Replying to LO25371 --
Aosta is a place in northwest Italia with nearby the Mont Blanc,
Matterhorn (in Italian: Monte Cervina), Monte Rosa and the Gran Paradiso.
All of these Alpine mountains are over 4000 metres. It is the area where I
did my PhD research 25 years ago. Following the main valley from Aosta
along the river Dora Baltea it first goes some 20 kilometres to the east
and then it sharply bends to the south. For another 20 kilometres it
continues as a very narrow U-shaped valley, bordered by steep walls of
high mountains. And then suddenly after passing the small city of Ivrea
the wild river meets the gentle undulating landscape of the Po-plain; the
mountains are completely disappeared. Near Turin, further to the south the
Dora Baltea meets the river Po and this river follows towards the east on
a safe distance from and roughly parallel to the Alpine mountain chain.
2000 years ago, it was Hannibal who followed with his elephants the Dora
Baltea and passed the Roman city of Aosta and soon thereafter the Alps.
Aosta is a nice small city, with according to the touristic information,
the highest density of Roman buildings. The entrance of Aosta is still
marked by a Roman arc. This is an interesting place, because the modern
road underneath the arc lies some 2 metres above the Roman pavement. In
only 2000 years, 2 metres of sediment has been deposited! An incredible
rate of sedimentation. This is however understandable, if one thinks of
the enourmous altitude differences (some 3500 metres over a distance of 20
kilometres). The southern side of the Alps is much more steeper than the
northern (Swiss) side.
Last week a disaster has happened again in this valley. Due to excessive
rainfall, the Dora Baltea could not cope with all the water running via
numerous smaller streams and sampled in the main stream. These masses of
water in such a narrow valley (the only way to escape the mountains) have
damaged lots of houses and the complete infrastructure, since the roads
and highway are also following the course of the valley. Something
similiar would hapen if the great dam in the Colorado river will break and
all the water behind this dam is forced into the Grand Canion. The
difference with the Alps is, that in Italy the valley is quite densely
populated. Some 18 victims are counted now.
Desert dunes are very interesting phenomena. They usually have a parabola
shape if seen from above/ The 'legs' of the parabola point in the
direction towhere the constant wind is blowing. If observed from the
ground, these dunes have a gentle and a steep slope. The gentle slope
points to the direction fromwhere the wind is coming, the steep slope is
on the other leeside. On the gentle slope the sand grains are constantly
'pushed' by the wind uphill, on the other steep side the grains fall and
roll dowhill. I have seen such sand dunes of over 80 metres high. This
steep slope could fairly well compared with the slope that devellopes
along the pile of sand in an hour glass. Notice that the angle of this
slope stays constant, even with tha addition of more sand. Notice too that
the slope is strait, neither concave, nor convex (unlike for instance the
bell-shape of the Gauss curve). It is a critical angle (called the Richter
angle), characteristic for certain size and shape of the grains. Look for
instance also to the debris at the foot of mountains and hills, the angle
is always the same! These steep slopes are very unstable. If one removes
some sand at the foor of the slope, the complete slope starts to 'flow'.
This flow will continue until again the critical Richter angle has been
reached again. If one has the chance to climbe against such steep sand
slope (which consumes a lot of energy!). one could observe the most
fascinating flow patterns along the slope surface. The sand grains behave
like water molecules. As a matter of fact, these sand dunes show now and
then fantastic fractal patterns: small sipples superimposed on larger
dunes, that again are superimposed on huge dunes; all with roughly the
The prisoner want to escape. But steel bars and high walls prevent him
from freedom. There is a great will, but he can't. The inhabitants of a
medieval castle that is under attack of army of brutal enemies don't like
to escape to freedom, the risk is that they are killed. However, they are
able to escape. Four examples of equilibrium: the Aosta valley, usually in
balance with landscape and rainfall; the desert sand dune, usually in
dynamic balance with the wind; the prisoner usually kept in prison; the
inhabitants usually stay safe in the castle.
I have thought much on what At has written in his very clear and clever
series of contributions: "Work and Free Energy -- The Dance of LEP on LEC"
(LO25369, LO25370 and LO25371).
For me the most intreguing part was at the end, where he sketched the
principles behind rheostasis and homeostasis: the two sides of labile
equilibrium. It turns down to the formula:
[Y(2)-Y(1)] x /_\X = 0,
intensive factors x extensive factor(s) = 0
force x flux = 0
In the case of rheostasis /_\X = 0. If the system will flow, will be
brought in disequilibrium, one has to do something on this /_\X, by
deliberating the impaired flux.
At de Lange gave the following examples:
"Consider a labile equilibrium. Then one of the two factors [Y(2) - Y(1)]
and /_\X cannot be zero. Consider the case
. [Y(2) - Y(1)] > 0 AND /_\X = 0
This case is called rheostasis. Something is preventing the entropic flux
/_\X to flow. This is nothing else than a serious impairing in at least
one of the seven essentialities. This impairing may be deliberate, for
example keeping a corrosive acid in a sealed, inert container so that it
cannot make effective contact (fruitfulness) with other reactive
substances. In a bomb it is usually the becoming of liveness which is
suppressed. By restoring that essentiality, the entropic flux /_\X will
increase once again from its zero value. Hence both factors are not zero
so that entropy is once again produced as is indicated by
. [Y(2) - Y(1)] x /_\X > 0"
(I think At should have written in the beginning of this paragraph:
"Consider a labile equilibrium. Then one of the two factors [Y(2) - Y(1)]
and /_\X SHOULD be zero.")
At continues with the homeostasis:
"The other case of a labile equilibrium, namely
. [Y(2) - Y(1)] = 0 AND /_\X > 0
is just as interesting. It is called homeostasis. The system has a
mechanism (cybernetic control loop) by which it keeps the intensive
parameter Y even so that differences do not occur. Whereas in the case of
rheostasis at least one essentiality is seriously impaired, in the case of
homeostasis the system is sensitive to at least one essentiality to
maintain a complex level according to the LRC (Law of Requisite
Complexity). When, for some or other reason, the cybernetic control loop
gets broken, the system's free energy suddenly decreases again to the
reach the next lower minimum value of a labile equilibrium or the final
lowest value of the stable equilibrium. In the case of a living animal,
the complete break of one of these loops entails death so the lowering of
the free energy will drive the subsequent decomposition of the body."
So if the homeostasis-equilibrium will be brought in disequilibrium, one
has to do something on the acting force(s).
So far I understood it. But then At continues a little bit further in his
contribution with another example of homeostasis. And this example brought
my mind in serious unbalance. In my mind it is essentially the same
situation as in the example that At gave for the rheostasis situation:
"release the foot from the break pedal against a slope and see what
(remove the seal of the container, and see what happens).
The thing is that nothing is changed in the acting forces. [Y(2) - Y(1)]
was and became >0 before and after the release or removal. So I think that
the car on the slope is an example that belongs to rheostasis.
Let's go back to the four examples that I gave in the beginning of this
The situation in the Aosta valey became dramatic. The aparent equilibrium
of the hydrologic cycle (rain - [river - sea]/[vegetation] - evaporation -
clouds - rain) became in unbalance: too much rain in too short time. The
first thought is that the essentiality "quatity/limit" became impaired:
rheostasis. The second thought was that forces are incredibly increased by
the vast amounts of water high in the mountains 'pushing' downward (the
'potential' between high altitudes and low altitudes increased), thus
homeostasis. I think this homeostasis is the main reason of
However, there is a difference with the Colorado dam. In that case it is
like the car on the slope: removing the dam and see what happens. Not the
forces were changed, but one of the impaired essentialities was removed.
The pushing force of the stored water came from above.
The desert dune is a very delicate example. When the dune is in (dynamic)
balance, the windforce, resistance and gravity are in perfect equilibrium.
All three forces 'neutralise' eachother, as I may say so: homeostasis.
Changing one of these forces (the easiest is the blowing wind), the
homeostasis situation becomes in unbalance and the dune starts to move.
With increased windforce, the dune 'walks' foreward.
If the steep slope is brought in unbalance for instance by a climbing
person, the delicate balance between gravity and resistance is changed,
and again homeostasis is changed.
But now the human factors: will and can - the intensive and extensive
will x can = 0
The potential difference between the prison and freedom defines the will
of the prisoner. Remove the bars and the prison wall and the prisoner is
gone. Like the Colorado dam. Although I think that there is a serious
difference: the force behind the dam was pushing, the will of the prisoner
was driven by the attraction of freedom - less destructive.
The balance of the inhabitants of the castle is defined by the dagerous
situation outside the castle and the restricted freedom in the castle. If
we want that these inhabitants start to move, we must do something to
unbalance the forces. Either making the situation worse in the castle (for
instance by deadly famine), or the situation outside the castle will be
made less harmsome (promising that they will not be killed).
Human rheostasis thus concentrates on the verb 'to be able' 'to can',
whereas human homeostasis concentrates in the verb 'to will'.
The dangers of bringing a subtle equilibrium into a flow again, lie mainly
GRADUAL removal of the impaired essentiality, or
changing the acting forces in such a way that ATTRACTION will be the
I hope that my thoughts have some sense and hopefully they will be of some
sense for you too.
dr. Leo D. Minnigh
Library Technical University Delft
PO BOX 98, 2600 MG Delft, The Netherlands
Tel.: 31 15 2782226
Let your thoughts meander towards a sea of ideas.
Leo Minnigh <firstname.lastname@example.org>
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