Does inflation allow for an infinite number of universes? (Advanced)

As I understand, thanks to COBE, it is now a sure bet that the universe will continue to expand forever. So at some distant epoch the universe will go out with a whimper. I find this new information depressing. It has always made sense to me that our universe was cyclical, or somehow self renewing, like some cosmic heartbeat, expanding and contracting. It makes sense to my layman's mind that this mechanism has always been here and it will always be in effect. I have felt that in this infinite rebirth I might somehow find myself in existence again, to meet my wife again and have children again and meet the challenges of this life I find somewhat enjoyable all in all.

So my question is this: Does inflation theory or quantum mechanics allow for an infinite number of universes, or does it appear that we occupy the only one?

If this is the only universe and it is open, it will expand forever into a maw of hideous and frigid darkness, hopelessness and oblivion.

The theories of inflation and quantum mechanics, and in fact every well-established physical theory today, cannot exclude the existence of more than one Universe than our own: that's because the laws of physics are only postulated to be valid in our Universe. There are theories that allow for multiple Universe, even some in which our Universe is only one of an infinite number! However, these "unified theories" such as string theory are truly in their infancy; it will be a long, long time before the existence of multiple Universes can be addressed quantitatively.

Perhaps as a consolation to your expanding Universe woes, consider that the fact that the Universe will expand forever given its current contents means that we understand very little about how it works; there appears to be all sorts of exotic physics in the Universe, more exotic than that in the wildest science fiction fantasies. In the end, this revelation will bring us closer to understanding who we are, why we're here and where we're going; and is that not the ultimate goal of it all?

This page was last updated June 27, 2015.

About the Author

Kristine Spekkens

Kristine Spekkens

Kristine studies the dynamics of galaxies and what they can teach us about dark matter in the universe. She got her Ph.D from Cornell in August 2005, was a Jansky post-doctoral fellow at Rutgers University from 2005-2008, and is now a faculty member at the Royal Military College of Canada and at Queen's University.

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