Is the Universe Infinite, or Just Really Big?


Is the universe infinite, or just really big?

Either way, it doesn’t make any sense. Take either scenario. An infinite universe: can you conceive of that? Is it even possible for the human mind to conceptualize what an infinite universe is like? I picture a spaceship traveling forever in one direction, never getting closer to any edge. An unending voyage of new sights. I try to mentally zoom out from the spaceship and imagine the larger soup through which its moving, but there’s no scale of zooming out at which any sense enters the picture. It just goes on…forever? (Incidentally, this would be good news for capitalist world-views predicated upon infinite growth, for then there must exist infinite resources, should we figure out how to harvest them from deep space).

Or a finite universe. The received cosmological view of a finite universe is not that space just hits a wall at some point, an edge which is the end of all things (I’m not sure how this could exist anyway, because how do we define a wall or an edge if not as the separation between one thing and another thing?). Rather, if the universe is finite, it’s most likely ‘edgeless’. That’s to say its fabric, spacetime, curves back on itself in any of 18-or-so potential shapes, like a donut, or möbius strip. In these scenarios, you can travel forever in a straight line, and you’ll eventually wind up back where you started.

But how can something finite be edgeless? Even donuts have edges. If something has a shape, it has an edge. These edges are what define the morphology of the space. Something edgeless is amorphous, no? There still has to be a border to the space beyond which, theoretically, there’s nothing. 

And this inevitable border between something and nothing is where I lose my grip on a finite universe. What could this border actually be like? Again, how can we make sense of an ‘edge’ but by there being something on the other side of that edge? Usually, when we talk about ‘nothing’ being on the other side of a border, we’re referring to empty space. But in this case, there’d be no space, no time. Just…what? A big black impenetrable vacuum? Or isn’t that a thing, something more than nothing? 

I can’t conceive of a finite universe because I can’t conceive of the edge of spacetime. The very existence of such an edge seems to imply, to me, that something exists beyond that edge, even if not connected to our matrix of spacetime. 

I’m not challenging the cosmological consensus, here. I’m a 25 year old guy wearing pajamas. But I am challenging my mind’s ability, and perhaps the human conceptual capacity, to grasp the full nature of our cosmic container. And it feels absurd to me, to admit this absolute inability to understand where we are, and then brush it off, put on some pants, and go back to work for $7.50/hr + tips at a job I don’t particularly enjoy, just so I can sustain a life that perpetuates this denial of the total unknowability of our situation.

Cosmological Carelessness

When it comes to questions of the universe, of our bursting onto the cosmic scene as sentient skin-bags aware of the improbability of our emergence, aware of the brevity of our sojourn through time and space, but unaware of its shape or size, I side with Annie Dillard. Why we are here is an opaque, though endlessly inviting question. But where we actually are, for this we might as well look for answers:

“I explore the neighborhood. An infant who has just learned to hold his head up has a frank and forthright way of gazing about him in bewilderment. He hasn’t the faintest clue where he is, and he aims to learn. In a couple of years, what he will have learned instead is how to fake it: he’ll have the cocksure air of a squatter who has come to feel he owns the place. Some unwonted, taught pride diverts us from our original intent, which is to explore the neighborhood, view the landscape, to discover at least where it is that we have been so startlingly set down, if we can’t learn why.”

We learn to fake it. We learn, because of the carelessness that’s tolerated in speaking of cosmology. A 2016 BBC headline read

“It took centuries, but we now know the size of the universe.”

Well, no we don’t. In the same article, they write that we don’t even know if the universe is finite or infinite. So where do they get off with that headline? What they’re referring to is the observable universe, estimated at 93 billion light years in diameter. 

Prone as we are to conflate what we know with all there is, what we can see with all there is to be seen, conflating the entire universe with only the subset of what’s observable to us stinks of negligence and hubris.

Or, Google the definition of Universe and observe the conflation:

Two errors here. First, the observable universe is the one we have size estimates for, because I repeat, we don’t even know if the entire universe is infinite or finite, so size measurements don’t make any sense. 

Second, we live in a universe. We have no idea if ours is the only universe. Our universe is not the universe — there might be others. So the universe is not “all existing matter and space”. Our universe is the entire area of connected spacetime birthed in the Big Bang. There might be other areas of connected space time in existence, they just aren’t connected to ours, so matter and energy cannot travel between them, leaving us all essentially marooned.

Observing Infinity in Nature

Printed on the back jacket of cosmologist Janna Levin’s book, How the Universe got its Spots: “is the universe infinite, or is it just really big?” 

That’s a good place to start, if we’re to explore where it is we’ve been so startlingly set down. She’s been guiding me through the universe, furnishing me with some answers, but mostly questions. 

But one comment, what appears a common stance in the scientific community, bugs me. 

“No infinity has ever been observed in nature”, she writes. 

But isn’t the opposite actually true? Show a Buddhist a finite object in nature, and they’ll show you the arbitrary intellectual distinction you’re using to slice up the interdependent, interwoven universe into cognitively digestible morsels.

Especially at a cellular level, the edges between objects break down upon closer inspection, the borders blur and mesh together. The solidity of objects dissolves into the mostly empty space comprising them. This empty space latent in all atoms is of the same spacetime fabric from which all things in our universe are woven. 

Finitude appears not a property of nature, but a limitation of human perception. The universe might be one big infinity, all of its finitudes are arbitrary intellectual and cognitive distinctions imposed by a grasping human mind. The beginnings of things and the ends of others don’t exist anywhere but the mind. In our spacetime, things all coalesce into the same tapestry, the same thing.

In this sense, maybe Buddhas — beings wholly liberated from mental grasping, clinging, and craving tendencies — see only infinity in nature, for there is nothing else. “Eternity in an hour.” 

These are basic features of our landscape. Any understanding of ourselves that doesn’t reach back to the big bang, before the big bang, and out into the sky, as far as an imaginary stretched hand can possibly go, is ignoring the basics. Constructions that ignore basics don’t fare so well.

But this is our project, such as it is. Janna Levin sums it nicely:

“Here we are. A small planet, an ordinary star, a huge cosmos. But we’re alive and we’re sentient. Pooling our efforts and passing our secrets from generation to generation, we’ve lifted ourselves off this blue and green water-soaked rock to throw our vision far beyond the limitations of our eyes.”

We’re here! I am here. Which is more strange, the inscrutability of the ‘I’, or the unknowability of the ‘here’? Or that in a potentially infinite universe, each ‘I’ experiences itself as the most interesting thing? Walker Percy writes: “Why is it that of all the billions and billions of strange objects in the Cosmos — novas, quasars, pulsars, black holes — you are beyond doubt the strangest?”

What a shame it would be, not to have a look around.