Temperature in Space: The Kelvin Scale

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Discussion Overview

The discussion revolves around the concept of temperature in space, particularly in relation to the Kelvin scale and the implications of temperature in environments with few or no particles, such as free space. Participants explore definitions of temperature, the role of radiation, and the statistical nature of temperature in relation to collections of particles.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants assert that the Kelvin scale defines temperature as a measure of kinetic energy of particles, questioning how this applies in free space where particles are absent.
  • Others introduce the concept of the Cosmic Microwave Background Radiation as a factor contributing to temperature in space.
  • One participant suggests that the definition of temperature is incomplete if it only considers kinetic energy, emphasizing the need to account for radiation and sparse matter in intergalactic space.
  • There is a contention regarding the existence of temperature "in the gaps" between molecules, with some arguing that temperature is a statistical property that requires a collection of particles to be meaningful.
  • Several participants express uncertainty about their understanding and interpretations of the topic, indicating a lack of consensus on the definitions and implications of temperature in low-density environments.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the definition of temperature in the absence of particles, with multiple competing views presented regarding the role of radiation and the statistical nature of temperature.

Contextual Notes

Limitations include the dependence on definitions of temperature and the unresolved nature of how temperature applies in environments with very few particles or radiation.

Niladri Dan
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The Kelvin scale states that the temperature is a measure of the kinetic energy of the particles(molecules) of the system. But what is the temperature of a system where there are no particles...for example free space, far away from the stellar civilisation...
 
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Niladri Dan said:
The Kelvin scale states that the temperature is a measure of the kinetic energy of the particles(molecules) of the system. But what is the temperature of a system where there are no particles...for example free space, far away from the stellar civilisation...

hi there

for a start have a read of some better definitions of the Kelvin scale compared to what you wrote

https://en.wikipedia.org/wiki/Kelvin

you will discover that temperature isn't just based on kinetic energy of the particlesDave
 
Niladri Dan said:
The Kelvin scale states that the temperature is a measure of the kinetic energy of the particles(molecules) of the system. But what is the temperature of a system where there are no particles...for example free space, far away from the stellar civilisation...

That definition of temperature in terms of the kinetic energy of the particles in a system is incomplete; we also have to include a contribution from whatever radiation, like the cosmic microwave background, is out there. And even intergalactic space is not completely devoid of matter - there are a few stray atoms floating around, and the occasional highly energetic cosmic ray coming through.
 
I have tried to think about the some thing but 'in the gaps' at molecular level of the atmosphere.
 
pBrane said:
I have tried to think about the some thing but 'in the gaps' at molecular level of the atmosphere.
The temperature "in the gaps" between molecules does not exist. Temperature is a statistical property of large collections of things such as atoms and molecules. If you restrict your attention to a setting with a collection of zero objects, temperature is no longer an attribute of that collection.

Apologies if I've misunderstood your posting.
 
jbriggs444 said:
The temperature "in the gaps" between molecules does not exist. Temperature is a statistical property of large collections of things such as atoms and molecules. If you restrict your attention to a setting with a collection of zero objects, temperature is no longer an attribute of that collection.

Apologies if I've misunderstood your posting.
Don't worry about it, I may have misunderstood my posting as well!
 
pBrane said:
Don't worry about it, I may have misunderstood my posting as well!
WOW ... over 2 years to respond ... almost a record :wink::biggrin::smile:
 
davenn said:
WOW ... over 2 years to respond ... almost a record :wink::biggrin::smile:
wuz time travlin, just sayin.. topic probably banned here so don't tell anyone!
 
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