Monty Python meets Landauer's principle

Landauer's principle tells us that computations in which we erase bits always release energy. In a very simple case, for example, when two electrons go into an AND gate and only one comes out, the additional energy carried by the second electron has to go somewhere. Landauer’s argument was essentially that if the number of thermodynamic states is cut in half then the entropy is reduced by k log 2 per bit, which then gets reflected in the energy of k T log 2. Quantum computing, which is inherently reversible, is interesting, in part, because it lets you avoid the limitations of Landauer's principle.

It turns out that not everyone agrees with Landauer's analysis. "Logic and Entropy" by Orly Shenker argues that Landauer's analysis is flawed, for example. Papers like this one spurred others to write rebuttals. An example of this is "Notes on Landauer's Principle, Reversible Computation, and Maxwell's Demon" by Charles Bennett.

With my limited understanding of thermodynamics, Landauer's principle certainly looks reasonable to me, but I'm certainly not an expert and I can't say that I really understand either side of this argument. When I read papers like these, however, I'm often reminded of Monty Python's argument sketch in which there's an exchange roughly like this:

"Yes, it is!"

"No, it isn't!"

"Yes, it is!"

There just seems to be more math in the arguments over Landauer's principle.