The BICEP2 gravitational waves discovery is officially dead. Most scientists still believe the Big Bang happened, and the case in its favor is still pretty solid, but we shouldn’t dismiss the alternatives. So what are we really saying if we say that time and matter didn’t originate with the Big Bang?
Egyptian scientist Ahmed Farag Ali and Canadian scientist Saurya Das have recently calculated one possible, mathematically sound answer: that the cosmic effects we attribute to the Big Bang may actually represent the steady state of a permanent universe that had no beginning. And even if their findings don’t hold up, it’s still entirely possible that the Big Bang represents a single event in the history of an infinitely old universe.
We haven’t reckoned with the implications of a finite or infinite universe; both seem to introduce problems we can’t resolve. If we say the universe exists because of the Big Bang and didn’t exist until the Big Bang happened, then we’re quite literally saying there was a point before time at which nothing became everything and exploded. I don’t think there are recreational drugs powerful enough to make that feel like a coherent idea.
But if we say the universe has always existed, that arguably makes even less sense. As University of Nottingham philosopher Mark Jago explains here, the idea of infinity is—perhaps by definition—marginally nonsensical, and certainly beyond our capacity to fully comprehend:
Imagine the cosmological timeline we’re accustomed to dealing with: 13.8 billion years, give or take. How much of an infinite universe’s timescale does that represent? An infinitely small portion. Compare a single hydrogen molecule with the scale of the universe; now, consider the fact that 13.8 billion years is literally infinitely smaller in relation to the age of the universe than that. Everything that has ever happened since the beginning of observable time would be infinitely recent in the grand scheme of things—shorter than a tenth of a second relative to 100 trillion years. Our lives and all timescales we can comprehend would be, quite literally, infinitely brief.
But at least most astrophysicists accept the idea that the universe began with the Big Bang, right? Sure. But an increasing number of them also think that our universe came from other universes. And how far back do these other universes stretch? Well, if they go infinitely far back, we face the same paradoxes we face in an infinitely old universe. And if they have a beginning, we’re back to saying that, at some point, nothing became everything and exploded. No matter what model of spacetime we accept, it probably won’t make any damn sense. Personally, I find that humbling—and a little bit liberating.