Consider a woman standing on a turntable, which can turn without any friction. Both are initially at REST. A woman (m kg) starts to walk around the rim of turntable clockwise. she walks at a constant velocity with respect to the earth. Obviously, the turntable (I kgm^2) starts to rotate counterclockwise. In any closed system, Angular monetum and linear momentum are conserved. So, angular momentum of the woman with respect to the center of the table has the same magnitude as the angular momentum of the turntable, but both vectors cancel each other out, creating zero-sum. (since both are initially at rest.) Also, the woman gains linear momentum. But I cannot think of an opposing linear momentum that would cancel out the linear momentum of the woman, when I consider the woman-turntable system. So here comes my question. Where is the other linear momentum that opposes that of the woman? Should the Earth be affected (very very slightly) so that the change in linear momentum of earth is the same as the change in linear momentum of the woman?