The idea that the Universe has an funky topology with periodic boundaries
of distant regions warped into each other like a Klein bottle or such, has been
around for a while. The main speculator along these lines has been Jean-Pierre
Luminet but most of the bru-ha-ha around the recent Nature article
http://arXiv.org/abs/astro-ph/0310253
was centered on on J. Weeks (maybe because he is a McArthur Fellow
and the only author based in the US). Their speculation apparently does not
pan out with the current WMAP data as they claim but I don't think it has
been put to rest quite yet. There will be better probes in the near future and
CMB anisotropies detail are only coming on line slowly.
Theories of the warpped universe are the spacial counterparts of the cyclic
(in time) universe scenario of Turok and Steinhardt that someone mentioned
recently in this list. This solves all of the problems addressed by inflation
in a
consistent way without recourse to dilatonics, false vacua and such lore. My
guess is that these two phenomenological pictures will evolve sometime into
one finite universe theory with nontrivial space-time topology... which will
vindicate Nitzsche!
And than again, I may be wrong.
-Joao Leao
Mirai Shounen wrote:
> Actually I wasn't thinking about "physically impossible things happening
> very rarely" (QM) but only about regular physics vs probability of things
> happening.
>
> If you consider quantum mechanics you are right in an infinite universe
> there could be areas in which physics just happens to work very differently,
> people there would formulate very different physical laws (if people could
> evolve, or spontaneously appear).
>
> So if the universe is infinite, it doesn't make much sense to talk about
> laws of physics. Still there need to be some fundamental rules that never
> change, for example the fact that something exists. You can't have areas of
> the universe in which the universe itself does note exist (I think).
>
> Frankly I don't believe the universe is infinite, occam's razor says it's
> just very big.
> Last month there was a report about someone finding a pattern in galaxies
> that would suggest the universe is much smaller than we thought but light
> "wraps around" making it appear infinite... the theory was discarded very
> soon after more experiments were carried out, but it reminded me of that
> star trek episode.. "state the nature of the universe" - "the universe is a
> hollow sphere 12 km in diameter" ... or something.
>
> Infinity is just our perception of things very big... something that
> originates from nothingness and expands has very little chances of becoming
> infinite in finite time.
>
> mirai++
>
> > > I think two things are being confused. First, the laws of physics,
> second,
> > > the laws of probability. A gas particle follow physical rules (movement,
> > > bumping, thermal vibrations) and lots of gas particles together follow
> > > probability rules (low probability of people suffocating in rooms).
> >
> > The problem is that all the laws of physics have been found observing the
> > world around us in an experimental way. But all the outcomes of an
> > experiment are probabilistc and we know the low of physics only with a
> > certain error. So the paradox in the laws of probability is a paradox in
> > laws of physics too. The whole physics is probabilistic.
> >
--
Joao Pedro Leao ::: jleao.domain.name.hidden
Harvard-Smithsonian Center for Astrophysics
1815 Massachussetts Av. , Cambridge MA 02140
Work Phone: (617)-496-7990 extension 124
Cell-Phone: (617)-817-1800
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"All generalizations are abusive (specially this one!)"
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Received on Thu Oct 30 2003 - 17:33:40 PST