Not sure how math/logic factors into this for you but the impossibility of proving a negative seems to apply here. It's one of the basic bits of logic I teach patients (at least when they ask about reality testing, which is rare). I tell them it's pretty near impossible to prove something doesn't exist or didn't happen, and that I find the best thing is to focus on what was most likely. It's very rare I don't find a very mundane reason for pretty much everything, and the few things I can't there's pretty much nothing I can do about anyway.
This is more of an "is it possible?" type of thing more than it is proving a negative.
For example is it possible for a human to grow 200 feet tall? The answer is no (im not a biologist but probably not) and then you can justify it with science
I'm not trying to prove that something doesn't exist. I'm asking if we follow the scientific method, does our current understanding of quantum physics allow for phenomena like this to potentially exist in reality?
The scientific method can't rule out the existance of supernatural stuff like gods or magic. And you can totally explain a black portal (or literally anything you want) with magic or the actions of a god.
Can they be explained by quantum states being in an incredibly unlikely but not impossible state?
Is it really an explanation if it requires something so incredibly unlikely?
I think you will have a much better chance for finding an explanation by looking into optical illusions or hallucinations.
Is it really an explanation if it requires something so incredibly unlikely?
Yeah, technically
Can you elaborate on the portal? What does it do, is it between two locations or is it just a hole, or is it just a black circle?
Physics