Hi. I am a Bulgarian researcher interested in the foundations of thermodynamics, and I wonder if this list would welcome challenges that usually meet hostility. There is a conference on the second law in San Diego this summer and I am going to participate, but why not an e-mail discussion as well. Please tell me if you see any difference between the following two Kelvin's versions:

K1: No process is possible in which the only result is absorption of heat from a reservoir and its complete conversion into work.
K2: No process is possible in which a system absorbs a heat from a reservoir, completely converts it into work and returns to its initial state.

In order to find the difference, please think of a creature belonging to the surroundings (I call it "operator") that e.g. sets the heat engine on and off, switches to a different work production etc. and UNDERGOES CHANGES IN THE PROCESS. So, for isothermal conditions, the two versions take the forms:

K1: In the absence of an operator, cyclical isothermal conversion of heat into work is impossible.
K2: Even in the presence of an operator, cyclical isothermal conversion of heat into work is impossible.

Clearly, K2 is more restrictive than K1, and it may turn out that K1 is correct whereas K 2 is not. At the San Diego conference, I am going to develop further the problem: K1 is related to "Entropy never decreases" whereas K2 is related to "Entropy is a state function".

Is anybody interested in such problems?

Best regards,
Pentcho Valev

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