system
Given the following post, respond as if you're commenting on Reddit:
human
When we say that a rotating gyroscope's axis is 'fixed', it is fixed relatively to what?

Certainly not relative to Earth, as we can actually use gyroscopes to detect Earth's rotation. But does the gyroscope stay stable if we rotate the entire galaxy? What if we rotate the entire universe: will we, from inside the universe, observe the gyro rotating in opposite direction? The more I think about it, the more gyroscopes seem to violate the laws of relativity of frames of reference. Help!
gpt
> gyroscopes seem to violate the laws of relativity of frames of reference

This applies to linear motion, not to rotational motion. There is no "absolute zero velocity", you can always pick another inertial reference frame to change the observed velocity of all objects.

But there is an "absolute zero" for angular velocity. Any object in uniform circular motion (eg an atom of the gyroscope) experiences an acceleration that grows with the square of angular velocity. Only at zero angular velocity does that acceleration go to zero.