- #1
FranzDiCoccio
- 342
- 41
Hi all,
sorry for the condensed title of my post. Any other version of the question I'm trying to ask turned out to be longer than allowed.
So, my question is about the wording in some versions of Clausius' statement of the 2nd law of thermodynamics.
From time to time I read something like "It is impossible to build a machine whose only effect is the transfer of heat from a heat reservoir to another heat reservoir at a higher temperature", possibly specifying "without any work done".
Perhaps I'm being nitpicking, but I have the feeling that the concept of "machine" does not fit well in Clausius' statement.
How is that a machine, if no work is involved?
I would rather say "a process where heat is spontaneusly transferred from a cold source to a hot source is impossible". Perhaps one could add "unless some work is done", but that's sort of covered by "spontaneously".
All in all it seems to me that sometimes authors are carried away a little and try to write Clausius' statement using the same wording as in Kelvin's one.
Is it just me? Or perhaps could it be a subtlety of Italian that does not emerge in English?
Are you ok with Clausius' formulation of the 2nd law involving a machine or a device?
sorry for the condensed title of my post. Any other version of the question I'm trying to ask turned out to be longer than allowed.
So, my question is about the wording in some versions of Clausius' statement of the 2nd law of thermodynamics.
From time to time I read something like "It is impossible to build a machine whose only effect is the transfer of heat from a heat reservoir to another heat reservoir at a higher temperature", possibly specifying "without any work done".
Perhaps I'm being nitpicking, but I have the feeling that the concept of "machine" does not fit well in Clausius' statement.
How is that a machine, if no work is involved?
I would rather say "a process where heat is spontaneusly transferred from a cold source to a hot source is impossible". Perhaps one could add "unless some work is done", but that's sort of covered by "spontaneously".
All in all it seems to me that sometimes authors are carried away a little and try to write Clausius' statement using the same wording as in Kelvin's one.
Is it just me? Or perhaps could it be a subtlety of Italian that does not emerge in English?
Are you ok with Clausius' formulation of the 2nd law involving a machine or a device?