Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

A Brief Explanation of Greg Egan’s Dust Theory

cephalopods.blog

Post reply on HN
Print view View original

31–40 of 133 posts

Re: A Brief Explanation of Greg Egan’s Dust Theory

#31

Post by foobarbecue »

db48x wrote: post #11
sxp wrote: post #6

This article doesn't actually explain Dust Theory to someone who hasn't read the book. I haven't found a good standalone explanation of the theory that explains it in a compact manner so my recommendation to people is to read the book. Permutation City is among my top 5 favorite books because I found Dust Theory so mind blowingly amazing from a philosophical standpoint. I haven't seen it discussed elsewhere outside t…

You'd probably like Neal Stephenson's Anathem. It's a Hemn Space argument.

Is that the one that had hundreds of pages of monks hanging around at the beginning? I got bored and couldn't make it through

Re: A Brief Explanation of Greg Egan’s Dust Theory

#32

Post by Flow »

db48x wrote: post #9
geuis wrote: post #4

I’ll take this one. Can someone provide some background as to exactly what is being discussed here?

A major plot point and thematic element from a novel by Greg Egan called Permutation City.

Would you consider this to be a spoiler for the book? I've not read my copy yet.

Re: A Brief Explanation of Greg Egan’s Dust Theory

#33

Post by throwaway_pdp09 »

codethief wrote: post #19
throwaway_pdp09 wrote: post #16

Looking at other stuff ISTM this is generated by one of them newfangled GPT3 things or whatever: "Nonetheless, It is because of my faith in science and its processes that I have always been of the opinion that the state pension, though grisly from a naive “one-worlder” perspective is actually a remarkably humane, efficient and (dare I say) generous social program." ( https://cephalopods.blog/ ) and if you look at the…

> and if you look at the home link https://cephalopods.blog/about/ anyone else think that looks like a generated face? More importantly, it's a new face every time you reload the page.

So it is! Well spotted. I think you've proven it.

Re: A Brief Explanation of Greg Egan’s Dust Theory

#34

Post by sdenton4 »

codethief wrote: post #7

He lost me right in the second paragraph: > Because computation is sort of subjective, just a set of relations that can be usefully interpreted as representing a function, this seems to imply that the function you identify with can be interpreted as being simulated by any sufficiently complex set of relations. Can anyone explain? I'm already struggling with the premise: Why should computation be subjective in the fir…

If you're living inside the simulation, there's a lot of flex in how the computations running the simulation get carried out that you would never notice. It's effectively saying there's a separation between the implementation of the simulation and the experience of living inside the simulation.

In the book, this is illustrated by computing some time-steps out of order. (This, it turns out, isn't a very realistic example, but is illustrative of the idea.) Someone inside the simulation doesn't realize they've been computed 'out of order.' It also doesn't matter how fast you run the simulation: the simulator clock and the simulated clock can be completely decoupled. You can run it on a single machine verrrrrrry slowly, or in a gigantic data center, and anyone inside the simulation would never know the difference.

So what is the simulation then? It's the collection of states, regardless of how and in what order they are computed.

The Dust Theory is taking this to a kind of logical extreme: Sometimes these states just naturally arise in random configurations of particles, because the universe is vast. It doesn't matter what /order/ they arise in (as we already saw), just that all of the states randomly arise at one time or another. "What if simulation by galactic bogosort?"

It's also similar to the Library of Babel, but for computation instead of books. (https://en.wikipedia.org/wiki/The_Library_of_Babel) And it has the same problem as the Library of Babel; typos are unavoidable when there's no intention. (hell, typos are unavoidable even when there IS intention...) So then we need to assert that the 'real' simulation is the one that just happens to have all of the 'right' random states, not to be confused with all of the untold billions of other almost-right states.

(and then you can ask, if you've followed things THIS far, is it even necessary for the 'right' states to arise, given that they must eventually due to the law of large numbers, alongside all of these slightly-wrong versions? Or is it enough for the simulation to be mathematically possible, so that we can assert that the right states exist?)

Re: A Brief Explanation of Greg Egan’s Dust Theory

#35

Post by sdenton4 »

foobarbecue wrote: post #31
db48x wrote: post #11

Earlier quoted context omitted.

You'd probably like Neal Stephenson's Anathem. It's a Hemn Space argument.

Is that the one that had hundreds of pages of monks hanging around at the beginning? I got bored and couldn't make it through

It is the BEST book, though. It becomes a madcap zany heist in the second half, but the 'boring' beginning bit is my favorite. I think back on 'The Book' every time I have to debug bad code... https://anathem.fandom.com/wiki/Book

Re: A Brief Explanation of Greg Egan’s Dust Theory

#36

Post by db48x »

Flow wrote: post #32
db48x wrote: post #9

Earlier quoted context omitted.

A major plot point and thematic element from a novel by Greg Egan called Permutation City.

Would you consider this to be a spoiler for the book? I've not read my copy yet.

You probably won't understand this brief "explanation" until after you read the book. It's brief largely because it assumes that you know at least the events in the book, even if you couldn't follow the definitions and other exposition.

Re: A Brief Explanation of Greg Egan’s Dust Theory

#37

Post by ahartmetz »

foobarbecue wrote: post #31
db48x wrote: post #11

Earlier quoted context omitted.

You'd probably like Neal Stephenson's Anathem. It's a Hemn Space argument.

Is that the one that had hundreds of pages of monks hanging around at the beginning? I got bored and couldn't make it through

Neal Stephenson tends to cram too many side stories into his books, some of them quite boring :/

I kind of regret that I slogged through Cryptonomicon and I would advise anyone to stop reading after 200 pages if bored, the next 700 won't really be better.

Re: A Brief Explanation of Greg Egan’s Dust Theory

#38

Post by codethief »

throwaway_pdp09 wrote: post #33
codethief wrote: post #19

Earlier quoted context omitted.

> and if you look at the home link https://cephalopods.blog/about/ anyone else think that looks like a generated face? More importantly, it's a new face every time you reload the page.

So it is! Well spotted. I think you've proven it.

Not sure I'd consider this a proof. Maybe it's just some weird dude :)

Re: A Brief Explanation of Greg Egan’s Dust Theory

#39

Post by TheOtherHobbes »

domenicd wrote: post #3

A while ago I wrote up my own take, inspired largely by Permutation City but also by Tegmark's mathematical universe hypothesis: https://blog.domenic.me/mathematical-consciousness/ To me this line of thinking is very attractive. As someone who has been a mathematical Platonist forever, this gives a very satisfying answer to big questions like "why is there something instead of nothing" and "why is our universe so per…

Our universe isn't perfectly described by mathematics. Parts of our universe can be described by mathematics on limited timescales while also assuming inherent randomness.

Math can't even predict the fate of the solar system out to infinity. Planetary systems aren't unconditionally stable, and the effects of limited precision - presumably relevant to any hypothesis of computability - make very long term predictions not just unreliable, but impossible.

This pretty much kills Tegmark's thought experiment, which is in any case a perfect example of begging the question - in spite of the increasing improbability of the examples.

Platonists need to explain if they believe that consciousness is possible on clockwork hardware. If Platonists actually believe that, they may as well dismiss everything that's happened in science since the days of Newton, because that's a very extraordinary claim with absolutely no evidence to support it.

Re: A Brief Explanation of Greg Egan’s Dust Theory

#40

Post by codethief »

db48x wrote: post #27
codethief wrote: post #21

Earlier quoted context omitted.

I would counter that by saying that: 1) this has nothing to do with computation. 2) my subjective experience is objectively there. No one questions what I am thinking. (That is, no one else looks inside my brain and claims: This is not what your thinking! ) My thoughts might be my own personal view and differ from other people's thoughts but their existence is not up for debate.

This has everything to do with computation, because the mind is just software running on a funny kind of computer. In the novel, many people have had their minds uploaded into regular electrical computers as well, though they're generally not able to run in real time. That's not a counter, because it's just what I said. We all have a subjective inner experience. The premise of the novel is that this subjective inner…

No offense, but I obviously haven't read the novel and can't follow at all. Otherwise I wouldn't be asking.

And no, what I said is not what you said. Having read the novel, maybe you're interpreting your own words and/or my words in terms of that novel? That is, maybe you're oblivious to how your words/my words get interpreted when you have not read the novel?

Back to the original discussion:

> This has everything to do with computation, because the mind is just software running on a funny kind of computer.

This still doesn't explain why computation should be subjective.

Post reply on HN