" see it. Dinosaurs, on the other hand . . . I doubt I need to explain dinosaurs. They were the dominant terrestrial vertebrates from 231 to 66 million years ago. Though both dark matter and dinosaurs are independently fascinating, you might reasonably assume that this unseen physical substance and this popular biological icon are entirely unrelated. And this might well be the case. But the Universe is by definition a single entity and in principle its components interact. "

― Lisa Randall , Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe