If you can’t observe it at all there is no reason to believe that it exists.

No scientific reason, no.

No computational reason, literally zero reason at all. Fundamentally unfalsifiable beliefs are completely arbitrary, and those fundamentally unobservable subjects of those beliefs cannot affect reality in any way - if they could, then they would be observable in principle, and therefore the belief in them would be falsifiable too.

Where did you learn all these things, and how did you determine them to be necessarily true?

Having proof of nonexistence is completely different from having no reason to believe in existence. There is an infinite number of nonexistent things you might want to believe in. How do you choose which one you like? In my opinion the things where you have no proof of existence and which you define to be causally independent from the universe are the least interesting things to believe in. For example I believe extraterrestial intelligence exists even though I have to proof for it.

Demonstrating that "is" derives from Belief, not Truth. Which I'm ok with, if it is realized. Otherwise, I consider (and therefore believe, but do not know) the risk to be high enough that something should be done about it. Not so unlike how normal people are passionate about others getting their vaccinations.

„Is“ is a model that is indistinguishable from truth.

How could you possibly obtain accurate information about the distinguishing abilities of all Humans?

They are irrelevant for the question of this thread. No human can observe unobservable things by definition.

> They are irrelevant for the question of this thread.

Then why did you mention it? And, you made a claim in response to my question...so what gives? This technique seems a bit unfair.

Regardless: is relevance objective? How is it measured?

Also: note that "are" is a conjugation of "is". This creates a bit of an epistemic problem does it not (considering your comment above)?

> No human can observe unobservable things by definition.

Religion is a classic counterpoint to this. Nonexistence is another. Relevance is another. Omniscience another. There are tons of examples, with new ones coming online every day!

Plus: does defining reality to be a certain way necessarily mean it takes on that form, or might it only cause it to appear to have taken on that form?

Not being observable directly or indirectly is the definition of non-existence.

The qualia of other people is something I cannot test, but we all presume exists.

Qualia as executed by the brain are observable in principle. Qualia that are not a brain process, well, what 'spugru said.

Ding ding ding.

> the(!) definition

Then what's this?

https://www.merriam-webster.com/dictionary/nonexistent

I found several others that don't match your the definition as well if you don't find this convincing.

What in tarnation is going on here eh? It's almost like we're in some sort of a simulation.

the science of finding ways to observe it is still science. we couldn't observe many phenomena before we developed the science to do so.

Sure, and once we can observe something we can science it. But not until then.

Does the word "observe" have any constraints? For example: claimed observations, but that lack a way of measuring scientifically. Could science study this phenomenon?

Nope. Science is a specific tool of thought with a definition that starts with observation. Science might help feed ideas for technological or other sorts of advancement that allows us to observer more than before, but just because it helps science doesn't make it science.

If you cannot observe it / falsify it in principle - not using currently economical approaches, but using any possible current or future tests - then it's not science. If you can prove it cannot possibly be observed or falsified, it's not science.

It also means it's nonsense and doesn't exist.

Science claims totality. Anything that affects reality in any way, is in domain of science.

> It also means it's nonsense and doesn't exist.

This depends on which meaning of "is" you are using, as well as "means".

Did you know they are rendered local to the observer, but in a way that appears to be global?