According to The statistical nature of the 2nd Law of Thermodynamics, the second law of thermodynamics probably hasn't been proven to be absolute. That doesn't necessarily mean it hasn't been proven that a perpetual motion machine of the second kind is impossible. It follows from the second law of thermodynamics that it's impossible but does not follow the other way.

The question Perpetual motion machine of the second kind possible in nano technology? doesn't have an answer that I think satisfactorialy answers this question. I think this answer could be wrong because the second law of thermodynamics probably hasn't been proven to be absolute. Some of its other answers probably satisfactorily answer that question but not this one.

  • $\begingroup$ I see that this question got one downvote. If it can be improved, can somebody write a comment suggesting how I can improve it and can nobody answer it before I make the improvement based on that comment so that it will be okay for me to edit it? $\endgroup$ – Timothy Apr 2 '18 at 21:54
  • $\begingroup$ As with all laws of physics, the only proof is that in all the history of humanity nobody has discovered any way a perpetual motion machine could exist. $\endgroup$ – Javier Apr 2 '18 at 22:33
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    $\begingroup$ What do you mean by a physical law being "proven to be absolute"? Can you give an example of a physical law that does satisfy that criterion? $\endgroup$ – probably_someone Apr 2 '18 at 22:45
  • $\begingroup$ I got the phrase of being absolute from Bubble's answer which I linked. I'm guessing saying it's absolute means we can assign an entropy value to any stable substance as a function of internal energy in such a way that no process contributes to a decrease in entropy of the universe and certain processes like even mixing and forming a solubility equilibrium always contributes to an increase in entropy. I suspect that's not the case. For 2 immiscible liquids, we can define entropy only for those 2 liquids in such a way that forming a thermal and solubility equilibrium maximizes entropy. $\endgroup$ – Timothy Apr 3 '18 at 1:27
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    $\begingroup$ I think the fatal flaw of your question is that science never "proves" anything. To have a proof you must start from an axiom, which is assumed true from the beginning. Since science is the pursuit of describing reality accurately, we do not begin by defining it in potentially inaccurate ways. Thus no axioms, and therefore no proofs. We can model and we can falsify: that's it. $\endgroup$ – Asher Apr 3 '18 at 18:42

There are two ways to derive the second law. One way uses microstates, probabilities, and statistics (this is how physicists would think about it) and the other way uses bulk properties (and is the way most engineers are taught the subject); see Thermophysics by Giedt, in which he does the derivation both ways- with the same result.

The fact that the derivation can be performed without microstates and statistics strongly suggests that your assertion that the 2nd law is "strictly statistical" in nature can be argued to be untrue.

Regarding your nanotechnology claim, have a look at treatments of something called "Maxwell's Demon". You'll see how nanotechnology fundamentally cannot beat the second law.

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  • $\begingroup$ en.wikipedia.org/wiki/Maxwell%27s_demon does not suggest that the second law of thermodynamics has been proven. Your answer just shows why a certain argument against the second law of thermodynamics fails. It doesn't prove the second law of thermodynamics. $\endgroup$ – Timothy Apr 3 '18 at 2:26
  • $\begingroup$ @user46757, did you check Giedt? $\endgroup$ – niels nielsen Apr 3 '18 at 3:13

Turbulent motion of water in an electric field:



The motion is powered by:

(A) electric energy?

(B) ambient heat?

If (B) is the answer (it is!), the second law of thermodynamics is violated - the work the motion is obviously able to do (e.g. by rotating a waterwheel) will be done at the expense of heat absorbed from the surroundings.

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