Pardon me I am just a high school student.
On basis of the fact that gravitational force is delayed.
Since angular momentum of planets around is conserved due to force and position vector being parallel (i.e zero net torque).
Using fact that gravitational forces are delayed.Therefore the force acting on the planet will be based on position at certain time before and then the direction of the force and present position might not came out to be parallel and therefore net torque should not be zero.
What's wrong in this reasoning?
