Give the extreme level at which we understand the basic functioning of the physical world (the Standard Model), yes, absence of evidence for a phenomenon that would contradict this model constitutes evidence of absence of such a phenomenon.
That is, since the only possible known interactions that the brain could pick up are electrical in nature, and given that no external electrical field changes are observed, that constitutes evidence that no external signal is being received by the person. The weak and strong forces don't work at such distances, so they are out of the question, and gravitational waves or neutrinos are far too weak to be detected by our brains, and impossible to make so targeted that only a single individual would receive the signal.
Now, is it conceivable that a different fundamental interaction that mammalian brains can detect but that none of our experiments have ever found could exist? Yes, but it is so extraordinarily unlikely that it can be dismissed out of hand, absent any proof. And the memories of people experiencing hallucinations are certainly not proof.
> ... constitutes evidence of absence of such a phenomenon.
Mostly everyone prefers that easy version of the question, but that isn't the one I asked.
The one I asked is:
Is it scientific consensus that an absence of evidence is proof of absence? ("proof" vs "evidence")
(Note also my question was about scientific consensus, but you are welcome to choose either version.)
> That is, since the only possible known interactions that the brain could pick up are electrical in nature
This seems "off" to me..."the only know to be possible" seems perfectly logical, whereas your wording almost sounds like you determine how Mother Nature runs the show. Granted, that's how it intuitively seems, but still. Regardless, for clarity: are you asserting that the final answered has been reached here, in fact?
Still outstanding (for bonus points):
>> And even if so: is it necessarily true?
>> PS: did you notice you're using the same methodology "believers" use: it's obvious?
For your troubles, an extra bonus question:
Did atoms exist before they were discovered to exist?
Proof and strong evidence are the same thing in my view of the world, for everything outside of pure mathematics. Of course, this means that even a previously "proven" fact can turn out to be wrong later on. But the alternative is that "proof" simply doesn't exist, as nothing about the physical world can be "proven" to the extent that 2+2=4 can be.
And yes, atoms have of course always existed. As the other poster points out, even before we could even understand the concept, we could detect them. Cats can detect them.
The thing about this posited entity that makes me so certain it is not an external phenomenon (or, if you prefer being mathematically pedantic, that gives me such a high degree of confidence that the probability of that is very very low) is that it is not detectable at all in many other experiments you can run. None of our finest instruments would pick up any increase or decrease in the physical quantities they can measure in the room with the person on psychedelics, if we were to waste money looking for this signal. And then, if they don't, then how could the brain of this person pick up such a weak signal? Why would it even have evolved to be able to detect this fifth fundamental force if it's so weak it can't even be detected by devices that are affected by a single atom passing them by?
"The" alternative is an interesting way to "think".
Psychedelics are a hell of a drug. So too is culture, and the conditioning of consciousness that comes with it. It starts the day you were born, and it never stops. This indoctrination is like the background noise of a city....you've never experienced it not being there, so you don't even notice it.
Many here seem to disagree with you, at least if one interprets their words literally. It's hard to know what they mean they since getting anyone to answer a question directly is typically not possible.
> ...so go away if that's the only standard you will allow discussion of.
What does "if that's the only standard you will allow discussion of" refer to?
>> Did atoms exist before they were discovered to exist?
> We were certainly able to detect atoms before we figured out the exact details.
Did atoms exist before they were discovered to exist?
No obligation to answer the question that is asked, just thought it would be fun to see if you have the ability.
> What does "if that's the only standard you will allow discussion of" refer to?
The way you blocked out everything else in the post to reiterate your question, which they had already answered fine unless you are doing the thing I accused you of, in which case I reiterate: go away
> Did atoms exist before they were discovered to exist?
Hmm, I think you misunderstood my previous answer. I'll try again.
We knew about the existence of atomic matter since humans have been a species, with overwhelming amounts of evidence. There is no "before" in that sense.
(If you mean "before humans and the concept of science existed" then the answer is yes but it has no relevance to a question of whether science is missing anything.)
> The way you blocked out everything else in the post to reiterate your question...
"Blocked out"? I didn't block out anything, I quoted specific text. Quoting specific text in no way disallows discussion of other things, which is what you accused me of.
> ...which they had already answered fine...
No, they answered a question more to their liking - they didn't answer mine at all. They, like many others, seem to have an aversion to discussing certain aspects of reality, so they chose to opt out of the conversation, a right which you too have.
> in which case I reiterate: go away
Why? Are there certain aspects of reality that you have an aversion to being pointed out? Well, simply click the X in your browser window and all this harshness can disappear.
> Hmm, I think you misunderstood my previous answer.
I understood it perfectly well, it is a highly predictable response to that class of prompt, one of three or so responses.
> We knew about the existence of atomic matter since humans have been a species, with overwhelming amounts of evidence. There is no "before" in that sense.
Humans knew about the existence of atomic matter since they've been a species?
>>> The concept of the atom that Western scientists accepted in broad outline from the 1600s until about 1900 originated with Greek philosophers in the 5th century BCE. Their speculation [1] about a hard, indivisible fundamental particle of nature was replaced slowly by a scientific theory supported by experiment and mathematical deduction.
Could you possibly share even one piece of evidence of this (you don't even need to link to it, quoting it from memory is fine, provided you include some detail)?
It sounds like I broke your prediction if you're this confused.
Atomic matter is right there and everywhere. We didn't know about the structural details of atoms, but we knew about the bulk effects.
When the topic of discussion is signals that no current equipment can measure, there are some pretty direct analogues that might be convincing in some ways, but when it comes to something as fundamental as atoms, we were only ever lacking nuance in our knowledge. Signals like that would be a lot bigger than nuance, and our physics experiments leave a lot less room for it.
I'll add to it that there's a wide range of documented cases of humans experiencing all sorts of weird phenomena when their brains are being physically poked at. A drug chemically circuit-bending your brain therefore seems much more likely explanation than opening it to perceive an extra dimension of reality.
That is, since the only possible known interactions that the brain could pick up are electrical in nature, and given that no external electrical field changes are observed, that constitutes evidence that no external signal is being received by the person. The weak and strong forces don't work at such distances, so they are out of the question, and gravitational waves or neutrinos are far too weak to be detected by our brains, and impossible to make so targeted that only a single individual would receive the signal.
Now, is it conceivable that a different fundamental interaction that mammalian brains can detect but that none of our experiments have ever found could exist? Yes, but it is so extraordinarily unlikely that it can be dismissed out of hand, absent any proof. And the memories of people experiencing hallucinations are certainly not proof.