Whenever we turn our eyes to the vast universe in which our little sphere of water and dirt resides, it expands around us. Prevailing scientific theories such as “The Big Rip” suggest that the universe is constantly stretching like a rubber band, growing into the incomprehensible nothingness that it inhabits. Although we may never fully understand the universe, each time we observe it, the picture becomes a little clearer.
When Copernicus pondered the nature of the universe, he realised we were not the centre of creation, and that maybe we’re not alone after all. When Edwin Hubble glimpsed oceans of stars and planets so fine they appeared like clouds of explosive, coloured dust, he realised that our Milky Way was just one galaxy amongst billions and billions – the universe went from “earth and its neighbours” to “endless, and ever expanding” in the space of just a couple of hundred years.
Now, in 2017, members of the scientific community are realising that “reality” within our universe may not be what we have always understood it to be – it may be so dense, so nuanced and so varied that the human brain could not even begin to comprehend the parameters in which to describe it, let alone visualise it. But just for fun, let’s try.
Imagine a fresh packet of A4 paper; all crisp and clean, each sheet resting perfectly on the others, forming a brick made up of hundreds of individual, flat sheets. Now imagine that each of those sheets of paper is a universe, and one of them is mine and yours. The theory of the “quilted multiverse” involves the idea that all of the matter and energy we can glimpse through our telescopes must have a certain density; in fact, they have the perfect amount of density to allow a gravitationally “flat” universe, which continues to extend outward forever rather than looping back on itself infinitely. If supporters of String Theory are to be believed, our universe is a sheet, referred to by cosmologists as a “brane”, stacked on top of tens of trillions of others. These hypothetically adjacent universes would not be billions of light years away from us but perhaps far more terrifyingly, they are hovering right next to you, right now. They are as much a thread of the fabric of reality as the computer you read this on, or you yourself.
The idea of multiple universes, or multiverses, was first raised by none other than Hugh Everett III, father of Eels frontman Mark Everett. Hugh suggested that all quantum possibilities must be real; whenever any decision is made, whenever an action occurs, or whenever a reaction occurs, each possible result comes true in its own timeline, in its own universe. Consider the six-sided dice; when you roll the die, it is equally as likely to land on one as it is to land on six. While the die is in the air, the outcome lives in a moment of absolute chaos. It has landed on one, two, three, four, five and six without landing at all; by creating the chance, by rolling the dice, you have created the possibilities. In your universe, the die may land on three and you go straight to jail for eight turns in Monopoly, but right next to you in a completely different universe, another version of yourself has rolled a six, meaning you get the community chest card, and collect five hundred bucks. Nice one, alternate universe you! Anything that could be possible is possible and always was possible. If you’ve ever watched the TV show, Rick & Morty, these ideas should sound pretty familiar to you.
When the big bang propelled our sprawling universe, or more likely universes, into existence, the resulting repulsive field caused space-time, the perfectly interwoven continuum of time and space, to be born. If that repulsive field was large enough, which it more than likely was, then the natural conclusion is that infinite space must have infinite repetitions of the volume of space, particles, atoms and matter that is visible from Earth. If it is true that infinite space contains infinite repetitions of volume, then there is no chance that our universe is a singularity. Rather, it is simply one patch in a quilted patchwork.
The quilted multiverse theory, of course, requires us to exist in the first place. The only problem is that we may not be – the universe may not be what we think it is. Rene Descartes once pondered the idea that everything we experience is actually the work of an evil demon, who is deceiving us all with the promise of existence systematically. The Chinese philosopher Zhuangzi, around the year 300BCE, realised that his dreams in which he was a butterfly were as vivid as his experiences in his everyday life, leading him to decide he could not say with certainty whether he was Zhuangzi dreaming of being a butterfly, or a butterfly dreaming of being Zhuangzi – the two realities had become indistinguishable. It seems to press on the minds of great thinkers through the decades – is reality simply an illusion?
Unfortunately, yes. But it’s not so much an illusion as it is a simulation.
In fact, it is almost a mathematical certainty that everything we know is simulated, simply binary messages floating in amongst the inner workings of a computer. The odds are almost infinity to one that we are all living in a simulation. You see, a technologically advanced society would eventually have the capability of creating a computer simulation that is indistinguishable from reality to the inhabitants of the simulation. We’ve already begun doing this on Earth – can you really prove that your Sim’s characters haven’t developed sentience? Perhaps their world is as real to them as ours is us. If an advanced society were to create a simulated universe, they wouldn’t do it once – they would do it over, and over again. Look at how many Sim’s games have been released! If they were left to run for long enough, the societies within these simulations would eventually be able to create their own simulations, also indistinguishable from their own reality.
Maybe we’re a simulation, maybe we’re simply one patch in a quilted multiverse, or maybe it’s just us and our universe. Either way, the fact that we exist at all is pretty amazing in and of itself. It’s just hard not to wonder about the where, why and how of it all.