James McGinn
2018-03-13 20:00:26 UTC
On Sunday, January 15, 2017 at 6:52:55 PM UTC-8, James McGinn wrote:
Ed Prochaks Dilemma -- Chan, Ed and Daltons Law
James McGinn wrote:
Chan, it's very hard to overcome the instinct to go along with what
everybody else believes.
Chan:
I think you and I earlier failed to understand how Dalton's law comes into
the picture.
James McGinn wrote:
Actually, I don't see it as being applicable. I'm wondering if maybe you
have made a common error. Vapor pressure of H2O and partial pressure of
different GASES are sometimes both called partial pressure. Maybe it is the
ambiguity in the phrase "partial pressure," that is the source of your
confusion.
Chan:
Vapor pressure contributes to total pressure as (partial) pressure.
James McGinn wrote:
Well, true but--to be candid--so what? Of course it does. But that doesn't
necessarily bring Dalton's into the discussion. Remembers, the underlying
cause of your confusion is, most likely, the ambiguity associated with the
fact that vapor pressure of H2O and partial pressure of different GASES are
sometimes both called partial pressure. (Read the previous sentence over and
over again until the distinction is clear in your mind.) The phrase partial
pressure, therefore, being ambiguous, should be avoided. (Or you could--as
many actually do--choose to remain in a state of permanent confusion. [If
that floats your boat . . . ]) Instead use either of these phrases depending
on which is applicable: 1) Vapor pressure of H2O; or 2) Partial pressure of
different GASES.
You have to be very deliberate about compartamentalizing these two different
concepts in your mind. (There is no substitute for being tough minded. It
does, however, get easier with practice.) Obviously the second of these two
is not applicable, that being Dalton's Law. And so, Dalton's law makes no
difference whatsoever.
More simply put: Dalton's law is a gas law. It is not a vapor law.
Chan:
There is no experimental evidence that moist air is lighter than dry air. It
is correct! Noone could provide a reference.
The experiment I proposed in my other thread "Why moist air lighter than dry
air" is one that could be done and it would indisputably establish the
result.
James McGinn wrote:
Yes, I saw it. I don't want to discourage you but, measuring water vapor is
very difficult. And this is mostly because knowing the size of microdroplets
and knowing the effect of other characteristics associated with
microdroplets--most significantly, the effects of H2O's huge heat capacity--
introduces huge unknowns into the equation. (This is the problem that I
think stumped Espy back in the 1840's.) And another complication is
associate with the amount of static electricity--which, for all we know--may
have a significant effect on size of microdroplets and other
characteristics. So, I'm not saying this makes your approach impossible. I'm
just saying that its success depends greatly on knowing things that, franky,
we don't know a lot about yet.
I think my idea to directly measure the weight of moist vs dry air
(controlling for all other factors) using simple items, like mason jars,
would be easier and much more reproducible. I could envision high school
students doing the experiment--or at least parts of it. The only
difficulting would be getting scales sensitive enough to measure small
differences in air with precision.
Ed Prochak:
http://nvlpubs.nist.gov/nistpubs/jres/83/jresv83n5p419_A1b.pdf
Of course JM thinks it is a conspiracy, so he won't read or understand this
paper. And infact he will deny it even exists.
James McGinn wrote:
LOL. I don't need to deny it. The fact that you can't/won't quote it
directly tells me everything I need to know.
Ed Prochak:
The current paradigm works.
James McGinn wrote:
Vagueness always appears to work.
Ed Prochak:
There is no justification to change the current paradigm until you can
produce better results.
James McGinn wrote:
Better than what? We're talking about measuring something that has never
been measured before. And if measuring something that has never been
measured before results in a change to the paradigm it's hard to imagine how
that would not be a good thing in the long run.
Ed Prochak:
I think Chan brought in the death blow to your premise. Given that using
Dalton's law works in calculating pressure and density in humid air, and you
agree it ONLY works for materials in a gaseous state, then the water must be
gaseous.
James McGinn wrote:
Actually, I am not in agreement with your imaginative reassessment of the
applicability of Dalton's Law. But I give you credit for being creative.
Ed Prochak:
Here are the key lines from the NIST paper I quoted above: "The air density
is conveniently calculated using an equation based on the equation of state
of an air-water vapor mixture. A new formulation of the air density equation
is developed below."
James McGinn wrote:
LOL. You just proved my point. Do you not know the difference between a
measurement/experiment and a calculation?
Ed Prochak:
Dalton's law provides the correct calculation.
James McGinn wrote:
LOL. You flipped from talking about Dalton's and started talking about the
NIST calculations and now you are flopping back to talking about Dalton
again?
Ed Prochak:
Using Dalton's law NIST calculates humid air density measured it and finds
the results match.
James McGinn wrote:
Matches what? It's never been measured. And, as has been explained to you
about 6 times now, Dalton's law deals with partial pressure of gases--not
vapors. It's that simple. The notion that Dalton's deals with H2O vapor is
your delusion. (Leave the rest of us out of it.)
Ed Prochak:
Go argue with NIST.
James McGinn wrote:
About what? Something you you just confirmed they don't have.
Ed Prochak:
Don't take my word.
James McGinn wrote:
You needn't be concerned about that.
Best,
James McGinn / Solving Tornadoes
Ed Prochaks Dilemma -- Chan, Ed and Daltons Law
James McGinn wrote:
Chan, it's very hard to overcome the instinct to go along with what
everybody else believes.
Chan:
I think you and I earlier failed to understand how Dalton's law comes into
the picture.
James McGinn wrote:
Actually, I don't see it as being applicable. I'm wondering if maybe you
have made a common error. Vapor pressure of H2O and partial pressure of
different GASES are sometimes both called partial pressure. Maybe it is the
ambiguity in the phrase "partial pressure," that is the source of your
confusion.
Chan:
Vapor pressure contributes to total pressure as (partial) pressure.
James McGinn wrote:
Well, true but--to be candid--so what? Of course it does. But that doesn't
necessarily bring Dalton's into the discussion. Remembers, the underlying
cause of your confusion is, most likely, the ambiguity associated with the
fact that vapor pressure of H2O and partial pressure of different GASES are
sometimes both called partial pressure. (Read the previous sentence over and
over again until the distinction is clear in your mind.) The phrase partial
pressure, therefore, being ambiguous, should be avoided. (Or you could--as
many actually do--choose to remain in a state of permanent confusion. [If
that floats your boat . . . ]) Instead use either of these phrases depending
on which is applicable: 1) Vapor pressure of H2O; or 2) Partial pressure of
different GASES.
You have to be very deliberate about compartamentalizing these two different
concepts in your mind. (There is no substitute for being tough minded. It
does, however, get easier with practice.) Obviously the second of these two
is not applicable, that being Dalton's Law. And so, Dalton's law makes no
difference whatsoever.
More simply put: Dalton's law is a gas law. It is not a vapor law.
Chan:
There is no experimental evidence that moist air is lighter than dry air. It
is correct! Noone could provide a reference.
The experiment I proposed in my other thread "Why moist air lighter than dry
air" is one that could be done and it would indisputably establish the
result.
James McGinn wrote:
Yes, I saw it. I don't want to discourage you but, measuring water vapor is
very difficult. And this is mostly because knowing the size of microdroplets
and knowing the effect of other characteristics associated with
microdroplets--most significantly, the effects of H2O's huge heat capacity--
introduces huge unknowns into the equation. (This is the problem that I
think stumped Espy back in the 1840's.) And another complication is
associate with the amount of static electricity--which, for all we know--may
have a significant effect on size of microdroplets and other
characteristics. So, I'm not saying this makes your approach impossible. I'm
just saying that its success depends greatly on knowing things that, franky,
we don't know a lot about yet.
I think my idea to directly measure the weight of moist vs dry air
(controlling for all other factors) using simple items, like mason jars,
would be easier and much more reproducible. I could envision high school
students doing the experiment--or at least parts of it. The only
difficulting would be getting scales sensitive enough to measure small
differences in air with precision.
Ed Prochak:
http://nvlpubs.nist.gov/nistpubs/jres/83/jresv83n5p419_A1b.pdf
Of course JM thinks it is a conspiracy, so he won't read or understand this
paper. And infact he will deny it even exists.
James McGinn wrote:
LOL. I don't need to deny it. The fact that you can't/won't quote it
directly tells me everything I need to know.
Ed Prochak:
The current paradigm works.
James McGinn wrote:
Vagueness always appears to work.
Ed Prochak:
There is no justification to change the current paradigm until you can
produce better results.
James McGinn wrote:
Better than what? We're talking about measuring something that has never
been measured before. And if measuring something that has never been
measured before results in a change to the paradigm it's hard to imagine how
that would not be a good thing in the long run.
Ed Prochak:
I think Chan brought in the death blow to your premise. Given that using
Dalton's law works in calculating pressure and density in humid air, and you
agree it ONLY works for materials in a gaseous state, then the water must be
gaseous.
James McGinn wrote:
Actually, I am not in agreement with your imaginative reassessment of the
applicability of Dalton's Law. But I give you credit for being creative.
Ed Prochak:
Here are the key lines from the NIST paper I quoted above: "The air density
is conveniently calculated using an equation based on the equation of state
of an air-water vapor mixture. A new formulation of the air density equation
is developed below."
James McGinn wrote:
LOL. You just proved my point. Do you not know the difference between a
measurement/experiment and a calculation?
Ed Prochak:
Dalton's law provides the correct calculation.
James McGinn wrote:
LOL. You flipped from talking about Dalton's and started talking about the
NIST calculations and now you are flopping back to talking about Dalton
again?
Ed Prochak:
Using Dalton's law NIST calculates humid air density measured it and finds
the results match.
James McGinn wrote:
Matches what? It's never been measured. And, as has been explained to you
about 6 times now, Dalton's law deals with partial pressure of gases--not
vapors. It's that simple. The notion that Dalton's deals with H2O vapor is
your delusion. (Leave the rest of us out of it.)
Ed Prochak:
Go argue with NIST.
James McGinn wrote:
About what? Something you you just confirmed they don't have.
Ed Prochak:
Don't take my word.
James McGinn wrote:
You needn't be concerned about that.
Best,
James McGinn / Solving Tornadoes