Thanks for the reply.

Yes, I think you're right and I still don't have enough karma points.

Well, I guess I will have to owe you an upvote in the meantime...

Thanks

Thanks for this summation.

Maybe we can divide item 7. to "our universe apocalypse" and "everything that (physically) exists apocalypse." since the two might not be equal.

Of course, there might be things that exist necessarily and thus cannot be "apocalypsed out", and it also would be strange if the principle that brought our universe to existence can only operate once.

So while it might be possible to have a Multiverse apocalypse, I think that there will always be something (physical) existing (but I don't know if this thought really can comfort us if we get wiped out...)

By the way, how do you (up)vote here?

Cheers

There's a guy named Donald D. Hoffman whom I saw on YouTube; unlike you, he is sort of "consciousness monist" (if I understand him correctly), that is, he claims that the most basic part of reality is consciousness and, in fact, reality is a network of relations between these basic particles.

I guess that if you can find some sort of an identity between this basic particle and a mathematical object we get your idea (If I understand your ideas correctly).

I also sort of remember him claiming that he could deduce the rules of quantum mechanics, but I'm not 100% sure.

You might want to check his ideas out.

Cheers

I guess you ask "why" when something is unobvious or unexpected.

The first one is relative, where obvious for a smart person might not be obvious to a less-smart one. So, like you said, it is not obvious why the null hypothesis does not obtain, and anyone who says that existence is obvious is fooling himself.

The second is less relative, for example, if a monkey randomly types Hamlet then it is unexpected, but if he just typed pure gibberish, it is not. Thus, a universe which is a totally chaotic will be more expected than a universe like ours (so not only need we ask why something exists, but why it is so ordered). However, I don't know if we can say that the null-hypothesis is more expected.

I guess, in a clumsy manner, I meant to say that the real question is what would a satisfying explanation be. Some people are satisfied with God, others with MUH, others with Suskind's landscape and others will never be.

Now, about "something" equal to existence. That's tricky, is a square circle something? Is a possible world something? If they are, do they "exist"?

I agree with you that the only type of existence that we are 100% sure about is our own (i.e. our consciousness). Now, if you are not a solipsist, then, as you said, you are willing to grant "existence" to things that you can interact with, but then would you deny it from causally independent realms of existence? Does a universe without observers, like the sound of the proverbial tree in the forest, really exist? I think Wheeler thought so, and I am sympathetic to that position, but who knows.

Furthermore, do the objects in our physical theories exist--like quarks, strings, other universes in Linde's chaotic realm--they might explain a lot, but their existence is always indirectly inferred or is a conclusion of some useful theory.

So to (sort of) answer your question, I don't think I can give an intensional definition of existence, but its extensional one will include consciousness; it might include other things but I think we'll need to know the intensional one first...

As for all logically consistent structures (or something like that) existing. Maybe, who knows. It's a bit like Lewis's and Tegmark's ideas, no? Also, I'm not an expert, but I think that theorems by Tarski(?) show that there isn't any universal notion of "Truth."

And what is "A"? A proposition? A sentence in first order logic? A sentence in set theory? A second order sentence?

What if A says about itself "I do not exist"? If it's true then it doesn't exist, if it is not then it does.

My head is starting to ache, so I'll better stop.

Cheers.

I think we need to get clearer on what "why," "something" and "exists" mean.

For example, if you assume that numbers "exist", that is, you are willing to attach the descriptor "exist" to numbers, then you already have your answer: "Because numbers exist necessarily!"

Voila! End of story! Move over, folks, nothing(...) to see here.

Still, if you think that numbers are "something" and that they "exist," then it still doesn't answer why THE PHYSICAL world exists, or consciousness. I guess that now you can follow Tegmark's footsteps and say that everything is mathematics, and that's it. (But maybe there is a separate answer?)

So now (for Platonists) the "why" question is not why something exists, it is how to prove physical existence from the necessary existence of numbers or mathematical structures.

So like I said, before one tries to answer this question one first has to give some working definition as to what "why," "something" and "exists" mean.

So when you ask, "Why did Sherlock Holmes tell Watson that...?"

You assume that Holmes exists?

Also, when you ask why some complicated theorem in number theory is true, you are basically asking for a proof from first principles (say Peano Arithmetic), you don't need to assume that numbers exist (which would make you a Platonist).