These Are Not the End
Ask a theoretical cosmologist how the universe will end, and one of the
first things you’ll hear is how many options are still on the table. “It’s
very difficult to tell how the universe will end just from local
measurements,” explains the University of Pennsylvania’s Mark Trodden.
There’s little we know for sure; in a universe of infinite possibilities,
anything can happen. But with the emergence of dark energy, a few of the
previous contenders for our ultimate fate are now much less likely.
The Big Crunch: The Big Crunch is a classic scenario for how the universe could end. The
driving idea: What if the expansion of the universe does not last forever?
At some point, the universe might stop growing because of the gravitational
pull of all the matter inside of it, and then it would start to collapse
back into itself.
The final result would be a universe that reaches a tiny singularity, a
dark reflection of the Big Bang. There was even some speculation that a
“Big Crunch” could produce a Big Bounce right afterward, Big Banging a new
universe into creation. Perhaps our universe was merely one iteration of an
infinite string of Big Bangs, Crunches and Bounces.
Unfortunately, the discovery of dark energy dealt the Big Crunch a
deathblow, since it suggests the universe will expand forever. Unless it
turns out dark energy can change its nature dramatically, the Big Crunch
seems an unlikely way for the universe to end.
The Dyson Scenario: One important question concerning the ultimate fate of the universe
concerns its inhabitants: Can intelligence and consciousness overcome
entropy, the eventual wearing down of our universe?
In the 1970s, Freeman Dyson was one of the first physicists to contemplate
the end of the universe using modern cosmology. He proposed that in the
distant future, intelligent beings might figure out a way to “cheat” a Big
Freeze-like scenario. First, as the end times approach, the beings would
need to store a finite amount of energy in the universe; they would then
use half this energy to power their thoughts (the only remains of their
Once this was used up, the beings would enter a state of non-energy
consumption; they’d be in stasis, while the energy remained. The universe
would continue to cool, running down, but after a certain point another
half of the remaining energy reserves would be released, thanks to an
as-yet-unknown technology created by the beings, allowing them to think
They’d effectively come back to life, never aware of the break in their
thoughts. Eventually, they’d use up their available energy and return to
stasis, with more energy in reserve. They could keep this cycle going
infinitely and, from their perspective, never face the end of the universe.
The beings’ thinking sessions would slow over time, but there could be an
infinite number of them through this energy rationing. Who would mind slow
thought processes if time stretches on forever?
Dyson’s concept on eternal intelligence was a good attempt at tackling how
the universe’s end might not be civilization’s, but like the Big Crunch, it
can’t overcome dark energy’s implications. An accelerating universe means
that eventually parts currently in contact will be isolated from each
other, and energy stored in these areas would be inaccessible. As such,
while some theorists have speculated our future descendants could transfer
information to new “baby” universes via wormholes or black hole formation,
it appears inevitable that after some point, intelligence in our own
universe will simply be impossible.