15. Does radiation of coldness exist? 

Me neither, but if I understood correctly, at the end of the experiment, he said that the thermal energy of the environment is reduced. This is exactly the point of view of official physics described in detail in f.eg. webspace.pugetsound.edu/facultypages/jcevans/Pictet's%20experiment.pdf As for my view of the whole problem, it is about the fact that the application of the 2nd law of thermodynamics in real-life situations inevitably leads to the claim that even cold bodies radiate heat. In my opinion, this is a contradictory statement indicating that we have not understood the phenomenon at a fundamental level.