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questions on hot and cold
Link | by Kotuso on 2005-11-28 18:53:29 (edited 2005-11-28 18:53:59)
If hot air rises and cold air sinks, how come it is very cold on top of mountians and very hot in below sea level places?

Re: questions on hot and cold
Link | by porkfryrice on 2005-11-28 19:18:32
I think its because of the theory that there is molten core in the center of the earth. As for it being cold I think it has to do with less oxygin at extreme heights.

If you can make sense of End of Evangelion's last episode then your a f**king genius

Re: questions on hot and cold
Link | by S-a-c-h-i-e-l on 2005-11-28 21:50:56
Yeah, because it's so hot in the center of the earth (thousands of degrees), some of the heat seeps out through the ocean floor and makes it hot in there.

Mountains are cold because there's less oxygen, and oxygen is the stuff that makes us warm when it's warm. So since there's low oxygen, there's low heat. I think.


Re: questions on hot and cold
Link | by gendou on 2005-11-29 15:14:59 (edited 2006-01-04 23:02:19)
Mountain tops are not cold due to lack of oxygen, per se. Rather, the atmospheric density is less the higher you go.

Also, hot air may rise whereas cold air sinks, but hot rocks do not rise in cold air and cold air does not fall into the ocean. It has to do with density: increased tempature reduces the density of a material. therefore hot air has a slightly lower density that cooler air, and tends to rise.


Re: questions on hot and cold
Link | by JM on 2005-11-30 17:33:29
well, water and the airs are much more fluent matters compared to the... moutains and ground... they don't move just because it is warm. haha it doesn't circumstance?

and... well, when the Sun rays get down to the ground it bounce up and.. it reaches to the upper parts. and other members said, there is Core and mantle under the surface area of the earth..

the important factors are.. CORE and the Reflection of... Solar engergy.

Ph.D

Re: questions on hot and cold
Link | by hoheshii on 2005-12-01 18:50:17 (edited 2005-12-01 18:51:20)
Goddamit........
You're all so stupid

Gendou is correct

Hot air rises because it is less dense that cold air. The energy stored in hot air causes it to occupy a larger volume, and therefore it is more bouyant than cold air, and it rises. As altitude increases, there is less gravity (though it is not very noticable to humans) and, in turn, there is less pressure exerted on the air. This allows the air to occupy an even greater volume, and it also causes the air to lose some energy. The loss of energy, and the decrease in pressure, is what causes it to get so cold on top of mountains.

Trust me on this, I am taking Geography 12 right now.

And to prove you are all wrong even more.....

If the molten core was what kept the planet warm, then there would be no variations in climate. It would be the same temperature wherever you went, and the oceans would boil, because the crust is thinnest under the oceans.

JM was correct about the solar radiation. The solar radiation comes down and bounces off the ground, heating it up in the process. The ground then releases that heat to the surrounding air. Places that recieve alot of solar radiation (or sunlight) have warmer climates, and places with little solar radiation have cold climates. I believe the term for this is "insolation" (No I did not spell it incorrectly)

Wise Man says: "Take a dog off its leash and it will wander."

Re: questions on hot and cold
Link | by h4xordude on 2005-12-02 04:40:17
I agree with you completely engineer, and
all of this references to one simple concept that Gendou I'm sure is familiar with:

Thermal expansion....hehehe

And the decrease in energy, such as heat for example is indeed what causes the air to get cold...oxygen is not the reason for heat Sachiel, now if you said Carbon Dioxide was that would be partly correct since CO^2 has greenhouse aspects that help store heat in the atmosphere, but lack of it doesn't result in cold temperatures.

Beware the quiet people, You don't know their intentions
(small signatures are sooo much cooler since they don't annoy people trying to read through posts!)

Re: questions on hot and cold
Link | by on 2005-12-02 07:44:12 (edited 2005-12-02 07:44:42)
uummm...can't argue with that. I'll take you and engineer's word for it.

Re: questions on hot and cold
Link | by rogueleader on 2005-12-03 11:18:41
They are right (engineer). There are some other little factors, but it's mostly pressure and energy loss. At least from what I remember in astronomy and physics.

Re: questions on hot and cold
Link | by h4xordude on 2005-12-05 04:29:09
I don't know if you guys or Gendou caught my joke though...

Beware the quiet people, You don't know their intentions
(small signatures are sooo much cooler since they don't annoy people trying to read through posts!)

Re: questions on hot and cold
Link | by lady_rin on 2005-12-05 15:53:53
Wait I know this one. We love in the desert. It's hot here because we are surounded by mountians and the cold air at the top of the mointains sinks toward the desert floor, that's over 11,000ft/>3000m. As the air sinks from the lower density altitude it gains in velocity and compresses. As the air compresses it gains heat. Remember compress a gas and it gains temperature. That's what gives us out fast hot winds here.


Re: questions on hot and cold
Link | by Kisuke on 2006-01-05 21:12:41
umm...but i'm pretty sure that as air compresses, it loses, not gains, velocity. Not to mention the tundra is a desert. A desert does not have to be hot, it is just any place lacking in water. So your explanation does not really explain why cold deserts aren't hot. Besides, the air over the desert isn't falling down past a mountain, so according to you it is cold in the middle of a hot desert?

"Death destroys a man, the idea of death saves him." E.M Forster

Re: questions on hot and cold
Link | by hoheshii on 2006-01-10 22:07:20
Ya, what Rin is said is partially correct.

As the air rises up the windward (not desert) side of the mountain range, it cools and condenses into clouds, then precipitates out all its water. The dry air continues over the top of the mountain and comes rushing down the leeward (desert) side of the mountain and heats up as it falls. It then goes rushing across the desert as a dry, hot wind.

That also explains why there is little rain in the desert. I believe the official designation of a desert is an area that recieves less than 500 mm of precipitation annually.

Wise Man says: "Take a dog off its leash and it will wander."

Re: questions on hot and cold
Link | by TIE_Defender2nd on 2006-01-10 22:13:44
hmm.... no wonder Vancouver gets like 3 months of rain in the winter...>< TNX for the info btw, engineer ;)

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Re: questions on hot and cold
Link | by hoheshii on 2006-01-10 22:19:36
Vancouver is right next to the Coast Mountains, and its right next to the ocean so it recieves alot of rain. I think Vancouver gets like 1800 mm of precipitation annually, which is just below the designation for a rainforest, at 2000 mm annually.

Wise Man says: "Take a dog off its leash and it will wander."

Re: questions on hot and cold
Link | by Kisuke on 2006-01-11 15:50:21
well, i have a question. take the tundra for instance. It is a dessert, but it is not hot.

"Death destroys a man, the idea of death saves him." E.M Forster

Re: questions on hot and cold
Link | by on 2006-01-11 16:34:51
I don't know! I think the lower you are, the hotter you are when it's cold! But when you are lower, the colder it is when it's hot!

Re: questions on hot and cold
Link | by hoheshii on 2006-01-11 18:16:12
Like I previously stated, a desert is any area that recieves less than 500 mm of precipitation annually. Kisuke is correct about the tundra being a desert, because 10 months of the year the tundra regions have sub-zero temperatures. Cold air loses its ability to hold water vapour, therefore clouds rarely form over tundra regions, and precipitation is even rarer.

Wise Man says: "Take a dog off its leash and it will wander."

Re: questions on hot and cold
Link | by Kisuke on 2006-01-12 13:20:52
So basically, to sum it up, hot deserts are desert because the water vapor in the clouds is dropped at the high altitudes of the mountains, and the cold air comes rushing down and heating up to cause the warming effect. However in deserts like the tundra, it is desert not because of mountains, but because the sub zero temperatures do not allow the air to hold water vapor.

"Death destroys a man, the idea of death saves him." E.M Forster

Re: questions on hot and cold
Link | by Flying on 2010-10-21 23:09:44
hot n cold just a mind state.

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