Because The Universe Is Expanding

(B)ecause the universe is expanding, any living creatures outside the observable universe are and will forever remain causally disconnected from us

I read an article last night on the MIT Technology Review website by Nick Bostrom of the University of Oxford. It was about the prospects of finding intelligent life, or any life, from another planet.

I enjoyed the article. I’ve linked to it. I’m not sure I’d recommend it. It’s short on fact and long on conjecture. How could it be anything else? Look how little we really know about the universe that surrounds us.

Oh – it’s really long too.

Bostrom’s theories center on a Great Filter. Great Filter describes some occurrence in the development of life, common to all development of life anywhere, that makes achieving life very difficult.

It could be something earlier on in development which makes the evolution from inert chemistry to self replicating life really difficult. That we’ve achieved life here doesn’t diminish the universality of the filter, nor the rarity of our achievment.

Or, the Great Filter might be in our future. It’s possible there’s a Great Filter that keeps advanced civilizations from living very long, and we just haven’t reached it yet.

As always, I’ve buried the lede. This really isn’t what I want to write about.

The one thing Bostrom talked about that stopped me in my tacks was throwaway sentence just past the halfway point.

Cosmological theory implies that because the universe is expanding, any living creatures outside the observable universe are and will forever remain causally disconnected from us: they can never visit us, communicate with us, or be seen by us or our descendants.

In other words, even if the universe is infinite, it is finite to us! And, it must always be finite. Period. End of story.

I’d never heard that expressed before. It makes our place in the general scheme of things seem smaller.