The swing of the pendulum is only an integral part of the pendulum, a greater majority of it is the fixed portion.Ok. So why does it swing in a plane while the earth rotates below it?
Your imaginary spoon is swinging.
That is a fair question, and it is a question that pertains to other systems besides geocentrism. I have not formulated the answer to this. I also don't really see it as the earth and the rest of the universe, they are both part of the universe. Martin Selbrede has some good explanations that show how the rotating universe "locks" the earth in the center. This is illustrated in the book Galileo Was Wrong. It is based on some concepts discussed in the tome Graviation by Wheeler, Thorne, and Misner.
In fluid dynamics, we have a concept of "no velocity at the boundaries". This relates to aether fluidic theories, your question of where the motion of the "rest of the universe" starts. Depending on the nature of interaction between aether and the atmosphere, the motion of the aether needs to stop or slow down somewhere relative to the atmosphere/surface of the earth. Also, there need to be some local vortices to support the slight velocity of the moon. This neutral zone may arise due to these interactions.
So the earth rotating beneath the pendulum forces the pendulum to swing in the non-rotating plane of the stars? That is the first time I have heard that one. Most people will say the pendulum swings in the inertial reference frame of the stars, or something to that effect. I don't think you understand my question.
The pendulum is a heavy object on a string or chain attached to a near frictionless bearing or bushing, which itself is attached to a building structure. The pendulum is free to swing in any plane it wants to. It "chooses" to swing in the plane not-rotating relative to the stars. The observer "sees" the pendulum rotating relative to the floor, but we are told it is not rotating, but rather the floor is rotating beneath the swinging pendulum. Regardless of what you believe is rotating or not rotating, there is a relative rotation between the swinging pendulum's plane and the floor of the building. That is why the bowling pins, cylinders, or whatever is on the floor get knocked down by the pendulum. The pendulum appears to be rotating on the frictionless bearing/bushing, and as it rotates it goes around the circle and knocks down the pins.
The key is that the pendulum swings in a stationary plane relative to the starfield. So either the earth is turning beneath the pendulum, advancing the pins to be knocked down by the pendulum, or the starfield is rotating above the stationary earth causing the pendulum to rotate around and knock down the pins.
I was asking why is the pendulum swinging in the plane it swings. The answer is [likely] because it is aligning itself to the reference frame of the starfield rather than the earth. But as you can see there are two explanations for HOW this is happening:
1. The earth turns beneath the pendulum, which is held in place by the starfield;
2. The pendulum is turning with the starfield above the stationary earth;
This all has to do with the nature of inertia, but it does not prove the earth is rotating.
If the Earth were not rotating, it would not.I was asking why is the pendulum swinging in the plane it swings.
"Starfield forces" are as far away from any forces on it as Major Tom is in his tin can wishing for a fixed point.
There are none.