Boltzmann's constant is evil!
Andrew Usher
simple
as possible, without extraneous 'magic numbers'. This is a
justification
given for choosing the maetic system over English units (when a
rational
justification is used at all for that). And yet, Boltzmann's constant
is
clearly such a 'magic number'.
For example, I write the Boltzmann function
f(E) = exp(-E/T)
where the standard way would be
f(E) = exp(-E/kT)
and the k serving as a meaningless constant or conversion factor.
More than that, it affects the notion of entropy, which is really
fundamental. More than physics, actually - entropy is a mathematical
concept at root, and therefore is always dimensionless. And yet,
idiot
thermodynamics force us to write 'J/mol-K'; as if those units matter
one
bit. Presenting a dimensionless number as otherwise is positively
misleading.
Heat capacity is also unitless, at least if measured on a molecular
basis, which is preferable at least for gases. I have given the
criterion
for convective stability
d log T / d log P = - 1/Cp
and this works only if Cp is dimensionless. Not only is this the
simplest
possible form but it expresses without words why it is correct, if
one
only looks at it.
Avogadro's number is similar, and I believe things should never be
measured on a molar basis when they can reasonably be done on a
molecular
basis. The heats on chemical reactions, for example, can be given in
molecular units just as sensibly as in molar units. Indeed, electron
volts are already used for related purposes often by astrophysicists,
and
the band gap of solids is normally given in ev, and that is a
sort of chemical reaction. That unit also has a particular advantage
that
it is also used for the energy of photons, and therefore one can
correlate the two without the need of any conversion factor.
Andrew Usher
Salmon Egg
<2453af29-1cbf-4648...@v39g2000pro.googlegroups.com>,
Andrew Usher <k_over...@yahoo.com> wrote:
> In science, I have always thought, equations benefit by being as
> simple
> as possible, without extraneous 'magic numbers'. This is a
> justification
> given for choosing the maetic system over English units (when a
> rational
> justification is used at all for that). And yet, Boltzmann's constant
> is
> clearly such a 'magic number'.
>
> For example, I write the Boltzmann function
>
> f(E) = exp(-E/T)
>
> where the standard way would be
>
> f(E) = exp(-E/kT)
>
<snip> I just cannot read allof this and stay awake.
The concept of setting fundamental constants equal to one is an old
practice among theoretical physicists. Typically the speed of light, c,
and electron charge, among others, is set to one.
Bill
Andrew Usher
> The concept of setting fundamental constants equal to one is an old
> practice among theoretical physicists. Typically the speed of light, c,
> and electron charge, among others, is set to one.
No, Boltzmann's constant is not a 'fundamental constant', it is
a conversion factor. For comparison, the speed of light has units
(length/time) that can't be defined away, though it can be set = 1.
Andrew Usher
dlzc
C / Co = e( -tau / t )
Evil set to one.
David A. Smith
Salmon Egg
<77cfdcfd-2e5b-4bb9...@n33g2000pri.googlegroups.com>,
Andrew Usher <k_over...@yahoo.com> wrote:
> No, Boltzmann's constant is not a 'fundamental constant', it is
> a conversion factor. For comparison, the speed of light has units
> (length/time) that can't be defined away, though it can be set = 1.
So the Boltzman constant has dimensions of energy/temperature. Big deal!
Bill
Lloyd
Yeah, because if I have 100 mL of water and I want to know how much
heat it absorbs, or how much Na it will react with, figuring it out
per individual atom is so much more convenient! Not!
Why not price everything in pennies instead of dollars? Why not use
the wt of an atom as the standard and report your weight as xxx many
of those? Why not use the diameter of an atom as the standard for
length?
Andrew Usher
> In article
> <77cfdcfd-2e5b-4bb9-ac24-2438403ea...@n33g2000pri.googlegroups.com>,
> Andrew Usher <k_over_hb...@yahoo.com> wrote:
>
> > No, Boltzmann's constant is not a 'fundamental constant', it is
> > a conversion factor. For comparison, the speed of light has units
> > (length/time) that can't be defined away, though it can be set = 1.
>
> So the Boltzman constant has dimensions of energy/temperature. Big deal!
Wrong, 'temperature' is not a physical quantity. The Boltzmann
constant
is dimensionless.
Andrew Usher
Andrew Usher
> > Avogadro's number is similar, and I believe things should never be
> > measured on a molar basis when they can reasonably be done on a
> > molecular basis.
>
> Yeah, because if I have 100 mL of water and I want to know how much
> heat it absorbs, or how much Na it will react with, figuring it out
> per individual atom is so much more convenient! Not!
For the first, it actually would be no harder to convert from
molecular
than molar quantities, though I wouldn't insist on it. Your second
example is irrelevant, as is requires only ratios.
I maintain that an equation written like
2 H2 + O2 -> 2 H2O + 584 kJ/mol
is actually incorrect, while
2 H2 + O2 -> 2 H2O + 6.05 ev
is perfectly clear.
Andrew Usher
Sam Wormley
> In science, I have always thought, equations benefit by being as
> simple as possible, without extraneous 'magic numbers'.
See: http://en.wikipedia.org/wiki/Boltzmann_constant
http://scienceworld.wolfram.com/physics/BoltzmannEquation.html
http://scienceworld.wolfram.com/physics/Stefan-BoltzmannLaw.html
http://scienceworld.wolfram.com/physics/Maxwell-BoltzmannDistribution.html
Sam Wormley
> The Boltzmann constant is dimensionless.
>
> Andrew Usher
http://scienceworld.wolfram.com/physics/BoltzmannsConstant.html
Andrew Usher
What the hell kind of reply is that? All those equations are indeed
simpler
without using Boltzmann's constant, and theoretically more elegant.
Andrew Usher
Andrew Usher
Since energy and temperature have the same units, that is
dimensionless.
If you don't believe me, try to calculate temperature in terms
of M, L, and T.
Andrew Usher
Fred Kasner
You apparently never bothered to stay awake during the single college
chemistry course you took. The equation 2H2 + O2 -> 2H2O + delta H is
well understood to be a NOT a molecular equation but a molar equation
wherein the statements are: 2 moles of H2 react with one mole of O2 to
produce 2 moles of water plus some specific amount of heate stated in
kilojoules (or as it used to be in kilocalories). As you wrote it it is
ambiguous as you can't tell whether the number of moles refers to the H2
or the H2O or refers to the O2. You are either stupid, or careless, or
ill educated.
FK
Andrew Usher
> > I maintain that an equation written like
>
> > 2 H2 + O2 -> 2 H2O + 584 kJ/mol
>
> > is actually incorrect, while
>
> > 2 H2 + O2 -> 2 H2O + 6.05 ev
>
> > is perfectly clear.
>
> You apparently never bothered to stay awake during the single college
> chemistry course you took. The equation 2H2 + O2 -> 2H2O + delta H is
> well understood to be a NOT a molecular equation but a molar equation
That's ridiculous semantics. Moles are only meaningful BECAUSE
they correspond to a certain number (an arbitrary magic number) of
atoms or molecules.
> wherein the statements are: 2 moles of H2 react with one mole of O2 to
> produce 2 moles of water plus some specific amount of heate stated in
> kilojoules (or as it used to be in kilocalories).
Molecules are reacting. Moles are not a physically meaningful
concept.
> As you wrote it it is
> ambiguous as you can't tell whether the number of moles refers to the H2
> or the H2O or refers to the O2. You are either stupid, or careless, or
> ill educated.
So you agree with me, then call me stupid etc. ? Wow.
Andrew Usher
Landy
"Andrew Usher" <k_over...@yahoo.com> wrote in message
news:e91c4504-a1cc-44e8...@x41g2000hsb.googlegroups.com...
> On Jul 25, 2:45 pm, Sam Wormley <sworml...@mchsi.com> wrote:
>> Andrew Usher wrote:
>> > The Boltzmann constant is dimensionless.
>>
>> > Andrew Usher
>>
>> http://scienceworld.wolfram.com/physics/BoltzmannsConstant.html
>
> Since energy and temperature have the same units, that is
> dimensionless.
No they don't. Energy is Joules and temperature is degrees (or Kelvins).
Andrew Usher
> "Andrew Usher" <k_over_hb...@yahoo.com> wrote in message
You snipped the important part of the post.
Here it is: If you don't believe me, try to calculate temperature in
Sam Wormley
Bzzzzt.... Try Again
http://physics.nist.gov/cuu/Units/units.html
Base quantity Name Symbol
------------------------------------------------
length meter m
mass kilogram kg
time second s
electric current ampere A
thermodynamic temperature kelvin K
amount of substance mole mol
luminous intensity candela cd
Sam Wormley
Andrews, you are a bit short on education. Boltzmann's constant has
physical units... And there are more base units than LMT, including
thermodynamic temperature.
Salmon Egg
<dcb31336-6dbf-4250...@34g2000hsh.googlegroups.com>,
Andrew Usher <k_over...@yahoo.com> wrote:
> Wrong, 'temperature' is not a physical quantity. The Boltzmann
> constant
> is dimensionless.
As they say: Do not try to make a silk purse out of a sow's ear. I am
done trying.
Bill
Andrew Usher
> Andrews, you are a bit short on education. Boltzmann's constant has
> physical units... And there are more base units than LMT, including
> thermodynamic temperature.
I know all this. The physical dimension of Boltzmann's constant is 1,
since both energy and temperature are ML^2/T^2.
> http://physics.nist.gov/cuu/Units/units.html
>
> Base quantity Name Symbol
> ------------------------------------------------
> length meter m
> mass kilogram kg
> time second s
> electric current ampere A
> thermodynamic temperature kelvin K
> amount of substance mole mol
> luminous intensity candela cd
While the first four are derived from the physical quantities
M, L, T, and Q, the last three do not correspond to anything
physically real.
The candela, especially, is defined using the CIE
luminosity function for the eye. Even if it were a perfect
description of the human eye's sensitivity, it obviously would
not be a fundamental quantity.
Andrew Usher
Andrew Usher
> Andrew Usher <k_over_hb...@yahoo.com> wrote:
>
> > Wrong, 'temperature' is not a physical quantity. The Boltzmann
> > constant is dimensionless.
>
> As they say: Do not try to make a silk purse out of a sow's ear. I am
> done trying.
In other words, you're wrong.
http://en.wikipedia.org/wiki/Boltzmann_constant#Value_in_different_units
Andrew Usher
Salmon Egg
"Landy" <no...@nowhere.net> wrote:
> > Since energy and temperature have the same units, that is
> > dimensionless.
>
> No they don't. Energy is Joules and temperature is degrees (or Kelvins).
>
This is for Landy. Usher is hopeless.
When heat was first being investigated, it was not well understood.
Certainly, the concept of temperature being related to the average
energy per degree of freedom of a molecule was to come much later. With
the invention of thermometers, temperature could be be measure and
became another fundamental entity such as length or time.
Bill
Andrew Usher
> In article <g6e2tc$ci...@news-01.bur.connect.com.au>,
How temperature is _measured_ is entirely irrelevant to what
temperature _is_.
Andrew Usher
hanson
>
Sam Wormley <sworml...@mchsi.com> wrote:
Andrews, you are a bit short on education. Boltzmann's constant has
physical units... And there are more base units than LMT, including
thermodynamic temperature.
>
I know all this. The physical dimension of Boltzmann's constant is 1,
since both energy and temperature are ML^2/T^2.
>
http://physics.nist.gov/cuu/Units/units.html
>>
Base quantity Name Symbol
------------------------------------------------
length meter m
mass kilogram kg
time second s
electric current ampere A
amount of substance mole mol
luminous intensity candela cd
>
While the first four are derived from the physical quantities
M, L, T, and Q, the last three do not correspond to anything
physically real.
>
The candela, especially, is defined using the CIE
luminosity function for the eye. Even if it were a perfect
description of the human eye's sensitivity, it obviously would
not be a fundamental quantity.
>
Guys, ALL physical constants can be expressed in
terms of M, L, T... even Q, A, K & cd... which must be
convertible into each other. ---- It has to be that way
else your entire house of physics will collapse like
a house of cards. -- Even the mole is not exempt. The
mole is simply a scale factor that tells you how many
units of something is in the same bag (Avogadros #).
The particular units in SI, MKS or cgs were chosen
by arbitrary choice, heuristic custom and convention.
Think about it: All we can do in physics is to COMPARE
things/processes/events to arbitrarily chosen standards.
There is nothing absolutely "fundamental"... ahahaha...
>
We went over that many times in the past few years...
....ahahahanson
Sam Wormley
> On Jul 25, 9:42 pm, Sam Wormley <sworml...@mchsi.com> wrote:
>
>> Andrews, you are a bit short on education. Boltzmann's constant has
>> physical units... And there are more base units than LMT, including
>> thermodynamic temperature.
>
> I know all this. The physical dimension of Boltzmann's constant is 1,
> since both energy and temperature are ML^2/T^2.
>
>> http://physics.nist.gov/cuu/Units/units.html
>>
>> Base quantity Name Symbol
>> ------------------------------------------------
>> length meter m
>> mass kilogram kg
>> time second s
>> electric current ampere A
>> thermodynamic temperature kelvin K
>> amount of substance mole mol
>> luminous intensity candela cd
>
> While the first four are derived from the physical quantities
> M, L, T, and Q, the last three do not correspond to anything
> physically real.
<laughing>
Androcles
"hanson" <han...@quick.net> wrote in message
news:O8yik.69$JH5.26@trnddc06...
as to think otherwise and so I scrolled up... and there was Wormey...
Mass/matter, the stuff protons and neutrons are made of... whatever it
is it needs a name. Mass, length and time are measurement... yet at the
fundamental level the neutron is eternal in time and finite in length.
Consider force as fundamental. Mass = F/a
Science is dragging its arse for want of language. The human psyche
is such that if you don't give names to things they do not get thought
about. A simple example of this is the ghost frame Einstein got confused
over.
A mathematical function is a mapping from domain to image (or codomain)
with some rule applied, so if we take the domain as all x in R with the
mapping rule x' = x-vt we have a function with codomain R.
We write
f: x |->x-vt and f(x) = x-vt
If we then have a second function g such that
g: x |-> x/sqrt(1-v^2/c^2) and g(x) = x/sqrt(1-v^2/c^2).
The composition of functions is this:
DOMAIN->function->CODOMAIN->function->IMAGE
x x-vt
(x-vt)/sqrt(1-v^2/c^2)
Now we give names to the generic term "domain" and look at what Einstein
says:
"If we place x'=x-vt, it is clear that a point at rest in the system k must
have a system of values x', y, z, independent of time."
DOMAIN CODOMAIN IMAGE
"stationary" frame ghost frame "moving" frame
system K "system of values" system k
The unnamed "system of values" is the ghost frame.
To get from the ghost frame to the moving frame we need a velocity
but we've already used it. How fast does the "moving" frame move
RELATIVELY to the ghost frame?
Einstein was never a mathematician and the reason his blunders
we not easily spotted is the failure to name the ghost frame.
Are scientists really this DUMB?
Two squaddies are eating a meal.
One says "This shit is awful, who called the cook a cunt and upset him? "
The other replies "Who called the cunt a cook?"
zzbu...@netscape.net
> In science, I have always thought, equations benefit by being as
> simple
> as possible, without extraneous 'magic numbers'.
Yes. Scientists ae that dumb.
Since many believe the generalization: "Given, some engineers built
Great Pyramids,
it natually follows that all engineers build great Pyramids".
That's the logical
fallacy of Faulty Towers.
Since the idiots have told since at least 1940 now, that the
difficulty with Boltzmann's
isn't units of anything. Since Boltzmann's constant is an IDEAL GAS
constant.
So use digital, A.I. and lasers, and the entire idiot "problem"
vaporizes.
Since it's not an problem. It's an idiot Avorado's number of
imaginary molecules
doing absolutely NOTHING.
This is a
> justification
> given for choosing the maetic system over English units (when a
> rational
> justification is used at all for that). And yet, Boltzmann's constant
> is
> clearly such a 'magic number'.
>
> For example, I write the Boltzmann function
>
> f(E) = exp(-E/T)
>
> where the standard way would be
>
> f(E) = exp(-E/kT)
>
> and the k serving as a meaningless constant or conversion factor.
>
> More than that, it affects the notion of entropy, which is really
> fundamental. More than physics, actually - entropy is a mathematical
> concept at root, and therefore is always dimensionless. And yet,
> idiot
> thermodynamics force us to write 'J/mol-K'; as if those units matter
> one
> bit. Presenting a dimensionless number as otherwise is positively
> misleading.
Well, since the Joule's don't matter to anything. That's why people
write it with DVD's and fiber optics anymore rather than pencils
for the idiots in science.
>
> Heat capacity is also unitless, at least if measured on a molecular
> basis, which is preferable at least for gases. I have given the
> criterion
> for convective stability
>
> d log T / d log P = - 1/Cp
>
> and this works only if Cp is dimensionless. Not only is this the
> simplest
> possible form but it expresses without words why it is correct, if
> one
> only looks at it.
>
> Avogadro's number is similar, and I believe things should never be
> measured on a molar basis when they can reasonably be done on a
> molecular
> basis. The heats on chemical reactions, for example, can be given in
Dirk Bruere at NeoPax
So how do you define charge in terms of MLT?
--
Dirk
http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.onetribe.me.uk/wordpress/?cat=5 - Our podcasts on weird stuff
hanson
news:6f0qtlF...@mid.individual.net...
>
hanson wrote:
http://groups.google.com/group/sci.physics/msg/a99b13a584dc5c5f?hl=en
>
ALL physical constants can be expressed in
terms of M, L, T... even Q, A, K & cd... which must be
convertible into each other. ---- It has to be that way
a house of cards. -- Even the mole is not exempt. The
mole is simply a scale factor that tells you how many
units of something is in the same bag (Avogadros #).
The particular units in SI, MKS or cgs were chosen
by arbitrary choice, heuristic custom and convention.
Think about it: All we can do in physics is to COMPARE
things/processes/events to arbitrarily chosen standards.
There is nothing absolutely "fundamental"... ahahaha...
>
We went over that many times in the past few years...
....ahahahanson
>
So how do you define charge in terms of MLT?
>
Charge squared = M * L^3 / T^2
Charge is M^(1/2) * L^(3/2) / T --- See here:
http://groups.google.com/group/sci.physics/msg/582ad81589e05346?hl=en
... or, one of the ways of doing it, in the cgs system, is
to take the relation of the square of the charge which is
e^2 = h*a*c/(2pi)
h = action = energy * time. -- a & pi are dimensionless.
h*c = M*L^2/T^2 * T * L/T = M*L^3/T^2 = also e^2
So, the charge e = sqrt(e^2) = M^(1/2)*L^(3/2)/T = gr^(1/2)cm^(3/2)/s,
For the quantitative amount look up the experimental
values of h, a, c and pi.
hanson
>
PS:
Dirk, as long as I have you on line check my post on
the issues of MeSal/Aspirin you were asking about:
http://groups.google.com/group/sci.environment/msg/eccb4521b62d0f3e?hl=en
hanson
to the Einstein Dingleberries in s.p.relativity to see them
go "aga-ooga" over it.... ahahahaha.... ahahahahanson
>
"Androcles" <Headm...@Hogwarts.physics> wrote in message
news:SBBik.15945$Gb2....@newsfe29.ams2...
>
Sam Wormley <sworml...@mchsi.com> wrote:
[snip] news:O8yik.69$JH5.26@trnddc06... or see here:
http://groups.google.com/group/sci.physics/msg/a99b13a584dc5c5f?hl=en
hanson wrote:
Guys, ALL physical constants can be expressed in
terms of M, L, T... even Q, A, K & cd... which must be
convertible into each other. ---- It has to be that way
else your entire house of physics will collapse like
a house of cards. -- Even the mole is not exempt. The
mole is simply a scale factor that tells you how many
units of something is in the same bag (Avogadros #).
The particular units in SI, MKS or cgs were chosen
by arbitrary choice, heuristic custom and convention.
Think about it: All we can do in physics is to COMPARE
things/processes/events to arbitrarily chosen standards.
There is nothing absolutely "fundamental"... ahahaha...
>
We went over that many times in the past few years...
....ahahahanson
>
>
>
hanson wrote:
ahahahaha... This is a good one that must be presented
to the Einstein Dingleberries in s.p.relativity to see them
go "aga-ooga" over it.... ahahahaha.... ahahahahanson
Dirk Bruere at NeoPax
Thanks - I saw it when you first posted it.
On of the reasons I was asking about MeSal was that I occasionally still
get the eye irritation of rosacea. I actually got it years before the
condition showed in the skin. What I do now is just rub a few mg of
MeSal on the bridge of my nose and it clears it rapidly.
Right now I'm more interested in the effects of grapefruit juice on
various drugs.
Lloyd
If Boltzmann's constant has no units, then entropy has no units:
S = k ln(omega)
Lloyd
Oh yeah, because we measure ev in the lab doing calorimetry so easily!
Lloyd
Especially if we write H2 + 1/2 O2 --> H2O (not good form, but
perfectly reasonable on a molar level; not so on a molecular level).
Andrew Usher
> If Boltzmann's constant has no units, then entropy has no units:
>
> S = k ln(omega)
That's correct.
S = log W
is the only correct form. Remember, entropy is a mathematical
concept, and thus must be unitless.
Andrew Usher
Andrew Usher
> Oh yeah, because we measure ev in the lab doing calorimetry so easily!
You're really, incorrigibly, stupid, aren't you? It's no harder to
convert your results into ev than into any other unit!
Andrew Usher
Andrew Usher
> Charge squared = M * L^3 / T^2
> Charge is M^(1/2) * L^(3/2) / T --- See here:http://groups.google.com/group/sci.physics/msg/582ad81589e05346?hl=en
> ... or, one of the ways of doing it, in the cgs system, is
> to take the relation of the square of the charge which is
> e^2 = h*a*c/(2pi)
> h = action = energy * time. -- a & pi are dimensionless.
> h*c = M*L^2/T^2 * T * L/T = M*L^3/T^2 = also e^2
> So, the charge e = sqrt(e^2) = M^(1/2)*L^(3/2)/T = gr^(1/2)cm^(3/2)/s,
> For the quantitative amount look up the experimental
> values of h, a, c and pi.
That's one way of doing it. I prefer not to define Q because
it's clearly a different thing than any of the mechanical
units.
Also, the coupling
constant of the electromagnetic force is not, properly, the
square of anything, while the Gaussian system tells us to
write
alpha = e^2 / hbar c
Andrew Usher
Richard Schultz
: Since energy and temperature have the same units
This news will come as a big surprise to the people at the Bureau International
des Poids et Mesures (http://www.bipm.org), who are in charge of the
definitions of the units of the SI, and who seem to think that temperature
is expressed in units of "Kelvin" (a base unit in the SI), while energy is
expressed in units of "Joules" (a derived unit equal to 1 kg m^2/s^2).
This news will also come to a big surprise to anyone who has studied
thermodynamics and/or statistical mechanics.
-----
Richard Schultz sch...@mail.biu.ac.il
Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel
Opinions expressed are mine alone, and not those of Bar-Ilan University
-----
"You don't even have a clue about which clue you're missing."
Andrew Usher
> In sci.chem Andrew Usher <k_over_hb...@yahoo.com> wrote:
>
> : Since energy and temperature have the same units
>
> This news will come as a big surprise to the people at the Bureau International
> des Poids et Mesures (http://www.bipm.org), who are in charge of the
> definitions of the units of the SI, and who seem to think that temperature
> is expressed in units of "Kelvin" (a base unit in the SI), while energy is
> expressed in units of "Joules" (a derived unit equal to 1 kg m^2/s^2).
Really, so if the SI standards are the final arbiter of what's
fundamental ...
a) what is the physical significance of the candela?
b) is current more fundamental than charge?
(The answers are obviously none and no.)
> This news will also come to a big surprise to anyone who has studied
> thermodynamics and/or statistical mechanics.
Not to anyone who understood them.
http://en.wikipedia.org/wiki/Boltzmann_constant#Value_in_different_units
Andrew Usher
Richard Schultz
: Really, so if the SI standards are the final arbiter of what's
: fundamental ...
:
: a) what is the physical significance of the candela?
AFAIK, it cannot be derived from the other six fundamental units.
: b) is current more fundamental than charge?
:
: (The answers are obviously none and no.)
In any system of units, one can define either a unit of current or a unit
of charge, in which case the other can be derived from the defined unit.
The Kelvin is a "fundamental" unit because it cannot be derived from the
other six fundamental units. The Joule is *not* a fundamental unit because,
once given the meter, kilogram, and second, it *can* be derived.
:> This news will also come to a big surprise to anyone who has studied
:> thermodynamics and/or statistical mechanics.
:
: Not to anyone who understood them.
Anyone who understands statistical mechanics knows that it is possible to
determine the energy of a single particle, but that it is meaningless to
even speak of the "temperature" of a single particle, temperature by
definition being a property of an ensemble of particles.
Andrew Usher
> In sci.chem Andrew Usher <k_over_hb...@yahoo.com> wrote:
>
> : Really, so if the SI standards are the final arbiter of what's
> : fundamental ...
> :
> : a) what is the physical significance of the candela?
>
> AFAIK, it cannot be derived from the other six fundamental units.
Avoiding the question.
> : b) is current more fundamental than charge?
> :
> : (The answers are obviously none and no.)
>
> In any system of units, one can define either a unit of current or a unit
> of charge, in which case the other can be derived from the defined unit.
Avoiding the question.
> The Kelvin is a "fundamental" unit because it cannot be derived from the
> other six fundamental units.
Wrong. It is equal to 1.380650e-23 J. Ir has to be.
ENTROPY IS MATHEMATICALLY DEFINED TO BE A PURE NUMBER.
Since mathematics is prior to physics or chemistry, arguing with this
is stupid, ignorant, or insane.
> :> This news will also come to a big surprise to anyone who has studied
> :> thermodynamics and/or statistical mechanics.
> :
> : Not to anyone who understood them.
>
> Anyone who understands statistical mechanics knows that it is possible to
> determine the energy of a single particle, but that it is meaningless to
> even speak of the "temperature" of a single particle, temperature by
> definition being a property of an ensemble of particles.
I don't speak of the 'temperature' of a signle particle. But the
temperature
in a system _is_ related to average energies per particle.
Andrew Usher
Dwib
> I don't speak of the 'temperature' of a single particle. But the
> temperature in a system _is_ related to average energies per particle.
Well, finally you've said something that makes some sense.
But don't you think you're arguing about... nothing! People were
referring to the "temperature" of things LONG before they referred to
the "average energy of a system".
Boltzmann's constant IS NOT evil.
Boltzmann's constant IS convenient.
Dwib
Lloyd
> On Jul 27, 3:23 am, schu...@mail.biu.ack.il (Richard Schultz) wrote:
>
> > In sci.chem Andrew Usher <k_over_hb...@yahoo.com> wrote:
>
> > : Really, so if the SI standards are the final arbiter of what's
> > : fundamental ...
> > :
> > : a) what is the physical significance of the candela?
>
> > AFAIK, it cannot be derived from the other six fundamental units.
>
> Avoiding the question.
>
> > : b) is current more fundamental than charge?
> > :
> > : (The answers are obviously none and no.)
>
> > In any system of units, one can define either a unit of current or a unit
> > of charge, in which case the other can be derived from the defined unit.
>
> Avoiding the question.
>
> > The Kelvin is a "fundamental" unit because it cannot be derived from the
> > other six fundamental units.
>
> Wrong. It is equal to 1.380650e-23 J. Ir has to be.
>
> ENTROPY IS MATHEMATICALLY DEFINED TO BE A PURE NUMBER.
> Since mathematics is prior to physics or chemistry, arguing with this
> is stupid, ignorant, or insane.
>
So how do you add delta-H and T-delta-S to get delta-G? You can't add
numbers that don't have the same units.
> > :> This news will also come to a big surprise to anyone who has studied
> > :> thermodynamics and/or statistical mechanics.
> > :
> > : Not to anyone who understood them.
>
> > Anyone who understands statistical mechanics knows that it is possible to
> > determine the energy of a single particle, but that it is meaningless to
> > even speak of the "temperature" of a single particle, temperature by
> > definition being a property of an ensemble of particles.
>
> I don't speak of the 'temperature' of a signle particle. But the
> temperature
> in a system _is_ related to average energies per particle.
>
> Andrew Usher
So does work have units? delta-E = q + w, and you've said q has no
units.
Fred Kasner
> On Jul 25, 6:55 pm, Fred Kasner <fkas...@sbcglobal.net> wrote:
>
>>> I maintain that an equation written like
>>> 2 H2 + O2 -> 2 H2O + 584 kJ/mol
>>> is actually incorrect, while
>>> 2 H2 + O2 -> 2 H2O + 6.05 ev
>>> is perfectly clear.
>> chemistry course you took. The equation 2H2 + O2 -> 2H2O + delta H is
>> well understood to be a NOT a molecular equation but a molar equation
>
> they correspond to a certain number (an arbitrary magic number) of
> atoms or molecules.
>
>> wherein the statements are: 2 moles of H2 react with one mole of O2 to
>> produce 2 moles of water plus some specific amount of heate stated in
>> kilojoules (or as it used to be in kilocalories).
>
> concept.
>
>> As you wrote it it is
>> ambiguous as you can't tell whether the number of moles refers to the H2
>> or the H2O or refers to the O2. You are either stupid, or careless, or
>> ill educated.
>
>
> Andrew Usher
Obfuscation on your part and refusal to admit the use of practical
quantities does not an argument make. A mole is a counting artifice
similar to a dozen or a hundred or some other bunch invented for
convenience. You inability to accept such means that you are blinded by
artifices of equally arbitrary nature that you learned from physicists
who really wanted to be mathematicians. Even the molecule suffers from
arbitrariness. The wave function for a particle in a "molecule" is
infinite in extent but is too ephemeral to deal with as such and so the
approach of the chemist to deal with it as if it were a
nonelectromagnetic field but rather some fuzzy particle with reasonable
boundaries and em properties only when you are very close to it. It is
you who engage in ridiculous semantics. Since names and properties for
real things make them useful as opposed to pure numbers which are good
only for counting items.
It appears to all others that I do not agree with you at all. Your last
equation is perfectly acceptable as way to deal with chemical
reactivity. However if you want to deal with amounts of things that are
to few to even be visible then you have to deal with dozens, or gross,
or moles.
FK
Andrew Usher
> > ENTROPY IS MATHEMATICALLY DEFINED TO BE A PURE NUMBER.
> > Since mathematics is prior to physics or chemistry, arguing with this
> > is stupid, ignorant, or insane.
>
> So how do you add delta-H and T-delta-S to get delta-G? You can't add
> numbers that don't have the same units.
No, they all have units of energy.
> > > :> This news will also come to a big surprise to anyone who has studied
> > > :> thermodynamics and/or statistical mechanics.
> > > :
> > > : Not to anyone who understood them.
>
> > > Anyone who understands statistical mechanics knows that it is possible to
> > > determine the energy of a single particle, but that it is meaningless to
> > > even speak of the "temperature" of a single particle, temperature by
> > > definition being a property of an ensemble of particles.
>
> > I don't speak of the 'temperature' of a signle particle. But the
> > temperature
> > in a system _is_ related to average energies per particle.
>
> So does work have units? delta-E = q + w, and you've said q has no
> units.
Again, all have units of energy. Perhaps you're confusing energy
and entropy?
Andrew Usher
Andrew Usher
> Obfuscation on your part and refusal to admit the use of practical
> quantities does not an argument make. A mole is a counting artifice
> similar to a dozen or a hundred or some other bunch invented for
> convenience.
I agree.
> You inability to accept such means that you are blinded by
> artifices of equally arbitrary nature that you learned from physicists
> who really wanted to be mathematicians.
I accept them as long as the people that use them acknowledge
them for what they are, which is to say they're not mystical
'base units', nor are they theorerically important.
> Even the molecule suffers from
> arbitrariness. The wave function for a particle in a "molecule" is
> infinite in extent but is too ephemeral to deal with as such and so the
> approach of the chemist to deal with it as if it were a
> nonelectromagnetic field but rather some fuzzy particle with reasonable
> boundaries and em properties only when you are very close to it.
Well, this is technically true, but it makes the world a lot easier to
deal with when you think of atoms and molecules as definite
particles!
> Since names and properties for
> real things make them useful as opposed to pure numbers which are good
> only for counting items.
So dimensionless numbers aren't useful? That's strange ...
> It appears to all others that I do not agree with you at all. Your last
> equation is perfectly acceptable as way to deal with chemical
> reactivity. However if you want to deal with amounts of things that are
> to few to even be visible then you have to deal with dozens, or gross,
> or moles.
I fully endorse this: the use of moles is convenient for practical
calculations but ought not to be used for theoretical equations.
Andrew Usher
Lloyd
>
> > In sci.chem Andrew Usher <k_over_hb...@yahoo.com> wrote:
>
> > : Really, so if the SI standards are the final arbiter of what's
> > : fundamental ...
> > :
> > : a) what is the physical significance of the candela?
>
> > AFAIK, it cannot be derived from the other six fundamental units.
>
> Avoiding the question.
>
> > : b) is current more fundamental than charge?
> > :
> > : (The answers are obviously none and no.)
>
> > In any system of units, one can define either a unit of current or a unit
> > of charge, in which case the other can be derived from the defined unit.
>
> Avoiding the question.
>
> > The Kelvin is a "fundamental" unit because it cannot be derived from the
> > other six fundamental units.
>
> Wrong. It is equal to 1.380650e-23 J. Ir has to be.
>
Uh, according to the CGPM, a K is: The kelvin, unit of thermodynamic
temperature, is the fraction 1/273.16 of the thermodynamic temperature
of the triple point of water.
Nothing about joules.
And I think the CGPM has a little more authority than you.
> ENTROPY IS MATHEMATICALLY DEFINED TO BE A PURE NUMBER.
Can't be. 10 g of O2 has a more entropy than 5 g. You've got to have
some numerical scale for reference so the units are the same,
otherwise you can make up any number.
See http://physics.nist.gov/cuu/Units/units.html -- the NIST doesn't
agree with you.
Andrew Usher
> > > The Kelvin is a "fundamental" unit because it cannot be derived from the
> > > other six fundamental units.
>
> > Wrong. It is equal to 1.380650e-23 J. Ir has to be.
>
> Uh, according to the CGPM, a K is: The kelvin, unit of thermodynamic
> temperature, is the fraction 1/273.16 of the thermodynamic temperature
> of the triple point of water.
That's exactly the same thing.
> And I think the CGPM has a little more authority than you.
No one has authority over the laws of nature.
> > ENTROPY IS MATHEMATICALLY DEFINED TO BE A PURE NUMBER.
>
> Can't be. 10 g of O2 has a more entropy than 5 g.
Of course it has twice as much. That doesn't say anything
about the units of entropy.
S = -sum(p log p) . No units in there.
> > Since mathematics is prior to physics or chemistry, arguing with this
> > is stupid, ignorant, or insane.
>
Andrew Usher
Richard Schultz
:> > > The Kelvin is a "fundamental" unit because it cannot be derived from the
:> > > other six fundamental units.
:> > Wrong. It is equal to 1.380650e-23 J. Ir has to be.
:> Uh, according to the CGPM, a K is: The kelvin, unit of thermodynamic
:> temperature, is the fraction 1/273.16 of the thermodynamic temperature
:> of the triple point of water.
: That's exactly the same thing.
I've never quite understood why some people get so much enjoyment out
of publically displaying their ignorance.
Andrew Usher
> In sci.chem Andrew Usher <k_over_hb...@yahoo.com> wrote:
>
> :> > > The Kelvin is a "fundamental" unit because it cannot be derived from the
> :> > > other six fundamental units.
>
> :> > Wrong. It is equal to 1.380650e-23 J. Ir has to be.
>
> :> Uh, according to the CGPM, a K is: The kelvin, unit of thermodynamic
> :> temperature, is the fraction 1/273.16 of the thermodynamic temperature
> :> of the triple point of water.
>
> : That's exactly the same thing.
>
> I've never quite understood why some people get so much enjoyment out
> of publically displaying their ignorance.
You should be calling Lloyd 'ignorant', not me. I'm sorry that you
refuse to accept statistical mechanics, but it doesn't change
the facts.
Fundamental equations should be written without spurious
constants. Yes, they can be, but teaching thermodynamics
using Boltzmann's constant is like teaching mechanics
using pounds-mass and pounds-force and therefore writing
F = ma/g
as the 'fundamental' equation of force.
Andrew Usher
PD
> In science, I have always thought, equations benefit by being as
> simple
> justification
> given for choosing the maetic system over English units (when a
> rational
> justification is used at all for that). And yet, Boltzmann's constant
> is
> clearly such a 'magic number'.
Actually, the metric system has a substantial amount of unnecessary
baggage as well. For example, there is no earthly reason why the speed
of light should be anything other than 1 and unitless. And indeed,
there are a number of variations of "natural units" which make as many
constants as possible disappear from laws of physics. A simple
Wikipedia search will illuminate.
However, you will note that it is not possible to come up with a
system of units where *all* of the constants relevant in natural laws
will disappear. It is certainly possible to choose one such that
Boltzmann's constant will disappear, but at the expense of another non-
unity constant appearing elsewhere.
PD
>
> For example, I write the Boltzmann function
>
> f(E) = exp(-E/T)
>
> where the standard way would be
>
> f(E) = exp(-E/kT)
>
> and the k serving as a meaningless constant or conversion factor.
>
> More than that, it affects the notion of entropy, which is really
> fundamental. More than physics, actually - entropy is a mathematical
> concept at root, and therefore is always dimensionless. And yet,
> idiot
> thermodynamics force us to write 'J/mol-K'; as if those units matter
> one
> bit. Presenting a dimensionless number as otherwise is positively
> misleading.
>
> Heat capacity is also unitless, at least if measured on a molecular
> basis, which is preferable at least for gases. I have given the
> criterion
> for convective stability
>
> d log T / d log P = - 1/Cp
>
> and this works only if Cp is dimensionless. Not only is this the
> simplest
> possible form but it expresses without words why it is correct, if
> one
> only looks at it.
>
> Avogadro's number is similar, and I believe things should never be
> measured on a molar basis when they can reasonably be done on a
> molecular
Lloyd
> On Jul 29, 12:24 pm, Lloyd <lpar...@emory.edu> wrote:
>
> > > > The Kelvin is a "fundamental" unit because it cannot be derived from the
> > > > other six fundamental units.
>
> > > Wrong. It is equal to 1.380650e-23 J. Ir has to be.
So you're saying a fundamental unit is based on a derived unit.
Circular logic mean anything?
>
> > Uh, according to the CGPM, a K is: The kelvin, unit of thermodynamic
> > temperature, is the fraction 1/273.16 of the thermodynamic temperature
> > of the triple point of water.
>
> That's exactly the same thing.
So what are the units on deg C? Is it also J? Can't be, as an object
can't have a T with 2 different values, both in J. And if not, how do
you change the units going from K to deg C?
And what do you do with heat capacity? If you add 200 J to 100 g of
iron and 200 J to 100 g of water, they come to different temperatures.
Andrew Usher
> However, you will note that it is not possible to come up with a
> system of units where *all* of the constants relevant in natural laws
> will disappear. It is certainly possible to choose one such that
> Boltzmann's constant will disappear, but at the expense of another non-
> unity constant appearing elsewhere.
This is not true, as SI is already such a system, if temperature
were measured in Joules. No additional constants would appear!
Andrew Usher
Andrew Usher
> > > > > The Kelvin is a "fundamental" unit because it cannot be derived from the
> > > > > other six fundamental units.
>
> > > > Wrong. It is equal to 1.380650e-23 J. Ir has to be.
>
> So you're saying a fundamental unit is based on a derived unit.
> Circular logic mean anything?
That's not circular, since the Joule involves only _other_ base
units (meter, kilogram, second).
> So what are the units on deg C? Is it also J? Can't be, as an object
> can't have a T with 2 different values, both in J. And if not, how do
> you change the units going from K to deg C?
Celsius is not strictly a unit at all, as it is not an absolute
scale, of course. An object has only one temperature in J
or any other unit. Everyone knows how to convert C to K.
> And what do you do with heat capacity? If you add 200 J to 100 g of
> iron and 200 J to 100 g of water, they come to different temperatures.
They do, and what of it? This has nothing to do with the units
of heat capacity, which is dimensionless.
Andrew Usher
Craig
This is precisely the problem with trying to treat temperature as
having the dimensions of energy.
Suppose you add 200 J to 100 g of water. Suppose you have chosen a
scale such that this represents a change of "2 J" in water temperature
(since we have 100 g). Now, add 200 J to 100 g of iron (which has
approximately a tenth the heat capacity of water). This would raise
the temperature of the iron about 10 times as much. So, now the same
200 J causes a rise of "~20J" of iron temperature? The same amount of
energy gets converted into more "iron joules" than "water joules".
This clearly violates conservation of energy.
Suppose you add 20 J to 1 g of water. Suppose you have chosen a scale
such that this represents a change of "20 J" in water temperature.
Now, add 20 J to 10 g of water. The temperature rise will be 1/10 as
large. Will you now claim that 20 J of heat turns into only 2 J of
temperature? How can "heat joules" and "temperature joules" possibly
mean the same thing?
This becomes an untenable proposition. Temperature simply doesn't
behave the same way energy does.
- Craig
PD
Well, since you didn't take the time to read up on natural units, let
me try one more tack.
In thermodynamics, there are intrinsic variables and extrinsic
variables, with the latter depending on the amount of "stuff" and the
former not. Temperature is an intrinsic variable, and energy is
extrinsic. Two reservoirs of identical material can have a common
temperature and be in thermal equilibrium, but have much different
internal energies. (As another example, mass is extrinsic while
density is intrinsic; a spring constant is extrinsic while Young's
modulus is intrinsic.)
The joule is a unit of energy and so is a unit of an extrinsic
quantity. The kelvin is a unit of temperature and so is a unit of an
intrinsic quantity.
So if you chose temperature to have units joules, so that the relation
PV=nRT would become PV=nT (with R rendered to be 1 mole^-1), on the
left side you would have an *extrinsic* energy PV in joules and on the
right you would have an *intrinsic* quantity T in joules, with the
connection between the extrinsic joules and the intrinsic joules being
n the number of moles.
This seems to be a very odd way to do things, with joules referring to
two completely different kinds of quantities.
PD
Matthew Johnson
Andrew Usher says...
[snip]
>They do, and what of it? This has nothing to do with the units
>of heat capacity, which is dimensionless.
Dimensionless? How did you reach this conclusion? Specific heat capacity is
expressed in units of energy per degree of temperature per unit of mass.
In fact, energy and temperature can be expressed in units reciprocal to each
other, but this still does not make specific heat dimensionless.
Matthew Johnson
Craig says...
[snip]
>This becomes an untenable proposition. Temperature simply doesn't
>behave the same way energy does.
Not only that, but temperature's units are reciprocal to those of energy. This
is clear from the modern, quantum mechanical definition as:
1/T = partial derivative of E w.r.t. Entropy.
Entropy, as the number of accessible quantum states, is dimensionless.
Andrew Usher
> In thermodynamics, there are intrinsic variables and extrinsic
> variables, with the latter depending on the amount of "stuff" and the
> former not. Temperature is an intrinsic variable, and energy is
> extrinsic. Two reservoirs of identical material can have a common
> temperature and be in thermal equilibrium, but have much different
> internal energies. (As another example, mass is extrinsic while
> density is intrinsic; a spring constant is extrinsic while Young's
> modulus is intrinsic.)
This is all right.
> The joule is a unit of energy and so is a unit of an extrinsic
> quantity. The kelvin is a unit of temperature and so is a unit of an
> intrinsic quantity.
No, both are units of energy, and therefore could be used
either way.
> So if you chose temperature to have units joules, so that the relation
> PV=nRT would become PV=nT (with R rendered to be 1 mole^-1), on the
> left side you would have an *extrinsic* energy PV in joules and on the
> right you would have an *intrinsic* quantity T in joules, with the
> connection between the extrinsic joules and the intrinsic joules being
> n the number of moles.
The last word should be 'molecules'.
The form I actually prefer is P = rho T where rho is the number
density.
That's even simpler, and illustrates the truth that pressure is a kind
of
energy density.
> This seems to be a very odd way to do things, with joules referring to
> two completely different kinds of quantities.
They can be considered two different kinds, but still have the
same dimension. Like, say, pressure and energy density. Or
temperature and change in temperature.
Of course, I actually state temperatures in electron volts,
rather than joules. This is due to its more convienient size,
use to measure atomic/molecular energy quantities, and
its use in the literature to state temperatures in certain
situations (whereas kJ/mol or cm^-1 are never so used).
Andrew Usher
Andrew Usher
> This is precisely the problem with trying to treat temperature as
> having the dimensions of energy.
No, you are confused. See below.
> Suppose you add 200 J to 100 g of water. Suppose you have chosen a
> scale such that this represents a change of "2 J" in water temperature
> (since we have 100 g). Now, add 200 J to 100 g of iron (which has
> approximately a tenth the heat capacity of water). This would raise
> the temperature of the iron about 10 times as much. So, now the same
> 200 J causes a rise of "~20J" of iron temperature? The same amount of
> energy gets converted into more "iron joules" than "water joules".
> This clearly violates conservation of energy.
This is not how temperature works! You can't divide Joules
by grams and get Joules! Actually, you'd need to divide the energy
by the heat capacity, then by the number of atoms or molecules
(more generally, formula units) to get the change in temperature.
Andrew Usher
Andrew Usher
wrote:
> In article <221a7beb-e33e-496d-96d4-d56f6e1f3...@59g2000hsb.googlegroups.com>,
> Craig says...
>
> [snip]
>
> >This becomes an untenable proposition. Temperature simply doesn't
> >behave the same way energy does.
>
> Not only that, but temperature's units are reciprocal to those of energy. This
> is clear from the modern, quantum mechanical definition as:
>
> 1/T = partial derivative of E w.r.t. Entropy.
Wrong way around, 1/T = dS/dQ.
> Entropy, as the number of accessible quantum states, is dimensionless.
Actually the logarithm of the number of states, but yes (as logs are
always dimensionless).
Andrew Usher
Borked Pseudo Mailed
> is an old practice among theoretical physicists. Typically
> the speed of light, c, and electron charge, among others,
> is set to one.
Ditto to this. When I was in junior high school and we ("the
smart kids") were becoming enamored with E=mc2 and other
"advanced" concepts we argued over whether light speed c or
some other natural constants should be unitary and
dimensionless and would then re-evaluate and re-define units
of mass, length, energy, etc. in terms of c.
It's a great exercise to learn the relationships in physics
but -- I repeat: JUNIOR HIGH SCHOOL -- rather juvenile and
unoriginal.
Craig
> On Jul 31, 7:55 pm, Craig <cager...@aol.com> wrote:
>
> > Suppose you add 200 J to 100 g of water. Suppose you have chosen a
> > scale such that this represents a change of "2 J" in water temperature
> > (since we have 100 g). Now, add 200 J to 100 g of iron (which has
> > approximately a tenth the heat capacity of water). This would raise
> > the temperature of the iron about 10 times as much. So, now the same
> > 200 J causes a rise of "~20J" of iron temperature? The same amount of
> > energy gets converted into more "iron joules" than "water joules".
> > This clearly violates conservation of energy.
>
> This is not how temperature works! You can't divide Joules
> by grams and get Joules!
This is exactly my point.
> Actually, you'd need to divide the energy
> by the heat capacity, then by the number of atoms or molecules
> (more generally, formula units) to get the change in temperature.
As I understand your assertion, energy and temperature should both
have dimensions of energy.
So we're all on the same page,
Heat = (Amount of stuff) * Heat capacity * DeltaTemperature
So, you want to work on an atomic/molecular scale, regardless of how
clumsy that may be on a macroscopic scale. Fine. Usually, I would
measure (Amount of stuff) in grams and use the specific heat
capacity. For you, we can measure (Amount of stuff) in molecules.
You stated elsewhere that heat capacity should be dimensionless. So
far, this is consistent: number of molecules * C * deltaT then works
out to have dimensions of T, which you assert should be energy.
Re-read what I wrote.
Divide the Heat (i.e. energy) by (Amount of stuff) * Heat capacity.
We all agree this should give a temperature. By your assertion,
(Amount of stuff) * Heat capacity ought to be dimensionless. This is
required to give temperature the same units as heat energy. However,
the point still stands that there is no consistent way to reconcile
the different changes in temperature of iron and water while claiming
that the Joules of Temperature are the *same* Joules that heat is
expressed in.
You might object that using molecular units means we should refer to
the molar heat capacity, rather than specific heat capacity. It is
interesting to note a certain regularity in the molar heat capacity of
solids (see: Law of Dulong and Petit). Despite this, many substances
(e.g. gases) do *not* obey this pattern. There is no "universal"
molar heat capacity. For example, the molar heat capacity of liquid
water is about three times larger than that for solid iron, both near
25 C. Suffice it to say, this potential red herring would not change
the essence of the argument. Temperature is *not* the same thing as
energy.
As a contrasting example, work and heat *are* the "same thing". I
could burn a fuel, release 100 J of heat, then use that heat to
generate, say, 20 J or work and 80 J of waste heat (or 10 J work + 90
J waste heat, etc. - always obeying a common sum). Or, I could exert
100 J of work against friction and deposit precisely 100 J of heat
into the sliding materials. In this case, Joules are Joules. They
indeed behave in a common way. Energy is conserved, one might say.
Temperature and energy do *not* behave like this. For example,
knowing that a material experienced a one degree rise in temperature
is *not* sufficient information to know how much energy was gained by
that unknown quantity of unnamed material.
- Craig
Richard Schultz
:> :> Uh, according to the CGPM, a K is: The kelvin, unit of thermodynamic
:> :> temperature, is the fraction 1/273.16 of the thermodynamic temperature
:> :> of the triple point of water.
:>
:> : That's exactly the same thing.
:>
:> I've never quite understood why some people get so much enjoyment out
:> of publically displaying their ignorance.
:
: You should be calling Lloyd 'ignorant', not me. I'm sorry that you
: refuse to accept statistical mechanics, but it doesn't change
: the facts.
Since you are the one who is confusing a statistical quantity (temperature)
with a quantity that can be defined for a single particle (energy), I would
guess that I'm not the one who refuses to accept statistical mechanics.
Andrew Usher
> In sci.chem Andrew Usher <k_over_hb...@yahoo.com> wrote:
>
> :> :> Uh, according to the CGPM, a K is: The kelvin, unit of thermodynamic
> :> :> temperature, is the fraction 1/273.16 of the thermodynamic temperature
> :> :> of the triple point of water.
> :>
> :> : That's exactly the same thing.
> :>
> :> I've never quite understood why some people get so much enjoyment out
> :> of publically displaying their ignorance.
> :
> : You should be calling Lloyd 'ignorant', not me. I'm sorry that you
> : refuse to accept statistical mechanics, but it doesn't change
> : the facts.
>
> Since you are the one who is confusing a statistical quantity (temperature)
> with a quantity that can be defined for a single particle (energy), I would
> guess that I'm not the one who refuses to accept statistical mechanics.
No, I'm not. I don't know why you keep claiming I am. They have the
same units but they (in the sense to which you are referring) are not
the same thing.
Now why did you snip my second paragraph, where I showed
explicitly my point?
Andrew Usher
Richard Schultz
: No, I'm not. I don't know why you keep claiming I am. They have the
: same units but they (in the sense to which you are referring) are not
: the same thing.
Which is why they don't have the same units.
PD
> On Jul 31, 7:58 pm, PD <TheDraperFam...@gmail.com> wrote:
>
> > In thermodynamics, there are intrinsic variables and extrinsic
> > variables, with the latter depending on the amount of "stuff" and the
> > former not. Temperature is an intrinsic variable, and energy is
> > extrinsic. Two reservoirs of identical material can have a common
> > temperature and be in thermal equilibrium, but have much different
> > internal energies. (As another example, mass is extrinsic while
> > density is intrinsic; a spring constant is extrinsic while Young's
> > modulus is intrinsic.)
>
> This is all right.
>
> > The joule is a unit of energy and so is a unit of an extrinsic
> > quantity. The kelvin is a unit of temperature and so is a unit of an
> > intrinsic quantity.
>
> No, both are units of energy, and therefore could be used
> either way.
That is simply incorrect, and here is the way you can tell.
Take two equal volumes of gas at the same temperature and combine them
into a single volume.
The temperature of the resultant gas stays the same, because
temperature is an *intrinsic* variable, but the energy has doubled,
because energy is an *extrinsic* variable.
This is the point I just got done making: temperature and energy are
fundamentally two different kinds of quantities: extrinsic and
intrinsic. Forcing them to have the same units would mean the unit
would be sometimes intrinsic, sometimes extrinsic, which would be a
highly questionable thing to do.
>
> > So if you chose temperature to have units joules, so that the relation
> > PV=nRT would become PV=nT (with R rendered to be 1 mole^-1), on the
> > left side you would have an *extrinsic* energy PV in joules and on the
> > right you would have an *intrinsic* quantity T in joules, with the
> > connection between the extrinsic joules and the intrinsic joules being
> > n the number of moles.
>
> The last word should be 'molecules'.
Not in PV=nRT. Volume is an *extrinsic* quantity, dependent on the
amount of stuff.
What you are attempting to do is to deny the presence of extrinsic
variables in thermodynamics at all.
PD
>
> The last word should be 'molecules'.
>
> The form I actually prefer is P = rho T where rho is the number
> density.
> That's even simpler, and illustrates the truth that pressure is a kind
> of
> energy density.
>
And on this point, I would FURTHERMORE remind you that many of the
quantities in thermodynamics are *ensemble* quantities -- they have no
*meaning* unless you are talking about a statistic average of a large
number of objects. Entropy, for example, has no *meaning* for a single
state. Temperature has no *meaning* for a single particle. Pressure
has no *meaning* for a single particle.
Carnot's law is *exactly* a statement about how much random energy can
be extracted into nonrandom energy (work) for two temperature
reservoirs, and the distinction between random energy and nonrandom
energy has no *meaning* for a single particle.
You can pick up any thermodynamics book and remind yourself of the
inherently statistical meaning of some fundamental quantities. This is
precisely the reason why both intrinsic and extrinsic quantities
appear in thermodynamics.
PD
hanson
"Richard Schultz" <sch...@mail.biu.ack.il> wrote in message
news:g6uuct$1rr$1...@news.iucc.ac.il...
>
In sci.chem Andrew Usher <k_over...@yahoo.com> wrote:
No, I'm not. I don't know why you keep claiming I am.
They have the same units but they (in the sense to which
you are referring) are not the same thing.
>
Which is why they don't have the same units.
>
... ahahaha... AHAHAHA... which is also why Andy-Pooh
has you going like a monkey up a greased tree... ahahaha...
Richie, let Andy stew in his beliefs & let'm be happy . Your
efforts will not alter the situation. Exploit it rather then fight
it, even if it's only for a laugh... ahahahaha....
-------- [ Schultz 1 : Usher 0 ] ----------
ahahaha... ahahahanson
Lloyd
The amount of heat in a body (measures in joules) is extensive; the
temperature (measured in Kelvins) is intensive. Do you understand
that? What you're arguing is like saying mass and density should have
the same units.
Andrew Usher
> > > The joule is a unit of energy and so is a unit of an extrinsic
> > > quantity. The kelvin is a unit of temperature and so is a unit of an
> > > intrinsic quantity.
>
> > No, both are units of energy, and therefore could be used
> > either way.
>
> That is simply incorrect, and here is the way you can tell.
> Take two equal volumes of gas at the same temperature and combine them
> into a single volume.
> The temperature of the resultant gas stays the same, because
> temperature is an *intrinsic* variable, but the energy has doubled,
> because energy is an *extrinsic* variable.
> This is the point I just got done making: temperature and energy are
> fundamentally two different kinds of quantities: extrinsic and
> intrinsic.
I've already told you I understand this.
> Forcing them to have the same units would mean the unit
> would be sometimes intrinsic, sometimes extrinsic, which would be a
> highly questionable thing to do.
If your'e talking about possible confusion to us, it's doubtful. We
really measure intrisic temperature in ev, which is never used
for macroscopic energies.
In any case the benefit of making our equations much more
elegant outweights this.
> > > So if you chose temperature to have units joules, so that the relation
> > > PV=nRT would become PV=nT (with R rendered to be 1 mole^-1), on the
> > > left side you would have an *extrinsic* energy PV in joules and on the
> > > right you would have an *intrinsic* quantity T in joules, with the
> > > connection between the extrinsic joules and the intrinsic joules being
> > > n the number of moles.
>
> > The last word should be 'molecules'.
>
> Not in PV=nRT. Volume is an *extrinsic* quantity, dependent on the
> amount of stuff.
In PV=nT (which is what you were talking about) the n must be
molecules.
> What you are attempting to do is to deny the presence of extrinsic
> variables in thermodynamics at all.
No, I simply haven't used the word 'extrinsic'. That's because
I assume we're all smart enough to know the difference without
my having to point it out.
Andrew Usher
Andrew Usher
> > The last word should be 'molecules'.
>
> > The form I actually prefer is P = rho T where rho is the number
> > density.
> > That's even simpler, and illustrates the truth that pressure is a kind
> > of energy density.
>
> And on this point,
My point that 'pressure is a kind of energy density'?
> I would FURTHERMORE remind you that many of the
> quantities in thermodynamics are *ensemble* quantities -- they have no
> *meaning* unless you are talking about a statistic average of a large
> number of objects. Entropy, for example, has no *meaning* for a single
> state. Temperature has no *meaning* for a single particle. Pressure
> has no *meaning* for a single particle.
Yes.
> This is
> precisely the reason why both intrinsic and extrinsic quantities
> appear in thermodynamics.
Again, I already know this.
Andrew Usher
Andrew Usher
> The amount of heat in a body (measures in joules) is extensive; the
> temperature (measured in Kelvins) is intensive. Do you understand
> that? What you're arguing is like saying mass and density should have
> the same units.
No, it isn't. Mass and density do not have the same units because
the ratio between them is volume (L^3) and there is no unitless
measure of volume.
The same is not true of temperature and energy.
Andrew Usher
Andrew Usher
> So we're all on the same page,
> Heat = (Amount of stuff) * Heat capacity * DeltaTemperature
>
> So, you want to work on an atomic/molecular scale, regardless of how
> clumsy that may be on a macroscopic scale. Fine. Usually, I would
> measure (Amount of stuff) in grams and use the specific heat
> capacity. For you, we can measure (Amount of stuff) in molecules.
> You stated elsewhere that heat capacity should be dimensionless. So
> far, this is consistent: number of molecules * C * deltaT then works
> out to have dimensions of T, which you assert should be energy.
Yes, that explains it.
> Re-read what I wrote.
>
> Divide the Heat (i.e. energy) by (Amount of stuff) * Heat capacity.
> We all agree this should give a temperature. By your assertion,
> (Amount of stuff) * Heat capacity ought to be dimensionless. This is
> required to give temperature the same units as heat energy. However,
> the point still stands that there is no consistent way to reconcile
> the different changes in temperature of iron and water while claiming
> that the Joules of Temperature are the *same* Joules that heat is
> expressed in.
Yes, they're not the same in that sense; for example, it wouldn't
make sense to compare them. I've never claimed this, though.
> You might object that using molecular units means we should refer to
> the molar heat capacity, rather than specific heat capacity. It is
> interesting to note a certain regularity in the molar heat capacity of
> solids (see: Law of Dulong and Petit).
Yes, metals are around 3 per atom.
> Despite this, many substances
> (e.g. gases) do *not* obey this pattern. There is no "universal"
> molar heat capacity. For example, the molar heat capacity of liquid
> water is about three times larger than that for solid iron, both near
> 25 C.
Actually, about the same per atom, as H2O has 3 atoms!
There is one that can be called universal: monatomic gases are 1.5
(constant volume). Anyway, the different values can be explained
theoretically and have nothing to do with units.
> Suffice it to say, this potential red herring would not change
> the essence of the argument. Temperature is *not* the same thing as
> energy.
Of course not.
> As a contrasting example, work and heat *are* the "same thing".
Yes, because they are both forms of energy. Though temperature
isn't a form of energy, it is best expressed in the same units.
That's been my contention in this whole thread.
Andrew Usher
Craig
> On Aug 1, 12:40 am, Craig <cager...@aol.com> wrote:
> > Divide the Heat (i.e. energy) by (Amount of stuff) * Heat capacity.
> > We all agree this should give a temperature. By your assertion,
> > (Amount of stuff) * Heat capacity ought to be dimensionless. This is
> > required to give temperature the same units as heat energy. However,
> > the point still stands that there is no consistent way to reconcile
> > the different changes in temperature of iron and water while claiming
> > that the Joules of Temperature are the *same* Joules that heat is
> > expressed in.
>
> Yes, they're not the same in that sense; for example, it wouldn't
> make sense to compare them. I've never claimed this, though.
So, if they aren't the same, it doesn't make sense to call them the
same!
Another analogy for what you're trying to assert is claiming that,
say, barrels of oil should be a unit of currency. I can buy oil for
dollars. I can obtain a conversion factor for so-and-so many dollars
per barrel of oil. Thus, we should measure all prices in volumes of
oil, since I perceive that to be a more fundamental unit of the
economy. In this case, the argument is flawed because there are more
moving parts to the economy than simply dollars and oil. A dollar
does not always buy the same amount of oil, for example. I could not
call a volume of oil a unit of currency, nor could I consider dollars
to be units of oil volume. They simply measure different things, and
it only confuses the issue to give them the same name.
> > You might object that using molecular units means we should refer to
> > the molar heat capacity, rather than specific heat capacity. It is
> > interesting to note a certain regularity in the molar heat capacity of
> > solids (see: Law of Dulong and Petit).
>
> Yes, metals are around 3 per atom.
>
> > Despite this, many substances
> > (e.g. gases) do *not* obey this pattern. There is no "universal"
> > molar heat capacity. For example, the molar heat capacity of liquid
> > water is about three times larger than that for solid iron, both near
> > 25 C.
>
> Actually, about the same per atom, as H2O has 3 atoms!
This is really a side point to the main discussion. However, the heat
capacity of ice (solid water) is about half that of liquid water.
This does not fit so neatly into the picture thus far presented.
Suffice it to say that reality is more complex.
> > Suffice it to say, this potential red herring would not change
> > the essence of the argument. Temperature is *not* the same thing as
> > energy.
>
> Of course not.
>
> > As a contrasting example, work and heat *are* the "same thing".
>
> Yes, because they are both forms of energy.
You would do well to keep cause and effect straight. Once upon a time
(~200 years ago), this equivalence was not clear. We have decided
that work and heat are both forms of energy because they *do* behave
in the same way. "Work is measured in Joules, heat is measured in
Joules, therefore they are both energy." This argument puts the cart
before the horse, as the saying goes. Hypothetically, if "calories of
heat" and "joules of work" were *not* reliably convertible (depending
on materials, temperature, phase of the moon, whatever), we would need
to describe a more complex relationship. In such a case, it would not
make sense to call both of them energy. Heat and work are both forms
of energy *because* they act like the same "stuff".
Conversely, since temperature does not act like energy, it is not a
form of energy. It cannot be reliably measured in the units of
energy.
For another example, consider gravitational and inertial mass. Deep
down, these are two qualitatively different properties. There is no
logical reason why resistance to motion (inertia) should have anything
at all to do with the strength of gravity. Yet, astoundingly, it
does. By contrast, the masses of a proton and electron have nothing
at all to do with the strength of their electrical interactions, and
we have a separate unit, electrical charge, to describe this
behavior. It wouldn't make sense to express electrical charge in
kilograms, for example. In every test ever conducted, gravitational
and inertial masses are identical. Consequently, we describe a single
unit, mass, which applies to both phenomena. Hypothetically, suppose
we discover something that, say, resists being shoved around but
floats in the air, immune to gravity. We might have to revise our
notion of mass as only a single unit, if "gravity-grams" did not
always match "inertia-grams" in a consistent way.
> Though temperature
> isn't a form of energy, it is best expressed in the same units.
> That's been my contention in this whole thread.
Because temperature and energy are not the same thing, they should not
be expressed in the same units. Joules, ergs, calories, BTU's all
behave the same, and in ways qualitatively unlike Fahrenheit, Celsius,
Kelvin. How can I measure them with the same yardstick, when I'm not
even measuring the same property? If there is not a unique
correspondence between quantity X and quantity Y, how can it make
sense to express Y in terms of X?
The longer something is, the more it weighs. Yet, no one seems to be
confused that meters and kilograms are distinct units, which are *not*
best expressed both as, say, meters. In some situations (e.g. coils
of uniform thickness wire), it might be convenient to discuss the
length of wire between two cities in terms of how many tons are
needed. In some situations, one might use temperature as a convenient
metric for energy (or vice versa). Still, one must recognize mass and
length, or energy and temperature as distinct.
Temperature and energy are not the same thing, so it makes no sense to
express them in the same units.
- Craig
Earle Jones
<261e0079-7b75-4137...@k37g2000hsf.googlegroups.com>,
Lloyd <lpa...@emory.edu> wrote:
[...]
*
Where does the Boltzmann equation (for entropy) appear carved in stone?
earle
*
Sam Wormley
> Where does the Boltzmann equation (for entropy) appear carved in stone?
>
The famous equation is engraved on Boltzmann's tombstone Headstone.
Vienna, Austria
S = k ln W
where S is the entropy, k is Boltzmann's constant, and W is the number
of states accessible to the system. Boltzmann first wrote down his
equation in 1872, although Planck was actually the first to write it
in this form. This equation is inscribed on Boltzmann's tomb.
Andrew Usher
> Earle Jones wrote:
> > Where does the Boltzmann equation (for entropy) appear carved in stone?
>
> The famous equation is engraved on Boltzmann's tombstone Headstone.
> Vienna, Austria
>
> S = k ln W
Of course, the equation should be written
S = log W
Andrew Usher
tdp...@gmail.com
> On Dec 8, 7:19 pm, Sam Wormley <sworml...@mchsi.com> wrote:
>
> > Earle Jones wrote:
>
> > The famous equation is engraved onBoltzmann'stombstone Headstone.
> > Vienna, Austria
>
> > S = k ln W
>
> Of course, the equation should be written
>
> S = log W
>
> Andrew Usher
I posted a picture I took of Boltzmann headstone at the web site
below.
If you zoom in you can see the equation above his head.
Many famous people are buried in this cemetery.
( I also posted a picture of Beethoven's headstonea at the site.)
There are hundreds of beautiful tombs and headstones there.
If you visit Vienna, be sure to visit the cemetery.
The web site removes the photos in a few weeks,
so if you want the pictures, download them before they expire.
--
Tom Potter
http://www.geocities.com/tdp1001/index.html
http://notsocrazyideas.blogspot.com
http://www.flickr.com/photos/tom-potter/
http://tdp1001.wiki.zoho.com
http://groups.msn.com/PotterPhotos
http://www.androcles01.pwp.blueyonder.co.uk/dingleberry.htm
Sam Wormley
> I posted a picture I took of Boltzmann headstone at the web site
> below.
> If you zoom in you can see the equation above his head.
>
> Many famous people are buried in this cemetery.
> ( I also posted a picture of Beethoven's headstonea at the site.)
>
> There are hundreds of beautiful tombs and headstones there.
> If you visit Vienna, be sure to visit the cemetery.
>
> The web site removes the photos in a few weeks,
> so if you want the pictures, download them before they expire.
>
> http://cl1p.net/boltzmann/
>
> --
> Tom Potter
>
That was nice of you Potter.
Cheers
Andrew Usher
> >http://cl1p.net/boltzmann/
>
> > --
> > Tom Potter
>
> That was nice of you Potter.
Although the pictures have nothing to do with this argument, I note
that
you are wrong about the inscription: it reads 'log', not 'ln'. Which
it should,
of course: the ridiculous 'ln' wasn't in use yet.
Andrew Usher
Tom Potter
"Sam Wormley" <swor...@mchsi.com> wrote in message news:uIj%k.416397$TT4.355943@attbi_s22...
Here is a picture I took of Boltzmann headstone in Vienna, Austria.
If you zoom in you can see the equation above his head.
Many famous people are buried in this cemetery.
( I also uploaded the headstone of Bethoven. to the site below.)
There are hundreds of beautiful tombs and headstones there.
If you visit Vienna, be sure to visit the cemetery.
The photos are automatically removed from the web site,
so if you want the pictures, download them before they expire.
--
Tom Potter
http://www.geocities.com/tdp1001/index.html
http://notsocrazyideas.blogspot.com
http://www.flickr.com/photos/tom-potter/
http://tdp1001.wiki.zoho.com
http://groups.msn.com/PotterPhotos
http://www.androcles01.pwp.blueyonder.co.uk/dingleberry.htm
** Posted from http://www.teranews.com **