Hmmmm you should really model your simulation on a real system.
Oh! That gravity term suggests that a large mass is nearby. The correllis effect is going to spin that pendulum unless an even larger mass has a tidal lock on the system.
Extra credit time! Stick your pendulum at a Lagrange point.
Another example of simulating work without any sweat! At least a pendulum is fairly efficient in a vacuum.
"Should be" isn't "Is" -Jay
