Are we living in a simulated universe? - Part 1

Are we living in a simulated universe?

By Bradley Bartholomew
February 2014

Mainstream scientists are taking very seriously the possibility that we are living in a universe that has been simulated by our own very advanced and technologically savvy descendants, presumably using a quantum computer with virtually infinite processing power.

John D. Barrow, the Professor of Astronomy at Cambridge University, wrote an article Living in a Simulated Universe. He refers to his own earlier theory about how an advanced civilization of our own descendants could be simulating us. He then goes on to talk about the ‘slippery slope’ that opens up before you once you accept that all possible real physical universes exist in parallel. “We see that once conscious observers are allowed to intervene in the universe, rather than being merely lumped into the category of ‘observers’ who do nothing, that we end up with a scenario in which the gods reappear in unlimited numbers in the guise of the simulators who have the power of life and death over the simulated realities that they bring into being. The simulators determine the laws, and can change the laws, that govern their worlds. They can engineer anthropic fine-tunings. They can pull the plug on the simulation at any moment, intervene or distance themselves from their simulation; watch as the simulated creatures argue about whether there is a god who controls or intervenes; work miracles or impose their ethical principles upon the simulated reality. All the time they can avoid having a twinge of conscience about hurting anyone because their toy reality isn’t real, is it? They can even watch their simulated realities grow to a level of sophistication that allows them to simulate higher-order realities of their own.”

You would think that Barrow as a sober and well-respected scientist would take a good long look at this slippery slope that has opened up before him and say: “Whoa! This is getting way too weird!” But he doesn’t. My guess is that he is actually a closet Trekkie and he has been spending way too much time perched in front of the TV imagining himself in the holodeck.
He goes on to suggest ways whereby we as software simulated primitive human beings might actually be able to spot flaws in the simulation and thus ascertain that we are not real biological beings like we thought, but are actually virtual beings living within the simulation. Here we come to the essential point of this whole simulation universe debate. Neither Barrow, nor others who have written on this theme, have ever doubted for even a moment that there is a real physical universe with biological ‘posthumans’ that did the initial universe simulation and thus started an indefinite chain of virtual universes. In this real physical universe there are real elementary particles, a real CMB (Cosmic Microwave Background) and real constants of Nature etc. I particularly draw your attention to the real constants of Nature. These are arbitrary numbers which the scientists have to stick into their equations to make them work! And all these real objects actually exist externally to the mind of the biological posthumans. Yes, even the real constants of Nature have to exist external to the mind of the posthumans because Nature is external to the mind of the posthumans. The external world existed long before there were ever humans in this first and only real physical universe so obviously the elementary particles had to ‘know’ the constants of Nature so they could do the math and figure out at any given instant where they are supposed to be and how fast they should be going. 

Barrow says: “Firstly, the simulators will have been tempted to avoid the complexity of using a consistent set of laws of Nature in their worlds when they can simply patch in ‘realistic’ effects. When the Disney company makes a film that features the reflection of light from the surface of a lake, it does not use the laws of quantum electrodynamics and optics to compute the light scattering. That would require a stupendous amount of computing power and detail. Instead, the simulation of the light scattering is replaced by plausible rules of thumb that are much briefer than the real thing but give a realistic looking result – as long as no one looks too closely.” (italics are mine) You can see that he has advanced the argument in as much as he now thinks the supersavvy posthumans with the most powerful quantum computer imaginable have to resort in their simulations to fudging techniques used by Walt Disney in his movies circa. 1950 in the Christian era. He clearly doesn’t realize that the real physical world that the biological posthumans see about them could actually be merely Disneyesque movies running on the visual cortex of their brains. They don’t ‘see’ the elementary particles, the electromagnetic waves, the constants of Nature either. All they see are images of ‘results’ on the cortex of their brain that tell them what these real physical microscopic objects are doing. All they ever see are Disneyesque movies of what appears to be an external world. How can it be that a very intelligent scientist like John D. Barrow who clearly thinks there is some possibility that he is living in a universe simulated by his posthuman descendants, can not go that one stage further and ask whether perhaps the original real physical universe was actually a simulation as well.

Barrow tells us that the posthumans would of course have an advanced knowledge of the laws of Nature, but it may be a philosophical impossibility for them to have a complete knowledge. “They may know a lot about the physics and programming needed to simulate a universe but there will be gaps or, worse still, errors in their knowledge of the laws of Nature. They would of course be subtle and far from obvious. Otherwise our ‘advanced’ civilization wouldn’t be advanced. These lacunae do not prevent simulations being created and running smoothly for long periods of time. But gradually the little flaws will begin to build up. Eventually, their effects would snowball and these realities would fail to compute.” If that happens then the posthumans might have to intervene in our universe with ad hoc patches to fix the problems. Simulated scientists like him might start to get puzzling results from their experiments. This is where he clearly misses the point. All the posthumans have to do is run Disneyesque movies of the macroscopic external world on the cortex of his brain to simulate his universe. THEY NEVER HAVE TO SIMULATE EVERY SINGLE ELEMENTARY PARTICLE.

Another group of distinguished scientists have recently published a paper Constraints on the Universe as a Numerical Simulation where they put forward a complex mathematical argument as to how we might possibly detect that we are living in a simulation. They state “In this work, we have taken seriously the possibility that our universe is a numerical simulation. In particular, we have explored a number of observables that may reveal the underlying structure of a simulation performed with a rigid hyper-cubic space-time grid.” Essentially they have assumed that the universe is simulated with the same lattice structure that is currently being used in Quantum Chromodynamics (QCD) to model the strong nuclear force among protons and neutrons. “These simulations are currently performed in femto-sized universes where the space-time continuum is replaced by a lattice, whose spatial and temporal sizes are the order of several femto-meters or fermis (1fm = 10-15 m), and whose lattice spacings (discretization or pixilation) are fractions of fermis”. We may note at this point that space-time is a highly artificial mathematical concept. Essentially you start with the Riemann curvature equations which are good for two and three dimensional curves and simply plug in time as a fourth dimension. You end up with something called the curvature of space-time but it can’t be visualized in our 3D world. So right from the outset it is clear that this is going to be a purely mathematical theory.