Sorry if that was confusing. What I am saying is that there is a finite possibility that a civilization might destroy itself through nuclear warfare if they have the technology. Or rather, through post-newtonian warfare (or related ecological or Malthusian catastrophes) . If civilizations survive their own discovery of trans-newtonian elements by 1,000 years on average and assuming that civilizations take 10,000 years to develop up to that point, then the total expected life-time of a civilization would be 11,000 years. If we have a uniform chance of meeting the civilization at any point in its lifetime, then we would have a 91% chance of meeting it in a pre-newtonian state.
One might argue that a lot of civilizations are probably more peaceful and would not destroy themselves so quickly. But then again very peaceful civilizations might not provide large enough incentives for advanced (military) technology that would presumably be a driver for the discovery of trans-newtonian technolgoy in the first place.
Of course I did not make up this argument myself, its simply a bit of an application of the Doomsday argument to the modified Fermi-Paradox that we are discussing here. I don't necessarily support the argument or the 1,000 year assumption, but this could serve to demonstrate why pre-newtonian civilizations exist in Aurora (and the apparent lack of extraterrestrial trans-newtonian visitors before 2025).
Ah, I see. Well, firstly there are a lot of assumptions here I can't accept, about the likely lifetime of a civilization and the probability of it destroying itself.
I ignored the total length of the lifetime of a civilization because a. we can only guess and b. it would be irrelevant to the particular discussion I was having anyway, because we're discussing specifically the chances of 2 pre-trans-newtonian civilizations and a transnewtonian civilization can be assumed to last approximately 10,000 years assuming similar development to humans (based on the default game setting being the year 2025). That's not an unreasonable assumption for our purposes, because that's the time scale of the only observed example. Given the age of the universe, it is very unlikely that two such civilizations, that last only for a fleeting 10,000 years, would align or overlap.
Of course, it could vary depending on the abundance of life, but I'm pretty sure the rate of life to planets would have to be pretty damn high to make any difference.
Thus, it doesn't actually matter if other races destroy themselves - that only decreases the likelyhood of meeting an advanced civilization. It doesn't increase the likelyhood of meeting a less advanced one.
Of course, I didn't do the math for this either, it's an already established idea. I just can't for the life of me remember what it's called. But I found it pretty convincing.