🚀 go-pugleaf

> pparso39@swbell.net wrote:
>> john baez wrote:
>>>  T. Haug <tjhaug@midusa.net> wrote:

>>> John:
>>> How do you define equilibrium?

>> In physics (and I'm posting from sci.physics), "equilibrium" is
>> a condition in which a physical system remains in the same state
>> as time passes.    According to this definition a sleeping dog is
>> not in equilibrium, because while it might look static to the casual
>> observer, it is actually breathing, metabolizing, pumping out heat
>> into the environment, and so on, and eventually it will wake up
>> and walk off.  By this definition, living systems are never in
>> equilibrium; you only reach equilibrium when you die and completely
>> decompose.

> No.  Equillibrium is a dynamic state.  For example, we take in air,
> water, and nutrients, which become components of our bodies, which
> give off waste products.  That is equillibrium.  The body stays the
> same, more or less, but the actual materials move through the system.
> Pat


James Clerk Maxwell provides good advice in relation to the 
extension of the field of theoretical and applicational physics
to the consideration of living systems ....

  Article 1 - Nature of Physical Science

  Physical Science is that department of knowledge 
  which relates to the order of nature, or in other words, 
  to the regular succession of events.
  The name of physical science, however, 
  is often applied in a more or less restricted manner 
  to those brances of science in which the phenomena considered 
  are of the simplest and most abstract kind, 
  excluding the consideration of the more complex phenomena, 
  such as those observed in living beings.

  Matter & Motion - Maxwell (1882)
  http://magna.com.au/~prfbrown/maxwell1.html


John however goes on to say ...

>>There is a sense in which living systems act to maintain the constancy
>>of certain parameters (body temperature, chemical concentrations, etc.).
>>A nice word for this is "homeostasis".  It's quite different from the
>>above sort of equilibrium, since it typically requires expenditure of 
>>free energy.  It's not too terrible in certain situations to use the
>>word "equilibrium" for "homeostasis", as long as one knows what's going
>>on.  For example, when one speak of someone being in "psychic equilibrium"
>>one doesn't usually mean that their brain has rotted completely away; one
>>means that they are homeostatic.   Also we might speak of an ecosystem 
>>being in "stable equilibrium" if it returned to its initial state after
>>small disturbances, though again this is really a kind of homeostasis. 


  Or a "dynamic equibrium".

  Consideration of individual living systems - let alone systems
  of living systems (ecosystems) - is really not in the domain of
  physics.  This is why there has emerged fields of research called
  environmental science, and ecological science.


>>In fact, it's pretty tricky to make precise the sense in which living
>>systems, ecosystems, etc. maintain a kind of constancy.  For example,
>>it used to be thought that the "balance of nature" meant that when small
>>natural disturbances in an ecosystem pushed it from its homeostatic
>>state, it would automatically move back to that state.  Now it seems
>>that this rarely happens so neatly.  


The sciences are evolving. Perspectives change. The "balance 
of nature" is also often referred to as a cyclic phenomena,
or leastways has this dynamic aspect.

Like the turning of the seasons,
or the rising of the sun 
or the phases of the moon.





Pete Brown
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A thrill of excitement ran through the meeting.

Barbicane, having by a rapid movement firmly fixed his hat upon
his head, calmly continued his harangue:

"There is no one among you, my brave colleagues, who has not
seen the Moon, or, at least, heard speak of it.  Don't be
surprised if I am about to discourse to you regarding the Queen
of the Night.  It is perhaps reserved for us to become the
Columbuses of this unknown world.  Only enter into my plans, and
second me with all your power, and I will lead you to its
conquest, and its name shall be added to those of the thirty-six
states which compose this Great Union."

"Three cheers for the Moon!" roared the Gun Club, with one voice.

"The moon, gentlemen, has been carefully studied," continued
Barbicane; "her mass, density, and weight; her constitution,
motions, distance, as well as her place in the solar system,
have all been exactly determined.  Selenographic charts have
been constructed with a perfection which equals, if it does not
even surpass, that of our terrestrial maps.  Photography has
given us proofs of the incomparable beauty of our satellite; all
is known regarding the moon which mathematical science,
astronomy, geology, and optics can learn about her.  But up to
the present moment no direct communication has been established
with her."

A violent movement of interest and surprise here greeted this
remark of the speaker ...."

                                   - Jules V.

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