On Sat, Sep 15, 2007 at 01:25:04PM -0000, Rolf Nelson wrote: > > If I understand the Measure Problem correctly, we wonder why we find > ourselves in a "Goldilocks Universe" of stars and galaxies rather than > a simpler universe consisting solely of blackbody radiation, or a more > complex, unpredictable Harry Potter universe.
I call this the Occam catastrophe in my book. The solution I give there is a requirement that observers have to be embedded in the universe they observe, ie are self-aware. > > 1. An attempt at the solution was that more complex universes are less > probable; they are less likely to be produced by a random UTM. This > explains why induction works, why we don't live in a Harry Potter > universe. But this also means a simple blackbody radiation universe is > more probable than a Goldilocks Universe. > > 2. So we say, "There are more observers in a Goldilocks Universe, > where observers evolve through natural selection, than in a blackbody > radiation universe, where observers can only occasionally emerge > through extremely infrequent statistical anomalies." But if both the > Goldilocks Universe and the blackbody radiation universe are infinite > in size, then both have an infinite number of observers. Unnormalisable measures are not an insurmountable problem. I give some examples where this can be done in appendix C of my book. Of course there are problems in the general case. ... > > Here is one possible solution: the UTM instead directly produces a > qualia (or, if you prefer, substitute "observer moment" or whatever > terminology you deem appropriate). We'll use a broad definition of > "qualia" that can encompass complex observations like "Rolf sits at > his keyboard, reflecting on past observations and wondering why he > seems to live in a Goldilocks Universe", since that's exactly the type > of observation that we're trying to explain when we ponder the Measure > Problem. > > Each qualia, in the proposed model, is a long, finite-length string > that is output by a UTM running every possible random program. (This > is the same type of UTM that some of you have been proposing, but it > outputs an attempt at a single qualia, rather than outputting an > entire universe.) Very few strings are qualia; most UTM programs fail > to produce qualia. The proposed model additionally postulates that > many qualia are compressible in a certain interesting way, such that > the World-Index-Compression Postulate (below) is true. > > World-Index-Compression Postulate: The most probable way for the > output of a random UTM program to be a single qualia, is through > having a part of the program calculate a Universe, U, that is similar > to the universe we currently are observing; and then having another > part of the program search through the universe and pick out a > substring by using an search algorithm SA(U) that tries to find a > random sentient being in U and emit his qualia as the final output. > This sounds kind of complex. Just how do you recognise sentience? > As an example, take two qualia, that we will call Q(Goldilocks) and > Q(Potter): > > Q(Goldilocks): "All my life I have read that all swans are white. And > indeed, today I just saw a white swan." > > Q(Potter): "All my life I have read that all swans are white. But, > today I just saw a black swan." > Funny you should say this - all my life I read that swans were white*, but all the swans around here are actually black. It was only at the age of 28 that I saw my first white swan - when living in Europe. * in fairy stories of course - I knew full well that the first European exporers to our land were amazed at the black swans, and that they feature on the state flag where I grew up. -- ---------------------------------------------------------------------------- A/Prof Russell Standish Phone 0425 253119 (mobile) Mathematics UNSW SYDNEY 2052 [EMAIL PROTECTED] Australia http://www.hpcoders.com.au ---------------------------------------------------------------------------- --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~----------~----~----~----~------~----~------~--~---