Editing Henri Poincaré (section)

====Gravitational waves====
In 1905 Poincaré first proposed [[gravitational waves]] (''ondes gravifiques'') emanating from a body and propagating at the speed of light.  He wrote:
{{blockquote|It has become important to examine this hypothesis more closely and in particular to ask in what ways it would require us to modify the laws of gravitation.  That is what I have tried to determine;  at first I was led to assume that the propagation of gravitation is not instantaneous, but happens with the speed of light.<ref>"''Il importait d'examiner cette hypothèse de plus près et en particulier de rechercher quelles modifications elle nous obligerait à apporter aux lois de la gravitation. C'est ce que j'ai cherché à déterminer; j'ai été d'abord conduit à supposer que la propagation de la gravitation n'est pas instantanée, mais se fait avec la vitesse de la lumière.''"</ref><ref name="1905 paper" />}}