Recently, there was a rapid communication published in Phys.Rev.D (PRD 83, 021502), titled "Gravity is not an entropic force", that claimed that an experiment performed in 2002 with ultra cold neutrons in a gravitational field, disprove Verlinde's entropic approach to Gravity.
The neutrons experiment gave results consistent with the predictions of Newtonian gravity for the lowest energy state.
As I understand it, the author claims that the fact that Verlinde's entropic force comes from a thermodynamic process that is irreversible (or approximately reversible), leads to non-unitarity in the evolution of quantum systems. The non-unitarity then exponentially suppresses the eigenfunctions, predicting results very much different than the Newtonian. Thus, that experiment is in contradictions to what is expected if Verlinde's approach is correct.
My questions are,
- First of all, is there anything else essential that I am missing?
- Is there any response to that argument?
- Is that a fatal problem with Verlinde's entropic approach?
- Is that a fatal problem for any entropic approach?
updates on the discussion: