Legend has it that Galileo Galilei dropped light and heavy objects off of the Leaning Tower of Pisa to see if the rate at which they fell was different From examining the results of this experiment, he inductively concluded that the rates of acceleration of falling objects was independent of their weight.

The validity of the results gained by using some model are therefore limited by the validity of the model: Galileo's prediction about objects falling at the same speed does not include air resistance, so the model works for objects like cannonballs, but not necessarily feathers.