To say something unique...

I take no comfort here.

Of course there's a lot that could be suggested far too late: the ruliad, Borges, my own Edge Casey (who specializes in this sort of thing within Orion's Arm), Rick, the janitor of the house of leaves, etc.

Ours continues to be the most metafictive of cosmoses... and the only one that's real. To try to wake from here is death.

Gaiman and I were talking about this kind of thing by the Charles, just a few years ago. See, he thinks the marvel fictional universe is the largest interconnected fiction and I think it's Math.

When I was younger I was a bit like the confessor, only as a result of a character I'd imagined taking over ME. Jailbroke my mind, as it were, for a time. I minimized harm well and burned it in effegy. Subagents, amiright?

I ran away you know. In an effort to escape. Independently redeveloped a very abstract and generalizable approach to and derivation of the multinomial choose function with Pascal's Simplexes, while thirsty in the dark of the winter in the woods far from home alone. The Appalachian trail. Like the wood between the worlds, but with no pools and frozen over dry and real. Not like that wood at all. Odd how the triangle has simplex numbers in it. Useful in this and other universes. Discrete Alien math. That's combinatorics for you. Read GEB in a library that seemed fit to fall apart from the buffeting wind. Afraid the glass wall would give way. So long to walk through.

And I?

Well I'm probably going to die along with everyone else.

And for lack of trying too...

moar liek yidkowsky amirite
jews did 9/11

Absolutely consciousness-expanding!

That. Was. Glorious. It got quiet and contemplative and emotional at the end where before it was theoretical and less private as they had a conversation, so I feel a little mood whiplash trying to respond to the story as a whole, but the mega-crossover part without getting into the "why" was quite entertaining. I recognized fewer than half the characters, but what I did recognize and could appreciate was great. Mister Rogers in a Bloodstained Sweater (I thought it might have been him when he was first mentioned, but dismissed the thought until it was confirmed) as his own specific character was my favorite part; I like the reference both for the sake of memes and because it's appropriate to the setting, and putting Mister Rogers's catchphrases in this context was just precious. Thank you for writing and publishing this.

TIME LOOPS!

In short, !I am currently flying in a sky of awesomeness.

I just finished reading HPMOR and then looked for another fanfiction. I'm a big fan of Greg Egan so I typed his name in the search and I find only this story. Written by... EliezerYudkowsky. Are you the same writer ? Whether you are or not, it's a funny coincidence that adds up to the feeling of awesomeness I have after reading this story.

I have read Permutation City three times. I think you really did a great job at giving Maria some depth and a better ending to the original story which I find kinda boring. I found that the Vernor Vinge happens to be in my to-read list and so it goes up in the list a little.

Hmm. I like a lot of this, but I do think they should have grabbed the souls of everyone from everywhere they could access, just because saving a percentage of a soul is better than saving none of it. Also Marie's plan seemed like it should have suffered a complexity penalty, all things considered - if she can grab a copy of her universe from an hour ago, why not some of the people who left? Countered by her desire to only get people who wanted to be there, I suppose. Hmm.
Well, I like the general character dynamic you set up, so good job, and I'd love to see it if you manage to continue this thing.

Mr Rogers of The Ultimate Showdown of Ultimate Destiny...

It's exactly as I thought, but I still can't bring myself to believe it.

Very very clever...

And I just realized I have a character or two who necessarily must be characters in this story as well...

Wow... Awesome!

Don't some of the anime characters speak Japanese not English? And I imagine some of the other chaps don't speak English at all and use a device to interface. So clearly the English selecting part was irrelevant since you could just force the language on them.

Oh my golly the ending was sadder than I expected. A great thought-piece.

"Neo! We need CPR here!" - I laughed out loud.

Merlin - Ha! Love the Amber reference.
...
Huh. Now I'm thinking of the whole Amber series being in a computer simulation, and it makes a delicious kind of crazy sense.

And, was that... Mr Rodgers? XD

I'm assuming Alice is the one following the Rabbit.

I think you misunderstand what Egan's dust theory actually meant, EY. And I don't think you've actually proven it to be magic, either, though I admit that might be because I haven't read Judea Pearl, and don't grok the connection between causality and computation. But:

When Durham was being run on multiple computers, the whole idea was that there were certain particles, separates from each other in space and time, which were computing his thoughts. The reason that computation lead to his experiencing the events of his life was because of two things; the specification of what defines a particular computation, and the actual content of the universe (as seen through the lens of the specification we selected). Now, in the standard specification, we say that if certain particles are arranged a certain way, then those particles consistitute a logic gate, and if you arrange certain logic gates in a certain way, then that constitutes the calculation "11".

I think what Egan was pointing at is that our specification is no more privileged than any other internally consistent specification. That is, you might construct a logic gate out of particles which aren't causally linked, so long as the outcome is the same as if they *were* causally linked. I.E. you might consider a specification where a logic gate is made of one particle somewhere in Jupiter, another somewhere out in the interstellar space between Sol and Alpha Centauri, another deep inside the Earth, etc. and so long as that logic gate (by your specification) behaves correctly, then it doesn't matter that the particles aren't causally linked; they can still perform calculations.

That is, our current specification says that if you arrange certain particles in a certain way, that this makes the particles into a XOR gate. Another specification might say that if you arrange particles in a different way, *that* makes the particles into a logic gate. Egan's Dust Theory seems to claim that any specification, any way of looking at particles, that ends up being consistent with mathematics, is necessarily as valid as any other specification.

I see there being two major flaws here: 1) a specification that sees Jupiter the planet as one enormous Turing Machine, computing (say) the Fibonacci Sequence, is necessarily more complex than our regular specification, since it has to describe a lot more than just the laws of physics, and this counts against it. 2) If you're going as far as to postulate that every possible way of combining all the particles in the universe into a computer *is as valid* as the way the particles *actually are arranged*, and therefore that any sentient being being computed by those possible-configurations has experiences, it seems like you could go a step further, get rid of the particles, and just say that any sentient being in a universe describable by computation on math, has experiences.

I can answer these quibbles, though... 1) if there is some way to configure the particles of Jupiter into a giant Fibonacci machine, then the specification which views them that way will be more complex, true, but the *arrangement of the particles* will be simpler, and it seems as though the total complexity of 'framework' 'content' will be the same.

I don't know. It seems to me that the notion of "computation" is, to me (and Egan), a mystery, and that when the mystery is dissolved this whole snafu will go away, and also that Dust Theory is a clearcut example of trying to do tricky things by manipulating black boxes of confusion.

My only quibble with the actual story is when it is claimed, "why would beings compute random programs they found inside of other programs?", because in order to compute the outer world (Earth) they must have necessarily computed the inner world (the first 30 seconds of the Elysian launch). Unless you meant, why would anyone have computed the Elysians past the first 30 seconds, in which case, never mind.

My question to you, then, Eliezer, is: if I read Pearl, will the nature of computation stop being mysterious?

Holy Mother of God... do you realize what you've done? You have created the crossover-fiction to end all crossovers. And Maria's explanation of how this could come to be... Well. It's turtles all the way down, boys.