Anders Sandberg wrote:
>
> One way of seeing why life in a state with no arrow of time is
> unlikely is that it cannot evolve, since evolution includes an
> irreversible selection step where the unfit are weeded out. In a
> reversible world individuals could un-die and and there would be no
> evolution. In the same way memory and learning would be impossible,
> since forgetting would be just as likely as learning.
Let me try an analogy. Suppose that your computer had all RAM randomized. After interpreting these random instructions, eventually a sort of order emerges where 1s clump together and 0s clump together and most computational transactions occur when two areas of 1s and 0s mix.
>From our perspective, our system is vastly more efficient than theirs,
which is built on top of several layers of abstraction and uses vast
clumps of near-random data to accomplish operations we could perform in
a single instruction. As for the arrow of time, that happens when a
system starts out as an unsorted list and becomes a sorted list. From
the Binary People's perspective, nothing has happened, but that's
because they can't see our kinds of order.
> > In fact, information is directly proportional to
> > entropy. The more information it takes to encode a system, the more
> > mathematically random ("normal") that system is, the more entropy that
> > system has. Ergo, maximally efficient information-processing takes
> > place at uniform temperature.
>
> Be careful about the word "information", it has different meanings in
> different fields. The information in information theory is rather
> different from the information concept used in daily life and not
> necessarily even identical to negentropy.
I am using "information" in the information-theoretical sense of "size of Turing machine needed to produce output".
> But remember that there were particle horizons; at time t only
> particles within each others past lightcone could have affected each
> other.
Yeah, hence the caveats. I'm afraid I don't know. I got the impression that during the very early Big Bang, everything was within everything else's light cone. Of course, that doesn't mean an infinite number of actions could be performed. What's the function for the radius of the Big Bang as a function of time? Anyone know?
> > Anyway, the question isn't whether there are macroscopic computations
> > (of the sort we're used to) taking place, but whether arbitrary
> > computations can be encoded in the physical process of the Big Bang.
>
> That is a different questions. There are arbitrary computations
> encoded in the thermal vibrations in my desk. Somewhere it is running
> my old ZX81 fractal program...
All computations are recorded/encoded, but not instantiated, in the digits of pi. Let me define "instantiated" a bit more nearly, to distinguish from "recorded". For one thing, it's obvious that recording can't be enough, or all computations would be real and everything is true, which could possibly the case and certainly explains everything, but is not useful for making choices. I once followed this path down as far as I could, and while there actually isn't any way to define an "instantiation", there are some partial definitions that will work most of the time.
So, by the Anthropic Principle, what are *we* doing in the Long Cold? My guess is because the first Power to evolve in that space gobbled up all the computing power. Alternatively, consciousness wasn't possible*. Anyway, between the two alternatives, you still don't have any way for mortal races to evolve. Not like here, where there's a long lightspeed separation. (Actually, I STILL don't understand why the stars are silent, so put it down as part of the Great Filter Paradox.)
Death is eternity. Eternity is starlight. Starlight is silent. For those who are encoded it is immortality of a sort.
(With apologies to Glen Cook.)
-- sentience@pobox.com Eliezer S. Yudkowsky http://pobox.com/~sentience/AI_design.temp.html http://pobox.com/~sentience/sing_analysis.html Disclaimer: Unless otherwise specified, I'm not telling you everything I think I know.