Some say the world will end in fire, some say in ice. I say boooringggg. Here are some grand scenarios of cosmic fail that have not been given as much press as the big crunch and big freeze.
1. Spontaneous Decompactification
String theorists believe the universe has several dimensions that, unlike the ones we know, loop back on themselves in tiny “compactified” shapes. It has been suggested that this situation may not be stable in the long run, and that in billions of years random fluctuations could cause the universe to “spontaneously decompactify”. That means these other dimensions blow up to a macroscopic scale — a bubble expands at the speed of light, and then suddenly your surroundings are roomier than ever, in directions you never heard of. Unfortunately, I doubt the process preserves the structure supporting your brain and body or superintelligent yogurt or whatever you’ll care about then.
2. Transition To a Supersymmetric State
Another speculation in string theory goes that the universe could randomly change from its current state, where supersymmetry is broken, to a different state, where supersymmetry is exact. Again, these things happen billions of years from now, if ever; else they’d have happened already. (What is supersymmetry? I don’t know, but I do know that even if I did know I still couldn’t tell you.) In such a universe, nuclear physics has to be redone from the ground up, and new kinds of matter replace our familiar ones; Louis Clavelli writes that “the physics of bulk supersymmetric matter is very much terra incognita”, and also that “a priori, it cannot be ruled out that Susyria is a new Galapagos teeming with abundant life”. Perhaps most intriguingly, he doesn’t rule out the possibility of supersymmetric bubbles coexisting and communicating with our normal world, although no life could survive the radiation blast at the transition event itself.
3. Naked Singularities
In general relativity, a singularity is a point or region in spacetime where there actually isn’t a point or region in spacetime because stuff blows up (this is not the technical definition that physicists use). A naked singularity is one that doesn’t have an event horizon causally separating it from the rest of the world. The so-called “Cosmic Censorship Hypothesis” says physical law prevents these from being created when big round things collapse under their own gravity; it is, however, unproven. According to Chris Hillman, it’s possible that such a naked singularity would set off a “thunderbolt” hole in spacetime expanding at light speed, leaving those in the vicinity without so much as a faint “om nom nom” to announce their instant death. Or to be exact, in Hillman’s words:
they are spindled and crushed by tidal forces which increase without bound in finite proper time.
Colliding gravitational waves and something called a “Wave of Death” supposedly could create the same result. Hillman dwells a bit on mad science applications, and it turns out that in the end there is also room for bright and happy optimism:
how can humans protect themselves against possibly inimical extra-terrestial
civilizations which might be -arbitrarily- more technologically advanced
than we are? The all-too-familiar logic of the Cold War suggests that the
only possible defense is to develop a way of generating a Wave of Death.
Then, if a powerful extra-terrestial threatens us, we can threaten back by
warning them that we will destroy the Universe if they try to destroy us.