To establish in a semi-rigorous way the (btw obvious) relationship between coarsening in physics and in stacked neural networks, as was done long after the latt

To establish in a semi-rigorous way the (btw obvious) relationship between coarsening in physics and in stacked neural networks, as was done long after the latter became a thing [1][2], is at the same level as observing the analogy between Black-Scholes and diffusion. It's cute, but it does not turn the subject into physics. It should go without saying that you can not, by definition, resolve fundamental questions about mathematical physics by experiment. The APS took a stand on climate change years ago [3]. It was clear enough to make Harold Lewis [4] and Ivar Glaever [5] resign in protest. P.S. Belief propagation was first proposed by Judea Pearl in 1982 [6]. The closest connection to physics one could realistically claim is that Pearl got a M.Sc. in physics before turning (back) to electrical engineering and then AI. [1] http://arxiv.org/abs/1301.3124 http://arxiv.org/abs/1301.3124 [2] http://arxiv.org/abs/1410.3831 http://arxiv.org/abs/1410.3831 [3] http://www.aps.org/policy/statements/climate/ http://www.aps.org/policy/statements/climate/ [4] http://dotearth.blogs.nytimes.com/2010/10/15/a-physicists-climate-complaints/?_r=0 http://dotearth.blogs.nytimes.com/2010/10/15/a-physicists-cl... [5] http://www.telegraph.co.uk/news/earth/environment/climatechange/8786565/War-of-words-over-global-warming-as-Nobel-laureate-resigns-in-protest.html http://www.telegraph.co.uk/news/earth/environment/climatecha... [6] https://www.aaai.org/Papers/AAAI/1982/AAAI82-032.pdf https://www.aaai.org/Papers/AAAI/1982/AAAI82-032.pdf