The simplest cause of the accelerating expansion of the universe I have an idea that could be the simplest explanation of the accelerating expansion of the universe . I'm surprised that I've never found such a simple explanation anywhere on the Internet . My idea is born from the fact that in the center of almost all the galaxies there is a super massive black hole . The objects near the black hole have a spiral motion towards the center of the black hole. There are different reasons that cause this spiral motion, including the dynamical friction . The stars and the other astronomical objects of a spiral galaxy have a spiral motion. This may be seen for example in the videos in the Wikipedia pages of the galaxy rotation curve and of the density wave theory (that is the theory that explains the spiral structure of the spiral galaxies ). Then in the universe we have: satellites that rotate around a planet planets that rotate around a star stars that rotate around a super ma...