Undermines· strongORCH-E017
Gran Sasso null result excludes the parameter-free Diósi–Penrose model
- what the source states
- The abstract reports a dedicated search for the spontaneous radiation predicted by gravity-related dynamical collapse, performed with an ultra-low-background germanium detector at the Gran Sasso underground laboratory, and states: "Our result sets a lower bound on the effective size of the mass density of nuclei, which is about three orders of magnitude larger than previous bounds. This rules out the natural parameter-free version of the Diósi–Penrose model."
- what we infer
- Methodologically the strongest experiment anywhere in this case, conducted with the model's own co-originator among the authors, and it came out negative. It substantially damages the physics conjunct ORCH-C001 requires. The scope of the exclusion is precisely stated in the authors' own words and should not be inflated: it kills the natural parameter-free stochastic completion, not every conceivable gravity- related collapse theory, and specifically not Penrose's original heuristic ℏ/E_G criterion, which makes no radiation prediction. That qualification is real (see ORCH-E019) and is also exactly the kind of escape that costs a theory its testability.
- limitations
- Tests a specific stochastic master equation; the map from Penrose's geometric argument to that equation is not unique.
- Constrains a parameter range rather than closing the question — non-Markovian and non-local variants evading the radiation prediction have been proposed.
- Does not test the ℏ/E_G lifetime scaling itself, which remains unmeasured.