One of the two big questions Jasnah is working on is Urithiru and the shattered plains.
It's suggested that Urithiru might have been at the shattered plains, and then it was destroyed, allowing the parshendi to take weapons from the ruins. Jasnah says this is incorrect. She doesn't give any explanations, however. It's possible that she knows where Urithiru is, but it's also possible she's wrong or even lying – it wouldn't be the first time brandon tricked us.
But what if Urithiru was stationed over the shattered plains. We know one of the stormlight powers is gravity based. We also know that specific stormlight powers, like soulcasting, can be inserted into fabrials. So what if all of Urithiru was a massive fabrial – or at least supported by one – that could float midair? When the knights radiant fell, Urithiru would have landed wherever it was stationed over. I'm assuming here that Urithiru wouldn't have been stationary. This allows the city to belong to no specific country, like the radiant in Dalinar's vision said, and also to help wherever help is needed. It would also explain why the radiants fall from the sky in the visions. (It's also possible they can fly, I admit, but we don't see that, just falling).
Thoughts?