English summary: If we, the physicist and philosopher decided to collaborate in order to write about physics' "black ideas," it was because the things that physics qualifies as "black" are fascinating: black sky, blackbody, black hole, dark matter, dark energy, etc. What lies behind these obscure terms? These are not just curious names, but ideas which have played - and sometimes still play - a critical role in physics, as astrophysicist Roland Lehoucq shows us. Moreover, not only is it necessary to examine how science is changing the meaning of the adjective "black," it is also vital to describe how this adjective "colours," in turn, the scientific term. That is why philosopher of science Vincent Bontems analyses what the adjective surreptitiously carries from the darkness of the imaginary into the scientific field. The black idea then becomes a black image, which inspires delectable daydreams. We therefore explain, on each occasion, the denotation of the adjective "black" - not only what it actually means to a physicist, but also its connotation; i.e., what it metaphorically, and at times unconsciously, brings to mind. In coupling the epistemological analysis of black ideas with a psychoanalysis of black images, we are following the example of philosopher Gaston Bachelard, who was already studying in tandem the historic evolution of thermal spread theories and the associations of images in ramblings on the topics of fire, science and the imaginary. French description: Ciel noir, corps noir, trou noir, matiere noire et energie noire: pourquoi les physiciens eprouvent-ils le besoin de noircir certaines de leurs idees ? Loin d'etre anecdotique, cette interrogation permet de traverser l'histoire de la physique et d'en soulever une bonne part des enjeux actuels. L'enigme du ciel noir a preoccupe les astronomes pendant des siecles; l'etude du rayonnement du corps noir est a l'origine de la revolution quantique; le trou noir est une singularite cosmique fascinante; la matiere noire et l'energie noire sont des hypotheses mysterieuses de la cosmologie contemporaine. A partir de leurs disciplines respectives, l'astrophysicien Roland Lehoucq et le philosophe des sciences Vincent Bontems eclairent tour a tour la signification du qualificatif noir pour chacune de ces idees. Il ne s'agit donc pas d'un livre de vulgarisation classique, mais d'un dialogue ou se repondent la signification scientifique de la couleur noire et la reverie sur les metaphores tenebreuses. Dans le sillage de Gaston Bachelard, qui fut le premier a pratiquer ainsi en parallele l'epistemologie et la psychanalyse de l'imaginaire, ces deux chercheurs proposent de maniere complice une excursion dans les meandres de la recherche en alternant les eclairages critiques et emerveilles pour en dissiper l'obscurite. Les idees noires de la physique s'y revelent instructives et inspirantes.