[ExI] conformal cyclic cosmology

[Anders Sandberg]

On 2012-06-11 03:02, Mike Dougherty wrote:
> http://t.co/3h0px63O
>
> Are layman analogies acceptable models for discussion on a topic like this?

The problem is that 1) we can not avoid using them if we want to have a 
popular discussion, and 2) they tend to be fundamentally flawed analogies.

Think of the spacetime as rubber deformed by weights analogy: it is 
fairly good for getting the gist of relativity, except that it makes you 
think spacetime has a basically 2D plane topology, that space is 
absolute, and that it is subjected by some kind of external gravity: 
wormholes and large-scale curvature does not make sense if your 
intuitions are shaped by the analogy. So we better be careful.


> I assume many here are actually able to discuss cosmology using math -
> but can you paint me a picture with a more colorful brush so I might
> recognize the scene?

What about this picture: you look at the history of the universe while 
zooming out to ever bigger scales. First you have a fairly homogeneous 
big bang, then various structures emerge and quickly dissipate. You zoom 
out, and the state again looks just like the big bang state. So you 
assume they are the same.


The big problem IMHO with Penrose's model is that it seems to be 
dominated by Boltzman brains. Most of the minds and observations in it 
would be due to random formation due to vacuum fluctuations. So why do 
we see a big and consistent universe rather than a small and random one, 
despite the later being a far more common "observation" among the BBs 
than the first?


-- 
Anders Sandberg
Future of Humanity Institute
Oxford University