The fate of the universe

After watching Carl Sagan's Cosmos I've came up to a lot of new stuff to think about. I've always been a thinking person, I had no problem being alone and do nothing because I've always had something to ponder about.

Sagan said that if there's enough matter for the gravitational forces to stop the expansion of the universe and start the contraction (Big Crunch) until it reaches a critical point at which big bang occurs and it starts expanding again then the universe might be oscillating and undergo an infinite amounts of cycles in which the universe expands and contracts. But such theory in not reconciled with the second law of thermodynamics and caused cosmologists to abandon the oscillating universe model.

However new understanding in dark matter suggest that its interactions with mass and gravity demonstrate a possibility where an oscillating universe could be possible. I somehow would prefer this idea of a cyclic universe to an open universe where the acceleration of expansion becomes so strong that it overwhelms the effects of gravitational, electromagnetic and strong forces.

If the universe was cyclic and once started to contract in exactly the same way it expanded, it might be that causality will be inverted and effects will precede causes. Which might not be easily understandable to us where the time might seem to be going backwards. Also a question arises if every universe and the laws of nature are randomly determined or are always the same and perhaps the same cycle is repeated infinitely.

I'd like to believe that same guy like me will live in another cycle of the universe but I know that most likely the universe is open and in many many years there will be nothing but particles left in the universe. But we never know.