CHAPTER 10 - PARTICLE IN A GRAVITATIONAL FIELD

Abstract

This chapter provides an overview of the particles moving in a gravitational field. In a gravitational field, all bodies move in the same manner, independently of mass, provided the initial conditions are the same. The property of gravitational fields provides the possibility of establishing an analogy between the motion of a body in a gravitational field and the motion of a body not located in any external field, but which is considered from the point of view of a noninertial system of reference. The fields to which noninertial reference systems are equivalent are not completely identical with actual gravitational fields that occur also in inertial frames for there is a very essential difference with respect to their behavior at infinity. The centrifugal force that appears in a rotating reference system increases without limit as one moves away from the axis of rotation; the field to which a reference system in accelerated linear motion is equivalent is the same over all space and also at infinity. The fields to which noninertial systems are equivalent vanish as soon as we transform to an inertial system. In contrast to this, actual gravitational fields cannot be eliminated by any choice of reference system. The number of particles should be greater than four.