Challenge to the absoluteness of the conservation of momentum or angular momentum

Conservation of momentum and angular momentum have long been regarded as the two basic laws in physics. However,an example that does not conform to the two laws is given; that shows that none of momentum and angular momentum is an absolute conserved quantity. We found that under certain conditions,the action-reaction pair acting between two bodies touching each other changes the momentum of one body and the angular momentum of the other one. That means that the total momentum of the system is changed without any external force,and the total angular momentum of the system is also changed without any external moment. Furthermore,we found that if the momentum and the angular momentum of a system are not conserved,the two kinds of non-conservation must occur at the same time; therefore,we predict that an unknown and more general conserved quantity of the system is still conserved in this case. We anticipate our study to be a starting point for reexamining the classical physics from a new viewpoint. Additionally,we anticipate our assay to also be a starting point for searching a new propulsion mode besides rocket recoil mode for an isolated system such as spacecraft.