conservation of angular momentum, how does it actually work?

Answer 1

In physics, the angular momentum of an object rotating about some reference point is the measure of the extent to which the object will continue to rotate about that point unless acted upon by an external torque.

As momentum is conserved so is angular momentum. The conservation of angular momentum is used extensively in analyzing what is called central force motion. If the net force on some body is directed always toward some fixed point, the center, then there is no torque on the body with respect to the center, and so the angular momentum of the body about the center is constant.

Answer 2

Angular momentum ; when it comes to a moving rotating mass structure it is defined as the product of Energy of rotation and the time that it takes for the complete rotation to take place.
Per Albert Einstein and or Ricardo Carezani Relativity theories,mass changes, when it aquires velocity of motion.
Therefore ;if momentum is to be conserved (that is maintain rotational energy equilibrium) a change of period of rotation,as well as the radius vector of rotation need to be changed, when the rotating mass changed.

Angular Momentum exists only and only when a real mass structure is in eliptical motion.
Angular momentum only exists in the presence of a real mass.
That means that a massles entity does not have an angular. momentum.
The old belief that photons were massless ,would mean that light has no angular momentum ,let alone linear momentum.

For example in the case of the electron it is a real mass structure. An increase of Electron mass causes the orbit to widen and a decrease of mass cause the orbit to shrink ,in order to maintain angular momentum constant.