As to #1, there's no reason to believe we're the first or only type of simulation. There could well be some life that said "hey, we've been running these simul

As to #1, there's no reason to believe we're the first or only type of simulation. There could well be some life that said "hey, we've been running these simulations of our world for a while, but what if we tried making carbon-based life forms for fun?". I imagine that would happen a lot: I don't see everybody doing exactly the same type of thing on their computers today for fun, nor can I imagine any reason people running life sims would be any different. All I know is that (if I can trust my memory) I'm in a relatively stable physical environment. When you can simulate a lifetime in an hour on commodity hardware, there's going to be a lot of people trying crazy stuff just to see if it ends up being stable. As to #2, I'm not sure I agree. We've got lots of computer environments ourselves that aren't very lifelike at all, from Conway's Life to Sim-(fill-in-the-blank) to World of Warcraft to extremely specialized (and non-entertaining) environments. To some extent, that's because we don't have the processing power to simulate real life, but even with infinite processing power, I would guess that most simulations would not be perfectly lifelike. There are more lifelike simulations available today, but I don't think they're a majority. For #3, yes, but maybe you're assuming the main purpose of simulation would be for experiments, and therefore that they're similar to the real world. From what I've seen of my world, the most common use of computers is entertainment, and for this, being different from reality (either a little or a lot) is very important. Research will have human brains-in-a-computer first, but a decade or two later the Playstation 7 will have a lot more of them. It's like asking: you're a master-level chess computer, who are you? You might be Deep Blue in 1996, but you're far more likely to be a chess program running on somebody's PC a few years later.