The evolutionary story of extinction and the rise of dinosaurs faces challenges, but survives when the glue of imagination holds fragmentary evidence together.
Some material that flaked off a fossil in Alberta was not stone; it was dinosaur skin. Discoverers were excited and puzzled: how could it last so long?
Some basic ideas about physics and astronomy remain so mysterious, and their explanations so flexible, they may lead some to question whether they should be called "hard sciences."