Re: (OT) climate change vs. energy supply (thermo)

[Guest guest]

In a message dated 2/27/04 8:18:25 PM Eastern Standard Time,

nativenutrition@... writes:

> HEIDI said (I think)- > was talking about:

> >1. " energy " in the form of oil ... which isn't

> >free energy, it is stored energy.

>

> replies - Wrong.

>

> Deanna chimes in - First, the statement attributed to seems quite

> reasonable, albeit a bit vague. If we take his statement to mean:

>

> 1. " energy " in the form of oil ... isn't free energy AND it is stored

> energy.

In thermodynamics, any chemical bond is considered to have an enthalpy of

formation, and an opposite enthalpy of breakage. Freen energy is defined as the

product of temperature and entropy subtracted from the enthalpy, and thus, any

measure of enthalpy is by definition free energy.

>

> Then the logic is sound. For the two conditions are both true.

>

> 1. Energy is not free, the cheapest energy being rain, at least that is the

> cheapest we know of, as it is nearly perpetual.

I don't see how you differentiate " free " and " cheap, " as if we were using the

term in an economic sense. Free energy means that it is available to do

work. Since free energy is the opposite of entropy (--G=S), essentially all

form

of order constitutes free energy, because it contains the potential to cross

the natural entropic gradient.

The energy of oil is not

> free is a true statement.

According to the thermodynamics I've learned, it is a false statement.

Furthermore, it took energy in the form of heat

> and chemical reactions to create the form of energy that is potential in

> oil. Not only that, it takes much energy to bring it up against gravity to

> our surface level for use.

I don't see what this has to do with anything.

>

> 2. The fact that oil is potential (stored) energy is obvious, until it is

> burned, whereby it releases energy and does work .

Which is why it is considered free energy.

>

> Heidi remarks- >It's one of those laws of thermodynamics.

>

> claims- No, it isn't. The first law of thermodynamics states that

> energy of the universe remains constant, but that says nothing about the

> energy of a particular system or the energy of it's surroundings.

>

> Deanna chimes in - First, the statement about energy being constant is true.

> However, it is true for any and all systems, but to take a system in

> isolation, that system must be closed. Otherwise, we can look at the

> universe, like you did at the beginning of your statement, and it

> serves us to conserve energy (since you brought up the macrocosm to begin

> with, why change to some partial measure later?).

You apparently have not been reading this from the beginning. and Heidi

had a dispute as to whether the energy of the earth system has declined.

said that it has, because we've used up energy in fossil fuels. I'm

essentially agreeing with that that must be factored into the equation,

because

if we are looking at the earth as a system (which , Heidi, and I, have all

been doing from the beginning of the dispute), the energy used in fossil

fuels is largely evolved to the surroundings and is unavailable to do further

work

(that is, the free energy of the system has declined).

Sure, a the energy of a closed system remains constant, but the earth isn't a

closed system, so why bother the argument with irrelevancies?

> Sometimes arguments don't concern opinions.

You just quoted plenty of thermodynamics, but didn't bother to apply any of

it, so I can't argue here. You also used quotes that put the thermodynamic

laws in contexts that aren't applicable to the system we're describing, with the

exception of the first quote, which supports my position. And none of them

gave a definition of free energy, which for some reason you insist on using in a

sense that is thoroughly divorced from its thermodynamic meaning.

If we must quote, I'll prove my point:

From Kotz, et al., _Chemistry and Chemical Reactivity_, 2001, p 924:

_____

Calculations of the sort done in the previous section would be simpler if we

did not have to evaluate separately the entropy change of the surroundings

from a table of delta H standard of formation values and the entropy change of

the system from a table of standard entropy values. Another thermodynamic

function, defined by J Willard Gibbs (1839-1903) a professor at Yale University,

solved this dilemma. In Gibb's honor this function is now called the Gibbs free

energy and given the symbol G.

In the previous section we showed that the total entropy change accompanying

a chemical reaction carried out slowly at constant temperature and pressure is

detal S universe = delta S surroudnings + delta S system

= --delta H system/T + delta S system

Multiplying through this equation by --T, the result is

--T delta Suniv = delta H sys -- T(delta S sys)

Gibbs defined the free energy function so that --T(delta Suniv) is equal to

the change in the free energy of the system, delta Gsys. That is

delta G sys = --T(delta Suniv) = delta H sys -- T(delta S sys)

Under standard conditions the equation becomes

delta G standard of the system = delta H standard of the system -- T(delta S

standard of the system)

______

Thus, you can see that the enthalpy of a given bond represents free energy.

Thus, potential energy is free energy. If the potential energy of a sytem

increases, the free energy increases as a result, as well as the converse.

By the way, most chemical reactions are reversible.

Chris

[Guest guest]

In a message dated 2/27/04 10:36:36 PM Eastern Standard Time,

nativenutrition@... writes:

> - Since free energy is the opposite of entropy (--G=S),

>

> Uh, no, by your own conveyance and reality, it is defined in simplest terms

> as

> G = H- TS.

Yes, which makes the change in free energy for a given reaction have the same

magnitude with opposite sign as the change in entropy of the universe for

that same reaction by substituting the equation where the change in entropy of

the surroundings is equal to the opposite of the change in enthalpy over the

temperature in Kelvin.

Sure, you subtract the entropy out and what remains is that

> energy that is free to perform work. Duh. Then it is all free after this

> calculation. So what?

So, my statement was correct. So why do you say " so what? " I'm trying to

make the simple and rather obvious point that the energy within fossil fuels is

evolved to the surroundings when it is burned, in part, which becomes

unavailable for use. Do you disagree with that? If not, then why are you

making an

argument out of nothing, and disparaging me for not having the same math

background as you, when the basic fundamental concepts were discussing do not

require any calculus?

> - In thermodynamics, any chemical bond . . .

>

> Thermodynamics deals with macroscopic variables only. Might I suggest

> looking at a thermodynamics book to learn about thermo, not a chemistry

> book.

Umm, so what do you consider the portion of chemistry that deals with changes

in free energy and enthalpy? The upper-level thermo you might have done

might deal with macroscopic variables only, but that doesn't mean that other

divisions of thermodynamics or the thermodynamic portions of chemical and

biological sciences aren't thermodynamic portions of those discplines-- they

are.

Chris

[Guest guest]

HEIDI said (I think)- > was talking about:

> 1. " energy " in the form of oil ... which isn't

> free energy, it is stored energy.

replies - Wrong.

Deanna chimes in - First, the statement attributed to seems quite

reasonable, albeit a bit vague. If we take his statement to mean:

1. " energy " in the form of oil ... isn't free energy AND it is stored

energy.

Then the logic is sound. For the two conditions are both true.

1. Energy is not free, the cheapest energy being rain, at least that is the

cheapest we know of, as it is nearly perpetual. The energy of oil is not

free is a true statement. Furthermore, it took energy in the form of heat

and chemical reactions to create the form of energy that is potential in

oil. Not only that, it takes much energy to bring it up against gravity to

our surface level for use.

2. The fact that oil is potential (stored) energy is obvious, until it is

burned, whereby it releases energy and does work .

Heidi remarks- > It's one of those laws of thermodynamics.

claims- No, it isn't. The first law of thermodynamics states that

energy of the universe remains constant, but that says nothing about the

energy of a particular system or the energy of it's surroundings.

Deanna chimes in - First, the statement about energy being constant is true.

However, it is true for any and all systems, but to take a system in

isolation, that system must be closed. Otherwise, we can look at the

universe, like you did at the beginning of your statement, and it

serves us to conserve energy (since you brought up the macrocosm to begin

with, why change to some partial measure later?).

Why don't we just spell it all out. My father taught thermodynamics and

fluid flow in college and university for decades, so this stuff has been

preached to me since I was a cognizer. He is big on the 2nd law as he

worked in a/c refrigeration too.

1st Law of Thermodynamics (in English) -

Energy is neither created nor destroyed.

2nd Law of Thermodynamics (in English) -

A quantity of energy is unavailable in an irreversible cycle. (note: the

only reversible cycles I can think of are biological processes)

Clausius stated it thus - " It is not possible for any cyclical machine to

convey heat continuously from one body to another at a higher temperature

without, at the same time, producing some other compensating effect.

Kelvin & Planck said jointly - " A transformation whose only final result

is to transform into work heat extracted from a source that is the same

temperature throughout it impossible. " (btw, Kelvin's temp scale should be

the norm, zero should be zero (-273 C))

3rd Law (aka the Zeroeth Law) of Thermodynamics Law of Thermodynamics (in

English with little math)-

Take three bodies a, b & c. If a and b are in thermal equilibrium with a

third body c (the " thermometer " ), then they are in thermal equilibrium with

each other. (just like math: if a=b and b=c, then a=c)

This concerns reversible processes.

Sometimes arguments don't concern opinions.

Deanna

[Guest guest]

In a message dated 2/27/04 11:45:27 PM Eastern Standard Time,

nativenutrition@... writes:

> Deanna - 1. Energy is not free, the cheapest energy being rain, at least

> that is the cheapest we know of, as it is nearly perpetual.

>

> - I don't see how you differentiate " free " and " cheap, " as if we

> were using the term in an economic sense. Free energy means that it is

> available to do work. Since free energy is the opposite of entropy (--G=S),

> essentially all form of order constitutes free energy, because it contains

> the potential to cross the natural entropic gradient.

> *****

>

> It is not about proving wrong. It is about edifying, learning and

> growing more mature through the process. We teach each other. Amen.

Agreed.

>

> You say, " Free energy means it is available to do work. " Ha, no kidding?

> Well, that is all well and good. Only it cost something in the form of

> entropy. Period. What you say is like, " I have $5. " Only you fail to

> mention the 50 cents you had to pay to access it. And I am not talking

> money, only as an example, I am talking energy cost. You can't access it

> (the 50 c), thus it ain't free, no matter what the spin.

Well this isn't the definition of " free energy " that is used in chemistry,

biology, etc, etc.

>

> So to expand upon the problem of you not seeing cheap and free meaning the

> difference between entropy taking away from (in other words costing

> something in terms of energy payback in the form of work) in the former and

> free being perpetual motion in the latter. I reiterate: Money was not a

> concern or consideration here when I wrote. Understand?

I understand that before. Did you think I thought you were talking about

money? *scratches head*

Entropy prevents > perpetual motion, and I'm sorry that those of us in the

> macroscopic world don't know much of the " free energy " blah blah in chemical

> bonds.

So you are denigrating microscopic chemistry because it is not your

discipline?

Gibbs is but a passing mention, and not one of the several physics and

> thermodynamicsbooks I have mentions ANYTHING about " free energy " , which is

> no new thingbtw - Gibbs passing what 1903? (my books are dated 10-23 years

> btw).

But Gibbs is mentioned in every single textbook that has anything to do with

chemistry or biology. Look in any decent textbook like _ Biology_,

Alberts etc., _Molecular Biology of the Cell_, every single chemistry textbook.

Gibbs free energy is one of the most important concept to microchemistry and

to biological systems.

So, if you are unfamiliar with the concept because it's not in your

discipline, and you admittedly have your strengths in macroscopic thermo, then

how can

you make a statement that the concept isn't important to *microscopic* thermo?

I'm > afraid such a notion is a joke to those who sweat over major

> mathematical

> derivations of known theories and laws day in and day out. I mean, to say

> " energy is " free " once you subtract the energy which is unavailable out " is

> hilarious to those of us who study/have studied physics seriously. But

> honestly, I am not current on my studies, so perhaps diluting things like

> this is the trend du jour (like it is in many fields).

The purpose of the Gibbs free energy equation is to determine the effect of

the reaction on the entropy of the universe. If the change in free energy is

negative, the reaction occurs spontaneously. The whole point of the reaction

is that it accounts for both the change in entropy of the system and the change

in entropy of the surroundings in the same equation, rather than figuring

them separately.

I'm sorry you have such a problem with the word " free " but you are obviously

reading connotations into it that just don't exist.

> No offense intended. Believe me, I am more the abstract mathematician than

> I am some real world engineer like my husband.

> take engineering calculus, then physics. Otherwise your physics will

> be a diluted solution of sugary ideas and will not be transferable to any

> serious scientific degree, especially if you should go physical science.

> There's nothing so yumptious as physics with REAL calculus. The choices

> offered now are pathetic. Business calculus, sewing calculus, physics for

> dummies. Chemistry, otoh, all you need is algebra.

I like chemistry better, but chemistry uses calculus, not just algebra,

anyway. Even in General Chemistry a lot of calculus is used, so I imagine it

only

gets worse from there in analytic and p-chem.

Anyway, I just get the impression your blowing off the whole crux of the

subject to flaunt your vast thermo knowledge in comparison to mine. You've

completely ignored the basic concept I was trying to convey in favor of

attacking my

terminology, after which you've admitted that terminology is not used in your

discpline.

Whatever.

The point is that a portion of the energy used in fossil fuels is evolved

from the system to the surroundings and is therefore unavailable for use-- a

fairly obvious point. My conceptual understanding is that the substances have

passed down the entropic gradient (from low entropy to high entropy) and

therefore cannot re-pass down the same gradient. Since this is an increase in

the

entropy of the universe, we say that the " free energy " of the system has

decreased. That's true by mathematical definition, and that's the Gibbs free

energy

equation. If you don't like the terminology, fine. But it's what the whole

world is using who deal with microscopic chemistry and biology.

So, for me to say the free energy of the earth system decreases is for me to

say the entropy of the universe increases, which, as far as I know, is basic,

obvious point fundamental to thermodynamics. Heidi took issue with my use of

the term " free energy " because she wasn't familiar with it, and you did the

same. Your both obscuring the issue.

Again, my point is that fossil fuel use decreases the energy available for

work in the earth system, and that it must be factored into the whole equation,

which also includes the input of light energy and its harnessing by biological

systems. And my grand point is that none of us have at our disposal the

resources to calculate whether there's been a net increase, decrease, or no

significant change in the total energy available for work in the earth system.

Chris

[Guest guest]

- Since free energy is the opposite of entropy (--G=S),

Uh, no, by your own conveyance and reality, it is defined in simplest terms

as

G = H- TS. Sure, you subtract the entropy out and what remains is that

energy that is free to perform work. Duh. Then it is all free after this

calculation. So what? A footnote to statistical mechanics, which deals

with microscopic variables and quite obvious, but thankfully quantifiable by

Gibbs, Boltzmann et al.

- In thermodynamics, any chemical bond . . .

Thermodynamics deals with macroscopic variables only. Might I suggest

looking at a thermodynamics book to learn about thermo, not a chemistry

book.

Deanna

[Guest guest]

>> According to the thermodynamics I've learned, it is a false statement.

If you haven't had 3 semesters of calculus, 1 of DifEq/linAlg and 3

semesters of calculus dependent physics, then you haven't taken engineering

thermodynamics.

Deanna

[Guest guest]

*****

Deanna - 1. Energy is not free, the cheapest energy being rain, at least

that is the cheapest we know of, as it is nearly perpetual.

- I don't see how you differentiate " free " and " cheap, " as if we

were using the term in an economic sense. Free energy means that it is

available to do work. Since free energy is the opposite of entropy (--G=S),

essentially all form of order constitutes free energy, because it contains

the potential to cross the natural entropic gradient.

*****

Sorry to be replying piecemeal like this. But the flaws in understanding of

Newtonian physics keep manifesting themselves to me :-) I am also a teacher

by trade. I certainly wish no ill will or malevolence. And hey, Weston A.

Price and his foundation (WAPF) said much about teaching, didn't he/don't

they? It is not about proving wrong. It is about edifying, learning and

growing more mature through the process. We teach each other. Amen.

You say, " Free energy means it is available to do work. " Ha, no kidding?

Well, that is all well and good. Only it cost something in the form of

entropy. Period. What you say is like, " I have $5. " Only you fail to

mention the 50 cents you had to pay to access it. And I am not talking

money, only as an example, I am talking energy cost. You can't access it

(the 50 c), thus it ain't free, no matter what the spin.

So to expand upon the problem of you not seeing cheap and free meaning the

difference between entropy taking away from (in other words costing

something in terms of energy payback in the form of work) in the former and

free being perpetual motion in the latter. I reiterate: Money was not a

concern or consideration here when I wrote. Understand? Entropy prevents

perpetual motion, and I'm sorry that those of us in the macroscopic world

don't know much of the " free energy " blah blah in chemical bonds. Gibbs is

but a passing mention, and not one of the several physics and thermodynamics

books I have mentions ANYTHING about " free energy " , which is no new thing

btw - Gibbs passing what 1903? (my books are dated 10-23 years btw). I'm

afraid such a notion is a joke to those who sweat over major mathematical

derivations of known theories and laws day in and day out. I mean, to say

" energy is " free " once you subtract the energy which is unavailable out " is

hilarious to those of us who study/have studied physics seriously. But

honestly, I am not current on my studies, so perhaps diluting things like

this is the trend du jour (like it is in many fields).

No offense intended. Believe me, I am more the abstract mathematician than

I am some real world engineer like my husband.

take engineering calculus, then physics. Otherwise your physics will

be a diluted solution of sugary ideas and will not be transferable to any

serious scientific degree, especially if you should go physical science.

There's nothing so yumptious as physics with REAL calculus. The choices

offered now are pathetic. Business calculus, sewing calculus, physics for

dummies. Chemistry, otoh, all you need is algebra.

Deanna

[Guest guest]

In a message dated 2/28/04 9:41:36 AM Eastern Standard Time,

nativenutrition@... writes:

> Gibbs work concerns statistical mechanics (micro thermo). It is very

> common

> sense, but of great value. Yes, I feel " free " is a bad choice. Usable

> energy might be more accurate description.

I disagree. You keep insisting on using " free " in an economic sense (it

isn't free because it " costs " entropy) despite there being numerous other common

meanings of " free " (it is " free " to do work, meaning not inhibited). Either

way, all of chemistry and biology is using it.

> Physics requires calculus to understand or derive any of the concepts

> properly. Chemistry requires algebra for the most part, calculus was never

> a prerequisite for any chemistry I took. But I haven't had more than 1

> year. Calculus is a prerequisite for mechanics In fact, thermo, optics,

> electromagnetism, wave etc. concepts require the second semester of calculus

> (integration mainly) as a corequisite. So, to get a good grasp on this math

> dependent subject, a good working knowledge of calculus is necessary.

I agree. I'm taking non-calc physics, but we actually use calc in it.

Basically they just tell us we can remember the equations or look up them in the

book if we don't want to understand how they're derrived.

I did Fourier wave analysis when I was " homeschooling " many years ago, and

the guy who was teaching us just gave us the calculus we needed as we progressed

through it.

For > Gibbs's equation, no, but we were originally talking about thermo

> dynamics.

Not really, because I brought up thermodynamics in relation to free energy,

which you insist is not " thermodynamics " even though the whole world calls it

that. You brought up " macroscopic " thermodynamics, so calculus is really

irrelevant to the questions at hand, no?

> So please take no offense. I still say oil that is stored is not free.

Then you put yourself in diametric opposition to the whole world of chemical

and biological sciences, who universally use " free energy " to mean Gibbs free

energy. You also do it on unsolid grounds, limiting the possible meanings of

" free " to an economic sense.

> Some of it will be lost to entropy.

This is EXACTLY MY POINT! It " costs " order (the order lost in conversion to

entropy). That's exactly the same thing as saying it costs free energy! Free

energy = order. Free energy equals -- (entropy).

And this applies to getting it out of

> the ground too. So if you'd like to subtract the entropy out and call it

> free, okay fine.

You're missing the whole point! The Gibbs free energy equation has two

variables: the entropy of the system and the entropy of the surroundings. It is

a

substituted form of delta S universe = delta S system + delta S surroundings.

The only reason enthalpy exists and temperature exist in the equation is

because delta S of the surroundings has been substituted with the equation:

deta S surroundings = --delta H system/T

Thus, you can't " subtract the entropy " out, becuase the entire equation is

pure entropy variables.

Look, even though you understand thermodynamics vastly more than I do, even

though you've had way more math than I have, etc etc etc, you still obviously

do not have a basic familiarity with the meaning of the Gibbs free energy

equation or it's derivation.

It's incredibly simple and doesn't involve even any algebra-- so it doesn't

make me smart to know it. But before you criticize my application of it, you

should learn it.

Furthermore, the " cost " you keep speaking of is precisely the " loss of free

energy " I speak of, so we are in complete agreement, aside from your refusal to

use the term " free energy " in the way the chemical and biological sciences

use it.

But then I am not sure what 's meaning was in the

> first place.

It really doesn't matter, since I was disagreeing with Heidi, not .

Chris

[Guest guest]

Dear

Gibbs work concerns statistical mechanics (micro thermo). It is very common

sense, but of great value. Yes, I feel " free " is a bad choice. Usable

energy might be more accurate description.

Physics requires calculus to understand or derive any of the concepts

properly. Chemistry requires algebra for the most part, calculus was never

a prerequisite for any chemistry I took. But I haven't had more than 1

year. Calculus is a prerequisite for mechanics In fact, thermo, optics,

electromagnetism, wave etc. concepts require the second semester of calculus

(integration mainly) as a corequisite. So, to get a good grasp on this math

dependent subject, a good working knowledge of calculus is necessary. For

Gibbs's equation, no, but we were originally talking about thermo dynamics.

You know, I took some course at Purdue a couple of years ago and I was

surprised at all the calculus courses offered now. It was not like that

when I took them long ago. Most of these courses are fluff and do not

represent core courses for engineers, or med students, or anyone else for

that matter. So that is why I differentiate them.

So please take no offense. I still say oil that is stored is not free.

Some of it will be lost to entropy. And this applies to getting it out of

the ground too. So if you'd like to subtract the entropy out and call it

free, okay fine. But then I am not sure what 's meaning was in the

first place.

I am the one who began this thread from the Pentagon report thread that

preceded it. I was interested in the Olduvai Theory:

http://greatchange.org/ov-duncan,road_to_olduvai_gorge.html

But I will gladly pass the talking stick on now.

Adieu,

Deanna