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you guys are asholes

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  you guys are asholes "James McGinn" <iwetmyself@yourhouse.com> - 2016-03-20 15:27 +0000
    Re: Why do you think you are not ? Poutnik <poutnik4nntp@gmail.com> - 2016-03-20 18:13 +0100
      Re: Why do you think you are not ? James McGinn <jimmcginn9@gmail.com> - 2016-03-20 10:17 -0700
        Re: Why do you think you are not ? Sam Wormley <swormley1@gmail.com> - 2016-03-20 14:51 -0500
    Re: you guys are asholes Sam Wormley <swormley1@gmail.com> - 2016-03-20 14:37 -0500

#563858 — you guys are asholes

I'm not so sure it's right to equate water vapor with steam. At least in the case of "vapor pressure," the word "vapor" implies a gas--not a foggy suspension of droplets, such as steam. I think in common usage steam counts as water vapor, but I'm not so sure about the usage in physics and chemistry. Wherever the article references the phyical chemical constants that apply to water vapor, I think the substance should not be described in way that that does not apply to whatever substance physical chemists mean when they title a column in a book of constants "water vapor" ;

    "Water vapor is the gas phase of water, one of three basic states in which water molecules can stably exist en masse and in pure form (ice and liquid water are the others). The gaseous form is water's thermodynamically stable state at temperatures above 100 °C or 212 °F and at pressures equal to or below standard atmospheric pressure (see water (phase diagram)). Water vapor can be produced either by evaporation or sublimation." 

Concerning the visibility of water vapor--it is visible in high concentrations, RH >90%, and it is still a gas. RadarCzar

            I don't know what RH stands for. What do you mean visible? Do you mean schlieren? Or do you mean the vapor has color and/or opacity? 168...


                RH is Relative Humidity. RadarCzar

Steam is a Gas

Also, steam is a gas, otherwise steam engines would not work.RadarCzar

            Or steam engines produce not only steam but vapor. When I changed the text to call steam a mixture of vapor and microscopic droplets, you did not object that this is inaccurate.168...

                Right, can you analyze steam? RadarCzar

            I don't know what you're getting at. Why analyze steam? 168... 21:04, 22 Aug 2003 (UTC)



1 Lets see if you know which one of these facts is fake.
A. If you put a drop of water on a scorpion, it will go mad and sting itself to death
B. Without water, a rat can last longer than a camel
C. Chicken nuggets in fast food places are less than 10% real chicken meat, rest is water and wallpaper glue
D. The glue on Israeli postage is certified kosher

2 Banging your head on a wall uses...
A. 20 calories of latent heat
B. 60 calories an hour
C. 150 calories an hour
D. 190 calories an hour
 	
3. Arachibutyrowaterphobia is the fear of what?
A. Consuming spiders
B. Twisting Twisters
C. Peanut butter sticking to the roof of the mouth
D. Spider excrement in your food

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#563870 — Re: Why do you think you are not ?

Dne 20/03/2016 v 16:27 James McGinn napsal(a):

> 
> Steam is a Gas
> 

Technical steam can be

   either scientific steam as aerosol of liquid water
         in air ( foggy breath )
         or  in water vapour ( technical "wet steam" )
         or in their mixture

   either scientific vapour as gaseous water phase
                                  ( technical "dry steam" )

   either mixture of scientific vapour and air

Water vapour above ice at -50 deg C
is not wet steam, definitely.

-- 
Poutnik ( the Czech word for a wanderer )

Knowledge makes great men humble, but small men arrogant.

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#563872 — Re: Why do you think you are not ?

On Sunday, March 20, 2016 at 10:13:08 AM UTC-7, Poutnik wrote:
> Dne 20/03/2016 v 16:27 James McGinn napsal(a):
> 
> > 
> > Steam is a Gas
> > 
> 
> Technical steam can be
> 
>    either scientific steam as aerosol of liquid water
>          in air ( foggy breath )
>          or  in water vapour ( technical "wet steam" )
>          or in their mixture
> 
>    either scientific vapour as gaseous water phase
>                                   ( technical "dry steam" )
> 
>    either mixture of scientific vapour and air
> 
> Water vapour above ice at -50 deg C
> is not wet steam, definitely.
> 
> -- 
> Poutnik ( the Czech word for a wanderer )
> 
> Knowledge makes great men humble, but small men arrogant.

I can't figure out what you point is.  Assuming you have one.  Sorry.

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#563913 — Re: Why do you think you are not ?

On 3/20/16 12:17 PM, James McGinn wrote:
> I can't figure out what you point is.


   Sublimation, evaporation and boiling all create water vapor, the
   gaseous phase of water.


   The physics and thermodynamics of steam – the long version
 > http://geosci.uchicago.edu/~moyer/GEOS24705/Notes/SteamNotes.pdf

 > Second, what is steam? The English language is a little fuzzy here.
 > Some definitions say that any water vapor (H2O in gaseous form
 > instead of liquid) is steam. By that definition, the atmosphere
 > itself is a very low-temperature steam engine. Other definitions say
 > that steam is water vapor if the water vapor happens to be boiling.
 > (Which brings up another question: what does "boiling" mean?)
 > Finally, a third definition says that steam is "pressurized water
 > vapor", i.e. water vapor at a pressure higher than 1 atmosphere.
 > Those are incompatible definitions, which makes clear thinking
 > difficult.

 > Let's start with the question of what boiling is, and even before
 > that, how vapors and liquids interact.

 > We all know from our experience that the atmosphere contains some
 > water vapor at all times, even at temperatures well below what we
 > might think of as the "boiling point". We talk about the humidity,
 > and know what a humid day feels like.

 > In a very qualitative explanation: whenever/wherever there is liquid
 > water, some of the water molecules "want" to be in gas phase. If you
 > bring a pot of water into very dry air and wait, you'll find that
 > some water from the pot evaporates (i.e. some of the molecules move
 > into the gas phase), until eventually the liquid and vapor reach
 > "equilibrium". At that point the liquid water and vapor are somehow
 > in the state they "want" to be in and their proportions stay
 > constant.

 > If you heat up that pot of water, however, more water "wants" to move
 > into the gas phase. You have some intuitive sense that hot air holds
 > more water vapor: a hot summer Chicago day feels damp to you, while
 > cold winter air feels dry.

 > The amount of water that evaporates as you warm the water is
 > described by a very simple and beautiful relationship, named after
 > its two independent discoverers, Clausius and Clapeyron. The
 > Clausius-Clapeyron equations states that the equilibrium "partial
 > pressure" over liquid water -- the pressure that you'd measure if you
 > had only water vapor and no extraneous air molecules -- is a function
 > only of temperature.


   There is much more, James.


-- 

sci.physics is an unmoderated newsgroup dedicated
to the discussion of physics, news from the physics
community, and physics-related social issues.

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#563907

On 3/20/16 10:27 AM, James McGinn wrote:
> I'm not so sure it's right to equate water vapor with steam.


   Sublimation, evaporation and boiling all create water vapor, the
   gaseous phase of water.


   The physics and thermodynamics of steam – the long version
> http://geosci.uchicago.edu/~moyer/GEOS24705/Notes/SteamNotes.pdf

> Second, what is steam? The English language is a little fuzzy here.
> Some definitions say that any water vapor (H2O in gaseous form
> instead of liquid) is steam. By that definition, the atmosphere
> itself is a very low-temperature steam engine. Other definitions say
> that steam is water vapor if the water vapor happens to be boiling.
> (Which brings up another question: what does "boiling" mean?)
> Finally, a third definition says that steam is "pressurized water
> vapor", i.e. water vapor at a pressure higher than 1 atmosphere.
> Those are incompatible definitions, which makes clear thinking
> difficult.

> Let's start with the question of what boiling is, and even before
> that, how vapors and liquids interact.

> We all know from our experience that the atmosphere contains some
> water vapor at all times, even at temperatures well below what we
> might think of as the "boiling point". We talk about the humidity,
> and know what a humid day feels like.

> In a very qualitative explanation: whenever/wherever there is liquid
> water, some of the water molecules "want" to be in gas phase. If you
> bring a pot of water into very dry air and wait, you'll find that
> some water from the pot evaporates (i.e. some of the molecules move
> into the gas phase), until eventually the liquid and vapor reach
> "equilibrium". At that point the liquid water and vapor are somehow
> in the state they "want" to be in and their proportions stay
> constant.

> If you heat up that pot of water, however, more water "wants" to move
> into the gas phase. You have some intuitive sense that hot air holds
> more water vapor: a hot summer Chicago day feels damp to you, while
> cold winter air feels dry.

> The amount of water that evaporates as you warm the water is
> described by a very simple and beautiful relationship, named after
> its two independent discoverers, Clausius and Clapeyron. The
> Clausius-Clapeyron equations states that the equilibrium "partial
> pressure" over liquid water -- the pressure that you'd measure if you
> had only water vapor and no extraneous air molecules -- is a function
> only of temperature.


   There is much more, James.


-- 

sci.physics is an unmoderated newsgroup dedicated
to the discussion of physics, news from the physics
community, and physics-related social issues.

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