Re: [asa] The Multiverse - Physics or Metaphysics?

Iain,

Nor am I an expert. But as I understand it any of the seminifinite solutions
are just as physical--each representing a local minimum, or a solution, as
you point out, and I think the canonical number has gone up--to 10^1000 or
thereabouts.

The fact that none of the other universes cannot be detected doesn't phase
Susskind, who argues that perhaps we will just have to give up on Popperian
falsifiability as a requirement for science. (Susskind also points out that
if the multiverse is incorrect, it will be hard to answer the IDists. In
fact, his book gives some of the clearest expressions of cosmological fine
tuning.)

As I said--the Super String Landscape is tantamount to the death of physics.

On 9/11/07, Iain Strachan <igd.strachan@gmail.com> wrote:
>
> I'll reply to David on this one, but in the same post respond to a comment
> of George's.
>
> On 9/11/07, David Heddle < heddle@gmail.com> wrote:
> >
> > The worst part of the string landscape multiverse is that it means the
> > death of physics in that it holds that the search for a fundamental theory
> > is a fool's errand. Susskind even likens such a search to a religious
> > endeavor, which is not intended as a compliment.
> >
>
>
> David,
>
> Perhaps you can answer a question for me on this, as I'm not a real expert
> on String theory so I might be talking nonsense.
>
> Is it the case that the "string landscape" corresponds to a finite (but
> large 10^500) set of solutions to the theoretical equations?
>
> The reason for asking is that just because there may be many solutions to
> the equations does not imply that all the alternate solutions actually
> exist in reality (though it's not clear what "reality" means for alternate
> universes which we can't see and can't interact with). We've all been
> through the exercise where you solve a quadratic equation to get the
> solution to an applied maths problem, and you churn through the (-b +/-
> sqrt(b^2 -4ac))/2a formula, and then you choose one solution and
> automatically discard the other one because it's obvious that it's
> non-physical.
>
> So what if it's the case that there is only 1 of the 10^500 solutions that
> is "physical reality", and none of the others are? It seems to me that then
> you are back with the fine tuning problem with a vengeance ( 1 chosen out of
> 10^500 ). And since none of the other supposed universes are detectable to
> us, I don't see any way of deciding whether just 1 exists or whether all
> 10^500 exist.
>
>
>
> Smolin can not take the high road, however. In spite of claims to the
> > contrary, his explanation of the anthropic coincidences vis his theory of
> > cosmic evolution:
> >
> > 1. Black holes beget new universes
> > 2. The child universes will have similar (but not quite the same)
> > physics
> > 3. Therefore universes good at producing black holes will evolve via
> > natural selection
> > 4. coincidentally they, since they have stars and galaxies, are the
> > same types of universes that can support life
> >
> > is not testable, beyond his challenge to imagine a universe that is
> > much better at creating black holes. Plus he never satisfactorily justifies
> > why the child universes should have "close to but not exactly the same"
> > physics.
> >
>
>
> Put that way, Smolin's cosmic evolution does seem to be a highly
> speculative theory, and furthermore, as you've described it, it runs into
> the same "origin of life" problem that Koonin's paper tries to address. The
> theory might work fine once you've got the first black hole. But how does
> the first black hole come about? Its existence implies, surely that stars
> and galaxies exist, which then collapse into black holes. In other words
> they must come from universes that are already capable of supporting life?
>
> In many ways it seems also to me that this is no different
> philosophically than the multiverse.
>
> The reason seems to me to be that the objections to Intelligent Design,
> the Multiverse, and invoking coincidence all fail in the same way as far as
> being scientific, in that they appeal to a universal explanatory mechanism -
> any of them can explain absolutely anything, and therefore they explain
> nothing. And once you've got this "explanation" from your universal
> solution provider, there is nothing else you can do to understand it
> further.
>
> It seems to me that the same applies to just invoking "evolution" as the
> explanation, without any further evidence. Now, in biological systems there
> is plenty of evidence to support the fact that evolution has occurred, and
> so it makes sense, when we come across some complex mechanisms, to look for
> explanations within an evolutionary framework. But just to say "it must
> have evolved" and not do anything more is really no more scientific than
> saying "it was designed by an intelligent designer", or "it was an anthropic
> coincidence that we happen to be in one of the universes in the multiverse
> that got lucky".
>
> At the end of the day, we MUST keep searching and try and understand
> things better. We can't just say "it must have evolved" and give up the
> search for HOW it evolved. But if, as you say, Smolin's ideas are
> untestable, then that is about as far as you can go. With biological
> systems we can look at fossil sequences, DNA sequences etc, and compare
> between species. But clearly we can't compare the genomes of different
> universes.
>
> When George said: "Those who regard natural selection as a kind of
> universal solvent for traditional beliefs, & especially religion ..." that
> also rang true with the way I'm thinking. Evolution without doing other
> science is indeed potentially a universal solution provider. [George, I
> don't know if you meant "solvent" in both senses of the word; ie something
> which dissolves something away, AND something which is a solution ie
> explanation to a problem. Hope I didn't misrepresent you by taking it both
> ways].
>
> Regards,
> Iain
>
>
> -

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Received on Tue Sep 11 13:48:59 2007