TL;DR

What is the opinion of the validity of Penrose -Dosi model

Hi to all! I want to ask the opinion of the forum about the conjecture on the collapsing wave function ##\psi## due to the presence of the gravity as assumed in the model of Penrose-Dosi ... It seems the only "true" way to understand the quantum mechanics (at least it is possible to verify it recently experimentally ...)
I think the theory of string or the quantum loop gravity (QLG) are elegant theories that for the moment it is impossible a verification. In the opposite the theory of Penrose-Dosi has not the complete condivision of all expert in the field ... Possible the true is in the "middle" ...
Ssnow

Ssnow said:

the model of Penrose-Dosi

Can you give a link?

physika said:

Nice, it looks like they are attempting to test the theory.

But it does seem like maybe the most simple version of the theory has been ruled out experimentally. See attached image from the Arxiv paper.

Just my personal opinion (and I give it here only because OP explicitly asked for "the opinion of the forum") -- I think this gravitation-based collapse theory is an interesting way to try to bring in gravity to quantum mechanics from a different angle, but ultimately, objective collapse theories (incl. GRW here) seem a bit "ugly" and "arbitrary" to me. It feels to me like nature just goes with Schroedinger, unitary, evolution and collapse is a mathematical artifact of our theories in order to connect the quantum world to the classical world where our measurements take place. Introducing collapse as a fundamental tenet of quantum theory just rubs me as a bit ugly in that sense.

Just my opinion though. I think Penrose himself has not allowed this result to deter him from pursuing the idea further.

Hi @Matterwave thanks for your opinion, I think that the original model of Penrose is a ''good idea'' in order to understand quantum mechanics in the theory of Newtonian-Relativistic gravity instead the inverse that is the "quantization of the gravity" (think about the geometric quantization program, or string theory or loop quantum gravity ...). I think that the Penrose model is in fact extremely simple and it seems as a little toy instead a rigorous theory ... but I think this direction can be considered, I belive it is possible an evolution of the Penrose model with the introduction of the pobability and the chaos ... at least in this direction we can think about expreriment; an important key is to understand as the collapse works, in this direction we can understand better the QM teory and, at the same time (if it exists ), the gravity and the gravitational field ...

Ssnow

physika said:

Thanks for references ....

Ssnow said:

Hi @Matterwave thanks for your opinion, I think that the original model of Penrose is a ''good idea'' in order to understand quantum mechanics in the theory of Newtonian-Relativistic gravity instead the inverse that is the "quantization of the gravity" (think about the geometric quantization program, or string theory or loop quantum gravity ...). I think that the Penrose model is in fact extremely simple and it seems as a little toy instead a rigorous theory ... but I think this direction can be considered, I belive it is possible an evolution of the Penrose model with the introduction of the pobability and the chaos ... at least in this direction we can think about expreriment; an important key is to understand as the collapse works, in this direction we can understand better the QM teory and, at the same time (if it exists ), the gravity and the gravitational field ...

Ssnow

I feel he had a nice idea -- gravity causes collapse. He put out some heuristics on how to look for it. The experimental community (based on that last paper) went and took a look but didn't find the effects and rules out the most naive, parameter-free version of the theory.

This is healthy science to me.

If there's a few more experiments and such that people can think of to test a few variants of the theory, that's great too. But, for my opinion, given the rather "arbitrariness" of objective collapse I (personally) wouldn't sink too much more time into the theory. It doesn't matter though since I'm no longer a practicing research physicist. :P

I don't begrudge Sir Penrose from being more stubborn about his theory and I would support those who want to investigate further. New avenues, beyond the standard theories, are always worth while.

Matterwave said:

I don't begrudge Sir Penrose from being more stubborn about his theory and I would support those who want to investigate further. New avenues, beyond the standard theories, are always worth while.

Well said. And, at least in principle, it is experimentally testable.

Plus, listening to a scientist of his stature is always a joy.

Thanks
Bill