Translations:Adventist Youth Honors Answer Book/Health and Science/Physics/94/en
From Pathfinder Wiki
Galileo probably did not drop objects from the Leaning Tower of Pisa, but he did experiments with an inclined plane or a ramp that he rolled objects down. This allowed him to slow down the falling action and thus minimize the "air friction". He was able to determine that objects are accelerating and that the mass does not affect the acceleration.
