ABSTRACT
When two American astronauts landed on the moon in the summer of 1971, their activities included an interesting and, for some, surprising demonstration. They showed that when the effects of friction are eliminated, a light object (a feather) and a heavy object (a hammer) will reach the ground at the same time when dropped simultaneously from the same height. This verification of a basic principle of high school physics delighted many viewers of the live televised broadcast, but probably few of them considered the fact that for hundreds of years before Galileo (who is thought to have predicted this outcome originally), Western scholars had accepted Aristotle’s hypothesis that heavy objects would fall faster than lighter ones. For most of us, Aristotle’s assumption seems intuitively correct, even though we know that it is contrary to scientific theory and empirical fact. Not all scientifically demonstrated phenomena contradict “commonsense”intuitions in this way, but this case serves to illustrate the difference between science and intuition as bases of understanding the physical and social world.
