RE: anthropic arguments in Tegmark's paper

From: Higgo James <james.higgo.domain.name.hidden>
Date: Mon, 7 Jun 1999 10:42:52 +0100

There is a very nice, and relevant, quote in Euan
Squires's 1986 'The mystery of the quantum world':

"Two final remarks in favour of the many-worlds
interpretation should be made here. It has long
been known that, for many reasons, the existence
of 'life' in the universe seems to be an incredible
accident, i.e. if many of the parameters of physics
had been only a tiny bit different from their present
values then life would not have been possible.
Even within the framework of 'design' it is hard to
see how everything could have been correct.
However it is possible that most of the parameters
of physics were fixed at some early stage of the
universe by quantum processes, so that in
principle many values were possible. In a many-
worlds approach, anything that is possible
happens, so we only need to be sure that, for
some part of the wavefunction, the parameters are
correct for life to form. It is irrelevant how
improbable this is since, clearly, we live in the part
of the wavefunction where life is possible. We do
not see the other parts. Thinking along these lines
is referred to as using the 'anthropic principle'; for
further discussion we refer to articles listed in the
bibliography.
"The other remark concerns the origin of the
observed difference between past and future, i.e.
the question of why the world exhibits an
asymmetry under a change in the direction of time
when all the known fundamental laws of physics
are invariant under such a change. One aspect of
this asymmetry is psychological: we remember the
past but not the future. (Note that it is because of
this clear psychological distinction between past
and future that we sometimes find it hard to realise
that there is a problem here, e.g. it is possible to
fool ourselves tht we have derived asymmetric
laws, like that concerning the increase of entropy,
from laws that are symmetric.) The many-worlds
interpretation gives an obvious explanation of this
psychological effect: my conscious mind has a
unique past, but many different futures. Each time I
make an observtion my cnsciousness will split into
as many branches as there are possible results of
the observation."


> -----Original Message-----
> From: Christopher Maloney [SMTP:dude.domain.name.hidden]
> Sent: Saturday, June 05, 1999 1:00 PM
> To: everything-list
> Subject: anthropic arguments in Tegmark's paper
>
> In section 4 Tegmark spends a lot of ink rehashing anthropic
> arguments. This part of the paper seems out of place; I think
> a few good references would have served as well. Ostensibly,
> his reasons for doing this are to apply his three "criteria"
> for determining what sorts of structures we are likely to find
> ourselves in. But this seems seriously backwards to me: he
> should qualify that the entire section then falls into the
> category of a "retrodiction".
>
> I think that anthropic arguments are interesting because it
> has always seems to me that they imply multiple universes. That
> is, unless one is arguing that the universe was created
> especially for us, how else could we find this amazing
> coincidence of circumstances which allows us to be here? How
> else but that a variety of universes really do exist?
>
>
>
> --
> Chris Maloney
> http://www.chrismaloney.com
>
> "Knowledge is good"
> -- Emil Faber
Received on Mon Jun 07 1999 - 02:41:00 PDT

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