Why is 100% efficient thermal insulator impossible?

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Discussion Overview

The discussion revolves around the question of why a 100% efficient thermal insulator is considered impossible. Participants explore concepts related to heat transfer mechanisms, including conduction, convection, and radiation, while examining the implications of entropy in relation to thermal insulation.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants suggest that stopping entropy would imply halting time, leading to the conclusion that a perfect insulator is impossible.
  • Others argue that while a vacuum can stop conduction and convection, it does not prevent radiation, which complicates the notion of a perfect insulator.
  • A participant mentions that a perfect insulator would require a perfect mirror that reflects all frequencies of radiation, which is currently unattainable.
  • There is a discussion about the theoretical existence of a perfect vacuum and its implications for thermal insulation, with some questioning how a vacuum could be considered a perfect insulator if it does not prevent radiation.

Areas of Agreement / Disagreement

Participants express differing views on the nature of thermal insulation and the role of entropy, with no consensus reached on the possibility of a 100% efficient thermal insulator. The discussion remains unresolved regarding the definitions and implications of a perfect insulator.

Contextual Notes

Participants highlight limitations in achieving a true vacuum and the challenges of stopping radiation, indicating that assumptions about perfect insulation depend on the definitions of heat transfer mechanisms.

linux kid
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Somebody told me this and I have yet to figure out even if the statement is true or not.
 
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Because if it could be done, you could stop entropy. Which you can't.

Even if you could stop conduction of heat, how would you stop a body from radiating heat?
 
If u can stop entropy its lik saying u cud stop time.SO i guess its not possible
 
anantchowdhary said:
If u can stop entropy its lik saying u cud stop time.SO i guess its not possible

Translation: If you can stop entropy it's like saying you could stop time, so I guess it's not possible.
 
Stop entropy? What does that mean?
linux kid said:
Why is 100% efficient thermal insulator impossible?

Somebody told me this and I have yet to figure out even if the statement is true or not.
If the question was, is there such a thing as a perfect insulator (i.e., has zero thermal conductivity), then the answer is "yes, a vacuum". Of course, you can't make a true vacuum, nor does a vacuum prevent radiation.
 
I like to look at such questions backwards: how could you make a perfect insulator? There are 3 types of heat transfer: conduction, convection, and radiation...

As Gokul said, a vacuum will stop conduction and convection completely, but we can't make a perfect vacuum and even if you could, you'd have to support the structure with something. So you can't completely eliminate either conduction or convection in a device (though you can eliminate conduction between objects that aren't touching. But you can get either well above 99%.

Stopping radiation is much more difficult than stopping either conduction or convection because it requires a perfect mirror that is perfect at all frequencies of radiation. And though you can get mirrors at in exess of 99% reflectance, the frequency range is limited.
 
Gokul43201 said:
then the answer is "yes, a vacuum". Of course, you can't make a true vacuum, nor does a vacuum prevent radiation.

Since a vacuum doesn't prevent radiation, how does that make it a perfect insulator?
 
It doesn't because it does not prevent readiation as gokul said.

But this perfect vacuum must exist a place farther away than light has reached since bing bang? Because if no radiation or mass have reached the point, nothing can be there.
 

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