A scientist who's never seen color sees red for the first time. Does she learn anything?

Philosopher Frank Jackson imagined Mary, a brilliant scientist raised in a black-and-white room who has mastered every physical fact about color vision. When she finally sees a red tomato, Jackson argued she learns something no physical description could have given her — a challenge to the idea that physical facts are all there is to know.

— Frank Jackson, Epiphenomenal Qualia — The Philosophical Quarterly, 1982