This question may sound like a duplicate of these two, but it is not (in my estimation):
- How attitude indicator (gyro horizon) works if Earth is curved?
- Gyroscope in an airplane following the curve of the Earth
My question is about the explanation some give for why a gyroscope stays upright while a plane travels around the Earth. The answers given in the other StackExchange posts claim that gyroscopes correct for the curvature over time. I accept this as true, however some other people (like the person in this YouTube video ) claim that gyroscopes would stay upright relative to gravity even if they were perfect gyroscopes without friction. In other words, that an ideal gyroscope would maintain an orientation with the gravitational field that it is in.
So, my questions are, specifically:
Does an "ideal" gyroscope tend to stay fixed relative to the gravitational field that it is spun up in, or does it tend to stay fixed independent of that?
What would I expect an "ideal" gyroscope to do while in a plane going large distances (assuming no turning of the plane except for maintaining the same distance from the center of the Earth, and assuming the gyroscope does not perform any "correction")?