So it was pointed out to me that one of the superior features of Cesium is the use of quaternions for model rotation implementation which, when done correctly, supposedly stops gimbal lock from occurring in 3-dimensional space.
I was surprised to find that trying to go directly over the north pole results in a gimbal lock. Here's a basic overview.
If you start in the western hemisphere with Canada at the top of your screen and drag down to rotate the earth's north pole towards you...
What should happen:
You should be able to continue rotating past the north pole to the point you see Oceania above Russia.
You can rotate until you're looking down earth's north-south axis. At that point the globe begins to spin to bring around the point on the map you are trying to rotate to.
For people most concerned with human-inhabited portions of the globe, this is no big deal. But for those of us interested in movements near and over the poles (e.g arctic/antarctic exploration, missile defense) this is fairly significant.
Is there a way to alter this behavior?