Why were dinosaurs big?
Dear Cecil: Whev I look at dinosaur skeletons in museums the thing that always impresses me is their incredible size. It has occurred to me that perhaps these animals could grow to such enormous size because effective gravity was lighter then. If earth spun faster at the time of the dinosaurs then centrifugal force might have counteracted gravity enough to make a substantial difference in the weight of massive animals. What are the scientific merits of this idea? I read somewhere that the Earth’s day is getting shorter by a fraction of a second every year. Extrapolating backwards, how much faster [etc.] — Andrew Murphy, Philadelphia Cecil replies: We have two questions here, Andrew–the one you asked, and the one you would have asked if the drugs hadn’t kicked in first. The best that can be said for question #1 is that if you mention it to a stranger on the bus you’re guaranteed to get the seat to yourself. Question #2 is more interesting: why were dinosaurs so big? Some theories: – Di
