But simulated universes exist as computer programmers have simulated them!
I kind of thought it would be obvious to everybody that we were talking about the Universe we live in, not some vastly simplified model in a programmer's computer.
Bostrom has introduced us to the idea of a pop up window appearing telling us what the real nature of the universe is. That casts a question mark over the unfalsifiability of the hypothesis.
Can you suggest an experiment we can perform in principle that would force this pop up to appear? No? Well we can't falsify the hypothesis then.
Vastly simplified models are acceptable to science though besides
computers are getting more and more sophisticated all the time and if we are dealing with an intelligent infinitely large and old universe who knows how many Gozilliobytes are possible.
What we have is a situation where the appearance of the pop up confirms the theory. So is the theory unfalsifiable? I don't know if it is in that case.