Changing Laws And Constants

In Olaf Stapledon's Last And First Men and in Poul Anderson's "Flight to Forever," cosmic time is literally a circle. Travelling forward on the Earth's surface returns us to our starting point. Travelling futureward from 1973 eventually returns Anderson's Martin Saunders to 1973 although he passes through the end, then the beginning, of the universe en route. Stapledon's Last Men reveal that the time between the beginning and the end of the universe is only a fraction of the time between the end and the beginning although they do not know what happens in that longer inter-cosmic period. But this is imaginative fiction. What really happens with cosmic time? 

Even if the universe really oscillates as in Eastern mythologies and in Anderson's Tau Zero, the same events will not recur. It will be a new universe with a new history each time. Recent cosmological thinking was that dark energy is accelerating cosmic expansion, preventing any collapse or contraction. Now we might hear something different although, in a period like the current one, the latest findings are never going to be the final word. 

Is the dark energy weakening? If so, is it weakening enough to make a difference? Might the expanding universe collide with others, causing it to rebound and contract? 

"-Here and now, our burnt-out cosmos, expanding, fleeing from itself, has intersected another. From this union, when it is complete, will arise a whole new world of worlds. (Praised be the chance that the other plenum is old itself, that no life - we pray - will perish in the genesis!) What the next cycle will be like, we cannot foretell.

"-Already the very laws and constants of physics are changing." 

-The Avatar, XLVI, p. 381.

The Others aim to become part of something new and strange. Universes are bubbles in a hyperdimensional ocean where their substance becomes part of something new as with stars and flowers.