[testestx]

> There must be something else in the Universe to observe the single proton for it to have rotation, etc, according to quantum physics.

No, according to the Copenhagen interpretation.

[whatshisface]

Even in the Copenhagen interpretation states can have well-defined angular momenta before wavefunction collapse.

[vorg]

I thought in QM you couldn't know both the degree of rotation and the direction of the axis for a particle. If so, I wouldn't call that "well-defined".