Thermodynamics and was looking at the second law

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SUMMARY

The discussion centers on the Second Law of Thermodynamics, specifically its application to isolated and non-isolated systems. Participants clarify that while the Second Law states that entropy increases in isolated systems, its implications for non-isolated systems are more complex and depend on interactions with the environment. The conversation references Rudolf Clausius's formulation from 1865 and highlights the importance of both empirical and axiomatic formulations of thermodynamics, particularly the neogibbsian approach influenced by Gibbs. The consensus is that the Second Law applies to non-isolated systems but requires different formulations.

PREREQUISITES
  • Understanding of the Second Law of Thermodynamics
  • Familiarity with entropy and its implications
  • Knowledge of isolated vs. non-isolated systems
  • Basic concepts of classical equilibrium thermodynamics
NEXT STEPS
  • Research Rudolf Clausius's formulation of the Second Law of Thermodynamics
  • Study the neogibbsian formulation of classical equilibrium thermodynamics
  • Explore Boltzmann's kinetic equation and its relation to entropy
  • Investigate the relationship between time flow and entropy increase
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Students of physics, thermodynamics researchers, and anyone interested in the foundational principles of entropy and thermodynamic laws.

misogynisticfeminist
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I'm new to thermodynamics and was looking at the second law. From what I know, the 2nd law is constantly violated locally (in a non-isolated system), but this violation locally causes an increase in entropy in an isolated system. Am I right here? or is my understanding flawed? if its not, then are there any examples of this?
 
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the second law is dealing with both system and its envirinment.
you can not tell anything by ignoring one of them. ok?
 
misogynisticfeminist said:
I'm new to thermodynamics and was looking at the second law. From what I know, the 2nd law is constantly violated locally (in a non-isolated system), but this violation locally causes an increase in entropy in an isolated system. Am I right here? or is my understanding flawed? if its not, then are there any examples of this?


The second law states that entropy increases in isolated systems (as it can be shown using Boltzmann's kinetic equation).The only isolated system physicsist know is the entire Universe,so applying the second law,in the entire Universe the entropy increases with time (and viceversa,though i don't know anybody having proven the fact that time flow is inextricably linked to entropy increase (maybe smb proved that,but i haven't read about it,but I'd like to)).
To say that
misogynisticfeminist said:
the 2nd law is constantly violated locally (in a non-isolated system), but this violation locally causes an increase in entropy in an isolated system.
is virtually wrong because the second law doesn't tell what happens to the entropy in non-isolated systems.It could be constant,increase,decrease,depends on the interactions between the studied system and the environment.

I've allways considered this (Rudolf Clausius 1865(?)) formulation of the second law as the most important achivement in physics in the XIX-th century,alongside Faraday's 1831 discovery of electromagnetic induction.
 
^ hmmmm, understood, so can it be safe to say that the second law does not apply to non-isolated systems ??
 
It does,but in other formulations.Clausius's formulation refers only to isolated systems and i guess it's the only one of them to do so.
The thermodynamics teacher told us that classical equilibrium thermodynamics has two formulations.The empirical one,and the axiomatical/theoretical one (due mostly to Gibbs,hence "neogibbsian" formulation of classical equilibrium thermodynamics).The former has a long history,and has numerous formulations for its principles (as I recall,they're 5 of them (i.e. principles)),and especially for the second principle.The latter is based upon the definition and the properties of the thermodynamical function called ENTROPY.It's formulation of the second principle includes Clausius formulation for the second principle in the so-called "CTPCN" (apud Clausius-Thomson-Carathéodory-Planck-Nernst) formulation (which is the name for the first formulation stated above) and it's essential to be taught for its beautiful derivation from classical &/V quantum equilibrium statistical mechanics.
 
dextercioby said:
I've allways considered this (Rudolf Clausius 1865(?)) formulation of the second law as the most important achivement in physics...
Clausius's formulation refers only to isolated systems and i guess it's the only one of them to do so.

Thanks for quoting me. Yes, in fact in those years we were a nice group of guys trying to figure out what the hell was entropy. :biggrin:
 
Clausius2 said:
Thanks for quoting me. Yes, in fact in those years we were a nice group of guys trying to figure out what the hell was entropy. :biggrin:

Dann Du muss ein Deutsche sein,nich wahr??
 
dextercioby said:
Dann Du muss ein Deutsche sein,nich wahr??

Selbstverständlich obgleich ich normalerweise meinen Feiertag in Benidorm verbringe.

:smile: :smile: :smile:
 

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