The simulation hypotheses is an interesting thought experiment that has received more media coverage than is justified by the paucity of science that supports it. As most people already know, the Bostrom thought experiment is as follows:
1. One possibility is that there is indeed an upper limit on a civilization’s development, and so before any imaginable human civilization has the chance to create reality simulators — to become posthuman — it is inevitably wiped off the planet.
2. Another possibility is that posthuman civilizations can come to exist, but that they are “extremely unlikely to run a significant number of simulations.”
3. The remaining possibility, assuming those two options don’t actualize, is that we ourselves are “almost certainly living in a computer simulation.”
I am tempted to dismiss the simulation hypothesis because it strikes me as a pseudoscience and is unfalsifiable, mainly because:
-even if civilizations survive long enough to build simulations, and some build simulations (because the technology exists to build them), that doesn’t prove our existence is a simulation. ‘Almost certainly’ is not something that can be made mathematical rigorous. It’s like saying ‘between 0 and 1’. This is the most obvious flaw of the Bostrom argument.
-impossible to prove a negative. Evidence against the existence of a simulation may be part of the simulation itself. The ‘creators’ may be taking painstaking efforts to make sure we don’t know we’re in a simulation. One could argue that if we were in a simulation, the programmers could erase or censor the possibility of anyone realizing it, but then that may be ‘too obvious’ and the programmers allow some discussion, and so on. But this isn’t really science – it’s just all hypotheticals and speculation.
-evidence of a simulation can be explained by exiting physical laws and phenomena, without the simulation hypothesis (Occam’s Razor is invoked).
-it’s ‘programmers all the way down’. A programmer programs the program, who is programmed by another programmer, ad infinitum.
Along with The Singularity and Transhumanism, some of likened it to ‘creationism for nerds’. But that seems too harsh and dismissive. The simulation hypothesis can be turned into a more rigorous science, by breaking the trilemma into components. This is a multi-disciplinary question combines mathematics, physics, computer science…and maybe even neurology.
Number one can be answered by checking every star for civilizations (which would be a massive undertaking but a least something that is theoretically possible), to determine if there are enough civilizations that at least one is advanced enough to simulate reality. Musk says it’s ‘one in billions’, but it would be interesting to see a rigorous mathematical attempt at estimating it. The ‘Drake Equation’ may provide a ball park estimate.
Number two can be answered by trying to better understand the mathematics of simulations: is a simulation that replicates our reality (within a margin of error) mathematically possible, and if so, how could it be created with existing or hypothetical technology? If it’s physically impossible (if there are not enough atoms or power to build a sufficiently powerful computer, etc.), then that is evidence against simulations. One can create some ‘rules’ that a simulation may obey:
-A simulation should be logically consistent for all observers. If I place a full coffee cup on a table and leave the room for an hour, the cup should not have moved. Furthermore, the coffee should have cooled, and some should have evaporated, in accordance with the laws of physics. If there is a video camera in the room and someone else is watching it, myself and the observer should not notice any discrepancies.
-To save computing power, a programmer may ‘black out’ regions not within ones perception. If I am walking down the street in California, Shanghai may be blacked-out, and then vice-versa for inhabitants in China. But if I turn on the computer to a live-stream of news in China, I better not see any ‘blacked out’ regions. Furthermore, physical events in ‘blacked-out’ regions must still occur. If I leave the room after placing the coffee cup, the room may be blacked-out but the evaporation and cooling must still occur. If someone else enters the room and places a book, when I return there must be a book. These events (placing of the book, cooling of coffee, etc.) must be saved even in ‘blacked out’ situations. The whole thing seems like a daunting undertaking. But some senses may be harder to black-out: if you leave the room, you may still smell the coffee. If someone knocks the cup and it shatters, you must hear it break (provided you’re not too far or another sound doesn’t overpower it). The pieces under no condition may reassemble or move without an external force acting on them.
Once the rules have been established, the simulation can be populated and initiated, but the amount of memory and computing power required must be determined, and if such a computer can ever be built within the reasonable limits of the universe and known physical laws.
Another way to save power may be to allow some inconsistencies but not so many as to arouse suspicion. A ‘bad’ simulation would have a lot of of logical inconsistencies – stuff moving when it shouldn’t, blacked-out regions that are supposed to be revealed but aren’t, physical laws being violated, etc. Even Newton’s inverse square law of gravity has been replicated to the micro scale, without inconsistencies, which suggests a very, very high ‘frame rate’ for the simulation. Given that how rare this is (it’s so uncommon that it’s considered paranormal) despite the billions of ‘events’ that occur every second, either we’re not in a simulation or it’s programmed very well. Maybe ‘dark matter’ and ‘dark energy’ is an inconsistency, or maybe we just don’t yet have a physical explanation for it. The ‘fine-tuning’ of certain physical constants may also be evidence of a simulation, but there are other explanations for this (such as possibly a ‘multi-verse’ in which our universe happens to be one with constants conducive to life).