Centrifugal force from GR perspective

[Chi Meson]

CHI Meson - you might want to read Feynman's short expose' on the subject in Volume 1 of his lectures on Physics. He questions whether gravity is a pseudo force like inertia since these forces are always proportional to mass. He ruminates that perhaps gravity is only a pseudo force that results from the fact we do not live in a Newtonian inertial frame.

Thanks, I have read it. This is what my initial viewpoint was primarily based on, and which was countered by the Wikepedia definition that has since been shown to be at fault.

I always turn to Feynman, but it has been over thirty years and a new position could have been solidified since then. I'm glad to know I'm not in the wrong tree (not very high up that tree mind you, but at least it's the right one).

 

[yogi]

I also am a Feynman fan - some years ago I wrote an article based upon Feynman's idea showing that Hubble expansion leads to a divergent volumetric acceleration of magnitude equal to the gravitational constant.

 

[Rob Woodside]

Fictious or inertial forces are dangerous. They can kill you! They differ from real forces in that they do not occur in action/reaction pairs. F=ma in an inertial frame only. If body A has an acceleration a relative to an inertial frame and body A' has a mass m and an acceleration a' relative to body A. Then for body A' in the inertial frame one has F= m(a+a') . In the accelerated frame, riding A, one has F-ma =ma'. The fictitious force -ma has no reaction partner and is in the opposite direction to the acceleration a. In relativity the acceleration is the covariant derivative of velocity and is made of two pieces: the usual coordinate partials plus a Christoffel piece which accounts for how the coordinate directions change from point to point. As others have said fictitious forces like centrifugal, coriolus, and the Newtonian mg arise from this second piece.