Crash Course Astronomy: The Death of the Universe

I’ll be honest with you, folks: I’ve been anticipating this moment with some trepidation.

I’ve always been fascinated with big explosions, doomsday stuff, apocalyptic scenarios. It’s one of the reasons I studied supernovae for my degree, and then became interested in asteroid and comet impacts. As long as you maintain a degree of detachment, they’re fun to study.

But they’re all too real as well. We know the Earth’s been hit in the past, and will be again if we do nothing. We know the Sun will expand into a red giant, blow off its outer layers, cook the Earth, and then eventually fade away as a cooling white dwarf. We know stars, galaxies, and perhaps even matter itself won’t last forever.

That can be tough to ponder. But it’s all part of science, part of understanding the Universe, and to shrink away from it would be to deny a very important part of reality. And it would also deny us the amazement of understanding how our cosmos behaves.

So, with that, I present to you Crash Course Astronomy Episode 45: Deep Time.

Writing this episode was tough. I did a lot of research for this topic when I wrote the final chapter of my book, Death From the Skies!, which is all about Deep Time and the eventual end of the universe as we know it. If you want more details on all this, please pick up a copy of the book (and The Five Ages of the Universe while you’re at it).

When I wrote that chapter I found myself getting upset over it. The topic isn’t exactly cheery, even though it’s critically important. But still, even though it got dark—literally—I ironically found myself inspired by it. First, as a writer, I had to find ways to express numbers so big they crush our souls to dust; who can truly grasp what 10⁶⁵ years is? The entire span of our Universe from the Big Bang to this very second is a subatomic mote of nothing compared with that stretch of time.

But I found myself working through it, and being amazed at the resilience of the human mind to push through problems like that, to find solutions. And I was also in awe at how other people, smart people, could take physics as we understand it today and extrapolate it so far into the future. White dwarfs powered by proton decay? Four hundred watts of emitted power spread out over the surface of an object the size of Earth? The eventual dissolution of black holes? Resetting the Universe by the collapse to the true vacuum energy state? These are concepts that stretch our brains to and perhaps past the breaking point, but the imaginations of a few people got past that, applying logic and mathematics to see what these situations would really be like.

I find that truly remarkable. Humans have a capacity to turn darkness into light, inevitability into curiosity, bleakness into wonder.

Yes, surely, this is a tough topic. The future will come, and we may or may not understand it. But we’ll struggle to try, and that makes us great.

Postscript: This is the penultimate episode of CCA; next week's is the last one in the series. But if we talked about the end of the Universe here, then what's left? You'll see.