If we're in a simulation then there aren't any alien civilizations. No sense wasting computational resources on them.
P.S. As far as I know, computational complexity is the only physical quantity that doesn't obey conservation laws. So we're probably not in a simulation. If we were, it would probably be the other way around.
P.S. As far as I know, computational complexity is the only physical quantity that doesn't obey conservation laws. So we're probably not in a simulation. If we were, it would probably be the other way around.