Richard Thaler, a behavioral economist and research, issued a call for previous held beliefs that were eventually disproved, and for extra credit, why were they held for so long.
Lots of good examples from a wide array of smart folks (Nicholas Carr, Howard Gardner, Clay Shirky and many many others). Some are obvious (gravity! flat Earth!) while others are arcane (prions/prions?).
- Plate tectonics
- The four humours theory of medicine
- One must be older in order to impart knowledge