Electromagnetic waves, gravitational waves and the prophets who   predicted them
  Using non-excessively-technical language and written in informal style, this article introduces the reader to the concepts of electromagnetic and gravitational waves and recounts the prediction of existence of these waves by Maxwell and Einstein, respectively. The issue of gravitational radiation is timely in view of the recent announcement of the detection of gravitational waves by the LIGO scientific team. 
Costas J. Papachristou
physics.pop-ph