Sunday, August 28, 2016


Mind-Blown: Is the Universe a Computer Simulation?



By John Michael Godier



One of the greatest unsolved mysteries of our universe is whether it's even real. While it may intuitively seem to be, after all we do live in and interact with reality our entire lives, the truth is that the matter is far more complicated than you might think. In fact it's so complicated that science itself cannot rule out that this universe may not exist at all. In fact, it's completely possible that we live in a computer simulation.



The idea that the universe isn't real isn't a new one, in fact it's very old. All religions are to varying extents based on the idea that this is all a simulation of sorts created by a deity. That idea began to move into the realm of science and philosophy with Rene Descartes' 'Evil Demon' concept. Descartes said that if you were possessed by a demon, you could never quite be sure that you weren't being deceived by it into thinking that the world around you was something that it wasn't.



An updated version of that concept goes like this. Your brain is entirely dependent on sensory input. Your eyes, ears, sense of touch, taste and smell all determine how your brain perceives the universe around it. But there is a catch: senses may not always tell the truth, as optical illusions show us. As a result, if you could trick all five senses at the same time, you could make a person believe in something that isn't reality. This is called the "brain in a vat" thought experiment and is the philosophical concept that underlies "The Matrix" series of movies. The idea is that if your brain was in a jar being fed sensory information with electrodes, you would live in virtual reality forever never knowing that there was an entire other real universe outside of the one you were being led to believe you live in.



But that's not the only possible way that the universe could be a fake. There is also the intriguing possibility that we are really artificial intelligences embedded inside a computer simulation. While this may sound outlandish, it's actually not and there are several aspects of our universe that might even hint that all is not as it seems. Enough so that none other than Neil de Grasse Tyson threw his towel in the ring at the recent 2016 Isaac Asimov Memorial Debate saying that he would not be surprised in the least if this all were a simulation.


The most marked of these phenomenon is quantum wave function collapse. In nature, subatomic particles can exist in different states. They can have different energies or move at different speeds etc. etc.. But in quantum mechanics, particles are thought of as existing in all possible states at the same time including existing in two places at the same time ... until you look at them. Then they choose a state to exist in. Yes, that's right, you can change the behavior of a subatomic particle just by looking at it. Its quantum wave function collapses the moment you look at it because when it's observed its actual position becomes known and it's no longer a matter of probability but of reality. In such a state of affairs, is the universe really there when you aren't looking at it? Well, in a sense, no it's not. Into the rabbit hole we go . . .


You may be thinking that this is all crazy hogwash, but think again. The phenomenon of quantum superpositions and wave function collapses are scientifically observable. The experiments can be repeated time and time again always yielding the same result. A famous example of this is the double-slit experiment. The way the experiment is set up is that a piece of paper with two slits in it is set up in front of a wall. Then we fire a beam of photons at the piece of paper one by one. When the experiment isn't being measured, i.e. looked at, then on the far wall we see an interference pattern like you would get if you had two ocean waves passing through the slits. But once you put detectors on either side of the paper and measure it, the interference pattern disappears and you see only two bars of light on the wall. This is because by looking at the photons, we have collapsed their wave function and forced them to either go through one hole, or the other. While this is all perfectly scientific, it also shows that observation is an integral part of our universe despite it being counterintuitive and, well, just plain weird. What does this point to? What is the nature of a universe that doesn't quite exist when you're not looking at it? I can't say.


Here's where we've left the rabbit hole entirely and are in some place else. Nature may, and I very much stress the word may, actually need conscious minds to perceive it in order to exist at all. Physicist and Nobel Prize winner Eugene Wigner proposed this very thing in the 1960's. He argued that quantum wave function required more than just an observer, but a conscious one and without one the wave functions of the universe would never collapse. At that point, the universe is simply a place were it's not possible for anything to happen and the only things that can exist are quantum superpositions. He then took this even further and suggested a line of consciousnesses observing each other all the way up to some sort of universal consciousness somehow observing itself into existence. While contentious and very much still disputed, this was all backed with more than just woo but actual physics. Crackpot Wigner was not. Did he misinterpret? Well, the current consensus is that he probably did. But current consensuses can be wrong.


But what of us being artificial intelligences embedded in simulation you ask? Well the answer to that may lie in a modern philosophical thought experiment similar to the brain in a vat concept. The Matrix and being a brain in a vat is an interesting thought experiment, but not a very likely one. I mean really, using humans as batteries? There are far better batteries out there than us. However when you consider that we may be some sort of artificially intelligent sub function in a computer simulation, things become really creepy. And that one may not just be possible, but even probable.

The whole thing comes down to a thought experiment that Philosopher Nick Bostrom at Oxford University has developed that may shed some light on whether or not we live in a simulation. His argument is simple, one of three things must be true.


Number 1. Humans never reach a level of technology that allows us to produce simulated realities, or the computers needed to create such realities are so complex that they cannot be physically constructed.


Number 2. Any civilization that gains the ability to simulate the universe simply doesn't go through with it either due to it costing too much in energy or ethical considerations over holding artificially intelligent entities captive in a simulated reality.


Number 3. We almost certainly live in a simulation.


That's certainly food for thought. And somewhat hard to shoot down when you think about it. And it begs a question, if this is a simulation, then who created it? Personally, I'm not sure I want to know. Could it be that there really is a creator of some sort? Could all religions have been preprogrammed into the system by the great God-programmer and thusly are all simultaneously valid? As a science-minded guy, those questions make my head hurt. I think I'll take the blue pill please.


Interestingly enough though there may be a way to scientifically test whether we live in a simulation or not. There's always been talk in physics that does seem rather weird that certain fundamental values in the universe are just right for life to exist. While that may just be due to the possibility that an almost infinite number of parallel universes exist and we just happen to be in the one that's just right, there's also the possibility that there is just one universe and the values just happen to be just right. The problem is that the odds of that are, well, astronomical. But there's a deeper level than that.


While we don't know if this is all a simulation or not, we do know that if someone were to create such a simulation, it has to follow certain rules. There has to be some sort of structure to it, an underlying lattice that holds it all together. At its smallest scale, the simulator must have a bottom line in the same way that how a television works. If you look at a television from a distance, you see a picture that conveys a message. You see a movie with an unfolding story before you. But if you look very closely and hit mute, you see only pixels and can't tell what the overall movie is about. The pixels are the limit to a television's ability to create a story, or a universe, for you. The universe may be the same. At some infinitely small point, we should be able to see the universe's pixels.


Scientists such as Silas Beane and his colleagues suspect that we might be able to do just that by studying the behavior of cosmic rays. Cosmic rays lose energy and change direction as they propagate. However, we know how much energy those particles have. The odd thing is that when you look at it, the whole thing might be consistent with the kind of thing you would expect to see if there was an underlying lattice governing the behavior of the universe. While not yet proven or studied deeply, we might be able to tell if this is a simulation or not by determining just how cosmic rays scatter. If it really does end up being consistent with a simulation, then things will get very interesting indeed. But, we could also be misinterpreting things. Much scientific study is needed before any conclusions can be drawn from this approach.




Another way of thinking about all of this is video games. A video game is just a mathematical construct, a program. Oddly enough, the universe also works on mathematics. Does that mean we live in God's video game? Possibly. And maybe we can some day hack the universe. Or worse, our games will become so advanced that Super Mario realizes that he's just a simulation and refuses to play anymore. But then one has to ask, if we go trying to game the system and we figure out what we really are then whomever created the simulation may simply choose to shut it down. Let's hope God doesn't get bored easily.



But there's a problem with the whole thing. As cosmologist Max Tegmark points out, if we do live in a simulation, then some day we will create a simulation of our own. And then our simulated universe will create a simulation and so on leading to huge numbers of simulations running within simulations. Perhaps even infinitely so, and that takes infinite computing power. Could there be such a thing that allows infinite computing power? Seems highly unlikely. Maybe, as Freud may or may not have said, a cigar is sometimes just a cigar and our universe is real and that's that. I hope that's the case. 

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