Doesn't this sort of make sense though? Like the Singularity?
Any intelligent civilization or life forms' technology will continue to advance at exponential rates, and the most natural thing (at least in our own experience) seems to be to use that technology to replicate reality. See simulation software used by scientists, movie effects, and video game worlds. It stands to reason that any civilization that survives long enough to develop computers would only need to survive a few decades or a couple of centuries longer to begin to create simulacrums of their own reality, either for testing, entertainment, or survival.
Now, keep in mind that there is a massive time differential between a computer simulation and "reality". Any intelligent being that was in a computer simulation would experience the passage of time MUCH faster than an observer watching them in reality. If one of the simulation inhabitants could look out at "reality" it would appear to almost stand still. So any civilization with sufficient technology could actually simulate the life and death of an entire universe within one of their lifetimes, provided the computing hardware was beefy enough. Whole intelligent (AIs? Beings? Simulation inhabitants?) could live and die while the programmers had a sandwich, and the simulated being would experience the full passage of "years" from their own perspective.
Let's take it one step further - let's assume that the simulation of reality is largely flawless, though optimized for speed and efficiency. At some point the technology level in the simulation itself will reach a sufficient point where the simulation inhabitants can create a virtual reality within their own virtual reality. You would have to assume that at some point the optimizations to replicate reality would compound to a point where further nesting was impossible, but theoretically you could have dozens or hundreds of nested universes at that point, only one of which (the top one) is real.
Shades of the Thirteenth Floor here.
Reality being a computer simulation could also account for things like the absence of life in the universe. Extraterritorial life could very well exist in the "real world", but the programmers may not know enough or care enough to simulate it - or they exclude everything but a sphere of the universe around the Earth to optimize the simulation and save on computing costs.
Ancient gods, miracles, inexplicable events, etc. could all be simulation operators hacking or using command line functions in the system. Such events could be a very real case of avatars of the "gods". How many of us make ourselves godlike when we play game simulations?
Also, simulated realities would be a great way to escape or delay extinction in the face of the heat death of the universe. Scientists have already developed quantum clocks that could continue to function past the end of the universe - imagine using such devices to power a computer simulation with all of mankind uploaded to it? Or because of the time differential, mankind could experience millions of more years of life and advancement within a simulation, using the last light of a dying star to power an orbiting computer. Each user could get rebooted and reincarnated an infinite number of times until they forgot about being "real" at all. Basically an ark or a lifeboat for humanity by way of a "reality mmo".
