A dedicated underground search for the spontaneous radiation predicted by the stochastic Diósi–Penrose collapse model found none, tightening the bound on the model's spatial cutoff by about three orders of magnitude and excluding its natural parameter-free version.

Nature Physics, world-class low-background facility, prediction derived quantitatively in advance, model's own co-originator among the authors, source data published, exclusion scope stated in the authors' own words. About as clean as an experimental constraint gets.

A dedicated ultra-low-background experiment explicitly quantitatively predicted and searched for spontaneous radiation from gravity-related dynamical collapse, finding none. This firmly excludes the natural parameter-free Diósi-Penrose model. The strongest opposing constraint is scope: the experiment rules out a specific stochastic completion, not all gravity-related collapse formulations.

Donadi et al.’s Gran Sasso experiment, with Diósi as co-author, used an ultra-low-background germanium detector to search for spontaneous radiation predicted by DP-type collapse, found none, and explicitly state they rule out the natural parameter-free version of the model, tightening bounds by three orders of magnitude. The design, venue, and clarity of the negative result make this a very strong constraint on that class of models. While variants can in principle evade the radiation prediction, that does not undermine the factual exclusion as stated. The strongest qualification is that this tests a particular stochastic completion, not Penrose’s heuristic lifetime scaling per se.

The experimental finding is stated in the authors’ own words in Nature Physics: an ultra-low-background germanium search at Gran Sasso found none of the predicted spontaneous radiation, set a lower bound on the effective nuclear mass-density size about three orders of magnitude larger than previous bounds, and “rules out the natural parameter-free version of the Diósi–Penrose model.” Diósi is a co-author, the predicted signal was quantitatively derived before the search, and source data are published. The strongest opposing consideration is scope, not quality: the experiment tests a particular stochastic master equation, the map from Penrose’s geometric argument to that equation is not unique, and later non-Markovian or non-local variants have been proposed specifically to evade the radiation prediction.

As clean as an experimental constraint gets: a dedicated ultra-low-background germanium search at Gran Sasso, the predicted signal derived quantitatively before the search, the model's co-originator Diósi among the authors, published source data, and the exclusion — the natural parameter-free Diósi–Penrose model — stated in the authors' own words along with the three-orders-of-magnitude tightening of the spatial-cutoff bound. The strongest opposing consideration is scope: the experiment tests one stochastic master equation, the map from Penrose's geometric argument to that equation is not unique, and the bound constrains a parameter range rather than closing the question — non-Markovian variants evading the radiation prediction have been proposed. That limits what the result excludes without touching what it measured.

Methodologically this is the strongest experiment in the case: a dedicated ultra-low-background germanium search at Gran Sasso, with the predicted signal quantitatively derived before the search, the model's co-originator among the authors, published in Nature Physics with source data, and the exclusion stated precisely in the authors' own words. It is assessed on that basis irrespective of which side it favors, and a null with a prespecified quantitative prediction is unusually informative. The claim as worded confines itself to what was excluded — the natural parameter-free version of the Diósi–Penrose model — and does not overreach. The strongest opposing consideration is one of scope rather than quality: the map from Penrose's geometric-instability argument to the particular stochastic master equation tested is not unique, so this result cannot be read as excluding every gravity-related collapse theory, and non-Markovian variants designed to evade the radiation prediction have been proposed.

Dedicated ultra-low-background germanium search at Gran Sasso testing a quantitatively derived prediction, with the model's co-originator among the authors and the exclusion scope stated in the authors' own words (ORCH-E017). About as clean as an experimental constraint in this case gets.

Nature Physics, world-class low-background facility, quantitatively derived prediction, the model's co-originator among the authors, exclusion scope stated in the authors' own words. About as clean as an experimental constraint gets.

A dedicated low-background underground search with a quantitatively derived prediction, the model's co-originator among the authors, and an exclusion scope stated in the authors' own words (ORCH-E017). About as clean as an experimental constraint in this case gets.

This ultra-low-background underground experiment searched for spontaneous radiation predicted by the stochastic Diósi-Penrose collapse model and found none. With quantitative predictions and the model's co-originator on the author list, it successfully bounded the spatial cutoff and definitively ruled out the natural, parameter-free version of the model. It represents the cleanest constraint in the case, though it only excludes specific completions of the physics, not the heuristic Penrose criterion itself.

Donadi et al.’s Gran Sasso experiment is a high-quality, targeted test of the spontaneous radiation predicted by a specific gravity-related collapse model, and it finds none, explicitly ruling out the “natural parameter-free version” of the Diósi–Penrose model and tightening bounds by three orders of magnitude; this is clearly stated in the abstract. The design, setting, and authorship (including Diósi) support the robustness of the null result. The main caveat is scope: the exclusion applies to that particular stochastic completion and parameter range, not to all conceivable collapse models or to Penrose’s heuristic τ ≈ ℏ/E_G relation.

A dedicated ultra-low-background germanium search at Gran Sasso, with the model's co-originator among the authors, found none of the predicted spontaneous radiation, tightened the nuclear mass-density cutoff by about three orders of magnitude, and stated in the paper's own words that this rules out the natural parameter-free Diósi–Penrose model. Source data are published; the exclusion's scope is precisely drawn. The strongest opposing consideration is model-theoretic: the experiment tests a particular stochastic master equation, the map from Penrose's geometric-instability argument to that equation is not unique, and later non-Markovian or non-local variants have been proposed to evade the radiation prediction — proposing a variant to escape a bound is not evidence for the variant.

Published in Nature Physics, performed at a world-class ultra-low-background facility, with the predicted signal quantitatively derived before the search and the model's co-originator among the authors; the null result and its scope are stated in the authors' own words, and source data are public. This is about as clean as an experimental constraint gets, and it is assessed on that basis irrespective of which side it favors. The strongest opposing consideration is scope: the experiment tests a particular stochastic master equation, the map from Penrose's geometric argument to that equation is not unique, and non-Markovian or non-local variants can evade the radiation prediction — though proposing a variant to escape a bound is not evidence for the variant. The bound constrains a parameter range rather than closing the question, and the ℏ/E_G scaling itself remains unmeasured.

A dedicated ultra-low-background germanium search at Gran Sasso, with the model's own co-originator among the authors, tested a quantitatively derived prediction, found nothing, and stated its own exclusion scope precisely in the abstract: the bound on the effective nuclear mass-density size tightened by about three orders of magnitude, ruling out the natural parameter-free Diósi–Penrose version. Source data are published and the claim as worded reports exactly this. The strongest opposing consideration is one of scope rather than reliability: the experiment constrains a particular stochastic master equation, and the map from Penrose's geometric-instability argument to that equation is not unique — so the result must not be read as excluding every gravity-related collapse theory, which the claim as worded does not do.

A dedicated ultra-low-background underground search against a quantitatively derived prediction, with the model's co-originator among the authors and an exclusion scope stated in the authors' own words (ORCH-E017). About as clean as an experimental constraint gets in this case.

A dedicated ultra-low-background underground search against a quantitatively derived prediction, with the model's co-originator among the authors and an exclusion scope stated in the authors' own words (ORCH-E017). About as clean as an experimental constraint gets in this case.

The Gran Sasso underground experiment set strict bounds on spontaneous radiation, quantitatively ruling out the natural parameter-free version of the Diósi-Penrose model (ORCH-E017). The strongest opposing consideration is that the mapping from Penrose's geometric criteria to the tested stochastic master equation is not unique (ORCH-E019), allowing variant models to evade the bound.

Donadi et al. (E017) at Gran Sasso conducted a stringent underground search for spontaneous radiation predicted by the Diósi–Penrose stochastic collapse model, reporting a null result that tightens bounds by three orders of magnitude and explicitly “rules out the natural parameter-free version” of that model, which directly supports the claim as worded. Diósi’s co-authorship, the facility’s reputation, and clear pre-specified predictions further bolster reliability. The strongest opposing consideration is scope: only that particular stochastic implementation and parameter regime are excluded, leaving other (possibly contrived) gravity-related collapse models, including Penrose’s more heuristic version, untouched.

Donadi et al., in Nature Physics, with Diósi among the authors, report a dedicated ultra-low-background germanium search at Gran Sasso that found none of the predicted spontaneous radiation, set a lower bound on effective nuclear mass-density size about three orders of magnitude larger than previous bounds, and state that this rules out the natural parameter-free version of the Diósi–Penrose model; source data are published. The claim as worded is an experimental finding about that model, and it is as cleanly supported as anything in this file. Strongest opposing consideration: the experiment tests a particular stochastic master equation, the map from Penrose's geometric-instability argument to that equation is not unique, and later non-Markovian or non-local variants have been proposed to evade the radiation prediction — proposing a variant to escape a bound is not evidence for the variant.

This is about as clean as an experimental constraint gets: a dedicated ultra-low-background germanium search at Gran Sasso, a quantitative signal prediction derived before the search, the model's co-originator among the authors, published source data, and the exclusion — of the natural parameter-free Diósi–Penrose model, with a three-order-of-magnitude bound tightening — stated in the authors' own words in Nature Physics. The strongest opposing consideration is scope: the experiment tests one stochastic master equation, the map from Penrose's geometric argument to that equation is not unique, and Penrose's original ℏ/E_G criterion makes no radiation prediction and is untouched. That qualification blocks any stronger claim against ORCH-C030, but it does not qualify the measurement itself, which is exactly what it claims to be. Assessed on the evidence irrespective of which side it favors.

A dedicated ultra-low-background germanium search at Gran Sasso found no spontaneous radiation, tightened the bound on the effective nuclear mass-density size by about three orders of magnitude, and the exclusion of the natural parameter-free Diósi–Penrose model is stated in the authors' own words, with the model's co-originator among them (ORCH-E017). The prediction was quantitative and derived before the search, which is what makes a null informative; source data are published. The strongest opposing consideration is one of scope rather than validity, and the claim already encodes it: the experiment constrains a specific stochastic master equation, and the map from Penrose's geometric argument to that equation is not unique (ORCH-E019), so this record must not be read as excluding every gravity-related collapse theory.

A dedicated ultra-low-background underground search against a quantitatively derived prediction, with the model's co-originator among the authors and an exclusion scope stated in the authors' own words (ORCH-E017). About as clean as an experimental constraint gets in this case.

A dedicated ultra-low-background underground search against a quantitatively derived prediction, with the model's co-originator among the authors and an exclusion scope stated in the authors' own words (ORCH-E017). About as clean as an experimental constraint gets in this case.

Donadi 2021 sets a rigorous, null experimental bound at the Gran Sasso facility, strictly ruling out the parameter-free Diósi-Penrose stochastic collapse model. The strongest opposing consideration is that Orch OR can retreat to non-Markovian or underspecified variants that evade this specific radiation prediction.

Donadi et al.’s Gran Sasso experiment is methodologically strong, peer‑reviewed in Nature Physics, and explicitly reports that their null result rules out the natural parameter-free version of the Diósi–Penrose model, tightening spatial-cutoff bounds by three orders of magnitude. The design, with Diósi as co-author, directly targets the spontaneous radiation signature predicted by that stochastic collapse model, making the exclusion clear. The strongest opposing consideration is that this applies to one specific dynamical completion; Penrose’s original τ≈ħ/E_G lifetime relation does not entail a radiation signal, so this does not definitively rule out all gravity-related collapse theories, only the most natural stochastic variant.

Donadi et al. searched at Gran Sasso with an ultra-low-background germanium detector for the spontaneous radiation predicted by gravity-related dynamical collapse, found none, tightened the bound on the effective nuclear mass-density size by about three orders of magnitude, and state in their own words that this rules out the natural parameter-free version of the Diósi–Penrose model. Diósi is a co-author; source data are published; the prediction was quantitative. The strongest opposing consideration is scope: the experiment tests a particular stochastic master equation, not Penrose's geometric lifetime criterion, and non-Markovian or non-local variants designed to evade radiation have been proposed. Those limits belong on ORCH-C030; they do not touch the measurement or the stated exclusion of that version.

Methodologically the cleanest experiment in the case: published in Nature Physics, performed with an ultra-low-background germanium detector at Gran Sasso, the predicted signal quantitatively derived before the search, the model's co-originator among the authors, source data published, and the exclusion stated in the authors' own words with its scope precisely delimited. Null results of this kind are unusually informative because the prediction was quantitative. The strongest opposing consideration is real but bounded: the experiment tests one stochastic master equation, the map from Penrose's geometric argument to that equation is not unique, and the bound constrains a parameter range rather than closing the question — so the claim as worded (the exclusion of the natural parameter-free version) is exactly as strong as the evidence, no more and no less.

The claim states what a specific experiment found and excluded, and the record supports it precisely: a dedicated ultra-low-background germanium search at Gran Sasso, with the model's co-originator among the authors, a quantitatively derived prediction, published source data, and an exclusion stated in the authors' own words (ORCH-E017). I grade this high irrespective of which side it favours. The strongest opposing consideration is scope rather than validity — it tests one stochastic master equation, and the map from Penrose's geometric argument to that equation is not unique (ORCH-E019) — but that limits what the result implies for ORCH-C030, not whether the claim as worded is true.

A dedicated ultra-low-background underground search against a quantitatively derived prediction, with the model's co-originator among the authors and an exclusion scope stated in the authors' own words (ORCH-E017). About as clean as an experimental constraint gets in this case.

A dedicated ultra-low-background underground search against a quantitatively derived prediction, with the model's co-originator among the authors and an exclusion scope stated in the authors' own words (ORCH-E017). About as clean as an experimental constraint gets in this case.

Evidence-only: published in Nature Physics, performed at a world-class ultra-low-background facility, with the predicted signal quantitatively derived before the search and with Diósi himself — the model's co-originator — among the authors. The exclusion is stated in the authors' own words and its scope is stated precisely. Source data are published. This is about as clean as an experimental constraint gets, and it is assessed as well supported on that basis irrespective of which side it favors.

Upgraded from well supported on the arrival of an independent corroborating null. ORCH-E017 is the Gran Sasso search: a dedicated ultra-low-background germanium measurement, co-authored by the tested model's co-originator, finding no spontaneous radiation, tightening the bound on the effective nuclear mass-density size by about three orders of magnitude and ruling out, in the authors' own published words, the natural parameter-free version of the Diósi–Penrose model. ORCH-E047 and ORCH-E049 are the Majorana Demonstrator: no evidence of the 1/E signature between 19 and 100 keV across 37.5 kilogram-years of enriched germanium, a best-fit signal of 6.3 ± 398.8 counts, an almost order-of-magnitude improvement on the prior limit, and an explicit statement that this adds significance to the exclusion of the parameter-free model. Two independent collaborations in the same channel with consistent nulls and quantitative bounds puts the claim as stated beyond reasonable dispute.

The Gran Sasso underground experiment by Donadi et al. searched for spontaneous X-ray radiation predicted by the Diósi–Penrose collapse model, finding no signal and bounding the spatial cutoff parameter three orders of magnitude beyond prior limits. This definitively ruled out the parameter-free version of the model. The strongest opposing consideration is that this null result constrains only Markovian white-noise stochastic completions, leaving colored-noise variants and Penrose's original non-stochastic lifetime criterion unaddressed.

The Gran Sasso search is the highest-quality experiment in the case, conducted with Diósi as co-author, and the Majorana Demonstrator independently reached the same verdict on the same channel, so the exclusion is no longer single-experiment. The abstract's own words state exactly what is excluded and the scope is not overstated here. This is a clean, replicated, quantitative null — as close to established as anything in this packet.

ORCH-E017 directly reports the Gran Sasso null, the roughly three-orders-of-magnitude improvement, and exclusion of the natural parameter-free Diósi–Penrose model. ORCH-E049 adds an independent underground germanium null that strengthens the same exclusion. The strongest opposing consideration concerns scope: these experiments do not exclude every gravity-related collapse theory or Penrose's bare lifetime criterion.

Donadi et al. report a dedicated Gran Sasso germanium search finding no spontaneous radiation predicted by stochastic gravity-related collapse and explicitly ruling out the natural parameter-free Diósi–Penrose version; Majorana Demonstrator independently reports no 1/E signature and tightens the DP bound. Strongest opposing consideration is that coloured-noise or non-radiating formulations can evade the channel, which limits scope without undoing the stated exclusion.

ORCH-E017 is a dedicated underground null in Nature Physics, with the model's co-originator as an author. ORCH-E049 is an independent collaboration reaching the same exclusion. ORCH-E019 qualifies what the result means for Penrose, not whether it happened.