allow
the cell to function properly.  The non-abstracted version contains
VASTLY more information, and we probably don't need that information to
do the job.

So if we wanted to create a specification for a cell with the minimum
amount of information possible, we would want to do as much abstraction
as we can get away with.  The result might look something like this:

Library 1: Definitions of the laws of quantum physics

Library 2: Definitions of each type of atom we will be using, in
  terms of the rules specified in Library 1

Library 3: Definitions of each basic type of molecule we will be using,
  in terms of the building blocks specified in Library 2

"High-level" specification:
  Definitions of a variety of 1- and 2-dimensional surfaces or 3-dimensional
    volumes, with a specifications on which type of and how many
    molecules/atoms to array across each surface or fill each volume.
    Volumes/surfaces/strings would be allowed to overlap.
  Example: specify spherical surface of radius R.  Fill with lipid
    molecules oriented in certain ways. (result: the cell membrane)
  
Even higher-level abstractions may be possible, such as reducing the
  DNA molecules to a simple bit stream, and even specifying the
  "junk" DNA regions as "fill the next X bits with random values".


If you wanted to abstract at higher levels than that, you're probably
going to start losing needed information.  For instance, the highest-level
abstraction would simply be the word "cell," but that obviously doesn't
contain enough information to build one.


> If our *additional information* is "on the hoof" then the question is, how
> big is the corral, how do we draw the boundary conditions to avoid
> including the entire solar system or more?  I believe someone has alluded
> to this question.

This question is basically, "how much of the cell's surrounding environment
do we want to include in our specification?".  It depends upon what you
want to do with the cell.  If you just want it to start functioning for
a little while, you only need to specifiy a little bit of water around it,
containing the appropriate mix of nutrients, etc.  If you want the cell
to avoid getting choked by its own waste products for longer time, you could
say, "extend the nutrient (etc.) solution to fill volume V".  If you want the
environment to change over time (e.g. to mimic the interior of a womb),
you'd have to specify that, too.  It could go on and on -- if the cell is
a human embryo, and you want it to grow up to be a lawyer, you'd need to
specify an entire human society for the organism to grow up in, including
educational institutions, a lot of history, etc.


> Consider that information, like energy, may be most clearly revealed in
> relationship or transaction.

Semi-related question: Einstein drew an equivalence relation between
matter and energy (E=mc^2).  Is it possible to draw an equally direct
equivalence relation between energy and information?

They seem to have very similar properties; for instance, energy seems
to requre a "medium" in order to exist, such as the motion of an object
or the height of an object above a certain level in a gravity field.  The
only place I have every heard of "pure energy" existing is in Star Trek.
In other words, energy is really just a mathematical construct; it needs
a medium of some kind in order to exist.  Similarly, you could define
information as "a pattern in a medium".  Have you ever heard of
information existing without something to represent it?

So is it possible that every possible instance of energy in a system
could be described as information about that system, and that every
instance of information that exists could be described as a form
of energy?

If it is true that energy = information, and energy = matter, 
then matter = information, doesn't it?  In other words, the universe
is composed of information only.  And so are you.


- Doug