Why Do People Believe in the Big Bang Theory?

[Chronos]

That is what Hawking said, but it was more parable than paradox. It is useless to attempt to describe what came before time for obvious reasons. Time was eternal until it chose to unwind in this corner of reality - a temporal thing. Occasionally an apparent, temporally bound universe emerges from the fog of quantum chaos.

 

[marcus]

If I remember correctly, Hawking said that its non-sense to ask what was before the big bang (or before the singularity) cause time started with the bb, so its like asking what's north of the north pole?

Starting around September 2005, Roger Penrose has taken the opposite position.

there is a great talk by Penrose online, given at Cambridge just two months after he changed his mind. He illustrates it with his own cartoons and vivid language so he gets the basic reasoning across without too much math.

http://www.Newton.cam.ac.uk/webseminars/pg+ws/2005/gmr/gmrw04/1107/penrose/

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At this point I think you can believe what you want. There is no scientific reason to think time began some 14 billion years ago (although people like Hawking used to say that, some years back).
And there is also no scientific reason to believe that time did NOT begin at some point back then. (because the new models that have time continue back before the big bang are not yet TESTED by observationally checking their predictions.)

Penrose November 2005 talk is not the latest on this, although it is visual and stimulating. If you want links to more up to date stuff, ask.

 

[George Jones]

Starting around September 2005, Roger Penrose has taken the opposite position.

there is a great talk by Penrose online, given at Cambridge just two months after he changed his mind. He illustrates it with his own cartoons and vivid language so he gets the basic reasoning across without too much math.

http://www.Newton.cam.ac.uk/webseminars/pg+ws/2005/gmr/gmrw04/1107/penrose/

Here is very interesting blog entry on Penrose's highly speculative idea for a crunchless, cyclic universe, and here is Penrose's own brief write-up.

In order for his idea to work, all the matter in the universe(including electrons!) has to decay eventually into radiation, and a conformal factor needs to "renormalized" (What physical mechanism effects this?) to get a new bang.

 

[marcus]

Thanks for the links.

http://ppcook.blogspot.com/2006/09/penrose-universe.html

http://accelconf.web.cern.ch/accelc...r penrose conformal gravity cosmology "EPAC""

I like Penrose drawings and exposition, but am not much taken by his idea.

I think there may be a basic fallacy in his application of the SECOND LAW. He begins by excluding the bounce idea because he thinks it violates the second law---and this drives him to concoct an extremely FAR-FETCHED reproductive scheme that involves a curious kind of conformal handwaving and only works in a far distant, rather vague future.

 

[gorgos]

Penrose cyclic model on YouTube

 

[robertm]

And what happens when the atoms will be pulled appart by the expansion, in the Big Rip?
http://en.wikipedia.org/wiki/Big_Rip



What frame of reference will show the atoms still in their place?

The current accepted theory in cosmology postulates that the rate of expansion of the universe is not low enough to point to a bounce, and not high enough to point to a big crunch, but it points to a 'heat death' of the universe in which (after many cosmological decades) all the matter in the universe will have been taken in and then emitted by black holes. Keep in mind that every theory is subject to discretion, this is just our current 'best guess' as to the future of our universe.