[yor_on]

what !!

Maybe
Keep on and I may, just may, change my mind..
But I want you to understand that our "Small pink teddy bears throwing fairy-dust" will have to go with that too. Are you really prepared to do that?


It's a cruel cruel world.
"Don't cry children, I'm sure the big meanies will change their mind now."

[Geezer]

I think the airmass that forms a cloud is quite dynamic, and this produces a mechanism that keeps the minute water particles aloft.

You may have noticed how the ride in an aeroplane suddenly gets rather bumpy as soon as it enters a cloud. I would think this is an indication how much turbulence there can be in clouds. However, that only just occurred to me, so I would not be very surprised to learn that it's wrong.

[QuantumClue]

I've had some time to study the science behind clouds. Clouds are as I suspected a gas phase, which as most of us will all know from elementary science is one of four well-known phases of matter. The gas phase is simply a water vapour, so it should be of no surprise clouds stay afloat. Eventually, this water vapour will condense - it is not condensed in the air, and is not kept afloat by any special mechanism, like which was mentioned perhaps ''droplets are tiny enough that updrafts in the atmosphere can hold them aloft'' - Droplets are not in this form in the sky - droplets occur when the gas phase changes into a liquid phase, and hence, which is why clouds condense into rain.

[QuantumClue]

Here's a little info courtesy of wiki ~ water vapour is in fact lighter than air. So air cannot keep water vapour afloat.

[CliffordK]

Density of water vapor (from my calculations above) is lighter than air, and is what gets single-molecule water vapor up into the air at the level of the clouds.  A very fine aerosol, while greater density than air, will tend to float in the air for some time, but slowly settles down.

(Quantum, remember, if density is lower than air, like hydrogen or helium, it will tend to rise, if it is heavier than air, like propane, it will tend to sink).

Condensation would tend to release heat (Soul Surfer) which would cause convection and updrafts.  

Condensation would also tend to cause a decrease in volume, and thus a decrease in pressure, and create more turbulence.

While we see clouds that leisurely float across the sky, my guess is that it is a much more dynamic process.  

For example, if clouds tend to form at 1000 feet due to high vapor density, and low temperatures, then as mentioned, that might tend to create some updrafts.  However, if the droplets fall down to 900 feet, the air temperature may be higher and the vapor density may be lower, and the falling droplets would evaporate back into vapor, which would cause a localized high pressure, and the now lighter than air vapor would tend to rise again up into the cloud, only to re-condense. 

As mentioned previously, not all clouds are created equally.  Thunderheads are likely much different from ordinary high floating clouds.  While not a meteorologist, I'm thinking that a thunderhead would be formed with very cold air combining with very humid air, with a more extreme gradient than normally experienced. 

[Geezer]

The gas phase is simply a water vapour, so it should be of no surprise clouds stay afloat.

I don't think so QC. Water vapour in the gas phase is invisible.

The reason clouds are visible is because some of the water vapour condenses around minute hygroscopic particles.

[QuantumClue]

Water vapour is a gas phase... I am confused. I am informed that ''Water vapor is a potent greenhouse gas along with other gases such as carbon.'' Water vapour you say in its gas phase cannot be seen - supposing this is true, then how can water vapour be seen when boiling water?

[QuantumClue]

But still yeh, I am confused about you treating water vapour as being conditional when talking about a gas phase... can you expand on this?

Thanks

[Geezer]

then how can water vapour be seen when boiling water?

Ah, right. Steam (which is the gas phase of water) is actually invisible. When you see stuff coming out of a boiling kettle, what you are seeing is water particles that condensed out of the steam when they lost their heat to the ambient air outside the kettle.

Superheated steam escaping from a boiler can be very dangerous because it can be invisible for quite a distance away from the boiler. Consequently, it can cause severe burns before the victim even realizes what's happening. 

[yor_on]

Take a look at this one. The writing is all together, in one big chunk of words, but you can always start with searching on ' buoyancy ' Clouds, Stability, and Buoyancy Be prepared though, really reading it you will learn more than you ever wanted to know about clouds

And if you still don't see what I mean?
"Don't you cry now.. The pixies will make it right children. The teddybears will come back."

Ah, where were I?

[QuantumClue]

then how can water vapour be seen when boiling water?

Ah, right. Steam (which is the gas phase of water) is actually invisible. When you see stuff coming out of a boiling kettle, what you are seeing is water particles that condensed out of the steam when they lost their heat to the ambient air outside the kettle.

Superheated steam escaping from a boiler can be very dangerous because it can be invisible for quite a distance away from the boiler. Consequently, it can cause severe burns before the victim even realizes what's happening. 

I'll just need to take your word for it ~ I know really nothing scientific about the subject, only what I read recently.

[Geezer]

then how can water vapour be seen when boiling water?

Ah, right. Steam (which is the gas phase of water) is actually invisible. When you see stuff coming out of a boiling kettle, what you are seeing is water particles that condensed out of the steam when they lost their heat to the ambient air outside the kettle.

Superheated steam escaping from a boiler can be very dangerous because it can be invisible for quite a distance away from the boiler. Consequently, it can cause severe burns before the victim even realizes what's happening. 

I'll just need to take your word for it ~ I know really nothing scientific about the subject, only what I read recently.

No need to take my word for it. From "Steam" on Wiki (although not necessarily the most reliable source)

"In common speech, steam most often refers to the visible white mist that condenses above boiling water as the hot vapor mixes with the cooler air. This mist consists of tiny droplets of liquid water. Pure steam emerges at the base of the spout of a steaming kettle where there is no visible vapor."

[Foolosophy]

The gas phase is simply a water vapour, so it should be of no surprise clouds stay afloat.

I don't think so QC. Water vapour in the gas phase is invisible.

The reason clouds are visible is because some of the water vapour condenses around minute hygroscopic particles.

This is correct.

Water vapour itself (ie steam) is not visible to the naked eye.

Notice the breath from your mouth when you exhale on a cold morning?

And we all know Why this doesnt occur each and every time we exhale?

(and of course density is NOT the reason clouds float. Smoke particles float away in plumes and yet the denisty of a smoke particle can be several thousand times greater than that of the surrounding air. So why dont the smoke particles settle out rapidly? Seek and thy shalt discover my child)

[yor_on]

heh
==

What is 'pressure'?

[Foolosophy]

heh
==

What is 'pressure'?

Only The Scientist can answer that sublime question

[yor_on]

(and of course density is NOT the reason clouds float. Smoke particles float away in plumes and yet the denisty of a smoke particle can be several thousand times greater than that of the surrounding air. So why dont the smoke particles settle out rapidly? Seek and thy shalt discover my child)

"So, so, so, he was only joking children."

"Yes, it's the fairy dust."
 
"N000, stop that, he did not mean that you should go out the window again Peter. We're on the tenth floor, remember?"

"YES! for the ninthyeleventh time. Tinkle bell will be here as soon as she can, Someone has to work."

Foolosophy, now you've upset the kids.

[Foolosophy]

(and of course density is NOT the reason clouds float. Smoke particles float away in plumes and yet the denisty of a smoke particle can be several thousand times greater than that of the surrounding air. So why dont the smoke particles settle out rapidly? Seek and thy shalt discover my child)

"So, so, so, he was only joking children."

"Yes, it's the fairy dust."
 
"N000, stop that, he did not mean that you should go out the window again Peter. We're on the tenth floor, remember?"

"YES! for the ninthyeleventh time. Tinkle bell will be here as soon as she can, Someone has to work."

Foolosophy, now you've upset the kids.

Careful Yoron, you may be ejected from this establishment for posting potentially humourous comments that have no scientific conservatism attached to them