Re: I had an interesting argument this week...

r norman <r_s_norman@xxxxxxxxxxx> wrote:
On Mon, 22 Mar 2010 17:23:49 +0000 (UTC), Paul J Gans
<gansno@xxxxxxxxx> wrote:

r norman <r_s_norman@xxxxxxxxxxx> wrote:
On Mon, 22 Mar 2010 02:25:07 +0000 (UTC), Paul J Gans
<gansno@xxxxxxxxx> wrote:

R. Baldwin <res0k7yx@xxxxxxxxxxxxxxxxxxxx> wrote:
Me <haroldfran@xxxxxxxxx> wrote in news:0c59f0f4-5eb5-41b5-bfad-
beeff855cfa5@xxxxxxxxxxxxxxxxxxxxxxxxxxxx:

This guy tried the old Second Law of Thermodynamics violates evolution
gambit. Now I am not a math major. I could explain why but when he
started using numbers. It was beyond my pay level. Here is his post.

In the Combined Law of Thermodynamics for a spontaneous process:

dG is less than or equal to 0

dG = 0 defines equilibrium

Where dG = dU + pdV - TdS

[please note there is no distinction between open and closed systems;
they are treated as the same]

(U =internal energy)
(p = pressure, V = volume)
(T = temperature, S = entropy)

At constant temperature and pressure; dG = dH -TdS

(H = enthalpy = dU + pdV)
(T = temperature, S = entropy)

When dS is positive and dH is negative (exothermic process), a process
is spontaneous [think explosion]

Spontaneous does not mean "explosion". It simply means a system change
that can proceed without an outside influence. Spontaneous processes can
proceed at any rate.

Reactions where dG < 0 are spontaneous. Certainly this is true when dS
is positive and dH is negative, but that is not the only way to arrive
at dG < 0. You could have dH and dS both positive, but TdS > dH, for
example.


When dS is negative and dH is positive (endothermic process), a
process is NOT spontaneous AT ANY temperature, but the reverse process
is spontaneous [think decay].

"Decay" does not always mean "spontaneous." Atomic decay is spontaneous.
Bacterial decay (organic decomposition) is a complex series of changes,
some of which are spontaneous and some of which are nonspontaneous.


Therefore, if the change in entropy is negative (as the evolutionists
must believe something comes from nothing) and the change in enthalpy
is positive (energy must be supplied for the process) the process is
NOT spontaneous at any temperature, but the reverse process of moving
to a less ordered and lower thermodynamic potential state is
spontaneous.


A negative change in entropy within a system is not "something comes
from nothing". Energy is simply supplied from outside the system. The
form of the energy is unimportant for satisfying the Second Law. It
could be solar energy, mechanical energy, geothermal energy, etc.


The way to overcome the limitations imposed by the Combined Laws of
Thermodynamics on spontaneous processes is the application of
information as the source of the negative change in entropy. This can
done through design, instruction, interpretation, or all three.


This is wrong. A spontaneous process does not require "application of
information." It simply requires energy. dG = dH -TdS gives you an idea
of how much energy is needed.

As a simple example, the conversion of oxygen gas (O2) to ozone gas
(O3), and its reverse, both occur naturally in the atmosphere. The decay
of ozone to oxygen is spontaneous. The formation of ozone from oxygen is
nonspontaneous, requiring energy input in the form of high-energy
photons or lightning.

This one example of oxygen to ozone and back demonstrates how specious
your corresondent's argument is.

Keep it up, you are doing a great job!

I sort of know where the "thermodynamics only works in an isolated
system" crap came from. But I want to get my hands around the neck
of the fellow that first misused information in thermodynamics.

As usually understood by the layman, information has NOTHING to do
with thermodynamics.

And by the way, the simplest example of a spontaneous decrease
in entropy is in the formation of rain or snow from water vapor
in the air.

One last thing, nobody should confuse "thermodynamically allowed"
and "takes place". Kinetics is a totally different field. The
change diamond --> graphite has a negative free energy and is
thus "spontaneous", but nobody should hold their breath waiting
for it to happen. The process, at room temperature and pressure,
takes a time long compared to the age of the universe.

I have been reading "From Eternity to Here: The Quest for the Ultimate
Theory of Time" by Sean Carrol, a highly regarded theoretical
physicist. This book will convince you that, according to modern
physical theories of cosmology, information has EVERYTHING to do with
thermodynamics. You just have to use the ideas of both thermodynamics
and information properly.

Of course. But the general notion of "information" and the
information that is talked about in statistical mechanics
are two entirely different things.

Information has a lot to do with quantum mechanics also, but
luckily creationist types don't seem to get involved in that.

The key point that both you and I agree on is that both "entropy" and
"information" are technical terms that are almost always abused in
being bandied about casually. You put it: "As usually understood by
the layman". I put it: "You just have to use the ideas of both
thermodynamics and information properly."

My main reason for posting was not to disagree with you on this point
but to emphasize to the many who seem to violently disagree that
information is closely connected to entropy when both are used and
interpreted properly.

I agree, and I agree that the last statement you made is the key.
Personally, I prefer to avoid talking about it in conjunction with
stat thermo unless I've got at least an hour and a blackboard.

--
--- Paul J. Gans

.

Relevant Pages

  • Re: Time. /My opinion./
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  • Re: I had an interesting argument this week...
    ... In the Combined Law of Thermodynamics for a spontaneous process: ... (T = temperature, S = entropy) ... At constant temperature and pressure; ... is positive (energy must be supplied for the process) the process is ...
    (talk.origins)
  • Re: Negative Entropies in Classical Statistical Physics
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    (sci.physics)
  • Re: I had an interesting argument this week...
    ... In the Combined Law of Thermodynamics for a spontaneous process: ... (T = temperature, S = entropy) ... At constant temperature and pressure; ... is positive (energy must be supplied for the process) the process is ...
    (talk.origins)