Regarding the quantum physics part, I was referring to the double slit experiment: https://en.wikipedia.org/wiki/Double-slit_experiment
Matter can interfere with itself in wave patterns that behave as if the matter no longer exists in a single position, but in all possible positions at once. This shows the matter doesn’t even exist in its physical form anymore while it is part of the wave function. “Quantum particles” are not even a thing, because this effect can be reproduced with large molecules too, and there is no apparent upper limit to this: https://science-atlas.com/strange-news/largest-molecules-yet-become-waves-in-quantum-double-slit-experiment/
This effect is real, and waving it away because it’s supposedly “too small” isn’t making it less so. It’s not too small to measure. The article mentions these molecules were fitting slits that were 50nm in size.
As for the brain waves, it seems we’re talking about different things. Of course we can mess with the brain and alter sensory experiences. But experience and awareness are a bigger thing than merely input/output. That’s something I know to be true about myself, but I suppose you can reason that away. I merely pity those who do.

Well, yeah, I’m not the one claiming to have all the answers. I merely am a witness of my consciousness, so I know that’s a real thing. I describe that whole of consciousness and awareness and “me-ness” as my soul, but I have no hard definition for it, I merely know there’s something there.
Science however is a man-made construct and can only operate on the observable and the independently verifiable. I’m not saying that to diminish its worth, because science is mighty cool, but I simply refuse to take it to the extreme position that anything that cannot be scientifically proven should be assumed not to exist.
I’ve experienced enough weird shit in my life that makes no scientific sense. They still happened though. So rather than denying these things, the sane thing to do is to shrug them off as “it’s dimensions or quantum or whatever” :)