There are a variety of “end of the universe” scenarios that physicists currently see as most likely:
- Heat Death
Because of a mysterious energy in the universe (aptly named “dark energy”), the universe’s expansion is speeding up. As things expand they cool down, so the heat contained in the universe will gradually dissipate until there is no light and no heat, just an immense void of cold darkness. This is the current leader for “most likely way the universe will end.”
- The Big Rip
Dark energy accelerates with time, eventually causing space itself to grow so much that objects grow very distant from each other. Professor Katie Mack’s description in her excellent book The End of Everything (Astrophysically Speaking), describes the last few months of the universe’s existence in this scenario:
From this point, the destruction picks up its pace. We begin to find that the orbits of the planets are not what they should be, but are instead slowly spiraling outward. Just months before the end, after we’ve lost the outer planets to the great and glowing blackness, the Earth drifts away from the Sun, and the Moon from the Earth. We too enter the darkness, alone.
Eventually the expansion of space itself explodes the planet and then all atoms inside of it get ripped apart.
- Vacuum Decay
Without getting too technical, the energy built into the vacuum of space switches in such a way that a wave of destruction at the speed of light consumes the entire universe. The other options on this list will happen long, long after we’re gone (so long after we can hardly fathom it); however, this could in theory happen at any time, although the chance is infinitesimally small.
- The Big Bounce
The expansion of the universe slows down, stops, then eventually contracts until it starts expanding again in a cycle of bangs and crunches.
I don’t need to belabor the bleakness of most of these options. The Big Bounce metaphysically comports with the cyclical universal births and rebirths that are found throughout ancient mythologies and religions, with the ashes of the old world forming the seeds of the new, but otherwise it’s beyond ashes to ashes and dust to dust, since in most of the likely even those iotas of organization will be destroyed.
If celestial glory is defined by ongoing creation, light, and truth, heat death seems like an apt description of outer darkness (and Jude’s “wandering stars, to whom is reserved the blackness of darkness for ever.”) So how to square the two? For me the options available for Latter-day Saints given our cosmology of eternal creation is 1) the Big Bounce, 2) there’s some other option that allows for eternal creation and light that we haven’t discovered yet, 3) a deus ex machina, where God simply stops the self-destruction of the universe, and 4) this universe will self-destruct, but ours is one of many universes, and others will continue the act of creation and generation.
I’m open to all the options, although I’m always a little suspicious of the deus ex machinas approach. If God has largely used natural principles to operate so far I don’t see why He would stop in the future, and I love the multiverse idea in regards to God’s statement that his creations “cannot be numbered unto man.”
For me one of the primary psychological benefits of the gospel is the knowledge of eternal and ongoing life, activity, and creation, otherwise our best scientific estimate is indeed that everything will end up floating in cold, unorganized darkness forever.
The book and movie Children of Men presents an interesting thought experiment of how we would live our lives if we knew the end was in the next 40 or so years. This is a more thought provoking scenario than if we knew a comet was hitting the earth tomorrow, because with a longer timeframe we are forced to grapple with deep questions of what exactly we are living for in our day-to-day lives. It’s not a huge reach to conjecture that a lot of art, reproduction, philosophy, and scientific exploration would come to a stop if we knew there was no future earth, which raises all sorts of subtle questions about the degree to which our strivings are intrinsically validated because of the mere existence of some hypothetical future society.
However, in his book The End of Time: Mind, Matter, and Our Search for Meaning in an Evolving Universe physicist Brian Green takes this thought experiment a step farther (I read it a while ago and am paraphrasing), if we know that everything is going to end up floating around in darkness for all eternity, how much of a difference is it really if everything ends tomorrow or 40 years or 4 billion years from now? Either way your existence is the smallest fraction of time compared to the time that the leftover particles that were you, your book, money, and all that you’ve strived for is floating around in the darkness of the universe. Part of the good news of the gospel is that our strivings are validated by permanence and the existence of an eternal future; that, as physicist Freeman Dyson said, “no matter how far we go into the future, there will always be new things happening, new information coming in…a constantly expanding domain of life, consciousness, and memory.”