Quote:
Originally Posted by CraigS
Hi Mark;
The traditional oscillating universe models are closed models, and are thus still constrained by the second law (entropy can only increase). This implies that each successive cycle gets longer and bigger. If you run this backwards in time, it ends up in a Big Bang. So which is it .. an initial BB with increasing longer and larger cycles, or an infinitely oscillating universe ? Externally provided energy would sort out this dilemma .. so an oscillating model requires Dark Energy which, for all intents an purposes, is externally added energy (ie: a fudge factor added).
(By the way .. I didn’t say the 2nd Law was violated by an oscillating model).
In the cyclic models, two parallel M-branes collide in higher dimensions. Our observable universe is on one of them. A contraction phase is kicked into a violent expansion (or BB) whenever there is a collision. The expansion during each cycle, prevents entropy from building up. No-one really understands the collision process, nor the origin of the forces that causes them to collide - mysterious quantum fluctuation forces between the branes, I believe.
Subtle differences .. one bounded by the 2nd Law, the other not necessarily bounded because no-one really understands it ! 
Cheers |
mmmmmmm........Interesting......you mention that:
"The traditional oscillating universe models are closed models, and are thus still constrained by the second law (entropy can only increase). This implies that each successive cycle gets longer and bigger."
Should not each succesive cycle emit radiation which is now beyond our/the known physical universe? (energy that cannot be reclaimed before the next cycle begins anyway, especially nutrino energy), and if so, then should the energy expelled by such radiation deplete the original matter used to create the universe? and if so, should not the cycles be getting smaller having less energy to expand on each cycle? therefore, cycles will get smaller and shorter?
If the energy/radiation expelled during each cycle's initial "Bang" is not reclaimed quick enough before the next cycle is created, it could be reclaimed in succesive cycles adding a kind of harmony (not the peace kind, although it would be good if it were
) rather than a fixed or slightly changing cycle frequency? I think If these specific harmony's exist they could tell us how old we really are.
Thanks Craig and Mark, you raise some interesting views on this matter and got me thinking! i will ponder this some more
Thanks!
