Paul that is a huge post about absolutely nothing ... I am pretty sure I know how to calculate centripetal force. What you haven't addressed is the centripetal force REAL, against what is it pushing to push the orbiting body out.
Go right to the center pivot of any gravitational centripetal setup and the force goes into a single point which is a singularity. Why a singularity because the pivot has a size of zero. Pressure is force per unit area and the pivot has an area of zero.
So Pressure at pivot space = Some force / zero
In other words the pressure on space for any given centripetal setup you just described is INFINITY. We can usually talk around it on physical bodies but now try a spaceship pulling a circle manouvre in empty space.
If you want to test the force and pressure put a weight on the end of a string and swing it around.
So in the physical situation the pivot or axle has width and structural strength. We don't have either of those in the gravity based version.
The very classical formula's you are using will also prove that what is happening can't happen.
That is why centripetal acceleration is called an fictitious force in classical physics, it arises from nowhere and disappears to nowhere. The force is much easier to describe from an inertia frame of reference but in classical physics there is supposed to be an absolute frame and this shows the problem. If I pull an absolute frame then I get an infinity.
Structurally gravity works the same way the force while measurable disappears to nowhere. It's the problem Bill G is struggling with it all sort of makes sense until you try to follow this to an absolute reference and it all blows up in your face and you will get infinity or zero.
What Bill G has not cottoned onto is when he is standing on earth he is in free fall it is just the fall is opposed. When he drops the gravimeter into free fall it will read zero because it is no longer opposed. You can either argue gravity is a fictional force and the gravimeter is just reading the fictional force or you can go the frame of reference is different route like your centripetal acceleration.
Last edited by Orac; 01/06/16 12:28 AM.
