ABSTRACT
This chapter considers a source of radiation, it is generally affected by radiation reaction. Radiation emitted by any field gives rise to a reaction. When gravitational waves are emitted, the orbital period in a binary star system is reduced since the stars approach each other. Because the gravitational interaction is relatively weak, the power of gravitational radiation for normal binary stars, let alone of the solar system, is rather small and the respective effects have not yet been observed—with one exception. The radiation reaction in general relativity and in other gravitational field theories has been discussed in a large number of papers. In these theories the emission of gravitational waves and, of course, their reaction on the emitting masses are generally different from the respective processes in general relativity.
