Here’s my consideration that the 2nd law of thermodynamics is full of hot air:
The 2nd law states that in an isolated system, entropy tends to increase. The corollary is that in order to prevent this, we must put energy into the system to counteract the natural tendency. One way to demonstrate this is to box off one region of space from another, in such a way that the “interior” is energetically isolated from the “exterior” and cannot be subject to energetic inputs. The molecules “inside” then tend to scatter into random, heterogeneous positions, thus “demonstrating” the 2nd law. I have two concerns about this model:
1. System vs. not –system seems to me as an arbitrary distinction. Moreover, setting up the rules of the game in this way stacks the game in favor of verifying the rules. Furthermore, by setting up the rules, we’ve put energy into the system. The result of putting energy into the system in this way in fact seems to increase the entropy of the system. So it seems to me that increases or decreases in entropy depend on how one sets up the system for observation, not on any natural or universal processes.
2. Consider a box which is, to a first approximation, energetically isolated from the surrounding environment. The entropy as we measure it inside the box will certainly increase. There will then exist an energetic potential across the material of the box. In fact, some atoms will tunnel through and some will not. So has the entropy really increased? Because now we have two regions, “higher entropy” inside and “lower entropy” outside. In fact, allowing the system inside to approach greater entropy seems to have created a new “order” when one considers the box and the potential across the surface of the box. Given that these two areas are in fact in communication with one another (atoms tend to slip through with some small but finite frequency), it seems as if in fact the entropy of the “system” has not decreased as much as we thought it would, if at all.
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