Re: lost in the many worlds

From: Hal Finney <hal.domain.name.hidden>
Date: Wed, 28 Jan 1998 15:27:41 -0800

Wei Dai, <weidai.domain.name.hidden>, writes:
> Suppose our universe is actually a wave function evolving in a computer in
> another universe acoording to the standard linear wave equations. If there
> is a way to send a signal to the administrator of this computer, how many
> bits of information would we need to send in order for him to be able to
> find us in the wave function?
>
> My impression (please correct me if I'm wrong) is that this would be a
> very large number, much larger than the number of bits needed to
> completely describe a human brain. If this is true, then in what sense
> does quantum mechanics offer an explaination for our perceptions of the
> world (i.e. the inside view in Max Tegmark's terminology)? It seems like
> a complete explaination would be longer than the data itself. By complete
> explaination I mean boundary conditions of the wave function, the wave
> equations, and the information needed to extract the inside view that
> we're seeing from the wave function.

I think you're right that the amount of data would be very large.
You'd have to count the information content of each wave function collapse
since the creation of the universe.

With many-worlds, and also with an all-universes TM, you get a short
program at the cost of creating multiple universes. Then if you want
to select just one of those universes, you would have to specify a lot
of information. These models do not offer an explanation for why we
see the specific universe we do.

What they do provide is a prediction that some observers like ourselves
should exist, and that they should see the universe as we see it.
So the model does, in that sense, predict what we see, and therefore
could be said to explain what we see.

I'm not sure what you are getting at in terms of comparing with the number
of bits to specify a human brain. Are you thinking that it would be
simpler to say that your brain was simply created in its current state
than that all these events happened throughout history to produce it?

Hal
Received on Wed Jan 28 1998 - 15:44:21 PST