RE: Small probabilities

From: Glenn Morton <>
Date: Mon Nov 07 2005 - 08:23:49 EST

> -----Original Message-----
> From: George Murphy []
> Sent: Monday, November 07, 2005 6:58 AM
> On the more general question - to paraphrase our ex-Pres, it depends on
> what
> "observe" means. If the consequences of multiverse theories explain
> observable phenomena better than other theories then they have to be taken
> seriously, even if the other universes aren't directly observable. & one
> also has to ask whether they're unobservable _in principle_ or just due to
> our situation. E.g., in Linde's "bubble" version of inflation we could (I
> think) observe another bubble if we were close enough to the edge of ours,
> but the conditions that make life possible in our expanding bubble make
> that
> extremely unlikely.

My understanding of Linde's version of inflation is untestable I quote Brian
"Instead, as Andrei Linde has proposed, there could have been mmany nuggets
scattered here and there that underwent space-smoothing inflationary
expansion. If that were so, our universe would be but one among many that
sprouted--and perhaps continue to sprout--when chance fluctuations made the
conditions right for an inflationary burst, as illustrated in Figure 11.2.
As these and other universes would likely be forever separate from ours,
it's hard to imagine how we would ever establish whether this 'multiverse'
picture is true. However, as a conceptual framework, it's both rich and
tantalizing." Brian Green, Fabric of the Cosmos, p. 320

Lee Smolin adds the view that universes produce offspring with only slightly
mutated physical constants via black holes. And in his view once again, no
one can see past the black hole horizon to verify that Smolin is right. The
multiverse idea is unscientific because it is untestable. Even the
discovery of higher dimensions doesn't guarantee that other universes occupy
those higher dimensions.

I would also note that inflation actually explains a prediction of the big
bang away. It explains why we don't see magnetic monopoles. Thus rather than
explaining the existence of something, it is explaining the non-existence of
Received on Mon Nov 7 08:25:13 2005

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