Galileo a 24 year old mathematics professor at the University of Pisa, Italy often sat in local cathedral when some nagging problem weighed on his mind.
Lamps gently swung on long chains to illuminate the cathedral. One day in the summer of 1598, Galileo realized that those lamps always at the same speed.
He decided to time them. He used pulse in his neck to measure the period of each swing of one of the lamps. Then he times a larger lamp and found that it swung at the same rate. He immediately set up an experiment that revealed the pendulum principle.
Over many days he timed the lamps and found that they always took exactly the same amount of time to travel through one compete arc.
On his essay On Motion, Galileo gave an argument in support of the idea that objects of different weights fall at the same rate – that is, that their speed of falling does not depend on their weight.
He stated that heavy objects would fall faster than lighter objects.
Galileo Galilei and Law of Free Fall Object
