Edward Green wrote:
Here's a question which has bemused me for some time.

Say at time 0, we have a non-rotating object just hanging out in
inertial space.

At some later time T we encounter the same object, still just hanging
out, but now rotated through some static angle relative to the first
orientation. In between, the object was free of external torques, but
free to vary its shape, acquire and dissipate internal kinetic energy
as needed -- like T2. Its final mass distribution is however just as
before, though rotated.

Does this violate Newtonian physics, or not?

Angular momentum is zero throughout, but does this preclude a
rearrangement of matter into a rotated version of its former
distribution? Justify assertions.

Do the experiment: Sit in your swivel chair (might want
to oil the bearing first) with your feet off the floor and
your hands in your lap. Put your right arm straight out in
front of you. Swing it to the right. Put it back in your lap.

Mark L. Fergerson