---
slug: school-di-si-penrose-model-gravitational-objective-collapse
title: Diósi–Penrose Model: Gravitational Objective Collapse
canonical: https://miscsubjects.com/a/school-di-si-penrose-model-gravitational-objective-collapse
---

## What the subject saw

Lajos Diósi and Roger Penrose each identified a tension between the superposition principle of quantum mechanics and the definite geometry of spacetime in general relativity. Superposed mass distributions would require superposed spacetimes, which cannot remain stable. Gravity therefore supplies an objective mechanism that reduces the wave function without external observers.

## Core results

The model yields a collapse timescale set by the gravitational self-energy difference between superposed states. Larger mass displacements produce faster reduction. The process operates continuously and objectively, independent of measurement.

## Primary works and passages

Diósi, L. (1987). A universal master equation for the gravitational violation of quantum mechanics. General Relativity and Gravitation. Diósi derived a stochastic master equation that incorporates gravitational fluctuations as the source of decoherence.

Penrose, R. (1989). The Emperor's New Mind. Penrose argued that objective reduction resolves the measurement problem and connects to non-computable processes in the brain.

Penrose, R. (2014). On the gravitization of quantum mechanics 1: Quantum State Reduction. Foundations of Physics 44, 557. Penrose showed that the equivalence principle conflicts with superposed spacetimes, forcing reduction on the gravitational timescale.

## Convergence patterns touched

The model derives an objective physical process that converts quantum difference into definite structure. It supplies a route from flow in the quantum field to bounded state transitions that resemble memory-like stabilization. The reduction event occurs at a scale where gravitational effects become comparable to quantum uncertainty.

## Distance from the full synthesis

The Diósi–Penrose model reaches the step from difference and flow to structure via an objective mechanism grounded in gravity. It stops short of mapping the full Ladder from structure through memory, life, and mind. Penrose links reduction to consciousness in later works, yet the model itself remains a quantum-gravity proposal rather than a complete account of biological or cognitive emergence.

## Honest limits and disconfirming edges

Energy non-conservation appears in Diósi’s dynamical version and remains experimentally testable. Recent analyses constrain the model parameter space. Gravitationally induced entanglement experiments may further limit or rule out certain collapse rates. The model does not yet derive the specific structural patterns such as branching or scale invariance observed across physical and biological systems.

## What the evidence actually shows

No direct observation of gravitational collapse has occurred. Laboratory bounds from matter-wave interferometry and radiation searches place upper limits on the collapse rate. The mechanism remains a candidate solution to the measurement problem rather than an established process.

## What scientists say

Penrose maintains that gravity supplies the missing objective element. Diósi developed the dynamical equations that make the proposal testable. Later authors note that Penrose’s geometric argument differs in detail from Diósi’s stochastic equation.

## What people say on Reddit

Discussions on physics forums treat the model as an elegant but speculative bridge between quantum mechanics and gravity. Participants note its connection to Penrose’s consciousness proposals while emphasizing the lack of empirical confirmation.

## What people say on X

Posts reference the model in threads on quantum gravity and objective reduction. Users cite the 2014 Foundations of Physics paper and note ongoing experimental constraints.

## What we do not know

The precise value of the cutoff parameter that sets the collapse threshold remains open. Whether gravitational reduction operates at biological scales relevant to neural processes is unresolved.

## Safety and limits

The model carries no direct safety implications. Its primary limit lies in the current absence of decisive experimental support.

See related articles at /a/oip-the-ladder and /a/oip-the-mirror-layer.
