The question posed by The Matrix films got everyone at the turn of the century thinking: what if reality isn’t real? Most of us just thought about the implications of being plugged into a machine that projected a fake reality in our brains for an afternoon, and then we moved on.
But some people, including some of the world’s best physicists and cosmologists, didn’t exactly move on. They did what scientists do, and they started investigating. And what they’ve found is pretty weird.
Below are three (very simplified) theories about what the universe really is. They are all pretty different, but they all agree: what we think is real, isn’t. When you look at the universe closely, it seems like The Matrix is real!
The universe is a simulation.
One theory suggests that we live in a complex computer simulation. German scientists at the University of Bonn conducted research in this area that was based on a thought experiment. The thought experiment posited that any sufficiently intelligent creatures would try to create a simulation of the universe, and if that simulation was accurate enough, it would eventually lead to the creation of intelligent creatures, themselves sufficiently intelligent to develop an accurate simulation of the universe, and so on. This would create an infinite series of simulations within simulations, so it would be statistically probable that our universe is a simulation, rather than the original.
The evidence they have is quite technical, but part of the thought experiment states that the simulated universe would have something called “underlying ‘lattice’ frameworks”. These frameworks would limit how much energy the simulated energy particles would represent, and the physicists have found evidence that our energy particles do have strict limits like that. Which in turn suggests that we may just be some higher intelligence’s simulation of its universe.
The universe is fields.
Another theory argues that instead of being a computer simulation, the universe is just a series of fields that we only perceive to be solids, liquids, gases and atoms. This theory, championed by California Institute of Technology (Caltech) cosmologist Sean Carroll, says that, when we break things down to their very smallest parts, we don’t get cells or atoms or electrons. Instead, we find everything is made of fields of energy.
This theory, called field theory, is best demonstrated by magnets. Magnets use their magnetic field to draw certain metals to them, and at the smallest levels, this is kind of how everything works. Fields draw each other to them, and thanks to the Higgs boson, these fields form the protons, electrons and neutrons that make up atoms, which make up chemicals, which make up every thing. So when you break it down, according to this theory, we are all just collections of fields that hold each other together so strongly that we perceive ourselves to be solid human beings.
The universe is numbers.
Swedish cosmologist and MIT professor Max Tegmark thinks the fields and computer simulation can be boiled down even further – to pure, advanced mathematics. He calls his theory the mathematical universe hypothesis, and instead of looking at what the universe is, this theory looks at why the universe is the way it is. Essentially, Tegmark and other eminent scientists wondered why mathematics could be used to predict the way the universe worked. After all, Newton proved his theory of gravity (the force that holds the moon in orbit around Earth is the same one that causes an apple to fall to the ground) using mathematics, since he couldn’t produce physical proof. And to this day, physicists use mathematics to prove or disprove their hypotheses.
But how can an abstract idea, one used to create order and spot patterns, be so applicable to a universe that on its surface is all random chaos? Simple: the universe is ruled by mathematics. When you get past the things that make up stuff, you get pure mathematical formulas.
At the very least, this theory gives maths teachers something to say when students ask why they need to learn geometry. But the implication – that we humans can be reduced to laws of mathematics – is a little bit harder to come to terms with.
According to the most advanced scientific thought, we may be computer simulations, a series of fields or just pure maths. Or we could be all three. But in the end, it doesn’t matter to our daily lives too much, because the universe is the way it is. Whether we live in an advanced computer simulation or not, we won’t be able to fly or stop bullets. Even if we become aware of what the universe really is made of, we’re still bound to its rules. Still, it’s fun to think about, isn’t it?