Galileo Galilei
Born 1546 Pisa
Died 1642 Florence
Aristotle’s Motion
• Until Galileo, Aristotle’s theory on motion
stood.
– Heavier objects fall faster
– Natural motion is toward earth
– Any other motion was violent motion and
required a force to move it.
Galileo
• Galileo quickly became aware that his
talents lay in mathematics.
• He rose through the academic ranks at
various universities in Italy
• One of his early accomplishments was
suggesting that theories could be tested
through experiment.
Galileo’s Experiments
Nova Experiments
Disproving Aristotle
• Heavier objects do not fall faster.
– Proved via experiment and stones tied
together thought experiment
• Projectile motion
– Vertical and horizontal motion act
independently
• Natural motion is circular
Inclined Plane Experiment
Galileo’s Motion
• An object remains in motion unless acted
upon by other forces.
• Natural motion is circular
• Galileo also invented the telescope and
used it to study the heavens
• Persecuted by church for supporting the
Sun centered model