gizmowiz July 8, 2016 12:26 PM That sounds logical a cyclic Universe with energy to matter and back again. MainframeGeek July 8, 2016 01:43 PM Evidence shows that expansion of our universe has been accelerating, not decelerating. Doesn't look like it fits a "Big Crunch" model. Ichabod Ebenezer July 8, 2016 01:58 PM SoundED logical until we discovered the rate of expansion was increasing. Dark energy will prevent the universe from ever being close enough to collapse for one of these bounces. There is no reason to expect there was a previous inflationary period where dark energy didn't exist. I thought I had heard the last of this theory 15 years ago... SomersetSmile July 8, 2016 04:09 PM There is a third possibility, the Big Rip with the expansion rate faster than the speed of light. The zero point vacuum could propagate a Big Bang. Another possibility could be based on the recent discovery that they have been able to create an atomic state which measurement propagates back into the past for that atom. If there were multiple past parallel universes that were only dependent on the differences in that atom. Then all of these alternate parallel universes might be pinched out of being, creating a void next to the remaining universes. This might explain the acceleration being blamed on Dark Energy. ljs July 8, 2016 05:33 PM No credit or refernce given to Roger Penrose? TimLong01 July 8, 2016 06:10 PM But if the red shift is caused by photon energy loss due to numerous mechanisms, rather than by the Doppler shift, then dark matter/dark energy isn't necessary nor is the expansion-contraction theories. (Less energy increases wavelength) BGriffin July 8, 2016 10:46 PM If the universe is curved such that traveling in one direction long enough brings you back to your starting point, then increasing expansion away from the point of origin could actually be collapse back to the point of origin. BGriffin July 8, 2016 10:51 PM This theory doesn't require that the same thing is bound to occur in the future, merely because it might have occurred previously. There might have only been one bounce after which we never really get things back together again. toddzrx July 8, 2016 11:21 PM This is just another attempt to prove that the universe has always and will always exist; i.e., the Steady State Theory, but in a different form where the universe goes through cycles of expansion and contraction. Sorry, but a simple thought experiment debunks the possibility: this model of the universe still requires infinite time into the past, but then how could we arrive at today? Additionally, this doesn't get around the requirement of the universe needing a cause. katgod July 9, 2016 03:16 AM Ichabod, While increasing rate of expansion would seem to argue against the bounce theory, this is only true if you think you understand the topology of the universe and I suspect that the topology is also up for grabs.