Thermodynamics, Information, and Life.

in article [email hidden], Jim Menegay at
[email hidden] wrote on 3/26/04 8:14 PM:

Quoted message said:

Guy Hoelzer <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

However, at the moment I am under the impression that the
laws of thermodynamics are argued to be universal and
without any contingencies, at least in this universe.

But earlier in this thread said:

Anyway, we are not /really/ talking about physics. The
second law of thermodynamics isn't /really/ a law and is
isn't /really/ physics.

Its a statement about statistical tendencies among
systems with large numbers of components.

It is not a "law" - since it can be broken - especially
on small scales - and it has more to do with statistics
than it does to do with physics.

:-) Guy, I'd like to introduce Tim. Tim, this is Guy.

Hi Tim.

Quoted message said:

Have fun you two, but play nice. Perhaps you both can find
some middle ground - you are welcome to join my position
that the laws of thermodynamics really are laws, but that
they only apply to the situations that they claim to apply
to - that is, in Guy's language, they have contingencies.

Hmmm. Contingent physical laws sound too much like "rules of
thumb" to me. What would be the difference between a law and
a pattern - the degree of generality?

I, for one, prefer to keep on the hunt for non-contingent
universalities. It may seem like a meaningless trick of
logic, but my view is that thermodynamic universalities take
the form of tendencies. This is slightly different from
Tim's view that thermodynamics is a statistical
(probabilistic) theory. A tendency is a physical propensity,
rather than a simple matter of frequency. For example, a BZ
reaction tends toward spatial self-organization, and the
resulting pattern takes a particular set of forms when
manifested in two dimensions. It takes a different form when
manifested in three dimensions. If you try to illustrate the
2D BZ reaction in an area that is too small, you will not
observe the self-organization of pattern. That does not mean
that the reaction lost its tendency for spatial self-
organization; rather it means that the constraints on the
system prevented it from expressing its inherent tendency.

I hope this begins to clarify the relationship between my
view and Tim's. Maybe it also helps to clarify the nature of
universality and non-contingency for which I am arguing.

Guy

in article [email hidden], Jim Menegay at
[email hidden] wrote on 3/26/04 8:14 PM:

Quoted message said:

Guy Hoelzer <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

As I understand it, entropy cannot be concretely defined
for anything other than a closed system.

I believe this is correct with respect to classical (pre-
Prigogine) thermodynamics.

Quoted message said:

The closest thing we know of that satisfies this
condition [closed system] is the universe as a whole ...

I believe this is incorrect. Perhaps you are confusing
"closed" systems with "isolated" systems.

A "closed system" is one that does not exchange matter
with its surroundings. It may exchange heat and work with
its surroundings. (We need to measure these flows, which
may be difficult in practice.)

Right. In your terminology, which I have seen before, I
meant an isolated system. In my terminology, isolation is a
matter of degree, but closure is absolute.

Quoted message said:

Examples of closed systems are the universe, the solar
system (approximately closed), or the contents of any
stoppered beaker.

Thanks for being clear on your semantics here. As I meant a
"closed system", neither the solar system nor a stoppered
beaker would qualify; although conditions like those
represented by stoppered bottles can approximate closure.
The solar system, on the other hand, is relatively insulated
from interaction with the outside compared with the
intensity and frequency of interactions on the inside. It is
a classic dissipative structure founded on flows in,
through, and out (IMHO). I take this to be a very important
distinction between the solar system and a stoppered bottle.

Quoted message said:

In principle, entropy can be measured for any closed
system by integrating dS = dQrev / T.

I am not comfortable interpreting your equation, and don't
have the time at the moment to investigate it, so I will go
with it for the sake of argument. What exactly is this
equation intended to measure? The entropy OF the system at
the level of pattern? The rate of external entropy
production by the system (as a process)? ...?

Quoted message said:

Qrev is the heat absorbed (reversibly) by the system as
the temperature is raised. The lower end of the range of
integration is at T=0, by the third law. In practice, you
start from any state where the entropy is already known.

There is nothing particularly mysterious or inaccessible
about classical entropy. But its definition does presume
that you can measure heat flow and temperature. This means
that you have to be close to (or at) thermal equilibrium.
You don't need to be close to chemical equilibrium, as
long as no chemical reactions are occuring.

These sound like non-existent conditions to me; heat is
flowing, but there is thermal equilibrium, and no chemical
reactions are occurring. How is this "accessible"?

Guy

Guy Hoelzer <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

in article [email hidden], Jim Menegay
at [email hidden] wrote on 3/26/04 8:14 PM:

Quoted message said:

Guy Hoelzer <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

As I understand it, entropy cannot be concretely
defined for anything other than a closed system.

I believe this is correct with respect to classical (pre-
Prigogine) thermodynamics.

Quoted message said:

The closest thing we know of that satisfies this
condition [closed system] is the universe as a
whole ...

I believe this is incorrect. Perhaps you are confusing
"closed" systems with "isolated" systems.

A "closed system" is one that does not exchange matter
with its surroundings. It may exchange heat and work
with its surroundings. (We need to measure these flows,
which may be difficult in practice.)

Right. In your terminology, which I have seen before, I
meant an isolated system. In my terminology, isolation is
a matter of degree, but closure is absolute.

Quoted message said:

Examples of closed systems are the universe, the solar
system (approximately closed), or the contents of any
stoppered beaker.

Thanks for being clear on your semantics here. As I meant
a "closed system", neither the solar system nor a
stoppered beaker would qualify;

[snip]

This is not some wild and wooly scientific frontier land of
"complex systems thermo", with unsettled terminology. We
were talking about civilized territory here - classical
thermodynamics. It is one thing for you frontier folk to use
Humpty Dumpty semantics, where words mean whatever you want
them to mean. But in the civilized world, words are taken to
mean what the textbooks say they mean - no more, no less.
And, sooner or later, if you frontiersmen succeed in your
mission of reintegrating with and enriching civilization,
you are going to have to start using the civilized meanings
of words, not your own.

Quoted message said:

Quoted message said:

In principle, entropy can be measured for any closed
system by integrating dS = dQrev / T.

I am not comfortable interpreting your equation, and don't
have the time at the moment to investigate it ...

There is no rush, take your time. You only need to
understand this if you wish to discuss classical
thermodynamics without looking like an uneducated fool. It
is not my equation. It is the textbook definition of
entropy. Has been for over a hundred years.

Quoted message said:

Quoted message said:

There is nothing particularly mysterious or inaccessible
about classical entropy. But its definition does presume
that you can measure heat flow and temperature. This
means that you have to be close to (or at) thermal
equilibrium. You don't need to be close to chemical
equilibrium, as long as no chemical reactions are
occuring.

These sound like non-existent conditions to me; heat is
flowing, but there is thermal equilibrium, and no chemical
reactions are occurring. How is this "accessible"?

Perhaps my statement was lacking in clarity here. Heat CAN
flow, but in a state of thermal equilibrium no heat is
actually flowing (between system and surroundings).
(Incidentally, "system" and "surroundings" are also
technical terms, defined in all of the textbooks).

Regarding chemical reactions, perhaps I should have said
that no net reactions are occurring at the macro level. At
the micro level, we of course continue to have, for example,
2H2O <--> OH- + H3O+, but no net flow in either direction.
As an example of a system far from chemical equilibrium, but
with a well defined entropy, I had in mind a beaker of nitro-
glycerin. Another example would be one of Tim's
supersaturated solutions, in the absence of a seed.

Thermodynamics is not rocket science. It is explained in any
good first year course in chemistry or physics. It is used
daily by millions of chemists, engineers, PBS auto
mechanics, and even rocket scientists. Thermodynamics is not
an enigma, though it can be used as a starting point for
those who like to discover, explore, or sell enigmas. And
finally, thermodynamics is not the same discipline as
statistical thermodynamics, though the two disciplines
illuminate each other and stand in a relationship that E. O.
Wilson would call discipline and anti-discipline.

Jim Menegay <[email hidden]> wrote or quoted:

Quoted message said:

Guy Hoelzer <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

Jim Menegay at [email hidden] wrote on 3/26/04
8:14 PM:

Quoted message said:

Guy Hoelzer <[email hidden]> wrote:

Quoted message said:

Quoted message said:

Quoted message said:

> As I understand it, entropy cannot be concretely
> defined for anything other than a closed system.
> [...]
>
> The closest thing we know of that satisfies this
> condition [closed system] is the universe as a whole
> ...

I believe this is incorrect. Perhaps you are confusing
"closed" systems with "isolated" systems.

"Closed" is *conventionally* used to mean "isolated",
though.

Quoted message said:

Quoted message said:

Quoted message said:

A "closed system" is one that does not exchange matter
with its surroundings. It may exchange heat and work
with its surroundings. (We need to measure these
flows, which may be difficult in practice.)

Right. In your terminology, which I have seen before, I
meant an isolated system. In my terminology, isolation
is a matter of degree, but closure is absolute.

Quoted message said:

Examples of closed systems are the universe, the solar
system (approximately closed), or the contents of any
stoppered beaker.

Thanks for being clear on your semantics here. As I
meant a "closed system", neither the solar system nor a
stoppered beaker would qualify;

[snip]

This is not some wild and wooly scientific frontier land
of "complex systems thermo", with unsettled terminology.
We were talking about civilized territory here - classical
thermodynamics. It is one thing for you frontier folk to
use Humpty Dumpty semantics, where words mean whatever you
want them to mean. But in the civilized world, words are
taken to mean what the textbooks say they mean - no more,
no less. And, sooner or later, if you frontiersmen succeed
in your mission of reintegrating with and enriching
civilization, you are going to have to start using the
civilized meanings of words, not your own.

Neutrinos, etc are *very* penetrating, though ;-)

I would defend using "closed" as a synonym of "isolated".

IMO, this is a case of popular usage swamping the theorist's
preferred terminology. Maybe "isolated" had too many
syllables, but - for whatever reason - its use has been
convincingly displaced by the term "closed".

Technically, the second law applies to *isolated* systems -
and /not/ to *closed* ones.

Yet - in a GoogleDuel:

google.comsearchOpen ↗"second+law"+closed 31,700
google.comsearchOpen ↗"second+law"+isolated
15,200

It's a landslide in favour of the "wrong" term.

IMO - those who still want "closed" to refer to the (rather
useless) concept of systems which exchange energy - but not
matter - with their surroundings should admit the defeat of
their preferred terminology at the hands of the masses - and
get with the program everyone else is plainly following ;-)
--
__________
|im |yler timtyler.orgtimtyler.orgOpen ↗ [email hidden] Remove
lock to reply.

in article [email hidden], Jim Menegay at
[email hidden] wrote on 3/31/04 4:07 PM:

Quoted message said:

Guy Hoelzer <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

in article [email hidden], Jim Menegay
at [email hidden] wrote on 3/26/04 8:14 PM:

Quoted message said:

Guy Hoelzer <[email hidden]> wrote in message
news:<[email hidden]>...

> As I understand it, entropy cannot be concretely
> defined for anything other than a closed system.

I believe this is correct with respect to classical (pre-
Prigogine) thermodynamics.

> The closest thing we know of that satisfies this
> condition [closed system] is the universe as a
> whole ...

I believe this is incorrect. Perhaps you are confusing
"closed" systems with "isolated" systems.

A "closed system" is one that does not exchange matter
with its surroundings. It may exchange heat and work
with its surroundings. (We need to measure these flows,
which may be difficult in practice.)

Right. In your terminology, which I have seen before, I
meant an isolated system. In my terminology, isolation is
a matter of degree, but closure is absolute.

Quoted message said:

Examples of closed systems are the universe, the solar
system (approximately closed), or the contents of any
stoppered beaker.

Thanks for being clear on your semantics here. As I meant
a "closed system", neither the solar system nor a
stoppered beaker would qualify;

[snip]

This is not some wild and wooly scientific frontier land
of "complex systems thermo", with unsettled terminology.
We were talking about civilized territory here - classical
thermodynamics. It is one thing for you frontier folk to
use Humpty Dumpty semantics, where words mean whatever you
want them to mean. But in the civilized world, words are
taken to mean what the textbooks say they mean - no more,
no less. And, sooner or later, if you frontiersmen succeed
in your mission of reintegrating with and enriching
civilization, you are going to have to start using the
civilized meanings of words, not your own.

I appreciate your point, but I agree with the point Tim made
in his response. Use of these terms have varied across
disciplines that are brought together under the umbrella of
complex systems science. I don't think I was being sloppy,
and I did not just make up my definitions without
considering traditional semantics. I have been strongly
influenced by the use of language in spatial population
genetics, in which the term "isolation" is conventionally
used as a continuous variable. It would be unusual to use
the term "closed" in this field, although I for one would
take it to mean complete isolation. Whether or not you find
my defense convincing, I think it is increasingly important
to keep an open mind regarding the different conventions
existing in different disciplines as new fields emerge, such
as complex systems science, that link historically disparate
disciplines.

Quoted message said:

Quoted message said:

Quoted message said:

In principle, entropy can be measured for any closed
system by integrating dS = dQrev / T.

I am not comfortable interpreting your equation, and
don't have the time at the moment to investigate it ...

There is no rush, take your time. You only need to
understand this if you wish to discuss classical
thermodynamics without looking like an uneducated fool. It
is not my equation. It is the textbook definition of
entropy. Has been for over a hundred years.

Right. This is the Clausius equation, which is only defined
for systems at or very close to equilibrium. To bring this
thread back from this diversion, the notion of entropy and
how it can be measured has had a bit of a tortured history
since Clausius' time. I won't bring up Shannon's information-
based notion of entropy here, but I would like to turn the
discussion to consider the role of entropy in systems far-from-
equilibrium (Prigogine's goal) because this is the framework
in which it would relate to biological systems like
organisms. I think that all biological systems are
dissipative systems, to use Prigogine's language.

Quoted message said:

Quoted message said:

Quoted message said:

There is nothing particularly mysterious or inaccessible
about classical entropy. But its definition does presume
that you can measure heat flow and temperature. This
means that you have to be close to (or at) thermal
equilibrium. You don't need to be close to chemical
equilibrium, as long as no chemical reactions are
occuring.

These sound like non-existent conditions to me; heat is
flowing, but there is thermal equilibrium, and no
chemical reactions are occurring. How is this
"accessible"?

Perhaps my statement was lacking in clarity here. Heat CAN
flow, but in a state of thermal equilibrium no heat is
actually flowing (between system and surroundings).
(Incidentally, "system" and "surroundings" are also
technical terms, defined in all of the textbooks).

Regarding chemical reactions, perhaps I should have said
that no net reactions are occurring at the macro level.
At the micro level, we of course continue to have, for
example, 2H2O <--> OH- + H3O+, but no net flow in either
direction. As an example of a system far from chemical
equilibrium, but with a well defined entropy, I had in
mind a beaker of nitro-glycerin. Another example would
be one of Tim's supersaturated solutions, in the absence
of a seed.

OK. These are unstable equilibria. This is not a novel
concept for me. However, neither of these examples represent
systems. I took the time to look up "system", and it
confirmed my understanding that a system is constituted as a
functionally integrated whole. An arbitrary volume of liquid
with externally imposed boundaries does not qualify.

Quoted message said:

Thermodynamics is not rocket science. It is explained in
any good first year course in chemistry or physics.

My threshold for absorbing condescension is being tested at
this point.

Quoted message said:

It is used daily by millions of chemists, engineers, PBS
auto mechanics, and even rocket scientists. Thermodynamics
is not an enigma, though it can be used as a starting
point for those who like to discover, explore, or sell
enigmas.

Are you claiming that what is "known" about thermodynamics
is perfect? It is both absolutely correct and complete?
There are no "enigmas" left in thermodynamics? I guess that
would explain your satisfaction with equilibrial models.

Quoted message said:

And finally, thermodynamics is not the same discipline as
statistical thermodynamics, though the two disciplines
illuminate each other and stand in a relationship that E.
O. Wilson would call discipline and anti-discipline.

This is an interesting point that I had not considered.

Guy

Tim Tyler <[email hidden]> wrote in
:"]news:[email hidden]:

Quoted message said:

Jim Menegay <[email hidden]> wrote or quoted:

Quoted message said:

Tim Tyler <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

Quoted message said:

[snip] Re: your idea of fitness increasing. You haven't
explained this - but - IMO - it would translate into
organisms having more and more surviving offspring as
time passed.

I believe you need a continuously-expanding -
environment to pull that trick off for very long ;-)

Nope. Just a continuously deteriorating environment.
Fisher's "fundamental theorem" says that the genetical
component of fitness is non-decreasing. But he avoids
having continuously increasing populations by claiming
that the environment is continually deteriorating. Only
recently have theorists realized that Fisher was
including the average fitness of competing conspecifics
as a component of the environment. So, we have a "Red
Queen" race - fitness continually increases, but number
of offspring do not.

I prefer the presentation on:

peregrine.dkFISH.HTMOpen ↗

It says - among other things - that Fisher's "fundamental
theorem" is toast.

Ignoring the more technical details of the argument, to my
mind the question boils down to whether e.g. a lion is "more
fit" than a sabertoothed tiger (I may well be comparing the
wrong species - I really don't know the niche of the
sabertooth and there is another discussion on sbe about that
topic). Over the short term the issue is decided based on
Fisher's idea of rate of increase, but over the long term
the rate of increase of any species will be close to zero.
But I don't think that means that fitness can't increase
(using the "red queen" analogy), if in fact a lion is more
fit than a sabertoothed tiger. There is of course the
problem that fitness is highly dependent on the environment,
so that it is very hard to compare a lion with a sabertooth
- one or the other might prevail based not on innate
superiority but based on better conforming to the niche.

However. Take a look at primitive fishes, and take a look at
tuna. There has been an increase in absolute fitness over
the last 500 million years
- with fitness being like pornography, I can't define it but
I know it when I see it. This type of definition is
unsatisfactory in a scientific forum, which leads me to
believe that we still need to work on defining fitness.

Yours,

Bill Morse

Guy Hoelzer <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

My threshold for absorbing condescension is being tested
at this point.

Guy's threshold is high. I have poured considerable
condescension into this thread and I am still dripping with
it. It appears that deliberate obscurantism, a refusal to
admit mistakes, and pseudo-erudition draw this secretion
from me like sweat. Readers will have to judge my assessment
of Guy on their own by reading thru this thread.

Guy's most infuriating habit is to quote some theorem and
then to construe the terms within it with entirely
different meanings:

Quoted message said:

Quoted message said:

As I understand it, entropy cannot be concretely defined
for anything other than a closed system. The closest
thing we know of that satisfies this condition [closed
system] is the universe as a whole ...

And:

Quoted message said:

I took the time to look up "system", and it confirmed my
understanding that a system is constituted as a
functionally integrated whole. An arbitrary volume of
liquid with externally imposed boundaries does not
qualify.

Guy then asks:

Quoted message said:

Are you claiming that what is "known" about thermodynamics
is perfect?

No Guy. Based on your instruction, I would have to conclude
that thermodynamics is a monstrous hoax.

Thankfully, I don't have to take your instruction, nor, if I
maintain my current determination, will you have to absorb
my condescension. We will not have one of these idiotic
discussions again. Goodbye.

btw, Tyler, if you are reading - what you write occasionally
makes sense. But your Google experiment regarding "isolated"
and "closed" was not one of those times.