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Tim Tyler · Guest

A sequel to my 2002 essay - on the subject of living systems
maximising entropy production:

http://originoflife.net/gods_utility_function/

Enjoy,
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Tom Hendricks · Guest

On Oct 10, 11:57=A0am, Tim Tyler <seemy...@googlemail.com> wrote:
[quote]A sequel to my 2002 essay - on the subject of living systems
maximising entropy production:

=A0http://originoflife.net/gods_utility_function/

Enjoy,
--
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=A0|im |yler =A0http://timtyler.org/=A0t...@tt1lock.org =A0Remove lock to
reply.
[/quote]
Very interesting Tim. Well done.

Perplexed in Peoria · Guest

"Tim Tyler" <seemysig@googlemail.com> wrote in message news:gco1gu$1bbn$1@darwin.ediacara.org...
[quote]A sequel to my 2002 essay - on the subject of living systems
maximising entropy production:

http://originoflife.net/gods_utility_function/
[/quote]
Tim, I>m afraid your logic isn>t very clear in this essay. You are discussing
"self organizing systems [in which the] rate of entropy production [is]
maximised. These were sometimes known as "dissipative structures" -
because they dissipated order, and produced disorder."

Close enough, but then you write: " ... a mechanism was found to explain
the phenomenon. At a low level, high- entropy states are more common
than lower entropy ones - so if a dynamical system changes in some
randomly selected way, it is likely to move into a higher-entropy state.
This simple principle drives systems of all kinds to rapidly move from
low-entropy states towards high-entropy ones."

Sorry, Tim. The mechanism you describe explains the 2LoT itself; i.e
it explains why *entropy* tends to be maximized.

It does nothing to explain why the *rate of entropy production* should
be maximized (and maximized only in *some* complex systems but
minimized in some other (slightly simpler) ones)

Tim Tyler · Guest

On Oct 13, 5:58=A0pm, "Perplexed in Peoria" <jimmene...@sbcglobal.net>
wrote:
[quote]"Tim Tyler" <seemy...@googlemail.com> wrote in messagenews:gco1gu$1bbn$1@=
darwin.ediacara.org...[/quote]

[quote]=A0http://originoflife.net/gods_utility_function/

Tim, I>m afraid your logic isn>t very clear in this essay. =A0You are dis=
cussing
"self organizing systems [in which the] rate of entropy production [is]
=A0maximised. These were sometimes known as "dissipative structures" -
=A0because they dissipated order, and produced disorder."

Close enough, but then you write: " ... a mechanism was found to explain
the phenomenon. At a low level, high- entropy states are more common
than lower entropy ones - so if a dynamical system changes in some
randomly selected way, it is likely to move into a higher-entropy state.
This simple principle drives systems of all kinds to rapidly move from
low-entropy states towards high-entropy ones."

Sorry, Tim. =A0The mechanism you describe explains the 2LoT itself; i.e
it explains why *entropy* tends to be maximized.

It does nothing to explain why the *rate of entropy production* should
be maximized (and maximized only in *some* complex systems but
minimized in some other (slightly simpler) ones)
[/quote]
See:
Maximum entropy production and the fluctuation theorem - R C Dewar
2005
http://www.iop.org/EJ/abstract/0305-4470/38/21/L01/

2LoT only gives the *sign* of entropy changes. Dewar>s idea deals
with rates -
and is more comprehensive.
--
__________
|im |yler http://timtyler.org/ tim@tt1lock.org Remove lock to
reply.

Perplexed in Peoria · Guest

"Tim Tyler" <seemysig@googlemail.com> wrote in message news:gd7rd9$grr$1@darwin.ediacara.org...
[quote]On Oct 13, 5:58=A0pm, "Perplexed in Peoria" <jimmene...@sbcglobal.net
wrote:
"Tim Tyler" <seemy...@googlemail.com> wrote in messagenews:gco1gu$1bbn$1@=
darwin.ediacara.org...

=A0http://originoflife.net/gods_utility_function/

Tim, I>m afraid your logic isn>t very clear in this essay. =A0You are dis=
cussing
"self organizing systems [in which the] rate of entropy production [is]
=A0maximised. These were sometimes known as "dissipative structures" -
=A0because they dissipated order, and produced disorder."

Close enough, but then you write: " ... a mechanism was found to explain
the phenomenon. At a low level, high- entropy states are more common
than lower entropy ones - so if a dynamical system changes in some
randomly selected way, it is likely to move into a higher-entropy state.
This simple principle drives systems of all kinds to rapidly move from
low-entropy states towards high-entropy ones."

Sorry, Tim. =A0The mechanism you describe explains the 2LoT itself; i.e
it explains why *entropy* tends to be maximized.

It does nothing to explain why the *rate of entropy production* should
be maximized (and maximized only in *some* complex systems but
minimized in some other (slightly simpler) ones)

See:
Maximum entropy production and the fluctuation theorem - R C Dewar
2005
http://www.iop.org/EJ/abstract/0305-4470/38/21/L01/

2LoT only gives the *sign* of entropy changes. Dewar>s idea deals
with rates -
and is more comprehensive.
--
I>m familiar with Dewar>s work, though I don>t claim to completely understand it.[/quote]
And I agree that Dewar does address the the mechanism for maximum entropy
production in systems like atmospheric flows. My complaint was that your
description of Dewar>s mechanism was wrong. You wrote:

[quote]At a low level, high- entropy states are more common
than lower entropy ones - so if a dynamical system changes in some
randomly selected way, it is likely to move into a higher-entropy state.
[/quote]
You should have written: "dynamic states in which entropy production is high
are more common than states in which entropy production is low - so ...
[mutatis mutandis]".

Edser>s response was a bit more interesting, and I will respond to his
suggestion here as well. John suggests that natural selection drives
each species toward maximizing its own entropy production. I doubt
that this is the case. My impression is that Lotka>s argument (like the
similar Lovelock argument in "Daisyworld") does not even require
that natural selection be in operation. All it requires is that you have
multiple species in the ecosystem and that you get entropy production
maximization simply from the process of each species completely filling
its niche. The argument is ecological and biophysical - NS has nothing
to do with it. (Neither, I think, does Dewar have anything useful to say
here. The causality has nothing to do with counting microstates within
a macrostate - unlike Boltzman>s or Dewar>s arguments.)

Tim Tyler · Guest

"Perplexed in Peoria" <jimmene...@sbcglobal.net> wrote or quoted

[quote]My complaint was that your description of Dewar>s
mechanism was wrong. You wrote:

At a low level, high- entropy states are more common
than lower entropy ones - so if a dynamical system changes
in some randomly selected way, it is likely to move into a
higher-entropy state.

You should have written: "dynamic states in which entropy
production is high are more common than states in which entropy
production is low - so ... [mutatis mutandis]".
[/quote]
Why do you think I should have written that?
What I wrote was good. Your criticism that it was a
restatement of the second law does not seem accurate.

The second law is another perspective on the same phenomenon -
but its expression omits quanification of the effect - it
says entropy increases, but doesn>t look into how fast
that happens.

Look at the rate at which a system explores adjacent microstates,
and their corresponding entropies, and you can see not just
that entropy tends to increase, but also how fast.

That allows you to set up a utilitarian model in which
what happens next is seen as being that which dissipates
the most entropy, subject to the constraints of physical law.

The thesis of the essay is that that utilitarian metric is the
same thing that turns biology into a gigantic optimisation
process. God>s Utility Function is entropy. Darwinism
is survival of the most degrading. Biology is a grand
contest to see who can dismantle the remaining residues
of order in the universe first and fastest.
--
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Tim Tyler · Guest

Perplexed in Peoria wrote:
[quote]"Tim Tyler" <seemysig@googlemail.com> wrote in message news:gd7rd9$grr$1@=
darwin.ediacara.org...
"Perplexed in Peoria" <jimmene...@sbcglobal.net> wrote:
"Tim Tyler" <seemy...@googlemail.com> wrote in messagenews:gco1gu$1bbn$=
1@=3D[/quote]

[quote]It does nothing to explain why the *rate of entropy production* should
be maximized (and maximized only in *some* complex systems but
minimized in some other (slightly simpler) ones)
See:
Maximum entropy production and the fluctuation theorem - R C Dewar 2005
http://www.iop.org/EJ/abstract/0305-4470/38/21/L01/
[/quote]
[...]

[quote]I>m familiar with Dewar>s work, though I don>t claim to completely unders=
tand it.[/quote]

Here is the specific bit of that document that relates to how
Prigogine>s
principle of minimum entropy production fits in:

``As noted after equation (22), Prigogine>s principle of minimum
entropy
production [5] can be interpreted within the MaxEnt formalism as a
special
case of the behaviour of the dissipation function D(=EB) under
variations in
=EB that are restricted to the plane =F0(c*). Maximum dissipation is a
more
general result which describes the behaviour of D(=EB) under all
possible
variations in =EB permitted by the imposed constraints and thus
represents
a physical selection principle under given constraints. MEP applies
both
close to and far from equilibrium.''

- http://www.iop.org/EJ/abstract/0305-4470/38/21/L01/
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reply.

Tim Tyler · Guest

Perplexed in Peoria wrote:

[quote]Entropy production within organisms
is rather high, and usually even higher in successful, active organisms than in
those which are barely holding on to life. At least among r-selected organisms.
For K-selected organisms, NS may well lead to minimal entropy production -
which is why I objected to my version of your suggestion.
[/quote]
I tried to think of some organisms which take pains to avoid metabolic
waste
in the short term.

Cacti, sloths, camels, hibernating creatures, seeds with long dormant
cycles -
and strains of the flu virus spring to mind.

The flu virus is on the list since there there is frequency-dependent
selection for small population size: the virus benefits from being
rare.

In my original essay I treated this topic in my
'Burning bright - or burning long?' section, as follows:

``I believe these strategies can usefully be seen as the result of
optimising over different time periods. The first is more short
sighted - while the latter takes a more long term view.''
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reply.


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