That is one big assumption to say that they went through some 'dark ages' event. And even if they did, the scale wouldn't be on such a massive scale as to affect for so long and so drastically to actually take their level of knowledge back. I mean, even the dark ages here, they still retained some of the intellectual works thanks to the middle east. That's another point, the dark ages wouldn't affect the entire world they were living in. And right after the dark ages, there was a burst of learning and intellect with the renaissance.
And another thing, 2000 years ago, man on earth were still living in tents and did not even come up with the scientific methods and a lot of knowledge. The peak of their knowledge would have been greek and egyptian knowledge. 2000 years ago for these colony village idiots would have been the knowledge we have currently. In 2000 years, they have not advanced beyond the civilization we live in now beyond merely skyscrapers? All advanced civilizations seek space travel. And it's not even travel, there's satellites for global communication and observing weather and climate changes and if there was a lingering petty rivalry between rush's peoples and young's, there would have been surveillance satellites. It's like they were all hit on the head and were made to forget all things space travel.
