Vacuum Cooling
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Putting heat into a system can increase it's temperature, but can also cause a change other than temperature, eg density, bonding strengths, volume growth etc. Temperature is a measure of the kinetic energy of the molecules as an average, whereas heat is a measure of all energy, kinetic, potential and chemical energy, not as an average, but as a total.
------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave
What you said. Heat is a HUGE factor in nanoscale semiconductor design. Increasing the heat in the semiconductor increases the energy of the charge carriers enough to cause them to jump from the valence band to the conduction band, among other things. [Hot channel effects, etc.] I like to use a thought experiment when I try to explain it to people who are having difficulty separating the two concepts: If I put a liter of water on the stove at 0C and heat it to boiling it will take a certain amount of time. If I put two liters on the stove it will take twice as long to heat to boiling. Obviously, it takes twice as much heat in the second case, yet both pots of water boil at 100C. As I said, it's more complex than that, but the example gets them thinking. Here's another one I throw at people occasionally: If opposite electric charges attract and like charges repel, how is it that the protons in the nucleus of an atom (which are positively charged) stick together instead of repelling each other? That usually gets them thinking instead of just regurgitating what they've been taught in school.
-Sean ---- Fire Nuts
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What you said. Heat is a HUGE factor in nanoscale semiconductor design. Increasing the heat in the semiconductor increases the energy of the charge carriers enough to cause them to jump from the valence band to the conduction band, among other things. [Hot channel effects, etc.] I like to use a thought experiment when I try to explain it to people who are having difficulty separating the two concepts: If I put a liter of water on the stove at 0C and heat it to boiling it will take a certain amount of time. If I put two liters on the stove it will take twice as long to heat to boiling. Obviously, it takes twice as much heat in the second case, yet both pots of water boil at 100C. As I said, it's more complex than that, but the example gets them thinking. Here's another one I throw at people occasionally: If opposite electric charges attract and like charges repel, how is it that the protons in the nucleus of an atom (which are positively charged) stick together instead of repelling each other? That usually gets them thinking instead of just regurgitating what they've been taught in school.
-Sean ---- Fire Nuts
Sean Cundiff wrote:
That usually gets them thinking instead of just regurgitating what they've been taught in school.
Wimps!
------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave
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Temperature is to heat as voltage is to current...
Rob Graham wrote:
Temperature is to heat as voltage is to current..
Not quite. Temperature is the average kinetic energy of the molecules in a substance. Voltage is the potential energy per unit charge. I think it would be a more appropriate comparison to say: Temperature is to heat as current density (J) is to current (I).
-Sean ---- Fire Nuts
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I've seen computers cooled with fans (airflow), tubes (water cooling), and fully submerged in oil (oil cooling), but I've never heard of a computer kept in a perfect vacuum (well, aside from those vacuum tube things that only the wisest of CPians remember). For all you pysicists, would keeping a computer in a vacuum at room temperature help cool it at all? Or would it perhaps cause it to overheat? Neither? For your reference, here is an "artist's" rendition of such a vacuum sealed computer:
+------------------------+
|\ /|
| \ / |
| \ / |
| \ / |
| \ / |
| +============+ |
| | | |
| | | | <--- Outer glass case contains no air.
| | | |
| | Computer | |
| | | |
| | | |
| +============+ |
| / \ |
| / \<--+-- Strings to suspend computer in outer case.
| / \ |
| / \ |
|/ \|
+------------------------+cooling happens by convection (transfer of heat from one material to another). so... in a vacuum, no heat would transfer or convect since there would be nothing to absorb the heat. hence... the computer would soon meltdown. it would be better to have some sort of superconducting heat convecting "diode"-like device (perfect convection with no resistance in one direction) attached to the computer's components. ==== actually in your diagram, heat would move along the strings
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Dalek Dave wrote:
Simple thermodynamics
Oxymoron? I kid, that does make sense... I wasn't quite sure how heat transfers in a vacuum. Would the same thing happen in space, where I hear the temperature is quite cold (near absolute zero)? It would be awfully ironic to boil in an absolute zero environment.
aspdotnetdev wrote:
I wasn't quite sure how heat transfers in a vacuum
The sun does it by radiation. That is the only way in a (near) vacuum. :)
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I've seen computers cooled with fans (airflow), tubes (water cooling), and fully submerged in oil (oil cooling), but I've never heard of a computer kept in a perfect vacuum (well, aside from those vacuum tube things that only the wisest of CPians remember). For all you pysicists, would keeping a computer in a vacuum at room temperature help cool it at all? Or would it perhaps cause it to overheat? Neither? For your reference, here is an "artist's" rendition of such a vacuum sealed computer:
+------------------------+
|\ /|
| \ / |
| \ / |
| \ / |
| \ / |
| +============+ |
| | | |
| | | | <--- Outer glass case contains no air.
| | | |
| | Computer | |
| | | |
| | | |
| +============+ |
| / \ |
| / \<--+-- Strings to suspend computer in outer case.
| / \ |
| / \ |
|/ \|
+------------------------+In space no one can hear your CPU blow a (figurative) gasket. Try this instead: Superfast laser cooling[^] This one will turn up sooner rather than later.
I just love Koalas - they go great with Bacon.
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aspdotnetdev wrote:
I wasn't quite sure how heat transfers in a vacuum
The sun does it by radiation. That is the only way in a (near) vacuum. :)
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There is also induction.
------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave
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aspdotnetdev wrote:
I wasn't quite sure how heat transfers in a vacuum
The sun does it by radiation. That is the only way in a (near) vacuum. :)
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Luc Pattyn wrote:
sun does it by radiation
by radiating pieces of itself. Not exactly what you'd want a CPU to do.
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There is also induction.
------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave
Yes there is, but it is not practical over long distances, and magnetic fields are not wanted in a computer environment (except right under the disc heads). :)
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Luc Pattyn wrote:
sun does it by radiation
by radiating pieces of itself. Not exactly what you'd want a CPU to do.
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http://obamacaretruth.org/ahmed zahmed wrote:
by radiating pieces of itself
aha, bits you mean. :)
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Luc Pattyn wrote:
sun does it by radiation
by radiating pieces of itself. Not exactly what you'd want a CPU to do.
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http://obamacaretruth.org/Thats what happens when the smoke gets out of the processor! You have to call the Techs to come and put the smoke back in so it will work again!
------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave
-
What you said. Heat is a HUGE factor in nanoscale semiconductor design. Increasing the heat in the semiconductor increases the energy of the charge carriers enough to cause them to jump from the valence band to the conduction band, among other things. [Hot channel effects, etc.] I like to use a thought experiment when I try to explain it to people who are having difficulty separating the two concepts: If I put a liter of water on the stove at 0C and heat it to boiling it will take a certain amount of time. If I put two liters on the stove it will take twice as long to heat to boiling. Obviously, it takes twice as much heat in the second case, yet both pots of water boil at 100C. As I said, it's more complex than that, but the example gets them thinking. Here's another one I throw at people occasionally: If opposite electric charges attract and like charges repel, how is it that the protons in the nucleus of an atom (which are positively charged) stick together instead of repelling each other? That usually gets them thinking instead of just regurgitating what they've been taught in school.
-Sean ---- Fire Nuts
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aspdotnetdev wrote:
I thought that was because the water molecules moved more freely in a low-pressure environment
Correct! That is what boiling is, increasing the escape velocity of the molecules. Where there is lower pressure, the temperature need not be so high to allow the escape.
aspdotnetdev wrote:
any of the components in the computer would break -- due to high-temperature -- in the vacuum of space
They would, the temperature increase within the components would cause a structural fail, they would disintegrate and disperse into space.
------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave
Stop it! You are ruining our image of you as a drunken buffoon!! :laugh:
I don't have ADHD, I have ADOS... Attention Deficit oooh SHINY!! If you like cars, check out the Booger Mobile blog | If you feel generous - make a donation to Camp Quality!!
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Stop it! You are ruining our image of you as a drunken buffoon!! :laugh:
I don't have ADHD, I have ADOS... Attention Deficit oooh SHINY!! If you like cars, check out the Booger Mobile blog | If you feel generous - make a donation to Camp Quality!!
A highly educated drunken buffoon!
------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave
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Temperature has nothing to do with heat! A bath of water at 1 degree C has way more heat that a cup of boiling water. Actually boiling at near absolute zero is EXACTLY what happens! Go to the top of Everest and water boils at 70C.
------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave
Dalek Dave wrote:
Go to the top of Everest and water boils at 70C.
No thanks, I'd rather boil water at 100C and have my tea here. :)
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A highly educated drunken buffoon!
------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave
Oh, well that's alright then! The world is back in order...
I don't have ADHD, I have ADOS... Attention Deficit oooh SHINY!! If you like cars, check out the Booger Mobile blog | If you feel generous - make a donation to Camp Quality!!
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Dalek Dave wrote:
Go to the top of Everest and water boils at 70C.
No thanks, I'd rather boil water at 100C and have my tea here. :)
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Luc Pattyn wrote:
No thanks, I'd rather boil water at 100C and have my tea here.
Supposedly old Ed and Tensing tried the tea at the top of Everest thing and agreed with you - apparently it tasted disgusting.
I just love Koalas - they go great with Bacon.
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I've seen computers cooled with fans (airflow), tubes (water cooling), and fully submerged in oil (oil cooling), but I've never heard of a computer kept in a perfect vacuum (well, aside from those vacuum tube things that only the wisest of CPians remember). For all you pysicists, would keeping a computer in a vacuum at room temperature help cool it at all? Or would it perhaps cause it to overheat? Neither? For your reference, here is an "artist's" rendition of such a vacuum sealed computer:
+------------------------+
|\ /|
| \ / |
| \ / |
| \ / |
| \ / |
| +============+ |
| | | |
| | | | <--- Outer glass case contains no air.
| | | |
| | Computer | |
| | | |
| | | |
| +============+ |
| / \ |
| / \<--+-- Strings to suspend computer in outer case.
| / \ |
| / \ |
|/ \|
+------------------------+There's a reason they build thermos flasks like they do, and it's not to generate efficient heat flow.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
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It would boil itself in minutes. The air is required to make the heat sinks work. Without the convection the only way energy could be expended from the system is by radiation, and that is not efficient as a cooler. Simple thermodynamics.
------------------------------------ I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave
Not bad for a bean counter... :-D
"A Journey of a Thousand Rest Stops Begins with a Single Movement"
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Dalek Dave wrote:
Temperature has nothing to do with heat!
Indeed. It's often more intuitive to explain temperature as 'heat density'. Of course it's more complex than that, but the concept is helpful.
-Sean ---- Fire Nuts
Until you get to something like spin temperature where temperature can actually decrease as you increase temperature and you can reach negative temperatures. It's actually a measure of change of randomness or entropy over change in energy, which for most objects is proportional to energy. Ha!
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon