Date: Tue 27 Jan 2004 - 04:37:54 CET
Dear Pedro, all,
Just my very subjective speculations on the topic...
Indeed, I very much agree to your notice that the levels we are discussing
here about (may) only partially belong to levels that do exist in nature
because limitations in our knowledge. On the other hand I tend to share
Pavel's suggestion - theory of levels is inevitable...
Probably many of us have been smashing into the disciplinary systems vs.
reality 'incompatibility' while trying to develop something about levels.
My own version (still incomplete after 4 years work) looks more like a 2D
table rather then a 1-dimensional list... Theory of catastrophes might
provide a formal background for us and to help distinguishing the real, as
you wrote, 'joints' of nature. In ecology (that's my field) there is a
relatively simple method to define hierarchical dependencies of species
groups (dominants, subdominants, etc...) within given assemblage of species
(in a sample) which we tend to interpret as directly related to community
structure. Difference between biomass or number of individuals starting from
the most abundant and ending with the least abundant species changes not
continuously, but in a jumpy manner. There are small jumps and big leaps...
So these leaps naturally group species into groups based on their relations
and role in an ecosystem. This approach is used in ecology since the
beginning of the XX century, so there is nothing new in it, except that the
theory of catastrophes is somehow "out of reach" among ecologists. The same
can be said about various environmental gradients (e.g. salinity,
temperature, granularity gradients) - they are never continuous. At smaller
scale they always occur in jumps. Seems like discontinuity rules everywhere.
. It reminds me a definition of information as 'difference that makes
difference. One may see that difference as a 'meaningful discontinuity'. Now
if we take jumps of scales (sizes) of all known systems, we will see that
they occur periodically when referenced to log (levels of scale). So this
was a good point to start. Symmetry of relative scales is an interesting
point here and also the symmetry in relative energy amounts needed to
disintegrate those systems shows up...
The next point in favor of the levels might be comparisons and alternatives
of neighboring levels noticed by the specialists in these fields. Particle
physicists frequently notice that interactions among elementary particles
reminds interactions among chemical atoms. Ecologists know that response to
stress of an ecosystem is in principle similar to stress handling at a level
of an organism. And so on...
But there are weak points in current definitions of what an ecosystem and
community are. This 'discontinuity filter' (as described above) seems to
require several levels of ecosystems and communities, which today remain
still unnamed. And the very definitions still hides some uncertainties
within... I guess the similar problems should appear in social sciences.
Ecologists sometimes try to describe systems of human individuals and their
interactions as cases of ecological populations or communities... No wonder
- even cities or towns with they suburbs are called urban ecosystems.
Natural biotopes here are supplemented by technology (incl architecture).
Seems like social/eco systems are at the same level...
********
Answering the question What is the meaning in the most simple and general
way ?
I would keep on the simplest definition of information as above -
meaningful discontinuity'. Valid for both differences/changes in space
(structure) and in time (signal)...
Signal (as a 'word') is meaningful when it is in it's context. Without the
context it is just a noise. So when one considers structure (as a system)
then based on the hierarchies theory (the case of nested hierarchies) system
is meaningful only as a part of yet another system (context)... This
directly relates to the purpose of this system which is a certain function
(role) within a system it makes a part of... Examples: stomach and
intestinal tract has to handle all the stuff we take in, but can never be a
replacement for brains; electrons - not neutrons- are responsible for
chemical interactions among chemical elements; mitochondria are responsible
for energy supply within a cell and not the chromosomes; population of
carnivores can not be replaced by a population of deposit feeders,
communities of plants, algae as elements of their ecosystems produce oxygen
which is required for the existence of animals (not vice versa) thus
supporting energy/matter/information cycles within ecosystems; ecosystems
have their meaning in the context of biomes, those are important for
biosphere which wouldn't not be possible without the existence of a
geosphere and hydrosphere, etc.... So it seems that the meaning in the most
simple and general way simply (?!.) is a function (role) of a system as an
element...
Are there any systems without a purpose (meaning) ? Maybe not... Because if
system stops functioning properly (looses it's meaning) it probably becomes
a 'mortal bucket :-)' and dies disintegrated by a 'higher' system as a
useless element because the 'higher' controlling system tends to minimize
amount of energy needed for its own existence. Otherwise useless elements
exhaust and kill the entire system parts of which they are as each element
is also an additional source of entropy, especially when it is useless :o)..
Systems have mechanisms to handle the internal entropy probably by
transporting and releasing it into yet another higher level of the hierarchy
..Thus systems that do nothing (no meaning) or do wrongly (out of context)
should not exist as their existence is not supported by the top hierarchy.
In any case loosing the meaning == death of a system.
Alternatively meaning could be considered as events (discontinuities)
happening in space among systems (as elements) which lets these elements to
function in sync. Thus meaning - source of synchronized actions of all
elements within a system (structure). Meaning does not let the system to
fall apart. Just my subjective opinion...
Viktoras
