Coriolis Field - Mach's View

Mach's View

In a theory that conforms to some versions of Mach's principle, this “apparent”, “fictitious” or “pseudo-gravitational” field effect can be treated as genuine.

As an example, when an object is set down on a rotating children’s roundabout, it is seen to slide away from the centre of the roundabout. In the non-rotating frame of reference, the outward motion is a consequence of the object’s inertial mass and the object's tendency to continue moving in a straight line. However, in the rotating frame as a reference, the object is pulled outwards by a radial gravitational field caused by the relative rotation of the outside universe. In that view, the (outward) motion is instead a consequence of its gravitational mass.

This dual description is used to unify the ideas of inertial and gravitational mass under general theories of relativity, and to explain why an object's inertial mass and gravitational mass are proportional in classical theory. In these descriptions, the distinction is purely a matter of convenience; inertial and gravitational mass are different ways of describing the same behaviour.