2nd principle of termoDynamics

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Discussion Overview

The discussion revolves around the second principle of thermodynamics, specifically addressing the implications of heat transfer between cooler and warmer objects in a closed system. Participants explore the concepts of heat equalization and the potential for reversing this process without introducing external energy or breaking system isolation.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants assert that heat flows from higher to lower temperatures and that this process is not reversible, even with mechanisms like heat pumps.
  • Others argue that the second law of thermodynamics is statistical and may allow for small variations, but it fundamentally applies to closed systems, which are theoretical in nature.
  • A participant questions how to restore temperature differences between objects in an isolated system after they have equalized, suggesting that introducing a third object might not break isolation.
  • Another participant suggests that insulation could slow the equalization process but acknowledges that perfect insulation does not exist, implying that temperatures will eventually equalize again.
  • One participant clarifies that while it is possible to separate objects in an insulated container, doing so without additional energy input is not feasible.

Areas of Agreement / Disagreement

Participants express differing views on the reversibility of heat transfer and the implications of the second law of thermodynamics. There is no consensus on whether it is possible to restore original temperature differences in a closed system without external energy.

Contextual Notes

The discussion highlights limitations related to the assumptions of closed systems and the practicalities of heat transfer, including the role of insulation and the nature of energy input.

deda
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The second principle of termodynamics says:
cooler object cannot give away heat spontaneously to warmer one.
I wonder then how do cooler and wormer object appear in a closed system after they have equalized their heat.Or in other words:
Is there a way back <=> Could this phenomenon be reversible in a closed system?

Billioners don't appear in the middle of desert but in the center of society.
 
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I'm not sure I understand what you are asking, but heat always flows from areas of higher temp to areas of lower temp. It is not reversible (not even a heat pump qualifies as reversing it).
 
I think I get it. He's asking how the second law can be true given that hot and cold things can spontanteously appear. The answer is compound:
1. the second law is statistical, there can be really small variations
2. It only holds for closed systems, but there are technically no closed systems, unless one has the whole universe be your system
3. You might be getting confused with you experience of the world. If you have a piece of metal sitting in a room at room temperature, and touch it, it will feel cold. This is because you are warmer than it and it conducts heat faster than the air, so it draws away your heat faster than the air does, cooling that area slightly below the usual cooling caused by the air, and makes itself warmer.
So pretty much, it is rare and unnoticable that hot and cold things spontaneously occur, so the second law is a really really good rule of thumb.
 
Last edited:
I was aiming more on this:
I have isolated one termo system with cold and warm objects in it.
I brought them in direct contact.
The warm object is giving it's heat to the cool until they become equally warm.
The system preserves all it's heat.
Now if I want to differentiate/distinguish them again I have to insert some 3rd object from outside into the system.
But this will not open the system or it won't break it's isolation cause how much heat the 3rd object is getting from the 1st one that much heat is giving to the 2nd.
In the end my intention is to close the circuit or to get where I started.
Unfortunatelly, this TD principle won't let me do so cause:
The 3rd object has same heat as for the 1st as for the 2nd object which means it will (according to this TD principle) equally worp up(cool down) both objects.
It's same as polarization and neutralization.

How do I polarize the object's heats again without opening the system?
 
Originally posted by deda
How do I polarize the object's heats again without opening the system?
Insulation?
 
Originally posted by russ_watters
Insulation?

This can slow the process (I know you know this Russ, but this is for the original poster) but there is no perfect insulator, so eventually the temperatures will again equalize.
 
If I am understanding your question correctly, you are placing two objects with significant temperature differences(hot and cold) into an insulated container. Then, you bring those two objects together, physically or environmentally, to effect a heat transfer from the hot object to the cold object, eventually equalizing an average temperature of both.
Then, if I understand this, your goal is to separate the objects again, with each object having their original temperature differances.
Can this be done in an isolated system? Of course! Very easily.
Can this be done without the introduction of additional energy? No.
 

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