# RE: Are we simulated by some massive computer?

At 09:58 13/04/04 -0400, Ben Goertzel wrote:

```> 6) This shows that if we are in a massive computer running in
> a universe,  then (supposing we know it or believe it) to
> predict the future of any experiment we decide to carry one
> (for example testing A or B) we need to take into account all
> reconstitutions at any time of the computer (in the relevant
> state) in that universe, and actually also in any other
> universes (from our first person perspective we could not be
> aware of the difference of universes from inside the computer).```

```Yes, but this is just a fancy version of the good old-fashioned Humean
problem of induction, isn't it?
```

That would be the case if there were no measure on the computations.

```Indeed, predicting the future on a sound "a priori" basis is not
possible.  One must make arbitrary assumptions in order to guide
predictions.```

```This is a limitation, not of the "comp" hypothesis specifically, but of
the notion of prediction itself.```

```You cannot solve the problem of induction with or without "comp", so I
don't think you should use problem-of-induction related difficulties as
an argument against "comp."
```

I was not arguing against comp! (nor for).

```In fact, "comp" comes with a kind of workaround to the problem of
induction, which is: To justify induction, make an arbitrary assumption
of a certain universal computer, use this to gauge simplicity, and then
judge predictions based on their simplicity (to use a verbal shorthand
for a lot of math a la Solomonoff, Levin, Hutter, etc.).  This is not a
solution to the problem of induction (which is that one must make
arbitrary assumptions to do induction), just an elegant way of
introducing the arbitrary assumptions.
```
```This can help for explaining what intelligence is, but cannot help
for the mind body problem where *all* computations must be taken into
account.```

```So, in my view, we are faced with a couple different ways of introducing
the arbitrary assumptions needed to justify induction:```

```1) make an arbitrary assumption that the apparently real physical
universe is real```

```2) make an arbitrary assumption that simpler hypotheses are better,
where simplicity is judged by some fixed universal computing system```

```There is no scientific (i.e. inductive or deductive) way to choose
between these.  From a human perspective, the choice lies outside the
domain of science and math; it's a metaphysical or even ethical choice.
```

```I am not convinced. I don't really understand 1), and the interest of 2)
relies, I think, in the fact that simplicity should not (and does not, I'm sure
Schmidhuber would agree) on the choice of the universal computing
system.```

Bruno

http://iridia.ulb.ac.be/~marchal/

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