Author: Prof. Douglas Ross of Southampton University - https://www.southampton.ac.uk/~doug/

me neither! How does the Einstein Rosen Podosky Paradox work? can the unknown that's being collapsed not be a pre-determined value that therefore is not traveling faster than the speed of light?

When I learned about causal sets program and algebraic quantum field theory, I finally (somewhat) understood quantum physics.

Tl;dr spacetime does not exist as a global background where things are "placed", it is not ontic. "Things" are first, and spacetime is derived from interaction statistics of "things". This eliminates nearly all naive paradoxes like double slit etc. Now, these "things" are somewhat complicated and non-intuitive (e.g. there are no individual "particles", they are a limit of discrete distributions), but that's a good start.

In a podcast, Alain Aspect (Nobel Prize winner) explained that he does use the power of visualization and his imagination to generate new ideas, but that he always needs to check them with actual calculations because no mental picture can be an accurate representation of quantum physics.

"I think I can safely say that nobody understands quantum mechanics."

- Richard Feynman

That pre-determined value idea is exactly local hidden variables, and Bell's inequality rules it out, Aspect's 1982 CHSH experiment measured the violation.

This piece looks great, adding to my ever-growing "to read" collection on Zotero.

If anyone is interested in self-studying quantum physics, QFT for the Gifted Amateur [1] is very well regarded.

1: https://academic.oup.com/book/36442?login=false

I take issue with "understand". I agree QM can not be understood in terms of everyday experience. One must build experience, language and proper metaphor for the understanding. For example, in the intro Ross uses the example of explaining a waterfall to someone who never saw it. He says that can be done but he relies on implicitly the listener knowing what people on Earth may take for granted. That understanding of a waterfall can only happen if the listener already has some understanding of fluid flow and gravity. We do, but say a newly found alien friend from a dry environment that had never experienced fluid flow would not have the mental building blocks to understand it. Feynman gave a famous interview where he said, essentially, "no, I can't explain it to you because you are too ignorant" (he said it more politely). Going the other direction, Physics steeped enough in quantum theory do understand QM enough to have meaningful discussions free (at times) of rigorous math. They do this because they have a shared language, vocabulary, metaphor. Sure, they must rely on math and experiment to ground that understanding in truth but I guarantee they do not communicate understanding (solely) in math and measurement data.

So do the rest of us.

We understand quantum mechanics well enough to build machines that depend almost entirely on quantum principles.

It sounds all superior and mysterious to quote Feynman here, but the fact is many people absolutely do understand quantum mechanics.