All adressed to BELLATOR:
"I think that the aliens? simulation would be subject to their own technological speed limit. In other words, if they cannot generate such advanced ideas for themselves, no simulation which they create would be able to do so either."
REP:
Step 1, they find out all the (needed and relative)rules that are present to create the universe we (they) experience. In other words they find a TOE.
Step 2, they turn this into a computer program, a simulation of the universe if you will
Step 3, say they have been evolving for 30000 years, they search through the universe simulation for a planet that can harbour life, and accelerate time in the simulation to say 50000000 years when the artificial organisms will have evolved into extremely intelligent beings. They then observe how these extremely intelligent life forms live, what they do, their technology etc... and copy it in the real world.
Regarding your REP to "Therefore, a true replica of the universe can never be made."...
Everything affects everything else. There is no way that a finite number of chips can simulate an infinite number of things happening -all at the same time. It may be able to simulate what's happening in one reigon of the universe, but it would have to pause calculations on any other reigons. Therefore the simulation would be inacurate because the other reigons affect the one in question. I might add, chaos would rule at the borders of these reigons.
P.S. How do you get italic script?
