Register | Sign In


Understanding through Discussion


EvC Forum active members: 64 (9164 total)
9 online now:
Newest Member: ChatGPT
Post Volume: Total: 916,839 Year: 4,096/9,624 Month: 967/974 Week: 294/286 Day: 15/40 Hour: 0/1


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   The Flood - Animals and their minimum food requirement
PurpleYouko
Member
Posts: 714
From: Columbia Missouri
Joined: 11-11-2004


Message 182 of 239 (346644)
09-05-2006 10:51 AM
Reply to: Message 170 by johnfolton
09-04-2006 11:57 PM


Re: Query about figures.
Hopefully this article will explain how your excessive steamtemps are chilled in near vacuum states (as would of existed within the upper atmosphere) to 46 Degrees F.
So all you now have to explain is where the excess heat from the powers supply for this process went.
Powered refrigeration of any type produces a net increase in temperature. Only the refrigerated part gets colder. the rest gets hotter, and by a larger amount too.

This message is a reply to:
 Message 170 by johnfolton, posted 09-04-2006 11:57 PM johnfolton has replied

Replies to this message:
 Message 186 by johnfolton, posted 09-05-2006 12:22 PM PurpleYouko has replied

  
PurpleYouko
Member
Posts: 714
From: Columbia Missouri
Joined: 11-11-2004


Message 188 of 239 (346674)
09-05-2006 12:44 PM
Reply to: Message 186 by johnfolton
09-05-2006 12:22 PM


Re: Query about figures.
The excessive heat upward simply pressed open the heavens thus opening them so the heat would of vented above the atmosphere.
You can't transmit heat through a vacuum. the only way for a body to lose heat in this way is black body radiation and that is SLOOOOOOW!
It says the fountains of the deep were broken up and and the windows of heaven were opened(heat rises)
Actually, heat doesn't rise at all. Hot things tend to be less dense than cold things. Therefore hot gas and vapors are lighter than cold gas and vapors so they will float to the top. This is called convection.
What they won't do is go above the top.
And what they most defininetly won't do it remove heat from the planet except for the slow trickle of black body radiation. The vacuum of space does not conduct heat.
Edited by PurpleYouko, : No reason given.

This message is a reply to:
 Message 186 by johnfolton, posted 09-05-2006 12:22 PM johnfolton has replied

Replies to this message:
 Message 197 by johnfolton, posted 09-05-2006 8:00 PM PurpleYouko has replied

  
PurpleYouko
Member
Posts: 714
From: Columbia Missouri
Joined: 11-11-2004


Message 213 of 239 (346941)
09-06-2006 9:16 AM
Reply to: Message 197 by johnfolton
09-05-2006 8:00 PM


Re: Query about figures.
Where did the heat go, did the vacuum absorb it away?
In a word NO.
Vacuum has ZERO heat capacity. It cannot and will not absorb heat under any (non magical) circumstances. Vacuum is a perfect (almost) insulator. That is why they make thermos flasks and cryogenic gas tanks with a vacuum between the layers. It keeps the heat or cold right where it is.
I have no physical problem with launching a bunch of stuff into space but it has nothing to do with heat rising in that circumstance.
What we would have then is a bunch of superheated steam being forced into space. (Of course you must realize that it would have to leave the geysers at something close to 25,000 miles per hour right?)
Once in space, the water molecules will spread out to put as much distance as possible between them and begin to (very very slowly) cool by radiating the excess heat away. Remember that this radiation will also go back down toward the earth as well as into space.
Now your situation is this. You have millions of cubic miles of superheated steam orbiting the earth. (original 800 degrees plus friction from the incredible velocity at which it was ejected.) When the stuff begins to fall back to earth it now has an additional (massive) ammount of energy stored up as potential energy due to its height above ground. It will release this energy into the atmosphere as it falls. That is one hell of a lot of heat!
They used heat to separate the two fluids; then they brought them back together in a near vacuum environment, the water experienced a phase change to remix with the salt at a very low temperature in an absorber, water vaporizes cold enough to produce 46F chilled water.)
There is nothing magical about this.
It is a perfectly well understood mechanism that any science undergrad and most high school students could explain to you.
The fact remains that you have to put energy into the system to cool the water. The system as a whole, increases in temperature.
This is not what happens in our upper atmosphere. If it did then the process itself would fry the earth with its excess heat.
The Earth is effectively a closed system, encased in the (almost) perfect insulator of interplanetary space. If you produce heat somewhere you are stuck with it for the next several thousand years.

This message is a reply to:
 Message 197 by johnfolton, posted 09-05-2006 8:00 PM johnfolton has replied

Replies to this message:
 Message 214 by JonF, posted 09-06-2006 9:29 AM PurpleYouko has not replied
 Message 216 by johnfolton, posted 09-06-2006 12:07 PM PurpleYouko has replied

  
PurpleYouko
Member
Posts: 714
From: Columbia Missouri
Joined: 11-11-2004


Message 218 of 239 (346971)
09-06-2006 12:48 PM
Reply to: Message 216 by johnfolton
09-06-2006 12:07 PM


Re: Query about figures.
I was under the impression that water becomes steam only because its under pressure remove the pressure and it cools quite quickly because its no longer under pressure.
Oh I see where your misunderstanding is coming from now.
Water becomes steam (converts from liquid to gas phase or boils) depending on pressure and temperature. At sea level, (one atmosphere) it becomes steam (gas) at 100 degrees C. If you move it up a high mountain then it boils at a much lower temperature.
Put it in a vacuum and it instantly boils no matter what the temperature is. Pressure is the only thing that keeps it liquid.
Have a look at the phase diagram for water/ice/vapor
Please explain black radiation making it not possible for steam to cool quite quickly in the natural once its pressure is removed as in a vacuum as stated in the article that it cools quite quickly to 46 degrees F to a clear chilled water vapor.
As for the temperature, that is down to the rate of molecular vibration and is independent of pressure entirely. The water molecule can only get rid of its heat (vibration) by passing it on to something else. In a vacuum there is nothing to pass it on too except for infrared low energy photons (black-body radiation) so it will remain very very hot for a long long time.
Gasses always want to expand to fill up all available space around them in order to equalize pressures. In space the volume to fill is pretty much infinite so the molecules will continue to move away from each other until they no longer interact with each other in any way. The vast majority of the stuff would never return to earth at all once it gets into space.
Explain why I need to keep heating my hot water heater if this black radiation takes so long to dissipate its heat.
because your hot water tank is NOT in a vacuum and can therefore lose heat to its surroundings by conduction. The pipes that come out of it feel hot right? That is conduction.
The compressed air enters the nozzle at ambient temperature but as it expands into the open air, this high-density air cools dramatically. It is doing work on the open air, pushing that open air out of its way to make room for itself as it expands to normal density and pressure. Doing this work takes away a good fraction of the compressed air's thermal energy, so it becomes quite cold. Heat flows into it from the water droplets and those water droplets freeze into artificial snow.
This is basic physics. Nothing tricky here.
and incidentally this is not the entire quote from your site. it makes more sense with the entire thing included.
First it asks the question.....
quote:
To speed the freezing process, the jet from the water nozzle mixes with the jet from a compressed air nozzle. Air spraying out of this second nozzle not only breaks up the water into tiny droplets, but it helps to cool and freeze those droplets as well. However, the compressed air and the water both enter their nozzles at the same temperature--about 0 C. Explain how this expanding jet of compressed air is able to help chill the water jet.
then it goes on to answer the question...
quote:
Answer: The expanding air does work on the surrounding air and its temperature decreases as a result. Heat flows out of the water jet into this expanding jet of air and the water freezes into ice
The jet of air absorbs heat from the jet of water as it expands.
In this example the air starts out at ambient temperature (which is actually Zero degrees C) then gives away heat to the surounding air as it expands (by conduction). It then absorbs latent heat from the water to re-equilibrate itself with the ambient temperature. This forces the water to go through a phase change (to ice) but without actually changing temperature at all.
As I said, basic physics. (and horribly over-simplified physics too)
No heat gained and no heat lost overall.
Now imagine the same scenario with a superheated jet of water vapor that is expanding into the atmosphere from a giant geyser.
Using the same principle it is going to cool (slightly) as it expands. How is it going to do this?
By giving up heat to the surrounding air. ie. making it hotter.
There is just no way that you could ever get ice out of this scenario. What you WILL get is steam cooling from 190 degrees to 150 degrees (number just dragged out of thin air at random) and the missing 40 degrees being given up to the surrounding air. If the air had an ambient temperature of 25 degree before, then it will now be at 65 degrees.
Somewhat uncomfortable to breath I would think.
certainly no ice forming anywhere on the planet.

This message is a reply to:
 Message 216 by johnfolton, posted 09-06-2006 12:07 PM johnfolton has replied

Replies to this message:
 Message 220 by johnfolton, posted 09-06-2006 6:59 PM PurpleYouko has not replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024