갈릴레오 갈릴레이가 떨어트린 각기 다른 두 물체는 무엇인가?
Between 1589–92, the Italian scientist Galileo Galilei (then professor of mathematics at the University of Pisa) is said to have dropped two spheres of different masses from the Leaning Tower of Pisa to demonstrate that their time of descent was independent of their mass, according to a biography by Galileo's pupil Vincenzo Viviani, composed in 1654 and published in 1717.
spheres of different masses