[ExI] Fermi Paradox and Transcension

[Anders Sandberg]

On 13/09/2012 14:59, Stefano Vaj wrote:
> On 13 September 2012 05:32, spike <spike66 at att.net 
> <mailto:spike66 at att.net>> wrote:
>
>     I have no way of knowing if such a thing would ever simulate
>     intelligence,
>     but I do have a way of knowing the alternative: a dead rock does not
>     simulate anything.
>
>
> If you believe in the Principle of Computational Equivalence, almost 
> everything - that is, everything which is beyond a very low complexity 
> threshold much below that of any single PC - can emulate anything 
> else, the only issue being that of the relative performance in the 
> execution of a given programme.

The relative performance is not neglible. If you try to implement 
Windows 7 on the thermal interactions in a rock, you will find that the 
mapping between computer state and rock state is exceedingly complex. 
The same would be true for mapping it onto genetic switches. (The first 
case is truth to be told not really Wolfram's principle, but just 
Searle's criticism of functionalism)

Universal Turing machines can emulate each other with a constant 
overhead, but even the move over to Wolfram's dear Rule 30 adds at least 
a linear slowdown. And Rule 30 is still nearly a Turing machine: it is a 
computational universe that is pretty optimal for doing computations 
like a Turing machine. As you move further away from systems designed to 
be computers the slowdown likely becomes exponential.

Taking a pre-existing object and programming it to do Windows requires 
you to find a subset of the causal interactions in the object that 
implements a Turing machine (it has to be very simple, the probability 
of getting something equivalent to a Pentium is vanishingly small. 
Wolfram's 2 state 3 symbol Turing machine contains about 18 bits of 
information - expect to find one for every 2^18 random systems) - this 
is already somewhat tricky, since there is often no selection for such 
subsets in nature, they just show up. In particular, there is no 
selection for subsets that are free from causal interactios with the 
rest of the system: they get swamped with noise all the time. While in 
principle the noise-free Turing-complete subsystem could run Windows, 
the noisy one is incapable of doing it. So you need to find a subsystem 
that can house a few billion bits, yet does not interact strongly with 
the rest of the system or the outside world. That is even tougher.

Wolfram's principle is cool for thinking about Tegmark level 4 universes 
and the problems of defining life and computation, but it does not give 
us much practical help. The fact that small parts of nearly any complex 
system (when placed in peculiar states) can emulate small parts of 
nearly any other complex system is interesting, but not useful for much. 
We need to engineer systems to become good at computation (large parts 
of them can emulate large parts of other systems) if we want actual results.



-- 
Anders Sandberg,
Future of Humanity Institute
Philosophy Faculty of Oxford University

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