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The Return of the Cyclic Universe - Synchronicity swirls and other foolishness

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February 27th, 2008


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03:23 am - The Return of the Cyclic Universe
It looks like the idea of the cyclic universe is back again. While obviously uncertain and unproven, I've been following this idea for a while, and it certainly seems at least as likely as the other options. On a purely aesthetic level, I like it because it avoids the rather dubious idea of cosmic inflation, and more importantly, it postulates an eternal universe without beginning or end, and where the idea of a beginning or end literally has no meaning, and that idea makes vastly more sense to me than the idea that the universe began on some Tuesday billions of years ago and will gradually expand into cold dark nothingness. However, my own tastes have no bearing on the actuality of the universe, so only more research will find out if this idea is correct.
Current Mood: hopefulhopeful

(15 comments | Leave a comment)

Comments:


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From:alobar
Date:February 27th, 2008 12:40 pm (UTC)
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I also like it because it makes the bible thumpers foam at the mouth and go into fits.
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From:silvaerina_tael
Date:February 27th, 2008 01:09 pm (UTC)
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That does have its advantages...
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From:silvaerina_tael
Date:February 27th, 2008 01:13 pm (UTC)
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I've know about this for a while now. It seems a much more natural idea, by giving the universe a "life cycle" like everything else has, than "infinity", which is the other postulation. I don't like the infinity postulation. Infinities are impossible in everything but mathematics.

And as Alobar mentioned, it gives certain religious wing-nuts fits.
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From:dancinglights
Date:February 27th, 2008 02:08 pm (UTC)
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I've always liked variations on this one, and I know some astronomers who do, too :)
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From:hasufin
Date:February 27th, 2008 04:16 pm (UTC)
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I didn't know the cyclic universe had left. I hope it enjoyed its vacation.
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From:cusm
Date:February 27th, 2008 04:20 pm (UTC)
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If I'm reading this right, he's suggesting that the darkenergy (the repulsive vacuum force) at some point breaks down and becomes attractive like a positive gravitational force, but the article gives no explanation as for why. Seems kuldgy. I can insert a theory that if spacetime is curved as Einstien suggests then expansion at some point does become attraction as curvature returns onto itself. Perhaps that is what the article is missing? Otherwise it seems more of a fanciful "what if?" than a measurable theory.
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From:xuenay
Date:February 27th, 2008 06:27 pm (UTC)
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Unrelated to this post, but can I quote what you (and preferrably also your anonymous friend) wrote in the post about depression? I think it would be great example to use in my transhumanism-related writings, to dispell the notion that modifying people's minds to make them happier means wireheading their pleasure centers or some such.
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From:heron61
Date:February 27th, 2008 07:51 pm (UTC)
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Most certainly, I think that this is exceptionally important information to distribute as widely as possible.
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From:xuenay
Date:February 27th, 2008 08:11 pm (UTC)
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Thank you. I know at least one place where I'll be using it - the book about transhumanism I'm (very) slowly working on. It'll be in Finnish, but given that my publisher didn't seem to think that distributing a free PDF copy would be a problem, I might get it translated at some point.

Once I get around finishing it, that is.
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From:helen99
Date:February 27th, 2008 06:39 pm (UTC)
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I've always thought that the Big Bang (whether it occurred in a cyclic or expanding universe) was a construct that people use to explain redshift phenomena that may have some other explanation (totally unprovable conjecture, I know). The big bang also provides people with a beginning point and an endpoint, as well as an implied center point (people like those). Whether or not these two points recur in subsequent cycles, each cycle has a beginning and an end. I would like to see astronomers look entirely outside of the "beginning and end" box -- they might see something they hadn't noticed before about the nature of things (more than one central point? Gravitational wells explaining redshifts? I don't know. In any case, further studies with the assumption of no big bang(s) might reinforce existing theories but from a different perspective.
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From:bluegodjanus
Date:February 27th, 2008 10:59 pm (UTC)
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Excellent. I've always liked the brane cosmology and ekpyrotic scenario. They both seem highly reasonable to me.
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From:alephnul
Date:February 28th, 2008 07:50 am (UTC)
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I remain a fan of inflation, but that looks interesting, and it seems to even have a testable feature, which is always nice. I particularly liked the bit about how time runs forward, then everything falls apart into atemporality, then time runs backwards. Presumably from the point of view of a being living in either the expansion or the collapse, it appears that they are living during the expansion. Somehow, it reminds me of the Connie Willis story "Daisy in the Sun."
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From:spoonless
Date:March 1st, 2008 07:29 am (UTC)
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My prediction is that this will be the first bet Hawking actually wins (having lost his previous 3).

I worked on the cyclic universe model for about 6 months. Although the funny thing is, I was sort of hired as an "assassin" to try to kill the theory, by physicists who prefer inflation (as the vast majority of physicists do). I failed to kill the theory, so it was suggested that I not publish the results which I complied with.

I have to say that in my opinion (and in the opinion of most physicists) inflation has far more going for it than the cyclic model. Among other things, it correctly predicted the nearly scale-invariant density perturbations that was measured in the cosmic background radiation. The cyclic universe by comparison doesn't have a shred of evidence supporting it... just pure speculation by Steinhardt and Turok on flimsy vague-philosophical ground. That's not to say it won't turn out to be true, just that it's a lot less likely than inflation.

I'm curious why you call cosmic inflation a "dubious idea". I would think that would be a much more apt adjective for the cyclic universe.
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From:heron61
Date:March 1st, 2008 09:13 am (UTC)
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I'm curious why you call cosmic inflation a "dubious idea". I would think that would be a much more apt adjective for the cyclic universe.

Fair enough. I'd actually call both inflation and the time reversal/collapse of the cyclic universe equally dubious ideas. In both cases, we have eras postulated where the universe acted in unexplainable and deeply odd ways with no (at least AFAIK) known mechanism for how or why this would occur. Both inflation and the cyclic universe collapse feel to me much like a black box on the side of which is written "and then a miracle occurred". OTOH, someone may have found some mechanism for inflation that I do not know about, and so my objection may be moot. If not, then I am left to aesthetics for the only guide as to which miraculous event I prefer, and I personally like the cyclic universe collapse better :)
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From:rjgrady
Date:March 1st, 2008 08:18 am (UTC)
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I'm not sure I even buy a cyclic universe. Just the idea that the speed of light changing suggests to me that the universe might simply stretch back infinitely in time, is always moving, and a lot of what we see is simply the result of lacking an outside vantage. I am not a physicist, but my intuition tells me it is simpler to believe that the Big Bang is just a point in the distant past at which things were moving much faster, relatively, than to try to invoke causality.

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