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A Brief Explanation of Greg Egan’s Dust Theory

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

#61

Post by j-pb »

boxed wrote: post #15
j-pb wrote: post #5

I don't know the original theory, but this explanation is brief to the point where it's nonsensical.

Might be because the entire thing is nonsense. Entropy shoots a hole in the entire thing as far as I can tell. The problem is that the information can never be retrieved, so if it exists or not is really pointless.

Yeah the whole thing is also way to handwavy when it comes to computational complexity of the encodings.

It also somehow simultaneously assumes the church turing thesis, the existence of non computable reals and arbitrary functions over them at the same time...

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

#62

Post by cmehdy »

ryukafalz wrote: post #59
cmehdy wrote: post #44

Earlier quoted context omitted.

I finished the book last night. It's not a long read in terms of pages, but in the first half particularly it took me quite a few stops to ponder about what had been laid in few sentences. Greg Egan is awesome. (Sort-of SPOILERS underneath) I can actually grasp the Dust theory thing pretty well as I followed Durham's realizations, however I somehow can't fathom the "more practical" TVC universe stuff, and perhaps you…

It has admittedly been a long time since I've read the book, so my recollection of it may be a bit hazy, but: > Why would a few minutes of compute offer Durham any more relief than a second of it, a theoretical proof of it, or a billion years of it? Since they are even in a position to kickstart something computable, it mathematically exists, therefore by the Dust theory they don't even need to start it in order for…

It makes sense, thanks. I guess I hadn't really thought about the fact that having a program written isn't having a program that is mathematically verified (as we likely all know, this is a particularly costly procedure and can hardly be done on extremely complex pieces of software - otherwise everyone would do it). So they run it long enough to "feel" like it is valid enough. And then they can't afford more.

From a software engineer point of view though, it's a bit short-sighted isn't it? I can't imagine anyone writing anything beyond a calculator app (and even that..) would be certifying to you that formal verification could work on their program by simply running it for a while. Durham could have bootstrapped further cash to keep things running once in a while for show and dedicate the rest of his life to mathematically proving as many chunks as possible. But that might just be me obsessing over the concept more than Durham himself..

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

#63

Post by dvt »

The problem with these kinds of theories (eternal recurrence, random quantum state fluctuations, simulation):

- There are plenty of things that aren't computable that our universe seems to do just fine (entropy being one)

- The universe seems to be intelligible, especially w.r.t. its causal chain -- if we only happen to be conscious in these very specific instants (where we have intelligibility, causality, etc.), the question is why?

At the end of the day, you end up with some kind of Maxwell's demon type of situation where there's all this trickery that needs to happen to support a theory where we're in a simulation or Boltzmann brains.

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

#64

Post by foobarbecue »

ahartmetz wrote: post #37
foobarbecue wrote: post #31

Earlier quoted context omitted.

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.

I enjoyed cryptonomicon but get where you're coming from! I think his books would be way better with aggressive editing. Seveneves was great but so many long lame sections should have been removed.

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

#65

Post by c1ccccc1 »

croissants wrote: post #22
tomrod wrote: post #2

Interesting article! As linked in the article, Egan posted some FAQ/counterarguments for issues raised here: https://www.gregegan.net/PERMUTATION/FAQ/FAQ.html

Nice, IMO this (short) FAQ has a lot more useful info than the featured article. His claim at the end that creating intelligent life through evolution is deeply immoral confuses me, though -- by all accounts, we arose through that process, and relatively few people seem bothered by it.

People are probably less bothered by it because it happened so long ago, and was not perpetrated by any kind of thinking agent. The process of evolution definitely entails a lot of suffering, though. Consider almost any attribute of modern day humans, fear of heights, say. Millions of creatures had to fall to their deaths (many of them very similar to modern humans) to etch that fear of heights into the surviving generations. Or take the gag reflex: many deaths by choking. The immune system: billions of deaths by disease and infection. It would certainly be immoral to inflict such things, if you had the ability to prevent them.

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

#66

Post by ryukafalz »

cmehdy wrote: post #62
ryukafalz wrote: post #59

Earlier quoted context omitted.

It has admittedly been a long time since I've read the book, so my recollection of it may be a bit hazy, but: > Why would a few minutes of compute offer Durham any more relief than a second of it, a theoretical proof of it, or a billion years of it? Since they are even in a position to kickstart something computable, it mathematically exists, therefore by the Dust theory they don't even need to start it in order for…

It makes sense, thanks. I guess I hadn't really thought about the fact that having a program written isn't having a program that is mathematically verified (as we likely all know, this is a particularly costly procedure and can hardly be done on extremely complex pieces of software - otherwise everyone would do it). So they run it long enough to "feel" like it is valid enough. And then they can't afford more. From a…

Well, part of what Durham wanted to demonstrate to himself was that he didn't need to be running the simulation for the TVC version of him to have a subjective experience of the simulation, right? And TVC-Durham has Durham's memories as of the last brain scan, so that's also "him" in a sense. So the fact that TVC-Durham knows that the simulation isn't being run on the outside is valuable knowledge as well.

It's sort of a balance between flesh-Durham having assurance that the simulation works, and TVC-Durham having assurance that his subjective experience of the TVC universe is going to continue.

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

#67

Post by athriren »

codethief wrote: post #41
Udik wrote: post #30

Earlier quoted context omitted.

Just by chance, I happened to try to explain the dust theory to a completely uninterested subject today over lunch :) I tried to make it as brief as possible like this: some people believe mathematical truths are necessary and therefore that they exist independently of us discovering them. For example, the entire set of theorems that can be proven from a given set of axioms is already there in the axioms themselves-…

Thank you, that's the first intelligible explanation I've read here on this thread!

yeah, i was struggling too. egan’s books are too much for me because i feel like i need a highlighter and a graphing calculator, but i totally admire them and wish i was smarter.

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

#68

Post by mdoms »

Greg Egan is truly one of the most creative minds on the planet. He has a book called Dichronaughts that's set in a universe with 2 space and 2 time-like dimensions. It's very hard to get your head around but the result is a universe with a hyperbolic geometry where movement on one axis implies changing your shape entirely.

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

#69

Post by athriren »

croissants wrote: post #22
tomrod wrote: post #2

Interesting article! As linked in the article, Egan posted some FAQ/counterarguments for issues raised here: https://www.gregegan.net/PERMUTATION/FAQ/FAQ.html

Nice, IMO this (short) FAQ has a lot more useful info than the featured article. His claim at the end that creating intelligent life through evolution is deeply immoral confuses me, though -- by all accounts, we arose through that process, and relatively few people seem bothered by it.

imagine a person gets cancer and dies. this is, by itself and with no context, an act that has no moral component—it just happened. now imagine YOU gave the person cancer.

this difference is the difference between the presumably undirected evolution that led to us, and the sort of fucking around with actual living things we would need to do to direct evolution ourselves.

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

#70

Post by goldenkey »

vladTheInhaler wrote: post #42
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 I understand correctly, it's not that the computation itself is subjective, but that the interpretation of the results is. Like how things are represented in lambda calculus - is this really an integer, or is it just a blob of function applications that has an interpretation consistent with being an integer? That part is subjective. Edit: to be more explicit, the parallel is "is that really a mind, or is it just a…

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