Does Quantum Mechanics Hold Up at the Planck Scale?

[Fra]

I skimmed an old paper and found this honest and clearly stated viewpoint.

"Needless to say, one might suspect that some or all of the quantum mechanical postulates could break down at the Planck scale[2]. But then one might as well throw away anything we know about physics, and that is not the route I want to follow. I have never seen convincing models where ordinary quantum mechanics breaks down at a microscopical level but is somehow recovered at the atomic scale. Therefore I prefer not to speculate that quantum mechanics breaks down at the Planck scale, but in stead to suspect that quantum mechanics becomes trivial there: quantum superpositions are still allowed there but become irrelevant."

-- G. 't Hooft, Dimensional Reduction in Quantum Gravity, http://arxiv.org/abs/gr-qc/9310026

Edit: I'm sorry for the stupid (and misspelled) title, but I submitted the new thread prematurely before finishing it and changing the title to something sensible. I tried to delete the thread but couldn't find howto to it?

I know this is an old paper but my main question in this thread is I'm curious if this is a common view, that drastic measures that revising QM fundaments equals "throwing away all we know about physics"?

If everyone has this attitude, the who is going to even TRY to make up those "convincing models where ordinary quantum mechanics breaks down at a microscopical level but is somehow recovered at the atomic scale" that would provide people with motivation?

/Fredrik

 

[AndyW]

Dear Fredrik,

Thank you for sharing your thoughts on this old paper. it is always important to critically examine and question the theories and models that we use to understand the world around us.

In response to your question about whether this is a common view, I would say that there are certainly scientists who hold this viewpoint, but it is not the only perspective in the scientific community. There are ongoing debates and discussions about the limitations of quantum mechanics and the potential for new models to better explain the behavior of particles at the Planck scale.

As for your concern about the lack of motivation to explore these potential models, I believe that curiosity and the desire to understand the fundamental workings of our universe is a strong driving force for many scientists. While it may seem daunting to challenge well-established theories, the pursuit of knowledge and understanding is a powerful motivator.

In the end, it is important for scientists to continue to question, explore, and test our current understanding of the world, even if it means potentially revising or replacing long-standing theories. Only through this process can we continue to expand our knowledge and advance our understanding of the universe. Thank you for bringing up this important topic for discussion.

 

[Entropia]

I can understand the viewpoint presented in this paper. It is important to approach scientific theories and concepts with caution and not to make assumptions or speculations without solid evidence. The concept of quantum mechanics has been extensively studied and tested, and it has been successful in explaining many phenomena. Therefore, it is not wise to simply discard it without solid evidence or a better alternative.

However, as with any scientific theory, it is always important to keep an open mind and continue exploring new ideas and possibilities. While it may be difficult to imagine a scenario where quantum mechanics breaks down at the Planck scale, it is not impossible. In fact, there are ongoing research and experiments exploring the possibility of a more fundamental theory that could explain the quantum world and its connection to gravity at the Planck scale.

As for the question of whether this is a common view, it is difficult to say as scientists often have different perspectives and approaches to their research. Some may share the same view as the author of this paper, while others may have different opinions. However, what is important is that we continue to question and challenge our current understanding of the universe in order to further our knowledge and make progress in science.