What is the probability that you are a simulation, and if so, how can you tell?
I ran across this idea a while back on one of the science blogs I follow, but had just glanced over and forgotten about it until someone asked about it on LinkedIn yesterday.
Nick Bostrom of Oxford University asked “Are You Living In a Computer Simulation?” in a 2003 paper. From the abstract: “This paper argues that at least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a “posthuman” stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation.”
Because it has continued to be a popular / controversial topic, Bostrom has set up a web site Are You Living in a Computer Simulation? where “[…] you can peruse the debate that followed the paper presenting the Simulation argument. The original paper is here, as are popular synopses, scholarly papers commenting on the first paper, and a couple of replies to these comments.”
Note that the paper itself isn’t an argument for or against #3 (we are a living in a simulation); rather that at least one of the three propositions is true. The interesting (and perhaps creepy to some) point is that if you assume some future post-human civilization can simulate their “ancestors” (us), and that they do so at all, then vastly more simulated humans will have existed than ever physical humans did. Thus any person at random who ponders this question is much more likely (p ~ 1.0) to be a simulation than an original physical human.
So, how can you tell? Well, you probably can’t, unless the entity running the simulation wants you to. If by some means you did discover (or came close to discovering) you’re a simulation … you get restored from backups … or deleted … or the whole simulation would get reset. Ouch.
At least read the NY Times article “Our Lives, Controlled From Some Guy’s Couch” (linked to from the site above) for a lighter take on the idea.
Oh, and the obligatory Wikipedia link: Simulated Reality.