1. The Weather
It seems like the weather patterns go around and around the edge of the Earth. All the models I have seen show this. If there wasn’t a dome, why would the weather be so consistent and well contained? You could make an arguement that the presence of the vast antarctic ice sheet and freezing temperature is produces acts as a weather barrier; keeping our air and weather localized. But knowing the way wind ‘whips’ I find it hard to believe that this could keep the weather localized. Ok, so add the effects of the sun…which keep thermal normals consistance. Pulling warm air in and up and recirculation it. That could be a contributing factor. But still I doubt that these effects alone or together would be enough. Plus, if we were constantly receiving new air from across the infinate plan, then why would the powers be sparying so much stuff in the air? Wouldn’t it just get swept away along the vast ice plan? I think so.
2. The Stars
If you look at time lapsed photography of the stars, they show a perfect circular pattern. This has to indicate that the stars above us are centralized above us. If not, we wouldn’t have a North Star. If there are lots of pockets of continents, surrounded by water, dotted across a vast ice sheet then we must share the same night sky. If the center of the circling stars is above US; then the other pockets are only be seeing streaks of stars crossing their night sky, moving in a more-or-less straight lines with a bit of a curve to them. Because they would be so far out on the edge of our night sky. This would make the visual paradimes of the other pockets radically different than ours.
3. The military
If the military is only trying to stop us from crossing over to the next continental ‘pond’, why bother? Surely the journey would kill almost everybody. And of the small percentage of people who did make it to the next pond, only a small percent of them would be dumb enough to come back. I think they miltary force present on the outer edge is designed to keep anyone from seeing the dome, or the edge.