Expansion of Universe Nearing End

The universe is not only expanding, but accelerating that expansion, leading most scientists to anticipate it will keep on growing for a very long time, if not forever. However, a trio of Princeton physicists have challenged this view, presenting a model of the universe in which this expansion is nearly at its end. The universe will start to contract in on itself, they claim, and that could happen surprisingly soon. This is a cosmologist’s “soon”, however, of the order of 100 million years, not something most people would recognize as imminent.

The discovery of acceleration in the expansion of the universe has shaken up cosmology perhaps more than anything else this century. Beforehand the primary debate was whether the universe would expand forever, albeit more slowly, or be dragged back into a “big crunch” as gravity overcame the movement apart.

Acceleration, and the Dark Energy used to explain it, appeared to end the possibility the universe would ever contract again, but a minority of physicists aren't ready to let the idea go. Professor Paul Steinhardt, in particular, has proposed “bouncing” models of the universe. Now Steinhardt and co-authors claim in Proceedings of the National Academy of Sciences that the turning point from expansion to contraction could be close without us being able to tell.

The authors do not assert certainty. They refer to three models of Dark Energy's nature. One of these would see the universe continue to expand faster and faster forever, while a second would see it slow at an unpredictable point, probably far in the future.  READ MORE...