I came across an interesting argument a few days regarding the nature of reality. However since this entry is pure philosophy, some of my serious science devotees may want to skip this one :)

Now that I have the disclaimer out of the way, here is the argument. Assume for a moment that we live in the real world (that may seem obvious, but you will see why this assumption is necessary in a moment). We have one Universe and one reality. But on a single uninteresting little planet in a single uninteresting galaxy there is a society (specifically the human race) that in a tiny span on only a few thousand years, has developed the technology required to simulate worlds.

In fact we have two ways of simulating worlds. Scientists with access to supercomputers enter the laws of physics (or theories of new laws of physics) and let the machine calculate the evolution of these virtual galaxies or universes. On a simpler level, one can look at video games and social software like SecondLife or The Sims as examples of people using home computers to simulate an alternate reality. Using these two types of simulations, our “reality” contains thousands if not millions of “virtual realities” which are distinguishable only in their complexity.

However the complexity is constantly improving. In my own lifetime video games have gone from Pong to games that feature thousands of artificially intelligent characters and huge expanses of photorealistic landscapes. Computers long ago proved capable of out-thinking humans in games like chess. I fully expect that within another decade we will see mass marketed video games in which the characters are so well developed and have sufficiently strong AI as to be indistinguishable from humans. At what point do we consider them self-aware living beings?

And that leads in to the heart of this debate. Since our one “real” universe has so quickly generated millions of “virtual” universes, and since they will very soon be as complicated and contain seemingly living beings, it is logical that a randomly selected being in a random universe is almost 100% likely to be a virtual being generated in the processors of some computer.

And that in turn means that we can be almost certain that we ourselves only exist in someone else's video game...