# How can the Objective Reduction theory of quantum mechanics account for macroscopic quantum systems?

In Penrose's OR (Objective Reduction) theory, the time taken for the wave function to collapse is τ ≈ ℏ / E_G (https://en.wikipedia.org/wiki/Orchestrated_objective_reduction). This implies that larger quantum systems will take a shorter time to collapse, since E_G tends to be larger. Isn't this idea falsified by the existence of macroscopic quantum systems such as superconductors that stay coherent for an indefinite period of time?

https://phys.org/news/2014-06-superconducting-secrets-years.html

https://en.wikipedia.org/wiki/Macroscopic_quantum_phenomena

• In its actual form, I'd say that the question is not well defined, because the Objective Reduction's model is not widely accepted. But a slightly related question, as whether the competition between wave function collapse and the notion of macroscopic quantum phenomena influence superconductivity (or an other example as ferromagnet, ...) may attract attention from people in the community of quantum information methods applied to condensed matter problem (or vice versa : condensed matter methods applied to quantum information problems). – FraSchelle Jan 18 '18 at 14:14
• The well-definedness of the question does not depend on whether or not OR is widely accepted. – ijt Jan 20 '18 at 19:04
• Sure. Anyways, many people in science prefer to discuss objective problems, the ones which can be probed by experiment. So, either you define carefully your question, or it's better to ask for a closure of the question as being inobjective, unclear and too broad. – FraSchelle Jan 24 '18 at 15:07
• The closest thing to an answer I've found is on p. 343 of Shadows of the Mind, in the chapter on Quantum Theory and Reality: "With superconductors, very little mass displacement occurs between the different superposed states. There is a significant momentum displacement instead, however, and the present ideas would need some further theoretical development in order to cover this situation." So at least at the time when that book was written, the OR theory had not been developed enough to make definite predictions about these macroscopic quantum systems. – ijt Jan 25 '18 at 16:19