The Folger is closing at 4:30pm on Sunday, February 23, for a staff training exercise. Normal hours will resume when the Folger opens on Tuesday, February 25, at 11:00am.
In 1543, this book presented a new approach to knowledge—and nothing was the same after it appeared. Copernicus was the first to propose a heliocentric theory of the cosmos, which describes the sun standing still and the earth revolving around it. In doing so, he set in motion one of the greatest ever shifts in the history of human thought.
