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Negative Absolute Temperature

temperature

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#1 Reva04

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Posted 16 June 2014 - 06:10 AM

I read an article which states that some systems temperature can be expressed as negative quantity on the Kelvin scale. How is this possible? I think it is impossible to go below absolute zero on Kelvin scale. And it is also stated that a system with an absolute negative Kelvin temperature is actually hotter than any system with a positive temperature and if a negative-temperature system and a positive-temperature system come in contact, heat will flow from the negative- to the positive-temperature system. How is this possible? can someone explain this in layman terms

 

Source: http://functionspace.org/topic/1771



#2 chemiboy11

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Posted 23 June 2014 - 01:14 PM

There is no such thing as a negative Kelvin temperature.



#3 frpe

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Posted 24 June 2014 - 02:05 AM

as far as I understand the point, it's a local perturbation where temperature is not measured but estimated from effects on volume,

I do not comment (my knowledge of matter is really limited)

but our knowledge changes through the course of time 

http://en.wikipedia....ars_of_Hercules


Edited by frpe, 24 June 2014 - 02:15 AM.


#4 Neelakantan

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Posted 25 June 2014 - 01:28 AM

The kelvin scale of measuring temperature is based on zero entropy at zero temperature. That is why it is called absolute scale as we all measure enthalpy and entropy change.

 

Schrodinger has talked about negative entropy (that is life processes using unlimited environment energy!) ; read these two: http://www.intotheco...m/energetic.php

http://www.bangalore...ive_entropy.htm

 

but this doesnot mean that negative absolute temperature is possible; for that we have to look at the meaning of absolute zero. this  is a point of singularity where time, space, energy, mass are interchangeable (yes time too!). This is in the realms of theorist physicists; this is because of our definition of temperature relating entropy and enthalpy; (i dont know how to create delta sign in this window!)

1/temperature = change in entropy/change in energy

in normal real world we can interpret it as a measure of kinetic energy but when we reach a situation where, there will be limited states for the molecules, by principles of average, some of the molecules have to be in negative temperature.. this is explained here:

http://www.physicsce...temperature.cfm

and here:

http://en.wikipedia....ive_temperature

 

regards

neelakantan






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