Topic: Penrose: WMAP Shows Evidence of ‘Activity’ Before Big Bang

[sam]

Have scientists seen evidence of time before the Big Bang, and perhaps a verification of the idea of the cyclical universe? One of the great physicists of our time, Roger Penrose from the University of Oxford, has published a new paper saying that the circular patterns seen in the WMAP mission data on the Cosmic Microwave Background suggest that space and time perhaps did not originate at the Big Bang  but that our universe continually cycles through a series of “aeons,” and we have an eternal, cyclical cosmos. His paper also refutes the idea of inflation, a widely accepted theory of a period of very rapid expansion immediately following the Big Bang.

http://www.universetoday.com/79750/penrose-wmap-shows-evidence-of-%E2%80%98activity%E2%80%99-before-big-bang/

[Clive]

Coming from Penrose it has to be taken seriously. 

[daveeb]

Very interesting.


I don't understand what happens to e.g. our universe when it has expanded infinitely (shouldn't this take an infinite amount of time) and what causes it to "shrink" and so lead to another big bang
 

answers on a postcard please 

[sam]

well depending on the cosmological constant, the universe might not always expand, this is really the driving "force" and well eventually it can collapse and come back in on itself. It really is all about this plot: http://en.wikipedia.org/wiki/File:Friedmann_universes.svg (with out current understanding; and would fit on a postcard :p ). This isn't a bad article: http://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe - but I'm sure I can dig out better journal articles / books.

A more worrying question IMHO (being the devils advocate of an astrophysicist)... what are we expanding into? Though I agree that the observation evidence proves expansion, from our current ideas, I'm always perplexed by a few subtle things, like this. Actually a nice podcast on this.. http://www.astronomycast.com/astronomy/episode-28-what-is-the-universe-expanding-into/

[Clive]

A more worrying question IMHO (being the devils advocate of an astrophysicist)... what are we expanding into?

But there is nothing to expand into.  All there is is on the inside.     At least that is my understanding of it.  But my name is not Roger Penrose.   

[daveeb]

But there is nothing to expand into.  All there is is on the inside.     At least that is my understanding of it.  But my name is not Roger Penrose.   

Couldn't we go across a brane and "leak" into a different universe 

[Clive]

Why not?     I love the multiverse theory and I don't find it at all bizarre.  But it's not yet become mainstream thinking. Maybe next week.    

[sam]

I think its fairly well probed in the world of crazy theorists...

[Clive]

The world would be a far duller place without them.  Don't we just love those guys?   

[daveeb]

Sounds like a good job, you can hypothesise just about anything as long as you have a bit of maths to back it up 

[Clive]

Which nobody else can understand anyway.