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Author Topic: Could the temperature of the earth's core ever approach 0 Kelvin?  (Read 2272 times)

Offline Michael Platts

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If we assume that the earth was thousands of light years from any other body would the temperature of the core ever approach zero kelvin?   Would the  radiogenic warming ever shut down?


 

Online Bored chemist

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"Would the  radiogenic warming ever shut down?"
Eventually, in principle. But there's plenty of bismuth and such in the world, and they have seriously long decay half lives.
http://en.wikipedia.org/wiki/List_of_radioactive_isotopes_by_half-life#1030_seconds

But, even with nothing around it keeping it warm, the Earth (or anything else) would never quite cool to 0K. The cooler it got the less heat it would radiate, so the more slowly it would cool down.
 

Offline Ethos_

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"Would the  radiogenic warming ever shut down?"
Eventually, in principle. But there's plenty of bismuth and such in the world, and they have seriously long decay half lives.
http://en.wikipedia.org/wiki/List_of_radioactive_isotopes_by_half-life#1030_seconds

But, even with nothing around it keeping it warm, the Earth (or anything else) would never quite cool to 0K. The cooler it got the less heat it would radiate, so the more slowly it would cool down.
Very true Bored Chemist, and even if all radioactive decay processes were to finally cease, we still have the Cosmic Background Radiation to deal with. Even the so-called emptiness of space has a temperature slightly above zero Kelvin. And a presumed heat death of the universe would ultimately only reach an equilibrium with a fraction of a degree above absolute. When speaking of absolutes, one needs to remember; "It is absolutely true that nothing is absolute."
« Last Edit: 05/03/2014 21:19:35 by Ethos_ »
 

Offline Michael Platts

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Thank you, Bored Chemist and Ethos_
 

Offline Bill S

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There's also the uncertainty principle that prevents us from ever being able to measure anything as absolute 0K - I think :)
 

Offline jeffreyH

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There's also the uncertainty principle that prevents us from ever being able to measure anything as absolute 0K - I think :)

You would still have zero point energy at 0K. This is a quantum effect.
 

Offline Bill S

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Quote from: jeffreyH
You would still have zero point energy at 0K. This is a quantum effect

Wouldn't uncertainty prevent you from measuring 0K, because if you could you would know the location and momentum of any particle thus measured?
 

Offline Bill S

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On reflection, I think I should have distinguished between zero energy and zero point energy.  (?)
 

Offline jeffreyH

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On reflection, I think I should have distinguished between zero energy and zero point energy.  (?)

This should make things clear. Note the section on the uncertainty principle.

http://en.wikipedia.org/wiki/Zero-point_energy
« Last Edit: 14/03/2014 22:37:27 by jeffreyH »
 

Online Bored chemist

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It doesn't matter.
Even if you had an infinite energy sink at ok
(Which is , of course, impossible) and you connected it to the earth via a link of infinite thermal conductivity, (which is, of course, impossible)
it would still take an infinite amount of time to cool down (classically) to  0K.
Non classically, 0K is, shall we say, poorly defined.
 

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